Study Finds Most Oncologists Have Discussed Medical Marijuana with Cancer Patients

Data indicates that a large majority of oncologists have discussed the use of medical marijuana with patients, yet feel they lack sufficient knowledge about cannabis to advise them.

Nearly half of oncologists in the United States have recently recommended medical marijuana to cancer patients, according to findings in a new study published in the Journal of Clinical Oncology.

In an effort to assess oncologists’ practices and beliefs around medical marijuana, researchers from the Dana-Farber Cancer Institute in Boston, Harvard Medical School, Brigham and Women’s Hospital, University of Massachusetts-Boston, and Massachusetts General Hospital conducted a random survey of 237 cancer doctors from around the country.

According to the survey, roughly 80 percent have talked with their patients about the use of medical marijuana for managing issues like pain and other cancer-related symptoms.

Sixty-seven percent of cancer doctors said they consider marijuana to be a useful addition to standard pain therapies, while half view cannabis as either equal to, or more effective than, standard treatments for managing cancer-related nausea. Three of four oncologists said they believe that cannabis posed less risk of overdose than opioids. Nearly two-thirds viewed cannabis as equally or more effective than standard treatments for poor appetite and extreme weight loss.

“Our study shows that medical marijuana is a salient topic in cancer care today, and the majority of oncologists think it may have utility for certain patients,” said study author Ilana Braun, MD, chief of the Division of Adult Psychosocial Oncology at the Dana-Farber Cancer Institute.

“While this topic is common, however, data on medical marijuana use is less so. We need to bridge this gap so oncologists have the unbiased information they need to assist with decision-making related to medical marijuana use.”

The study revealed that while cancer doctors are recommending cannabis, many feel unprepared to do so. Fewer than 30 percent of oncologists said they feel that they have sufficient knowledge to advise their patients about cannabis’s medicinal use. Of those who recommended marijuana, 56 percent said they lacked adequate knowledge. According to the study, the patient initiated most conversations about medical marijuana.

“[Doctors are] not as close-minded as you might think, and they also feel they have a lot to learn,” Braun said.

For the study, Braun and her colleagues mailed a survey to 400 practicing oncologists in the U.S. that were randomly selected from a national database. Of the 237 doctors who responded, 55 percent practice in states where medical marijuana is legal.

oncologists support marijuana

Limitations on Research

Of the 29 states with medical marijuana laws in place, all have included cancer as a qualifying condition that allows for it to be recommended by doctors.

Under federal law, however, marijuana is considered an illegal drug, which imposes restrictions that have hindered the collection of research on cannabis and its cannabinoids.

The studies that have been done suggest that cannabis is helpful in managing symptoms of chemotherapy, including pain and nausea. Earlier this year, Israeli researchers found that cannabis allowed cancer patients to reduce their intake of opioids and still effective manage pain. While cannabis plays a role in today’s cancer care, there are still knowledge gaps about medical marijuana use in oncology and more data is still needed.

“Unfortunately, at this time, the evidence base to support medical marijuana’s efficacy in oncology is young,” Braun told NPR. “So, often oncologists are borrowing from clinical trials for other diseases, or extrapolating from evidence on pharmaceutical-grade cannabinoids.”

In response to the study’s findings, Andrew S. Epstein, MD, American Society of Clinical Oncology (ASCO) Expert in Patient Care, reiterated the need for more research, saying:

“It’s clear from this study that patients and their families want to know more about medical marijuana for the treatment of cancer-related symptoms, and often initiate discussions with their oncologists. We need to be prepared to have these conversations, and that means having research to support our recommendations. This study highlights the important need for more research on the use of medical marijuana in oncology, so we can provide informed guidance and care that meets all of our patients’ needs.”

Full text of the new study, “Medical Oncologists’ Beliefs, Practices, and Knowledge Regarding Marijuana Used Therapeutically: A Nationally Representative Survey Study,” is available through the Journal of Clinical Oncology.

More on Medical Cannabis for Cancer

A separate study last year found that one-quarter of cancer patients use marijuana where it’s legal. Read about the history of marijuana use for cancer HERE.

You can learn more about what studies have found so far about cannabis’s therapeutic potential for cancer and cancer-related symptoms by visiting our education page.