Talking with Your Doctor About Medical Cannabis and Breast Cancer

Overview of Research on Cannabis for Breast Cancer

Cannabis for Cancer: The Fight to Get Mainstream Medicine Onboard

Taking Matters into Her Own Hands: A Nurse’s Journey to Self-Educate on Medical Cannabis Benefits and Risks

On the Other Side of the Nurse’s Station: A Nurse Turned Medical Cannabis Patient

Breast Cancer Doctors See the Value of Cannabis for Treatment—But Stop Short of Advocating for it

Articles

View our interactive October/November 2021 digital edition.

October/November 2021 Digital Edition

! The focus of this issue is breast cancer. Most of us are no stranger to breast cancer: According to the world health organization, 2.3 million women globally were diagnosed with breast cancer in 2020 (1). In addition, breastcancer.org reported that about 1 in 8 women in the US are diagnosed with breast cancer in their lifetimes (2). Indeed, it seems as if everyone has had some experience with breast cancer either personally or with a loved one or friend going through breast cancer treatment. In my own family, two of my aunts have gone through treatment and luckily went into remission after.

There is a lot of talk about the benefits of medical cannabis and if it can be an anticancer agent. In this issue, we discuss this subject carefully. The biggest takeaway for me from preparing this content was that not all cancers—and breast cancers—are equal. There are subtypes upon subtypes. In addition, there are many more treatment options available to patients than even say, 10–15 years ago. What is clear to me after speaking with various doctors, nurses, patients, and advocates is that more research is desperately needed as well as clear communication with your medical team and education all around.

In our first article in this issue, we spoke with Dr. Marissa Weiss to get some tips and talking points to help patients start a conversation about the therapeutic use of cannabis for breast cancer. Dr. Weiss shares how cannabis can be utilized for symptom management before, during, and after breast cancer treatment, why cannabis can be a complicated topic for doctors to discuss with their patients, and why it is important for patients to advocate for themselves.

Next, Ruth Fisher offers us a high-level overview of the current research efforts focused on medical cannabis and breast cancer. She noted that research on cannabis as a potential treatment specifically for breast cancer didn’t begin until the 1990s; since then, there have been several thousand preclinical studies, most of which have been conducted only within the last 10 years. Scientific research on breast cancer is thus still in its early stages, but Fisher provides an update on where it stands.

As with most medical cannabis uses, patients continue to push for more information and research. In our “Patient Focus” article we spoke with breast cancer survivor Nicole DiMonda, who, along with her husband, Jaime Brambila faced life and death decisions and turned to cannabis for help.

Nurses play another special role on your medical care team—often on the “frontlines” with patients and relaying pertinent information to doctors. Kristin L. Wohlschlagel, RN, identifies herself as a nurse who understands that we need conventional treatments, standard of care treatments, and that cannabis has a place for symptom control and potentially as a therapeutic. In the article on page 20, Wohlschlagel shares a wealth of information from various patients she interviewed, her own personal experiences, and more.

The piece titled “On the Other Side of the Nurse’s Station: A Nurse Turned Medical Cannabis Patient” shares the unique story of Nique Pichette, MSN, RN, who is a two-time breast cancer survivor and medical cannabis patient. Pichette’s journey led her to life-changing decisions and reframed her view on medical cannabis as a drug of abuse.

Finally, David Hodes spoke with several doctors in the US to find out more about the role medical cannabis plays in a breast cancer treatment plan. He noted that mainstream breast cancer doctors, working on treatments for one of the more successfully treatable type of cancers, are watching medical cannabis research developments carefully.

On October 27th, we hosted a special breast cancer webcast with a presentation from Dr. Marissa Weiss and a panel discussion with Nicole DiMonda and Jaime Brambila. If you missed the live event, please sign up to watch on demand (for free) and learn valuable insights: 

https://www.cannapatientcare.com/cpc/breast

https://www.who.int/news-room/fact-sheets/detail/breast-cancer

https://www.breastcancer.org/symptoms/understand_bc/statistics

Tackling Breast Cancer with Medical Cannabis

Marisa Weiss, M.D., is the founder and chief medical officer of 

, a leading online resource for expert medical and personal information on breast health and breast cancer. With more than 35 years of active practice in the Philadelphia region, Dr. Weiss currently practices at Lankenau Medical Center, part of Main Line Health, a five-hospital health system in the suburbs of Philadelphia, where she serves as director of breast radiation oncology and director of breast health outreach.

Patients have been utilizing medical cannabis for many years to manage symptoms, side effects of treatment, and other mental health challenges that often come along with the diagnosis of cancer. In fact, one of the most widely studied therapeutic applications for cannabis is in the treatment of nausea and vomiting associated with cancer chemotherapy. Yet for many patients, talking with their healthcare providers for the first time about utilizing cannabis in their treatment regimen can feel intimidating and scary.

Healthcare providers are accustomed to patients bringing ideas to them about treatment options and preferences, and cannabis therapeutics should be no different. Just like traditional medications, cannabis can interact with other medications and treatments, so it is important to make sure that your provider has the full picture and can monitor your progress or make adjustments if needed.

We sat down with the founder and chief medical officer of 

, Dr. Marisa Weiss, to get some tips and talking points to help patients start this conversation about the therapeutic use of cannabis for breast cancer. Dr. Weiss shares how cannabis can be utilized for symptom management before, during, and after breast cancer treatment, why cannabis can be a complicated topic for doctors to discuss with their patients, and why it is important for patients to advocate for themselves.

How did you first start hearing about cannabis use for symptom and side effect relief from breast cancer?

