A new study has found that men who smoke one marijuana cigarette, or joint, daily for 10 years or more had an estimated 36% increased risk of developing testicular cancer compared with men who had never smoked the substance.
Researchers have analyzed 25 studies that looked at the link between marijuana use and testicular cancer, lung cancer, oral cancer, and head and neck cancer.
Though the researchers found no association between regular marijuana use and lung, neck, or oral cancer, they did find that regular weed smoking over many years could heighten a man’s risk of testicular cancer.
That’s because cannabis, the plant marijuana is derived from, is like any other plant in that it burns and releases smoke when you light it, according to the researchers.
The study’s researchers were unable to determine why their meta-analysis showed a link between smoking pot and testicular cancer but none of the other three cancers they analyzed.
They did, however, note that the varying populations of each study they analyzed could have contributed to their findings.
According to the National Organization for Rare Disorders, though testicular cancer accounts for only 1% of cancers in men, it’s the most commonly diagnosed cancer in men between 15 and 35.
Every year in the US, an estimated 8,850 men are diagnosed with the disease.
According to NORD, the most common symptom of testicular cancer is a firm but painless bump — a cancerous tumor — on the testicle. If one testicle swells, that can also be a sign of cancer.
Testicular cancer is one of the most treatable forms of cancer, according to NORD. It’s usually curable with surgery, and sometimes also requires radiation or chemotherapy.