Medicinal Cannabis: Expanding Cancer Research Brings New Hope

Medicinal Cannabis: Expanding Cancer Research Brings New Hope

Great strides are being made in developing cannabis-based therapies for cancer patients, especially those for whom standard, pharmaceutical regimens have been less than successful. 

The therapeutic benefits of phytocannabinoids, the active compounds found in marijuana that directly interact with the human Endocannabinoid System (ECS), are becoming universally acknowledged. Despite U.S. classification of marijuana/cannabis as a Schedule I Narcotic under the Controlled Substance Act (CAS) of 1970, significant progress has been made in identifying specific, medicinal benefits for a growing number of diseases and disorders. This expanding awareness about potential medicinal uses, spurred by legalization of medical marijuana in 23 states, is opening new doors for researchers, with U.S. lawmakers expected to reschedule marijuana within the next five years. Even the National Cancer Institute has begun to acknowledge, on its consumer site, that there is therapeutic value in cannabis treatments. 

Although no human studies have, as yet, been conducted in the U.S., preliminary research has brought remarkable hope for new, effective treatments and cures.  The following study profiles do not yet provide all of the answers, but access to cannabis dispensaries in 23 states has enabled many patients to develop their own, successful cannabis treatment therapies.

Bladder Cancer

  • A paper published in the Feb., 2015 Journal of Urology found that whole-plant cannabis use is associated with a decreased likelihood of developing bladder cancer.
  • The California Men’s Health Study (2002 – 2003), which collected data from 84,000 men ages 45 to 69, found that overall, cannabis use was associated with a 45 percent decrease occurrence of bladder cancer over the next seven years. 

Brain Cancer

Gliomas represent about 80 percent of all malignant brain tumors and glioblastoma multiforme (GBM) is the most common, and the most fatal, with a reported survival rate of less than 10 percent in the first five years. 

At least a dozen studies have been performed since 2000 on the anti-tumor effects of cannabinoids on gliomas alone, with early research leading to the unexpected discovery that THC had anti-tumor properties.

  • In 2006, patients with GBM took part in a Complutense University, Madrid, clinical study to assess THC’s anti-tumor effect on humans that resulted in significantly reduced tumor growth in each case.
  • A St. George University, London, study published last year found that the combination that showed “dramatic reductions in tumor volumes when both cannabinoids [THC and CBD)] were used with irradiation” in some forms of high-grade glioma.
  • The Colorado Department of Public Health & Environment has been authorized to fund a cannabis trial titled, “Medical Marijuana in the Pediatric Brain Tumor Population (Palliative Care).” 
  • Another trial to determine whether pure CBD can reduce tumors in terminal cancer will be conducted by the Hadassah Medical Organization in Israel. 
  • Trials are currently underway by GW Pharma to investigate whether Sativex, a pharmaceutical product made with phytocannabinoids, is an effective treatment for patients with recurrent tumors.

Breast Cancer

  • Excerpted from the National Cancer Institute:
    • A laboratory study of cannabidiol (CBD) in estrogen receptor positive and estrogen receptor negative breast cancer cells showed that it caused cancer cell death while having little effect on normal breast cells. Studies in mouse models of metastic breast cancer showed that cannabinoids may lessen the growth, number, and spread of tumors.
  • Excerpted from the National Cancer Institute:
    • A laboratory study of cannabidiol (CBD) in human glioma cells showed that, when given along with chemotherapy, CBD may make chemotherapy more effective and increase cancer cell death without harming normal cells. Studies in mouse models of cancer showed that CBD together with delta-9-THC may make chemotherapy, such as temozolomide, more effective.
  • Excerpted from the National Cancer Institute:
    • A laboratory study of delta-9-THC has been shown to have antitumor effects by acting on molecules that may be found in breast cancer cells.
  • According to research from the California Pacific Medical Research Center, Cannabidiol (CBD) can help inhibit metastasis (spreading throughout the body) in breast cancer cells. CBD inhibits key genes involved in the progression of tumor growth. This is good news for patients in whom chemotherapy is ineffective, and offers an alternative to what can be crippling side effects. Researchers acknowledge that CBD therapy work best in concert with traditional treatments.
  • Research published in the Journal of Biological Chemistry last year found that pure THC may be effective for shrinking cancer cells found in some tumors, by acting through specific cannabinoid receptors.  