 From my patients. So, it never came from any medical source. It was patient after patient asking about it. And initially, I would say ‘You know, that’s a really good question, you need to talk to an expert about it’ and I would encourage them to find somebody who could answer their questions. A few of them came back and said, ‘I’m still interested in that subject but couldn’t find any experts in that arena of cannabis for the management of quality of life, symptoms, etc., for people with breast cancer. Then a specific patient of mine came back and said: ‘That’s not a good enough answer, you really need to get more knowledgeable about this. You’re a leader in the field of patient centric care through 

 and you really need to become a leader in this arena.’ And I said: ‘Well, you’re right!’

These patients were really suffering from symptoms and nothing else seemed to help them. Patients have to go through their state medical cannabis program in which they have to pay out of pocket for the cost of the doctor visit, certification, and all products, paid for in cash without the help of insurance. So it was clear that this was an important enough issue for which people were saying ‘I’ll use my precious personal funds to pay for it,’ which is not really fair if people have to pay out of pocket for something that is helping them from a medical point of view and is not covered by insurance. So, right now it is only an available option for those people who are privileged enough to be able to access and afford it.

What did you do to help educate yourself about the therapeutic use of cannabis for patients with breast cancer?

 I first did the course work that’s required to certify a medical cannabis patient in the state of Pennsylvania and then the state of New York. But that’s only a four hour course that’s required, so it’s not enough knowledge to really be able to understand the potential role that cannabis products may have to solve difficult issues for people going through breast cancer, especially those who are seeking natural remedies or who don’t want to go on pharmaceuticals or who want to avoid narcotics and associated risks. So I did extensive training and started to see patients within my own practice.

 we decided that we needed to know more details about people’s lives: what symptoms they’re suffering from; which of those symptoms are they getting relief through traditional medicines; for which symptoms are they seeking medical cannabis; are they talking to a doctor about their interest or use of medical cannabis; are they using it before, during, or after treatment; what type of products are they using; how many products are they using; what was the source of their products? Breastcancer.org did a national survey of the population going through, about to go through, or have gone through breast cancer. We learned a tremendous amount and we published that data, which reinforced the fact that people were suffering from symptoms which they could not find relief from with other medications.

What did you learn through your survey about which symptoms or side effects breast cancer patients were most able to find relief with or control with the use of medical cannabis?

 The most common symptoms were pain, anxiety, insomnia, and nausea or vomiting. We also found that nearly 80% of cannabis users are using it during treatment. More and more people are using it and understanding its role. More patients are saying it’s helpful with symptomatic management, and noting that nothing else was helpful in the same way.

Is there anything you would caution breast cancer patients about in regards to medical cannabis use?

 There are a lot of claims on the web about cannabis being an anticancer therapy. I would say that the data showing that cannabis can slow the spread of cancer, that’s all based on petri dishes, not people yet. We don’t know if there is any basis for that from a scientific perspective. So, I would stick with traditional proven therapies, because we don’t know if it’s safe or effective. We don’t know how it will interact with traditional therapies.

Do you ever suggest cannabis to patients who don’t ask about it specifically?

 Definitely. Breast cancer and most of these cancers affect women who are typically in charge of the family and who are usually very risk averse. They don’t want to get into trouble.

Women are looking for solutions, not looking to get high. They’re looking for ways to live their life the way they want to. With symptoms like pain, anxiety, and nausea or vomiting, they aren’t going to be able to function in these crazy busy lives that they have where they’re not just taking care of themselves but also their families, they’re working, they’re involved in the community.

When I hear about a problem that stands as a barrier to living their best quality of life then I’ll say: ‘Well what have you been doing to improve that?’ Many patients will say they’re afraid of pharmaceuticals, and afraid of dependence. They want natural remedies, not drugs that can make them feel intoxicated. So that’s a natural way to ask if they’ve considered medical cannabis. It’s part of the holistic way we help people recover.

Why are so many healthcare providers apprehensive about talking with their patients about cannabis?

 Most doctors in the breast cancer community are apprehensive for a variety of reasons. First, cannabis is not part of most medical schools’ curriculum, so most doctors are without any formal training. In the absence of insurance, you would need a second track in your practice just to handle it. Another important component is that none of it is integrated into the electronic medical record for patients, so it’s not integrated within a patient’s holistic care within the traditional medical system like pharmaceuticals are. If I were to see somebody and they were to go to a dispensary to get products, the list of products they get from a dispensary are not entered into the database, so you have no idea what types of products your patients are using. That’s an uncomfortable place for a doctor to be in; you qualify someone for a medicine but you don’t know what they’re taking, in many cases they don’t know what they’re taking. They’re not allowed to bring the product on campus to show you what they’re taking because it’s illegal. So there’s a lot of logistical requirements that are deterrents.

Most importantly, even though we have about 34+ states that have legal programs, cannabis is still illegal at the federal level, and many doctors do not feel comfortable talking about products that are illegal. Even when it is legal at the federal level doctors may not be comfortable until there is a scientific research foundation on which to base recommendations. So that is why I’m committed clinically to perform vital foundational research to determine what our needs are, patterns of use, knowledge, attitudes, behaviors, and beliefs to determine the role of cannabis, and to have it based on something scientific.

What would help encourage more healthcare providers to recommend cannabis?

Well the main thing that has to occur is cannabis medicine education in medical schools and the commitment to research. Because we have many individual anecdotes, for centuries, of the individually reported value of products but it has not been collected in a scientific format. So we need better clinical trials to collect data on the effectiveness and the role it plays in the treatment of cancer.

Can you tell us about your chemotherapy-induced peripheral neuropathy (CIPN) study?

