As the legalization of medical marijuana becomes more common worldwide, medical cannabis is being prescribed by doctors and caretakers to help treat cancer-related side effects—either from the cancer itself or from treatments like chemotherapy. Countless scientific studies have shown that medical cannabis offers palliative care benefits, including appetite stimulation, pain relief and more.

But early research indicates that cannabinoids can do so much more. Data is showing that medical marijuana has antitumor effects and may one day be used as a cancer treatment, not just as a drug to ease symptoms of the disease. Well over 100 types of cannabinoids—the compounds within cannabis containing different properties and chemical profiles—have been identified to date, yet few have been studied for their specific effects. Medical marijuana’s proven palliative care benefits and the complexity of the drug indicate clinical studies are necessary to uncover the drug’s full potential.

In 2017 there were more than 1.6 million new cancer diagnoses in the United States, and by the year 2030, cancer cases are projected to increase by 50 percent worldwide compared to 2012 rates. Given these alarming statistics, new treatment options are now more important than ever. Chemotherapy, surgery, radiation, targeted therapy and immunotherapy are the most common cancer treatments, but side effects are often severe, ranging from fatigue, hair loss, nausea, infection and more. Medical marijuana offers important relief to patients dealing with these unwanted effects, but what if we were able to offer the drug to patients as an alternative cancer therapy? We may be able to avoid or reduce the severe side effects of other treatments, while combatting the cancer and its symptoms.

We’re not there yet, but while the available data are limited, research that has been conducted around antitumor effects of cannabinoids so far shows great promise. The International Journal of Oncology published a study last year, for example, indicating that cannabinoids successfully kill cancer cells, and the benefits increase when combined with chemotherapy. An early preclinical study we recently conducted also found that cancer cells derived from patient blood samples were differentially sensitive to the two main active compounds in cannabis—tetrahydrocannabinol (THC) and tetrahydrocannabinolic acid (THCA).

A number of other laboratory and animal studies have been conducted in recent years on colon, breast and brain cancers. They indicate that cannabinoids may inhibit tumor growth by blocking cell growth, causing cell death and blocking the development of blood vessels that tumors require to grow. We have yet to make the leap to study these promising effects on humans.

The current approach to medical marijuana research and treatment in the United States is limiting the potential for new discoveries in the cannabinoid field. The current impact of the U.S. market cannot be understated, as its responsible for 90 percent of all global cannabis sales. By 2021, the American share of the market is expected to drop to 57 percent as other countries like Israel and Canada adopt medical marijuana policies and more aggressively fund research.

Thirty states and the District of Columbia have legalized marijuana for medicinal purposes, but the federal government still classifies marijuana as a Schedule 1 drug—a category for substances with high potential for abuse and no accepted medical purpose. This categorization has clearly impacted the scope of research in the United States.

There is currently only one marijuana farm in the country currently approved for the cultivation and procurement of research-grade cannabis. The Drug Enforcement Administration previously restricted the total number of American research facility permits but relaxed these limitations in 2016. Even so, the attorney general has not approved permits for any of the additional 26 facilities that have applied. Despite a growing number of states legalizing medical marijuana, federal restrictions mean that scientists are unable to conduct high-quality research required for FDA approval that would provide necessary clarity on the benefits of cannabinoids for medical practitioners and the patients they serve.

With millions of new cancer cases each year, clear disadvantages to mainstream treatment options, and positive indications from preclinical antitumor medical marijuana studies, the benefit of gathering additional data is clear. We must conduct large-scale research studies to gain a better understanding of medical marijuana’s capabilities beyond palliative care.