Buzz Kill: Marijuana Use Linked To Testicular Cancer

Cancer of the testis can and does appear in teenage boys as young as 14. The incidence of this cancer is rising, and some experts think there may be environmental links.

Smoking marijuana appears to double the risk of developing more serious forms of testicular cancer, according to a new study.

Recreational cocaine use, however, appeared to lower the risk of certain types of testicular cancer.

There are risks of any mood-altering substance.

Researchers at the University of Southern California in Los Angeles were looking to see if recreational drug use was in anyway associated with testicular cancer.

Victoria Cortessis, MSPH, PhD, assistant professor of preventive medicine at the Keck School of Medicine of USC in Los Angeles, led the study.

About 8,600 men in the United States are diagnosed with testicular cancer every year, and the vast majority live normal lives after treatment. It’s the most common form of cancer that appears in young men between the ages of 15 and 35.

Her team interviewed 163 young men with testicular cancer about their history with marijuana, cocaine and amyl nitrite (an inhalant known as “poppers” on the street). A total of 293 healthy men of the same age and ethnic backgrounds were used as comparison controls.

Men who had ever smoked marijuana were twice as likely as non-users to have two types of testicular cancer – non-seminoma and mixed germ cell tumors.

These types have a slightly poorer outlook than the seminoma subtype.

"We do not know what marijuana triggers in the testis that may lead to carcinogenesis [development of cancer]…,” Dr. Cortessis in a press release. Scientists think an active ingredient in marijuana affects the network of cells that form sperm

These findings support those found in two earlier reports published in the journal Cancer that associated marijuana use and testicular cancer.

The authors suggest this link should be considered by young men when making choices about smoking marijuana. Also, clinicians should be aware of this when prescribing men any therapies that contain marijuana compounds.

One such drug is Marinol (dronabinol). It's prescribed to treat chemotherapy-related nausea and increase appetite in AIDS patients and provide pain relief for multiple sclerosis.

Interestingly, cocaine use seems to lower the risk of these types of testicular cancer. Scientists aren’t sure why this is, but in animals the drug kills germ cells that produce sperm.

The authors say more study is needed to explore this association.

This study was published online September 9 in Cancer, a peer-reviewed journal of the American Cancer Society.

The National Cancer Institute supported this study.