I decided to identify a clinical problem that was really awful and common for which medical cannabis seemed to have a unique role. That is in the treatment of patients with chemotherapy-induced peripheral neuropathy (CIPN); symptoms include pain, numbness, as well as pins and needles in the hand from some of the most commonly used chemotherapy. Medications that are commonly used in most cancers but especially breast, colon, colorectal, ovarian, and uterine cancer. The data we had showed that cannabis could play a role in preventing that problem as well as treating that problem. This came from a study on mice that a woman named Dr. Sarah Ward did which showed that if you gave cannabidiol (CBD) from hemp together with chemo that it would reduce the chances of CIPN from chemo. So, I wanted to study that. Not only does CIPN impact quality of life when people have pain in their hands and feet, it hurts fine motor skills like buttoning a shirt or opening a peanut butter jar. It ends up impacting quality of life and survival making people less likely to complete their chemo, meaning their care is compromised.

I decided I was going to do a randomized double blind trial looking at prevention of CIPN with cannabis. So I went to all these researchers and they said: “oh, no, no, no, you’ll never get that through the FDA, you’ll never get that through NIDA, nobody’s done it before.” She told me it’s not gonna happen, just do it as an observational study, which is not a research approach that is going to change anyone’s mind or establish a scientific basis for insurance coverage. The FDA wouldn’t let me do it together with chemo because they said: ‘We don’t know what’s going to happen when you give both at the same time. There may be a drug-drug interaction where the chemo won’t work as well and we can’t do that until chemo is over." So basically I started a randomized double blind control trial a year and a half ago that is the first one to be FDA approved and the only one to look at hemp-based CBD and right now we’re the only one to do it with any cannabis for people with CIPN. We have a goal of treating 100 patients and we’re 1/3rd of the way there. The trial is CBD and placebo for three months. After three months there is a one month wash out where we see what happens when you stop the product. After that we offer three months of CBD again. People don’t know if they have CBD or the placebo upfront, but later on, they will have access to CBD for three months free of charge. We’re not just looking at neuropathy, we’re also looking at factors like your energy level, your sleep, your anxiety, hot flashes, all kinds of symptoms, not just from CIPN. There’s been a lot of positive interest and we look forward to sharing the final results when the clinical trial concludes. To learn more about participation in our CIPN study, please email: 

What type of products did you use in your study?

 To do a randomized double blind controlled trial, the FDA scrutinizes the products. It has to be pharmaceutical grade. Most products out there that may be FDA approved are nutraceutical guidelines where the amount of CBD on the product has to be within 20% of what’s on the label. Pharmaceutical products have to be within 10% and also free of heavy metals, pesticides, and mold. Cannabis is a bioremediator product, it is a plant that you would use for centuries to clean fields because it has the amazing ability to suck all the junk out of the ground. So it’s very important that the source of hemp or marijuana is medical grade. You have to be sure that you see a certificate of analysis (COA) so that you don’t expose yourself as a patient, especially a cancer patient, to the junk that could be in these products. Mold, arsenic, mercury, or other stuff. So the FDA scrutinizes the product. We’re using medical grade products and have COA’s on everything that we use.

Through our study we learned that of the people who are using cannabis, 79% were using it during treatment which is pretty scary when you think about what’s in treatment like chemotherapy, radiation and you add to that a cannabis product that may be vaped or smoked or something like that. You want to make sure these products are safe. So it was clear we needed to learn more about the basis for which these products are used, that means doing more research to establish a better understanding of knowledge to base medical decisions on that would be required to get FDA approval and insurance companies to pay for this type of medical care.


 Well let me just encourage patients to participate in clinical studies. We’re very grateful to the people who’ve participated in our clinical study which has advanced the understanding of the role of cannabis and presented it to the largest organizations of cancer doctors. We’re very thankful to the participants of the clinical trial studies in the hospital because that’s how we’re going to get a better understanding of what cannabis does and doesn’t do and with that we can give people a better quality of life and increased odds of survival.

But just like in other aspects of your care, you have to be your own best advocate. If you don’t let your doctor know how they can be helpful to you, then you might not be heard, you may not get help and you’re the one who will miss the opportunity for better care. So be the one to ask.

Dr. Marissa Weiss is the author of four critically acclaimed books on breast cancer and breast health: 

, coauthored with her mother, Ellen Weiss (1998, 2010); 

Taking Care of Your “Girls:” A Breast Health Guide for Girls, Teens, and In-Betweens

, coauthored with her daughter, Isabel Friedman (2008); and 

7 Minutes!: How to Get the Most from Your Doctor Visit 

(2007). A renowned leader in the field of breast cancer, Dr. Weiss is frequently called on by the media as a subject matter expert and respected voice of breast cancer patients.

 is the Executive Director of Americans for Safe Access (ASA), a medical cannabis patient advocacy non-profit whose mission is to ensure safe and legal access to cannabis (marijuana) for therapeutic use and research. Debbie oversees all organizational and program operations in regards to education, training, policy, research, product safety and business compliance. Current projects include national campaigns such as ASA’s End Pain, Not Lives campaign and No Patient Left Behind campaign and programs such as ASA’s Patient Focused Certification (PFC) program and the Cannabis Care Certification (CCC) program. She serves as a writer and final editor on ASA publications including the 

Medical Cannabis Access for Pain Treatment

Dr. Marissa Weiss offers some tips and talking points to help patients start a conversation about the therapeutic use of cannabis for breast cancer.

