Medical Cannabis Cannabis refers to a family of plants from which marijuana and hemp are produced. These plants are grown around the world and have been used in herbal remedies for centuries. CBD oil can’t treat or cure breast cancer, but it may ease side effects of treatment like pain, anxiety, insomnia, nausea, and vomiting. Here’s what to know about using CBD oil for breast cancer. Effect of combining CBD with standard breast cancer therapeutics Breast cancer is the most common malignancy in women worldwide. Sixty-five percent of breast cancers are estrogen and/or
Cannabis refers to a family of plants from which marijuana and hemp are produced. These plants are grown around the world and have been used in herbal remedies for centuries.
Cannabis refers to a family of plants from which marijuana and hemp are produced. These plants are grown around the world and have been used in herbal remedies for centuries.
In modern times, marijuana has generally been viewed as a recreational drug. But there is growing interest in its medical uses. The terms “medical marijuana,” “medical cannabis,” “medical hemp,” or “medical CBD” refer to the use of products made from the cannabis plant to treat certain health conditions.
Many people diagnosed with cancer report that cannabis products are effective for managing their symptoms and treatment side effects. There is some research supporting the use of medical cannabis for managing certain conditions, but federal laws in the United States make it difficult to study medical cannabis.
It’s important to know that cannabis is not a cure or treatment for cancer itself, even though there are many such claims online. You should not use medical cannabis instead of proven cancer treatments.
What are cannabinoids?
Cannabis plants contain many chemicals known as cannabinoids. Cannabinoids cause certain effects when you consume them. They do this by interacting with your body’s endocannabinoid system, which actually produces its own cannabinoids called “endocannabinoids.” Scientists are still working to understand how the endocannabinoid system works, but it seems to play a role in many processes in your body.
The research done on cannabis so far suggests that most of its medical benefits are related to the effects of two main cannabinoids:
THC (delta-9-tetrahydrocannabinol), which causes the high associated with marijuana
CBD (cannabidiol), which does not cause a high
THC and CBD seem to offer different medical benefits. A good example of these differences can be seen when comparing the only cannabinoid medicines approved by the U.S. Food and Drug Administration (FDA): Marinol (chemical name: dronabinol) and other synthetic THC medicines are approved to treat nausea caused by chemotherapy. The CBD medicine Epidiolex is approved to treat seizure disorders in children.
Different forms of cannabis contain different amounts or combinations of cannabinoids. Marijuana contains enough THC to cause a high (more than 0.3%) and varying amounts of CBD. Hemp contains mostly CBD and only trace amounts of THC, which does not cause a high.
Cannabis products made from extracted oils can contain all or mostly THC or CBD, or different combinations. “Whole plant” marijuana products are often grouped by “strains” to describe their balance of THC and CBD. Whole plant or “full spectrum” products often contain other cannabinoids that can cause other effects.
The effects of cannabinoids also vary depending on how they are consumed. The most common ways to consume medical cannabis are:
eating “edibles” or taking capsules, oils, or tinctures by mouth, which can take one to a few hours to take effect and can last for up to 6 hours
inhaling cannabis smoke or vapor, which takes effect within minutes and fades over a few hours
What conditions is medical cannabis used for?
It’s extremely important to know that cannabis is not a cure or treatment for breast cancer, despite many claims. It’s dangerous to use cannabis instead of proven cancer therapies. It’s also important to talk to your doctor before using cannabis products to make sure it won’t interact or interfere with any of your medicines or treatments.
People use cannabis products to manage cancer symptoms, treatment side effects, and other challenges along the cancer journey. The most common reasons people with breast cancer use cannabis are to manage:
pain (including joint and muscle aches, discomfort, and stiffness)
anxiety and stress
nausea, vomiting, and loss of appetite caused by chemotherapy
Some studies support the use of cannabis for these conditions. Still, because marijuana is federally illegal in the United States, research on medical cannabis to manage cancer symptoms and treatment side effects is limited.
Patient surveys have provided important insights about how people use medical cannabis. About 42% of people diagnosed with breast cancer who completed our survey said they used medical cannabis products to manage breast cancer symptoms or treatment side effects. The people who used medical cannabis ranged in age, cancer stage, and treatment phase, and most (75%) found it to be “very” or “extremely” helpful.
