Cannabis and cancer

This is part one of a two-part series. Part two examines the evidence that cannabis can cure cancer.

Cancer has touched the lives of nearly every American, either directly or through a loved one. Although the US Food & Drug Administration hasn’t approved marijuana as a cancer treatment, America’s shifting legal landscape has encouraged many patients to consult their physicians about the effects it can have on cancer and cancer-related symptoms.

The medical benefits of cannabis are no secret. In October 2003, the government patented medical marijuana under US Patent # 6630507, which mentions the antioxidant properties of cannabinoids. The patent also identifies the active chemicals in cannabis that cause drug-like effects on the body, and cites their benefits for patients going through chemo, radiation, or other sources of oxidative stress.

What is Cancer?

Cancer is not one disease, but the name given to a collection of related diseases characterized by an abnormal growth of cells. There are more than 100 different types of cancer that are caused by both external factors (such as smoking, viruses, or carcinogens) and genetic factors (such as genetic mutation inherited from one’s parents). Trillions of cells compose the human body, meaning cancer could start anywhere.

Like humans, cells grow old or become damaged and eventually die. Other cells grow and divide to form new ones to replace these old and damaged cells, but when cancer develops, abnormal cells including the old and damaged ones survive even though they should die. Some of the body’s cells will start to divide interminably and spread into surrounding tissues, creating new cancerous cells that aren’t needed. And since these new cells won’t stop growing and dividing, they are likely to hide in the immune system and form abnormal growths like masses of tissue known as tumors.

Cancerous tumors can spread into and invade nearby tissues because they’re malignant. Although they can be removed, these tumors are likely to grow back. As tumors grow, cancer cells can break off and travel through the blood or the lymph system to any other part of the body to form new tumors — often far away from the original one. This process is known as metastasis.

Benign tumors, on the other hand, don’t spread to or invade nearby tissue and won’t grow back after being removed. Unfortunately, benign tumors in the brain can be life-threatening.

What are the Symptoms of Cancer?

Cancer (and its treatments) leave its host feeling weak and dizzy. Symptoms may differ depending on where in the body the cancer is located, but may include:

• Blood in pee or stools
• Bruising
• Changes in genitalia
• Coughs lasting more than a month or accompanied by blood
• Depression
• Difficulty breathing
• Difficult bowel movements
• Discomfort after eating
• Fever
• Fatigue
• Heartburn
• Lumps or swelling
• Persistent indigestion
• Night sweats
• Spots and growths on the skin or changes in size, shape, and color of an already-existing mole like yellowing, darkening, or redness
• Sores that won’t heal
• Weight loss
• Weight gain
• Unexplained bleeding
• Unexplained joint pain

What are Current Cancer Treatments?

Cancer treatment can be costly and time-consuming, often requiring repeat visits to administer treatments in cycles. Doctors will likely begin by performing a biopsy to determine which treatment will be most effective.

Surgery: Surgeries can be performed to remove or debulk tumors and ease the pains and pressure they’re causing. Tumors can sometimes be removed using minimally invasive surgery. Surgeons will often remove some healthy tissue and lymph nodes as well.

Radiation: High doses of radiation can kill cancer cells after weeks of treatment or slow their growth, as well as shrink tumors. Sadly, it can take months for the cancerous cells to die and radiation can leave patients feeling exhausted by killing or damaging healthy cells.

Chemotherapy: Chemo, which is the use of drugs to directly kill cancer cells, became one of the most common ways to treat cancer in the 1940s. It is often administered in cycles. Today, more than 100 drugs are used to treat cancer, while more are being investigated and developed.

Immunotherapy: Immunotherapy is the administration of living organisms to stimulate the immune response, which often leaves the patient with flu-like symptoms.

Hormones: Administered orally, via injection, or during surgery, hormone therapy can be used to stop or slow the growth of cancer cells and reduce or prevent cancer symptoms from arising. It can be used with other treatments to lessen the chance of the cancer returning. Along with nausea, diarrhea, and fatigue, hormone therapy may weaken bones and cause menstrual changes in women.

