Study: Marijuana may lower risk of bladder cancer

In Cancer, Research Updates and News by David Silverberg

Smoking marijuana might lower a user’s risk for bladder cancer, a new study shows.

Researchers at Kaiser Permanente in California found that patients who reported cannabis use were 45 percent less likely to be diagnosed with bladder cancer than patients who did not smoke at all, a news report states.

“It’s very exciting because bladder cancer is hard to treat,” said Anil Thomas, a urologist at the Southern California Permanente Medical Group. He warned the study’s results did not mean smoking marijuana would prevent bladder cancer, adding more research is needed to understand the connection.

Dr. Thomas and his colleagues analyzed a survey of 82,050 men from Northern and Southern California Kaiser Permanente, a health maintenance organization, conducted in 2002 and 2003. The participants were 45 to 69 years old.

In all, 41 percent reported using cannabis, 57 percent reported using tobacco, and 27 percent reported using both.

During 11 years of follow-up, 279 men, around 0.3 percent, were diagnosed with bladder cancer. Eighty-nine marijuana smokers (0.3 percent) developed bladder cancer compared to 190 (0.4 percent) who did not smoke marijuana.

“We know that tobacco smoking is the best established risk factor for bladder cancer,” Dr. Thomas told reporters attending a news conference. “But to date, there are no epidemiological studies accurately characterizing the association between cannabis use and bladder cancer.”

Marijuana has a long history of easing cancer-related symptoms. Scientists ave reported that THC and other cannabinoids such as CBD (cannabidiol) slow growth and/or cause death in certain types of cancer cells growing in laboratory dishes, as the American Cancer Society points out.

Photo courtesy Libertas Academica