But again, it’s important to talk to your doctor about using cannabis products, especially during cancer treatment, to make sure it’s a safe option for you. If you find that your doctor is not knowledgeable or experienced with cannabis, you may want to seek advice from an oncologist who participates in your state or country’s medical cannabis program.
“It’s important for people to know that anything they ingest that produces a change in their bodies is acting like a drug, and it has the potential for side effects, interactions with other drugs, as well as benefits,” said Virginia F. Borges, M.D., MMSc., professor of medicine and director of the Breast Cancer Research Program at the University of Colorado Cancer Center. “People have to be as diligent about researching medical marijuana as they would be with any other supplement or drug they were taking.”
Because marijuana has been legal for both medical and recreational use in Colorado for many years, Dr. Borges has cared for a number of breast cancer patients who use or have used medical cannabis to ease treatment side effects.
“I’ve mainly seen it used in conjunction with prescription drugs to control pain and other side effects in patients living with metastatic disease,” she said. “It’s rare that a person living with metastatic breast cancer would have only one side effect to manage. So, by adding in medical marijuana, it often allows me to cut back on the number of drugs I prescribe. With a high-quality source for medical marijuana and knowing how it affects an individual, using medical marijuana can put more control back in the hands of my patient.”
Is medical cannabis legal?
The legal status of cannabis for either recreational or medical use varies across the world and continues to change. It’s important to understand the laws in your state or country before you purchase or use cannabis.
Marijuana (the form of cannabis that contains more than 0.3% THC — enough to cause a high) is illegal nationwide under federal law in the United States. At the same time, most U.S. states have passed their own laws either legalizing the use of marijuana entirely or to treat certain medical conditions. But even in states where marijuana is legal, U.S. federal government employees and people who work for companies that receive federal grant funding cannot legally use marijuana under the Drug-Free Workplace Act.
Many other countries also allow the use of medical marijuana, including Australia, Canada, the United Kingdom, and many others in Europe and South America.
Marijuana laws vary from state to state in the U.S. Some states allow people with certain health conditions to get a medical marijuana card through their doctor, which allows them to buy cannabis products at an approved dispensary. Other states only allow the medical use of CBD to treat certain serious conditions. In states where marijuana is legal for recreational use, anyone of legal age can buy cannabis products from a dispensary, but some of these shops carry medical products that are only available to people with certain health conditions.
If marijuana is legal where you live, it’s important to know that quality control of these products can be uncertain. Most cannabis products, even those sold at medical dispensaries, are not regulated like other medicines. They may contain contaminants such as mold, heavy metals, and pesticides, and the labels may include incorrect information about types, doses, and ingredients. You can ask the dispensary for a “certificate of analysis” for the products you might buy, which tells you about ingredients, dose, and contaminants.
Medical cannabis is not approved by the FDA for use in people with cancer. But three synthetic THC medicines have been approved to treat nausea and vomiting caused by chemotherapy:
Cesamet (chemical name: nabilone)
Marinol (chemical name: dronabinol)
Syndros (chemical name: dronabinol in liquid form)
In Canada and some European countries, Sativex (chemical name: nabiximols), an oral spray containing equal amounts of THC and CBD, is approved for the treatment of certain types of pain related to cancer.
Epidiolex, a medicine with CBD extracted from marijuana, is FDA-approved for use in children with severe seizure disorders. It is not approved for people with cancer, but studies are ongoing.
CBD products can be made from marijuana or hemp (the form of cannabis that contains only trace amounts of THC and does not cause a high). In the U.S., CBD products have typically only been available at medical marijuana dispensaries.
However, the U.S. Congress passed a federal law called the 2018 Farm Bill. This law made it legal for companies to produce and sell CBD products made from hemp. Now, many more companies are selling CBD products. You’ve probably seen them everywhere from grocery stores and pharmacies to gas stations and online ads.
But just because CBD products made from hemp are sold everywhere, in all kinds of products, and their legal restrictions have been loosened, you shouldn’t assume they are safe, effective, or even legal where you live (some state laws still consider hemp CBD illegal).