The earliest scientific research on the effects of cannabinoids on cancer cells date back to the mid-1970s, with Louis Harris’ investigations of tetrahydrocannabinol's (THC) inhibition of cancer growth (1,2). Research on cannabis as a potential treatment specifically for breast cancer didn’t begin for another 20 years, until the 1990s. Since then, there have been several thousand preclinical studies, most of which have been conducted only within the last 10 years. Scientific research on breast cancer is thus still in its early stages. What have we learned about cannabis to treat breast cancer? Let’s take a look.

Breast cancer tumors are extremely heterogeneous in nature, as noted by Rahman and colleagues (3): “Breast cancer shows intra-tumor heterogeneity at molecular, genomic and phenotypic levels.” One aspect of this diversity is tumor cells’ different patterns of expression of both hormone receptors and cannabinoid receptors.

The most reliable way of stratifying different breast cancer types is that based on hormone receptor expression, that is, whether or not the tumors contain estrogen receptors (ER), progesterone receptors (PR), or human epidermal growth factor receptor 2 (HER-2). The presence of any of these hormone receptors provides a target or pathway by which to attack the cancer (see 

Breast cancer tumors that express hormone receptors (Luminal A, Luminal B, or HER-2+) may be treated using hormone therapy, which interferes with the body’s own production and effects of these hormones on promoting tumors. However, breast cancer tumors that do not express hormone receptors (triple negative breast cancer, or TNBC) do not respond to hormone therapy. Other treatment options for all breast cancer types include chemotherapy (oral or IV administration of drugs to stop cancer cell growth) or radiation therapy (4).

Cannabis Has Diverse Effects on Breast Cancer

Cannabis has been found to “selectively and differentially affect” different types of breast cancer cells (5). This is due to a combination of factors. First, the patterns in which cannabinoid receptors (CB1 and CB2) are expressed on tumors differ across cancer cell types (3,5). Next, CB2 receptors are more prevalent than CB1 receptors: CB1 is detected in 28% of breast cancer carcinomas, while CB2 is detected in 72% of carcinomas, where both CB1 and CB2 are found more often in HER-2 positive tumors (3). Finally, different cannabinoids that bind to the same type of receptor can cause different downstream effects on cancer cells. This phenomenon is known as 

Research on Cannabis Use for Breast Cancer

There is a large body of preclinical and clinical research that includes all three forms of cannabinoids: endocannabinoids (made by the body), phytocannabinoids (made by plants), and synthetic cannabinoids (man-made). The research examines how cannabinoids may be used to treat cancer in general, as well as to treat specific forms of cancer, such as astrocytoma, glioblastoma, head and neck, breast, Hodgkin lymphoma, leukemia, skin, and squamous cell cancer. The research reported herein is focused specifically on studies of cannabinoid treatments for breast cancer.

Cannabis has been found to provide relief to breast cancer patients in three different ways: (i) cannabis addresses the symptoms associated with either the cancer itself or the side effects from cancer medications; (ii) cannabis increases the efficacy of complementary cancer treatments; and (iii) cannabis attacks the cancer itself. At the same time, however, a few studies have, in fact, found that cancer may 

 tumor growth in breast cancer cells. Let’s take a closer look at what the studies have to say for each of these types of effects of cannabis on breast cancer.

Addresses Symptoms and Side Effects of Treatment

The list of side effects associated with cancer and cancer treatments is lengthy. Commonly reported side effects include, among others, pain, anxiety, depression, fatigue, insomnia, nausea or vomiting, and weight problems (7). There is a large body of research supporting the efficacy of cannabis for use in treating most of these symptoms and side effects of breast cancer.

Surveys of patients with breast cancer indicate that a significant portion of patients (42% in one study) have used cannabis to treat their symptoms. These patients tend to find cannabis provides relief for most symptoms or side effects, including insomnia; joint and muscle aches, discomfort, stiffness, or pain; anxiety, stress; and nausea or vomiting (8,9).

No clinical trials have yet been performed to assess cannabis’s efficacy for treating symptoms and side effects specifically of breast cancer. However, many clinical trials of generic “cannabis,” as well as of specific cannabinoids have been tested and shown to be efficacious for treating symptoms generally associated with cancer and cancer treatment, including nausea or vomiting, pain, appetite, fatigue, anxiety, and depression. Notably, three of the four cannabis pharmaceuticals that have been government-approved—Dronabinol (1986 in US), Nabilone (1981 in Canada, 1985 in US), and Sativex (2010 in UK)—were approved to treat cancer-related symptoms and side effects. [Note: The fourth cannabinoid pharmaceutical approved for medical use is Epidiolex, approved by the FDA in 2018 for the treatment of epilepsy.]

Increases Effectiveness of Traditional Treatments

In preclinical studies, researchers have shown that cannabinoids enhance the anti-cancer effects of various other chemotherapy treatments in breast cancer cells (10), as well as in other cancer cell types (11).

Scientists have discovered multiple pathways for preventing the growth and spread of breast cancer cells. Preclinical studies have well-established the potential for cannabis to address most of these pathways. Yet, while there are case reports, there have not yet been any clinical studies on cannabis for preventing the growth or spread specifically of breast cancer.

Preclinical studies on breast cancer cell lines have established the following findings.

