Question: What is the relationship between the use of cannabis and the risk for testicular cancer?
Answer: A systematic review and meta-analysis reports “Using meta-analysis techniques, we observed that a) current, b) chronic, and c) frequent cannabis use is associated with the development of testicular germ cell tumors (TGCT), when compared to never-use of the drug. The strongest association was found for non-seminoma development – for example, those using cannabis on at least a weekly basis had two and a half times greater odds of developing a non-seminoma TGCT compared those who never used cannabis (OR: 2.59, 95 % CI 1.60–4.19). We found inconclusive evidence regarding the relationship between cannabis use and the development of seminoma tumours. It must be noted that these observations were derived from three studies all conducted in the United States; and the majority of data collection occurred during the 1990’s.” (Gurney J et. al. Cannabis exposure and risk of testicular cancer: a systematic review and meta-analysis. 2015 BMC Cancer 15:897-907)