Like all cannabis products, hemp CBD products are not regulated the same way medicines are. So it’s hard to know if they are made safely, contain contaminants, or are labeled accurately. It’s also illegal for companies to market any cannabis product as a cure, treatment, or dietary supplement. The FDA has warned many companies that have marketed CBD products in this way.
Medical grade CBD products from a medical marijuana dispensary or an independent pharmacy are likely a safer and more effective option, because you can ask for a certificate of analysis that tells you about the ingredients, dose, and if there are contaminants such as mold, heavy metals, or pesticides.
What to expect when using medical cannabis
The ways cannabis can affect you depends on many factors and can be hard to predict. The effects of cannabis can vary from person to person.
Also, cannabis comes in a variety of strains, each with different potency and amounts or combinations of cannabinoids. Of note, products that contain THC may cause a high, while products with CBD only or trace amounts of THC will not.
The way you consume cannabis can also influence the effects. Cannabis products come in many different forms, including:
edibles, such as cookies, candy, mints, or brownies
gelcaps or pills
dried leaves or buds for smoking, vaporizing, or making tea
tinctures or sprays that are used under the tongue or along the gum line
oils for inhaling with a vape pen or vaporizer
oils for mixing into tea, honey, or food
creams and other products that are applied to the skin
Eating edibles or taking oils by mouth can take one to a few hours to take effect and can last up to about 6 hours. It can be difficult to know the dose in some edibles and how long the effects will last. Oils, sprays, and tinctures may give you more control over the dose you take.
Inhaling cannabis smoke or vapor takes effect within minutes and fades more rapidly. Inhaling can give you more control over the dose you take, when the effects will start, and how long they will last. But many oncologists prefer that their patients not smoke or vaporize cannabis products, especially during active cancer treatment that can affect the lungs or immune system. That’s one reason why it’s important to talk to your doctor before you start using cannabis.
Every person’s situation is unique. The best forms and doses of medical cannabis and the reasons for using it will vary from person to person.
Side effects and safety of medical cannabis
Information on cannabis side effects is limited because research on medical cannabis in people with cancer is limited. Side effects are also likely to vary depending on the dose you take and the amounts and combinations of THC and CBD in each product.
Reported side effects of marijuana, which has THC, include:
increased heart rate
low blood pressure
dizziness and falling
tiredness, fatigue, sleepiness
CBD is usually well-tolerated, but reported side effects include:
drowsiness and fatigue
It’s not well understood how cannabis products may interact with other medicines, including cancer therapies. That’s why it’s important to talk to your doctor about using medical cannabis both before and during treatment. Working together, you can come up with the best way to relieve your symptoms.
“The medicines and therapies you use can interact with each other. They may meet up and cause no effect, a beneficial effect, or a harmful effect,” said Marisa Weiss, M.D., founder and chief medical officer of Breastcancer.org and director of breast radiation oncology at Lankenau Medical Center. “For example, a helpful effect is when cannabis reduces nausea from chemotherapy. But a harmful effect can happen if cannabis interferes with the benefit of chemotherapy or increases the risk of lung damage during radiation and chemotherapy if cannabis is smoked or vaped.”
Important things to consider before using medical cannabis
If you decide that you’re interested in trying medical cannabis to treat your breast cancer symptoms or treatment side effects, here are some things to consider before you do:
Talk to your doctor: As with all vitamins, supplements, herbs, and over-the counter medicines, always tell your doctor if you are using any type of cannabis product to make sure it won’t interact or interfere with your cancer treatments.
Find a doctor in a medical marijuana program: If you live in a place where medical marijuana is legal, make an appointment with a doctor who participates in your state or country’s medical marijuana program. These are doctors who are trained and certified to qualify patients for medical cannabis and oversee their care. Some states also certify trained nurses, physician’s assistants, and pharmacists to qualify patients for medical cannabis.