Caffarel and colleagues provide a succinct description of 

, together with cannabis’s role in managing the process when it goes awry (12): "There are very few critical decisions that cells must take during their lifetime. Basically, these are whether to proliferate, differentiate, or die. A tight regulation of the cell cycle is crucial to control all these decisions, and its deregulation has devastating consequences, such as cancer. It has been proposed that cannabinoids, the active components of 

, play a role in the control of the aforementioned decisions. For example, they can modulate survival, proliferation, and differentiation depending on the cell type and its physiopathologic context."

 is the speed at which cancer cells replicate themselves. “If the cancer cells are dividing more rapidly, it means the cancer is faster growing or more aggressive” (13). There is a substantial body of preclinical research establishing that endo-, phyto-, and synthetic cannabinoids inhibit the proliferation of breast cancer tumors with cell types ER+ (11,14), HER-2+ (15,16), and TNBC (15,17).

 is a natural process used by the body to rid itself of unneeded or abnormal cells (19). As with cell proliferation, there is also a substantial body of preclinical research establishing that endo-, phyto-, and synthetic cannabinoids promote apoptosis in breast cancer tumors with cell types ER+ (12,21), HER-2+ (12), and TNBC (21-22).

—the formation of new blood vessels—through which tumors draw their resources (23). Several preclinical studies show that endo- and synthetic cannabinoids block angiogenesis in TNBC (24,25).

Blocks Invasion, Metastasis, and Migration

Cancer cells spread from one location in the body to another using a specific process, called 

 of individual cells that detach from the primary tumour, enter lymphatic vessels or the bloodstream and seed in distant organs.” There is a substantial body of preclinical research establishing that endo-, phyto-, and synthetic cannabinoids inhibit invasion, metastasis, and migration in breast cancer tumors with cell types ER+ (6,18), HER-2+ (3,6,14,16), and TNBC (3,6,14,16).

Despite a wealth of studies supporting the breast cancer-fighting effects of cannabis, there are two studies that have shown that cannabis may actually promote tumor growth in breast cancer cells. Noteworthy is the fact that in both of those cases, the researchers indicated that the breast cancer cells that were examined expressed “low to undetectable levels of cannabinoid receptors” (20,29). The lack of cannabinoid receptors could thus be used as a marker for cases in which cannabis should not be used for cancer therapy.

Breast Cancer Markers for Cannabinoid Treatment

So, what we have is that breast cancer is diverse and may be classified based on the types of receptors the breast cancer cells express. In particular, a large portion of breast cancer cells have cannabinoid receptors and should thus react to cannabis. Indeed, surveys of breast cancer patients indicate that a significant portion of patients uses cannabis to relive symptoms, and clinical studies establish the efficacy of cannabis to treat the symptoms of cancer in general as well the side effects of cancer treatments. While clinical evidence assessing the benefits of cannabis for treating breast cancer have not yet been conducted, there is a large body of preclinical research establishing a theoretical basis for using cannabis, not only to treat the symptoms of breast cancer, but also to attack the cancer itself. Yet, there is reason for caution, as a few studies have shown that cannabinoids may, in fact, promote the growth of breast cancer cells.

So, then, what we need is a good marker not only for determining when cannabinoids should be considered as a treatment for breast cancer, given cannabis’s anti-cancer potential, but also for determining when cannabinoids should 

 be considered for treatment, due to its pro-cancer potential.

Cannabinoid receptors (CBRs) are not expressed in non-tumor breast tissue (12,32).

Cancer cells that have higher CBR expression tend to be more aggressive (11,12,15,31,32), as well as more responsive to cannabis (29,31,32).

Cancer cells that have lower CBR expression tend to be either less responsive to cannabis (12) or even stimulated by cannabis (11,29,30).

Cannabinoids may suppress immune system functioning (31).

Taken together, researchers have concluded that when CBR expression is low, then the negative effects of cannabinoids on inhibiting other immune responses to cancer growth outweighs any tumor-suppressing effects cannabinoids might have (30,31). Clearly, then, when CBR expression on breast cancer tumors is low, cannabinoids should not be considered as an anti-cancer therapeutic.

If, on the other hand, CBR expression on breast cancer tumors is high, then the beneficial effects of cannabinoids on suppressing tumor activity outweigh their negative effects on suppressing immune system activity (30,31). So, then when CBR expression on breast cancer tumors is high, cannabinoids should be considered as an anti-cancer therapeutic.

(1) L. Harris, A. Munson, M. Friedman,. et al, "Retardation of tumor growth by D9-tetrahydrocannabinol," 

(2) A. Munson, L. Harris, M. Friedman, W. Dewey, and R. Carchman, "Antineoplastic Activity of Cannabinoid," 

 DOI: 10.1093/jnci/55.3.597. Retrieved from 

(3) S. Rahman, et al, "The onus of cannabinoids in interrupting the molecular odyssey of breast cancer: A critical perspective on UPRER and beyond," (2019). 

. DOI: 10.1016/j.jsps.2019.01.005 Retrieved from 

www.sciencedirect.com/science/article/pii/S1319016419300064

(4) Breast Cancer Treatment (Adult) (PDQ®)–Patient Version. (2021, Apr 8) National Cancer Institute. Retrieved from 

www.cancer.gov/types/breast/patient/breast-treatment-pdq

(5) L. Baram, E. Peled, P. Berman, B. Yellin, E. Besser, M. Benami, I. Louria-Hayon, G. Lewitus, and D. Meiri, "The heterogeneity and complexity of Cannabis extracts as antitumor agents," 

 DOI: 10.1016/j.jsps.2019.01.005. Retrieved from 

www.semanticscholar.org/paper/The-heterogeneity-and-complexity-of-Cannabis-as-Baram-Peled/ca3a543b372e5474439fbfc4bd5cbc4f41e904cf

(6) J. Glogauer and J. Blay, "Cannabinoids, Their Cellular Receptors, and Effects on the Invasive Phenotype of Carcinoma and Metastasis" 

. DOI: 10.1002/cnr2.1475. Retrieved from 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8842690/