Colon Cancer

  • Excerpted from the National Cancer Institute:
    • A study in mice showed that cannabinoids may protect against inflammation of the colon and may have potential in reducing the risk of colon cancer, and possibly in its treatment. 
  • A team of researchers from Italy and the UK report that cannabis extracts high in cannabidiol (CBD) can help prevent the spread of colon cancer in mice. According to their results, high levels of cannabidiol (CBD) inhibited the growth of tumor cells, but not healthy ones. 

Liver Cancer

  • Excerpted from the National Cancer Institute:
    • A laboratory study of delta-9-THC in hepatocellular carcinoma (liver cancer) cells showed that it damaged or killed the cancer cells. The same study of delta-9-THC in mouse models of liver cancer showed that it had antitumor  effects. Delta-9-THC has been shown to cause these effects by acting on molecules that may also be found in non-small cell lung cancer cells and breast cancer cells.

Lung Cancer

  • In a 2007 Harvard University Study researchers found that, in both laboratory and mouse studies, delta-tetrahydrocannabinol (THC) cuts tumor growth in half in common lung cancer while also impeding the cancer's ability to spread. 
  • A German study on the interaction between cannabis and lung cancer suggests that cannabinoids make tumors more susceptible to cancer “killer cells.”

Multiple Myeloma

  • Multiple myeloma (MM) is an incurable cancer of immune plasma cells. The US-Israeli cannabis research firm, One World Cannabis (OWC), conducted a multiple myeloma study of three repetitive tests on the effect of cannabis THC and CBD extracts, with a result of cell death in more than 60 percent in malignant cells. More results of pure THC and CBD are under further analysis.

Skin Cancer (Melanoma)

  • A study by researchers in the U.K. and Spain, published in the Journal of Investigative Dermatology in February 2015 found that treatment with equal amounts of THC and CBD helped to decrease the viability of melanoma cells.


  • Excerpted from the National Cancer Institute:
    • Studies in mice and rats have shown that cannabinoids may inhibit tumor growth by causing cell death, blocking cell growth, and blocking the development of blood vessels needed by tumors to grow. Laboratory and animal studies have shown that cannabinoids may be able to kill cancer cells while protecting normal cells. 

Treatment Related Appetite Stimulation

  • Excerpted from the National Cancer Institute:
    • Delta-9-THC taken by mouth: A clinical trial compared delta-9-THC (dronabinol) and a standard drug megestrol) in patients with advanced cancer and loss of appetite. Results showed that delta-9-THC was not as effective in increasing appetite or weight gain in advanced cancer patients compared with standard therapy. However, a clinical trial of patients with HIV/AIDS and weight loss found that those who took delta-9-THC had increased appetite and stopped losing weight compared with patients who took a placebo. 

Treatment Related Nausea and Vomiting

  • Excerpted from the National Cancer Institute:
    • Delta-9-THC taken by mouth: Two cannabinoid drugs approved in the United States are available under the names dronabinol and nabilone. Both are approved by Food and Drug Administration (FDA) for the treatment of chemotherapy-related nausea and vomiting in patients who have not  responded to standard therapy. Many clinical trials have shown that both dronabinol and nabilone worked as well as or better than some of the weaker FDA-approved drugs to relieve nausea and vomiting. Newer drugs given for chemotherapy-related nausea have not been directly compared with Cannabis or cannabinoids in cancer patients. 

The Strains Directory provides some insights on which marijuana strains have been effective in alleviating symptoms of cancer.