Find a medical cannabis dispensary you are comfortable with: Most oncologists prefer that their patients get their medical cannabis products from a medical cannabis dispensary if they are available where you live. Medical dispensaries focus on medical patients rather than just recreational users. They should have knowledgeable staff members or a pharmacist who can answer your questions about their products. It can be helpful to call the dispensary ahead of time to explain the issues you’re having and ask if you can schedule an appointment with a knowledgeable staff member. Ask if there is a pharmacist or doctor available at the dispensary. You should share a complete list of medications and supplements you’re taking to avoid any unsafe interaction between products. You also should let the dispensary know if you have any allergies. For example, if you’re allergic to coconut, then you should avoid the commonly used coconut oil-based products.
Learn about different medical cannabis products: Every medical cannabis dispensary has its own menu of products. Depending on where you live, medical cannabis dispensaries may have pharmacists on staff who can review your unique situation and make tailored recommendations. When choosing products, it’s important to understand the different effects of THC and CBD. THC and CBD each offer different medical benefits. For example, CBD may be better at easing anxiety, while THC may be better at controlling nausea caused by chemotherapy. THC and CBD are present in different levels in different strains of marijuana. Most medical cannabis products are made by extracting these cannabinoids from the cannabis plant and putting different amounts of them into the products. The label on the product usually shows the ratio of THC to CBD. Hemp products mostly contain CBD, but can have trace levels of THC and other cannabinoids which are unlikely to be listed on the label. It’s also important to ask questions about the safety and quality of the products you are buying. Some doctors who certify people for medical marijuana suggest asking the dispensary staff member some general questions before you start talking about your symptoms and side effects, such as:
CBD Oil and Breast Cancer
If you’re being treated for breast cancer, you’ve probably had some side effects like pain, fatigue, nausea, discomfort, and anxiety. Maybe you’ve heard other people with the disease talk about using CBD products to ease these symptoms — or you’ve run across CBD at your local gas station or drug store. But what exactly is CBD? How does it work? And can it really help people who have breast cancer?
Defining the Terms
First, let’s break down the terms, which can be confusing.
- Cannabis is a type of flowering plant that has more than 500 chemicals. Hemp and marijuana are both forms of cannabis.
- Tetrahydrocannabinol (THC) might be the best-known chemical, known as a cannabinoid, in the cannabis plant. Its psychoactive ingredients create intoxication, or a “high.”
- Cannabidiol (CBD) is another well-known chemical in cannabis. Even though it’s also technically considered psychoactive, CBD is not intoxicating because it affects the brain differently than THC. CBD that’s extracted from hemp is federally legal, but it’s not legal in every state. CBD can also be extracted from marijuana.
- Hemp is any cannabis plant that contains mostly CBD and has a maximum of 0.3% THC. The 2018 Farm Bill made it legal to grow industrial hemp in the United States.
- Marijuana is any cannabis plant that has more than 0.3% THC, an amount that causes a high. It contains various amounts of CBD. Marijuana is not federally legal, and its legality varies from state to state.
How CBD Can Help
Your body has a natural endocannabinoid system, “a complex network of receptors on cells that regulates your daily body functions, such as inflammation, mood, and sleep,” says Marisa C. Weiss, MD, chief medical officer and founder of Breastcancer.org and director of breast radiation oncology at Lankenau Medical Center in Wynnewood, PA.
CBD works by interacting with this system, which means it can help reduce side effects of breast cancer treatment like pain, anxiety, insomnia, nausea, and vomiting.
That said, it’s important to note that there is no evidence that CBD can treat or cure breast cancer itself.
“As a doctor, I make the distinction between complementary and alternative medicine,” says Andrea Mathias Schmucki, MD, a patient advocate for the Living Beyond Breast Cancer Hear My Voice advocacy program and a former family physician. She is herself being treated for metastatic breast cancer, or cancer that’s spread to other parts of her body. “I look at CBD as complementary, using it in addition to, rather than as an alternative to, traditional treatment.”
Before she had a double mastectomy, reconstruction surgery, chemotherapy, and radiation for breast cancer in 2015, Mathias Schmucki says, she wouldn’t have put much stock in something like CBD (though she would have supported her patients’ choice to use it). But ibuprofen wasn’t relieving the itchy, scratchy, painful sensations she was having. She was so uncomfortable, “I was open to anything.” She knew that she didn’t need or want the mind-altering effects THC can create, so she decided to try CBD oil.