(7) Treatment Side Effects (2021, Mar 29). Breastcancer.org. Retrieved from 

www.breastcancer.org/treatment/side_effects

(8) J. Aviram, et al, "Short-Term Medical Cannabis Treatment Regimens Produced Beneficial Effects among Palliative Cancer Patients," 

. DOI: 10.3390/ph13120435. Retrieved from 

www.researchgate.net/publication/346484148

(9) M. Weiss, et al "A survey of cannabis use for symptom palliation in breast cancer patients by age and stage,"

https://ascopubs.org/doi/abs/10.1200/JCO.2020.38.15_suppl.12108

(10) A.I. Fraguas-Sánchez, A. Fernández-Carballido, R. Simancas-Herbada, C. Martin- Sabroso, and A.I. Torres-Suárez, "CBD loaded microparticles as a potential formulation to improve paclitaxel and doxorubicin-based chemotherapy in breast cancer," 

. DOI: 10.1016/j.ijpharm.2019.118916. Retrieved from 

(11) M.M. Caffarel, C. Andradas, E. Pérez-Gómez, M. Guzmán, and C. Sánchez, "Cannabinoids: A new hope for breast cancer therapy?" 

. DOI: 10.1016/j.ctrv.2012.06.005. Retrieved from 

www.semanticscholar.org/paper/Cannabinoids%3A-a-new-hope-for-breast-cancer-therapy-Caffarel-Andradas/998e07defe9c75215c34acae8118718f0e5bf55f

(12) M. Caffarel, et al, "D9-Tetrahydrocannabinol Inhibits Cell Cycle Progression in Human Breast Cancer Cells through Cdc2 Regulation," 

 DOI: 10.1158/0008-5472.CAN-05-4566. Retrieved from 

cancerres.aacrjournals.org/content/canres/66/13/6615.full.pdf

(13) Breast Cancer Ploidy and Cell Proliferation. (2019, Sep 20) American Cancer Society. Retrieved from 

www.cancer.org/cancer/breast-cancer/understanding-a-breast-cancer-diagnosis/ploidy-and-cell-proliferation.html

(14) L. Dobovišek, et al, "Cannabinoids and Hormone Receptor-Positive Breast Cancer Treatment," 

. DOI: 10.3390/cancers12030525. Retrieved from 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7139952/pdf/cancers-12-00525.pdf

(15) D. Ladin, et al, "Preclinical and Clinical Assessment of Cannabinoids as Anti-Cancer Agents," 

. DOI: 10.3389/fphar.2016.00361. Retrieved from 

www.ncbi.nlm.nih.gov/pmc/articles/PMC5054289/pdf/fphar-07-00361.pdf

(16) M. Elbaz, et al, "Modulation of the Tumor Microenvironment and Inhibition of EGF/EGFR Pathway; Novel Anti-tumor Mechanisms Of Cannabidiol In Breast Cancer," 

. DOI: 10.1016/j.molonc.2014.12.010. Retrieved from 

www.meta.org/papers/modulation-of-the-tumor-microenvironment-and/25660577

(17) R. Murase, et al, "Targeting multiple cannabinoid anti-tumour pathways with a resorcinol derivative leads to inhibition of advanced stages of breast cancer," 

(18) Apoptosis. (n.d.) National Cancer Institute. Retrieved from


www.cancer.gov/publications/dictionaries/cancer-terms/def/apoptosis

(19) A. Tomko, et al, "Antitumor Activity of Abnormal Cannabidiol and Its Analog O-1602 in Taxol-Resistant Preclinical Models of Breast Cancer," 

. DOI: 10.3389/fphar.2019.01124. Retrieved from 

www.frontiersin.org/articles/10.3389/fphar.2019.01124/full

(20) A. Sultan, M. Marie, and S. Sheweita, "Novel mechanism of cannabidiol-induced apoptosis in breast cancer cell lines," 

. DOI: 10.1016/j.breast.2018.06.009. Retrieved from 

(21) A. Shrivastava, et al, "Cannabidiol Induces Programmed Cell Death in Breast Cancer Cells by Coordinating the Cross-talk between Apoptosis and Autophagy," 

 DOI: 10.1158/1535-7163.MCT-10-1100. Retrieved from 

(22) Angiogenesis. (n.d.)National Cancer Institute. Retrieved from


www.cancer.gov/publications/dictionaries/cancer-terms/def/angiogenesis

(23) P. Picardi, E. Ciaglia, M. Proto, and S. Pisanti, "Anandamide inhibits breast tumor-induced angiogenesis," 

elea.unisa.it/jspui/bitstream/10556/1634/1/Picardi_Ciaglia_Proto_Pisanti_Anandamide_inhibits_breast_tumor_induced_angiogenesis.pdf

(24) N. Farsandaj, M. Ghahremani, and S. Ostad, "Role of cannabinoid and vanilloid receptors in invasion of human breast carcinoma cells," 

 DOI: 10.1615/jenvironpatholtoxicoloncol.2013005859. Retrieved from 

(25) P. Friedl and K. Wolf, "Tumour-cell invasion and migration: diversity and escape mechanisms," 

www.nature.com/articles/nrc1075/briefing/signup/

(26) S. Takeda, et al, "Cannabidiolic acid, a major cannabinoid in fiber-type cannabis, is an inhibitor of MDA-MB-231 breast cancer cell migration," 

. DOI: 10.1016/j.toxlet.2012.08.029. Retrieved from 

(27) S. Takeda, et al, "D9-Tetrahydrocannabinol enhances MCF-7 cell proliferation via cannabinoid receptor-independent signaling," 

. DOI: 10.1016/j.tox.2007.12.019. Retrieved from 

www.sciencedirect.com/science/article/abs/pii/S0300483X07008566

(28) R. McKallip, M. Nagarkatti, and P. Nagarkatti, "∆-9-Tetrahydrocannabinol Enhances Breast Cancer Growth and Metastasis by Suppression of the Antitumor Immune Response," 

 DOI: 10.4049/jimmunol.174.6.3281. Retrieved from 

(29) B. Dariš, M. Verboten, Z. Knez, and P. Ferk, "Cannabinoids in cancer treatment: Therapeutic potential and legislation," 

. DOI: 10.17305/bjbms.2018.3532. Retrieved from 

www.ncbi.nlm.nih.gov/pmc/articles/PMC6387667/pdf/BJBMS-19-14.pdf

(30) T. Kisková, et al, Retrieved from Future Aspects for Cannabinoids in Breast Cancer Therapy. 