Heat: Local hyperthermia can destroy small areas of cells (like a tumor), while regional hyperthermia, or whole-body hyperthermia, can be used in conjunction with other treatments to help them work better. Hyperthermia may be created externally, using a machine’s high energy waves aimed at the tumor, or internally, when a thin needle is put right into the tumor to release heat energy.

How Can Cannabis Help Cancer?

Cannabis contains at least 85 different types of cannabinoids, the active chemicals that create drug-like effects throughout the body. The impact of these cannabinoids in treating cancer symptoms as well as the side effects of cancer therapies is so favorable, cannabinoids are synthesized for legal, prescription use. Dronabinol and Nabilone/Cesamet, two synthetic pill forms of THC, are FDA-approved and currently being used to treat nausea and vomiting associated with chemo.

Cannabinoids that are known to benefit people living with cancer include CBC, CBD, CBDa, CBG, THC, and THCa. Cannabidiol (CBD) is known to relieve pain, lower inflammation, and decrease anxiety without the “high” of THC, the primary psychoactive ingredient in cannabis. In Canada, a cannabis extract containing THC and CBD called Nabiximols/Sativex is approved for pain relief in patients with advanced cancer and multiple sclerosis.

According to the U.S. government’s National Cancer Institute, other effects of cannabinoids include anti-inflammatory activity, blocking cell growth, preventing the growth of blood vessels that supply tumors, fighting viruses, and relieving muscle spasms.

NCI also acknowledges that inhaled cannabis is attributed to improved mood and sense of well-being. Studies suggest cannabis can be used for symptom management in cancer patients by preventing vomiting, stimulating appetite, providing pain relief, and improving sleep as well as inhibiting the growth of certain types of tumors.

Other studies leading scientists down promising avenues of cancer treatment include:

• A 1996 study discovered the protective effects of cannabinoids on the development of certain types of tumors. Cannabinoids were observed causing cell death, blocking cell growth, and preventing the development of the blood vessels tumors needed to grow — suggesting cannabinoids may be able to kill cancer cells while protecting normal cells.
• A series of studies on brain tumors conducted in 2003 proved CBD may make chemo more effective and increase the deaths of cancer cells without harming normal cells.
• A 2004 study on mice which showed cannabinoids protect against inflammation of the colon, thus reducing the risk of colon cancer and possibly aiding in its treatment.
• In 2011, the American Association for Cancer Research revealed CBD kills cells associated with breast cancer while having little to no effect on normal breast cells. When studied in mice, CBD reduced the growth, number, and spread of tumors.
• The National Institute of Health published a study in 2011, Cell Death & Differentiation, that demonstrates THC and JWH-015 (a cannabinoid receptor), decreased the viability of liver cancer cells. Cannabinoids were also shown to inhibit tumor growth and the accumulation of fluid in the abdomen. These are significant findings as they may be helpful in the design of therapeutic strategies to manage liver cancer.
• A study published in February 2015 found rates of bladder cancer are 45% lower in cannabis users, compared to those who do not use it.
• According to the National Cancer Institute (NCI), preclinical studies demonstrate the efficacy of cannabinoids to inhibit tumor growth by protecting healthy cells while killing cancer cells and obstructing the growth of cells and blood vessels needed for tumors to grow. The NCI also claims that a lab study of THC killed or damaged cancer cells, and when the study was repeated in mouse models, showed it had anti-tumor effects that could aid in the fight against lung and breast cancer.

Cannabinoid receptors have been discovered in the brain, spinal cord, and nerve endings throughout the body, suggesting cannabis may play a larger role in immunity as well.

Several studies are in progress on the effects of cannabis on cancer in adults, including:

• Treating solid tumors with oral CBD
• Treating recurrent glioblastoma multiform with a THC/CBD oral spray
• Treating graft-versus-host disease with CBD in patients who’ve undergone stem cell transplants

Don’t miss part two of our Cannabis and Cancer series, where we look at whether cannabis can cure cancer.