She bought some at her local pharmacy and took it by mouth every day for a month, noticing that it seemed to help on some days. But she wasn’t convinced that the changes were due to the CBD oil, so she didn’t get more when it ran out. Within 3 weeks, the horrible discomfort was back. She researched CBD in-depth and found a reputable company. Now, she’s a believer. “It has made a significant improvement in my daily quality of life,” she says.
How CBD Is Used
Weiss notes that there are all kinds of CBD products beyond oil, such as edibles, capsules, tinctures, creams and oils for skin, and sprays that you can use under your tongue.
Mathias Schmucki still takes CBD oil orally. She also uses a topical CBD oil for the skin on her radiation-treated side to help with the dryness and discomfort, plus a CBD extract in a coconut-oil-based suspension as a personal lubricant for intercourse. “A lot of women with breast cancer experience sexual side effects because one of the mainstays of treatment is anti-estrogen,” she explains.
Side Effects and Risks
According to Weiss, some people who use CBD have reported side effects including:
- Drowsiness and fatigue
- Less appetite
Mathias Schmucki notes that there aren’t a lot of studies on the potential risks of CBD oil, so it’s not clear exactly what they might be. However, “CBD is usually well-tolerated,” Weiss says.
Weiss offers these cautions:
- Don’t use cannabis products if you’ve had a heart attack within the past 6 months or if you have severe heart disease.
- Some medications can have a negative interaction with cannabis products, such as warfarin (Coumadin, Jantoven). Give your doctor and pharmacist a complete list of all the medications and supplements you’re taking so they can keep an eye out for interactions.
- Watch out for product ingredients that you might be allergic to, like coconut oil.
- It’s best to steer clear of cannabis products altogether if you’ve had serious side effects from using them before, like uncontrolled vomiting.
- Be aware that many CBD products may contain trace amounts of THC that can show up on a drug test. Check your employer’s medical cannabis policy before you use CBD.
Talking to Your Doctor
Weiss and Mathias Schmucki agree that it’s critical to talk to your doctor before you use CBD, especially if you’re in active treatment for breast cancer. For one thing, you need to make sure it’s a safe option for you.
If you’re taking certain medications like blood thinners and thyroid and seizure medications, you’ll need periodic blood tests to make sure your levels are where they should be. If you’re on a medication like this and you’re going to use CBD products, Mathias Schmucki says, your doctor will need to monitor you to make sure your levels stay on track. “Everybody’s different, so you won’t really know how CBD will affect your body’s metabolism of other medications,” she says.
Your doctor may not be enthusiastic about you using CBD, but that doesn’t necessarily mean they’re resistant to the idea. “Remember that your doctor wants to help manage your symptoms and pain, so being open and honest about what you need is the best way to communicate,” Weiss advises.
If you’re having breast cancer treatment side effects or symptoms that aren’t being controlled, or if you think your doctor isn’t listening to your needs or doesn’t have the experience to give you advice on CBD products, get a second opinion, Weiss suggests. She recommends talking to an oncologist who is knowledgeable about cannabis products if your doctor can’t help.
“I tell my doctors that I’m not holding them responsible for my decision to use CBD, but I want them to know this is a choice I’m making,” Mathias Schmucki says. “I’m giving them information they need to provide the best care that they can.”
How to Buy CBD
What should you look for if you decide to give CBD products a try?
- Medical-grade CBD products. “Just because CBD products made from hemp are now widely available, you shouldn’t assume they’re safe, effective, or even legal where you live, since some state laws still consider hemp CBD illegal,” Weiss says. She recommends looking for medical-grade CBD products because they’re “probably a safer option.”
- Certificate of analysis. Weiss recommends asking for a certificate of analysis (COA) from the company or dispensary you use. A COA comes from a third-party laboratory and tells you the quantity of cannabinoids in the product so that you know exactly what you’re getting. Some COAs also show the levels of potential toxins like pesticides, arsenic, and heavy metals.
For Mathias Schmucki, finding a company that provided a COA with all this information was a must. She says there are several online companies that send it with every product. “The companies with the best reputations will often have very robust websites with educational resources,” she says, so look for these.
Mathias Schmucki says other options, like how the CBD is extracted or what the best delivery method is, are a matter of personal choice.
