Talking with Your Doctor About Medical Cannabis and Breast Cancer

Published on: 
Cannabis Patient Care, October/November 2021, Volume 2, Issue 3
Pages: 8-11

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

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?

Dr. Weiss: 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?

Dr. Weiss: 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.

At 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? 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?

Dr. Weiss: 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?

Dr. Weiss: 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?

Dr. Weiss: 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?

Dr. Weiss: 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?

Dr. Weiss: 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?

Dr. Weiss: 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: or call: 484.476.2756.

What type of products did you use in your study?

Dr. Weiss: 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.

What can patients do to help?
Dr. Weiss: 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.

About the Interviewee

Dr. Marissa Weiss is the author of four critically acclaimed books on breast cancer and breast health: Living Beyond Breast Cancer and Living Well Beyond Breast Cancer, 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.

About the Author

Debbie Churgai 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 State of the States Report, the Patients Guide to CBD, and the Medical Cannabis Access for Pain Treatment report.