. DOI: 10.3390/ijms20071673. Retrieved from 

www.ncbi.nlm.nih.gov/pmc/articles/PMC6479799/pdf/ijms-20-01673.pdf

Ruth Fisher, PhD, is a systems design researcher and analyst. She analyzes markets to determine how environments shape outcomes. She is co-founder of CannDynamics, Inc., and author of 

The Medical Cannabis Primer and Winning the Hardware-Software Game: Using Game Theory to Optimize the Pace of New Technology Adoption.

 Dr. Fisher has worked in the technology and healthcare sectors on behalf of technology companies, early-stage researchers, physicians, and technology start-ups.

Scientific research on breast cancer is still in its early stages, but here we take a look at what we have learned about cannabis to treat breast cancer thus far.

Kristin L. Wohlschlagel is a registered nurse. She identifies herself as a nurse who understands that we need conventional treatments, standard of care treatments, and that cannabis has a place for symptom control and potentially as a therapeutic. She strongly believes cannabis should be researched and studied. There should be lots of support for patients to educate themselves in at least the basics of medical cannabis—and so, Wohlschlagel took matters into her own hands and started seeking out researchers in other countries to understand what the current research was revealing about medical cannabis and then she started compiling data from patients she was working with. Here, Wohlschlagel shares her journey to understand medical cannabis, how it translates to breast cancer patients, and her plans to continue educating herself and others.

Kristin L. Wohlschlagel has been an RN for 16 years, becoming an oncology nurse in rural Hawaii right after graduation. She explained that the first year of her oncology nurse work was very hard so she soon transferred to be an ER nurse where she remained for 6 years. After that, Wohlschlagel went on to hospice and oncology supportive care nursing for patients that needed care at home. In 2016, she started hearing more about medical cannabis from some of her patients, who reported that it helped with nausea and sleep—her stance was always that it was fine as long as their doctors were aware.

There was one patient in particular that changed Wohlschlagel’s perspective quite dramatically. She explained that this patient was in hospice and there would be meetings for the group of nurses on the care team. “We would discuss patients that were struggling to get their symptoms controlled,” she said. “We were giving this particular patient more and more medicine to control symptoms and it got scary, so much so that we were having to deliver the medicines every day because the pharmacist and doctor were afraid the patient would just overdose in desperation to find relief.”

Then something remarkable happened. “The nursing team noted that the patient wasn’t using as many of the pills. They were being left in the box, so the nurses asked what was being used and were shown a little bottle of homemade cannabis oil. The patient said it helped more than the other things that were brought,” she said. “A couple of months later, it was noticed that the patient’s abdomen that had been swollen with cancer had begun to shrink. And the next thing I knew the patient was gone from hospice care. I never heard more about that patient again, but I made a note of what kind of cancer it was.”

This particular case was a form of neuroendocrine cancer. Wohlschlagel is always careful to point out that not all neuroendocrine tumors shrink on THC. But this experience opened her mind to the possibilities of cannabis medicine. Shortly after that experience, she had to take time off work for a back surgery. “I had begun to look online for information about the use of cannabis. First, I was worried about drug interactions because this patient was swallowing this oil, not smoking it. And I knew that when you swallow chemicals, you increase the risk of drug interactions through the liver because a lot happens in the liver. I was looking online for resources. I couldn’t find anybody telling me what were safe doses or when drug interactions would happen,” said Wohlschlagel.

Next, she started digging into the scientific articles discussing the interaction potential. “I noted that some of these articles I was reading were written by scientists in Spain, Israel, or other countries. They were studying the potential for anticancer use of cannabinoids. Well, I felt a chill go up my spine because I had witnessed something that I felt was like seeing Bigfoot. You are afraid to talk about it, and question if you believe you really saw what you saw, but once you see it, you can’t unsee it,” she said.

Wohlschlagel reached out to those scientists and told them what happened with that patient. The scientists explained that there was a little bit of research on that type of cellular cancer in a different setting—prostate cancer. “The fact that they could point me to research showing that THC or a similar chemical that binds to the same receptors in the same ways was able to push back on that neuroendocrine differentiation of cancer cells in prostate cancer studies in the lab—it really hinted that what I saw with that patient might be scientifically explained if they all paid attention. So, with that, I didn’t assume that cannabis was the cure for all cancers, but I realized that this was worthy of my study,” said Wohlschlagel.

Continued Education and Social Media Outreach

Armed with this new information, Wohlschlagel decided to become a medical cannabis patient in Hawaii to help recover from her back surgery in 2017. She used it to sleep because it relieved her back and leg spasms and got support from people who understood how to dose carefully. Medical cannabis helped her sleep and get off all the pain pills and muscle relaxers she was initially prescribed.