Keep this in mind, too: “Everyone reacts differently to cannabis products, so don’t feel discouraged if your symptoms aren’t reduced with the first product you try,” Weiss says. “You may need to test different products to find what’s best for you, including the delivery method and dosage.” She suggests starting low and slow, making changes as you go.
“There’s a lot of information out there, but I think you really have to be careful about where you get that information,” Mathias Schmucki says. She advises looking to see if your local medical center has an integrative oncology department that includes nontraditional therapy like CBD and can give you guidance. Other good resources include pharmacists trained in cannabis, experts at medical cannabis dispensaries, and pain management doctors, Weiss says.
Mathias Schmucki has also found that talking to other people who currently have or previously had breast cancer is invaluable. A private Facebook group called Fighting Breast Cancer with Cannabis has been helpful in her own journey.
The Future of CBD
“Research on medical cannabis products, including CBD oil, has been limited because federal laws in the United States have made it difficult to study,” Weiss says. But now that hemp production is legal, it can be studied, Mathias Schmucki notes. “Lifting federal regulations off of the growing and scientific study of cannabis plants will help over time in answering some of these questions about areas like safety, dosing, and contraindications,” she says.
“In the meantime, more research is being done to provide better answers,” Weiss says. For example, she’s the principal investigator on a research team at Lankenau Medical Center that’s testing CBD in cancer patients with chemotherapy-induced peripheral neuropathy (CIPN). This is the first and only FDA-approved CBD study for patients with CIPN, “a common and difficult side effect of the most commonly used chemotherapies, which can damage the nerves and lead to pain, discomfort, or numbness, most often in the hands and feet,” she explains.
Johns Hopkins Medicine: “Side Effects from Breast Cancer Treatment.”
Marisa C. Weiss, MD, chief medical officer and founder, Breastcancer.org; director of breast radiation oncology, Lankenau Medical Center, Wynnewood, PA.
National Center for Complementary and Integrative Health: “Cannabis (Marijuana) and Cannabinoids: What You Need to Know.”
PBS NewsHour: “Is CBD legal? Here’s what you need to know, according to science.”
Project CBD: “Is CBD Really Non-Psychoactive?”
U.S. Department of Agriculture: “Hemp and Farm Programs.”
Breastcancer.org: “Medical Cannabis.”
Andrea Mathias Schmucki, MD, patient advocate, Living Beyond Breast Cancer Hear My Voice advocacy program.
Citizen Truth: “What is a CBD Certificate of Authenticity (COA) (And How to Read It).”
Effect of combining CBD with standard breast cancer therapeutics
Breast cancer is the most common malignancy in women worldwide. Sixty-five percent of breast cancers are estrogen and/or progesterone receptor positive. Estrogen receptor expression is a prognostic and predictive biomarker of response to endocrine therapy, which consists of the selective estrogen receptor modulator tamoxifen, aromatase inhibitors, and the selective estrogen receptor degrader fulvestrant. Cannabidiol is a phytocannabinoid that is emerging as a potential therapeutic agent. The aim of this study was to investigate the effect of cannabidiol on estrogen receptor-positive and estrogen receptor-negative representative breast cancer cell lines in combination with standard therapeutic agents used in clinical practice. To compare the effects of cannabidiol on breast cancer cell viability, cancer cell lines were exposed to increasing concentrations of cannabidiol. The effects of cannabidiol in combination with the endocrine therapeutics tamoxifen, fulvestrant, and the cyclin-dependent kinase inhibitor palbociclib on breast cancer cell viability were examined. We demonstrated that cannabidiol dose-dependently decreased the viability of all breast cancer cell lines independent of estrogen receptor expression. The addition of cannabidiol to tamoxifen had an additive negative effect on cell viability in ER+ in estrogen receptor positive T-47D line. Cannabidiol did not attenuate the effect of standard treatment of hormone receptor-positive breast cancer with fulvestrant and palbociclib. In addition, cannabidiol did not attenuate the effect of standard treatment of triple-negative breast cancer and human epidermal growth factor receptor 2 positive breast cancer cell lines with trastuzumab and cisplatin.
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