Her desire for more education was still growing, so in April 2017 Wohlschlagel attended her first cannabis conference hosted by Patients Out of Time. It was there she met many researchers, doctors, and like-minded nurses who were interested in learning of the potential medical cannabis had to help patients. One nurse practitioner, Eloise Theisen, was particularly helpful in mentoring her about the use of cannabis in patients with cancer.

Wohlschlagel decided to start interviewing every patient that she could who had shared stories of medical cannabis success on social media pages, such as Facebook. She quickly discovered that there were a lot of Facebook groups focused on particular forms of cancer and the use of cannabis. “There were big websites that were kind of wild and crazy, truly. They were just focused on the use of cannabis oil and implied that they were all success stories. I encountered bullying happening that if a person tried using cannabis like they’d read and then if it didn’t work instead of accepting that cannabis might not have been capable of working in that case, the patient would be told, ‘oh, you must have eaten too much sugar. You didn’t have the right strain. You need to do this. You didn’t use enough. You need a gram a day.’ It was quite scary! There were also many kind people—medicine makers and advocates—all trying to help. And many tried to help raise awareness about these problems. But the overwhelming situation was what I described. If a patient admitted they were using conventional treatments, there was often chemo shaming. And these people who had 'failed' in the use of cannabis, in their opinion, they just left. They were ashamed or dealing with metastatic cancer and they left. Their voices were being missed,” said Wohlschlagel.

“I didn’t have a negative attitude about cannabis, but what I witnessed was a lot of problems happening because of the fact that there were no medical professionals that understood cancer seeming to rise up and help. So, I began to just put myself out there. I joined a couple of the groups quietly and would do what I could to encourage the women to understand, for example, breast cancer,” explained Wohlschlagel. “Breast cancer is not breast cancer is not breast cancer. There are subtypes. And then there are subtypes within subtypes. And in most cases, they really need to do conventional therapies.”

Wohlschlagel said she doesn’t mean every single conventional therapy, every single time, but patients really need to consider the hormonal aspect if they have hormonal breast cancer. “If they have HER2 positive breast cancer, there’s a monoclonal antibody treatment that is usually very effective. That drug is called Trastuzumab or Herceptin and it may work a lot better if combined with at least some chemotherapy, especially Taxol type. And I found that these patients believed that they had to do one thing or the other and never consider how it might all work together,” she said.

Actually, Wohlschlagel said it’s not surprising because there was nobody telling patients this information or answering questions like: Can you use these things together? Is it safe? Is it logical? Is it supported by even a little bit of science?

As Wohlschlagel continued speaking with these patients and documenting as much information as she could, she began to gather large amounts of anecdotal evidence that in some subtypes of some cancers there seemed to be a pattern of response. “These people could explain their pathology report to me or share it with me. They could tell me how many milligrams of THC they were getting, where they kept track of how many grams of Rick Simpson Oil or other cannabis medicines they used in a month or so. I began to study these so I could estimate. And patterns of response began to show up,” she said.

Wohlschlagel’s interviews with real-world patients also brought to light the potential for drug to drug interactions. She found that there was a significant drug interaction with commonly used CBD oils and a particular breast cancer drug called Ibrance (palbociclib) and likely similar medications such as Kisqali (ribociclib).

“I accumulated over 100 cases where women on the drug Ibrance had started using CBD oil heavily because they could,” explained Wohlschlagel. “These patients thought more CBD was better because it didn’t make them horribly high. A couple of weeks later, their blood counts dropped in significant ways, particularly their neutrophil counts. That was actually the blood cell that was counted every two weeks when patients were on Ibrance because that drug could reduce neutrophils. Suddenly, the neutrophil counts dropped, and there was a big warning on Ibrance against using anything that would inhibit one particular metabolic pathway. That pathway was called CYP3A4. People know that pathway is also called the grapefruit pathway.”

Wohlschlagel explained that people often get prescription bottles with warnings against use with grapefruit or other inhibitors of CYP3A4. What people don’t realize is that CBD could inhibit that same pathway and would likely do so much more potently than THC because of the complexity of the molecules and how much processing is needed by the liver. Stunned by these findings, Wohlschlagel presented her data at the Cannabis Science Conference in 2018 and shared her poster with researchers in Spain and Israel.

Wohlschlagel is quick to point out that she is not a PhD or molecular biologist. She is a nurse just trying to do right by patients. “The scientists in Israel and Spain appreciated what they called ‘getting feedback from the bed to the bench.’ The lab bench normally sends info to the bed,” she said. “In this case, the bed was informing the bench, meaning I was working with real humans. They were working with lab animals. They appreciated learning what I was seeing and they applauded my efforts, generally speaking.”

However, they were all in agreement that more research was called for—ideally, clinical trials. Wohlschlagel pointed out that research on that level has been slow to come by because of the federal status of cannabis as a schedule I drug in the US. She continued on her own path of interviewing as many patients as she could to gather anecdotal evidence and learn as much as she could.

Educating Patients and Medical Professionals

By 2017, Wohlschlagel was getting contacted every day by people who were curious about the benefits of cannabis for their cancer treatments. “It wasn’t an officially endorsed thing, but I knew it was important because I realized that people were lost out there,” she said.

The best-case scenario was when a patient’s doctor also got on a call with her. “When it was really good, it was because their doctor was willing to get on the call with me. Their doctors would sometimes send people to me and ask me to talk to them about cannabis,” explained Wohlschlagel. “I spoke to doctors and patients from around the world. But the key here is that I tried to do my best to learn from all the patients and the cannabis medicine makers who would share their stories.”

Kristin L. Wohlschlagel, RN, shares a wealth of information on medical cannabis from various patients she interviewed, her own personal experiences, and more.