Does cannabis use increase the risk of testicular cancer?

It's almost an editorial chestnut, and so it reappears this December: cannabis is said to increase the risk of testicular cancer. While the titles of the publications all condemn cannabis consumption, their content is less virulent, pointing to the generally inconclusive results of studies and calling for more research.

Example: Doctissimo speak for example, of a «new American study», even though it had already dealt with the subject (and the same study) in 2009. The «new study» is in fact a meta-analysis of 25 studies designed to assess the risk of developing lung, head and neck, urogenital and other cancers in the event of cannabis consumption.

Yet you don't have to go very far in the paper to read that «in meta-analyses, regular cannabis use was associated with the development of testicular germ cell tumors, although the evidence was weak; evidence for other cancers was insufficient.

Meaning Cannabis: sustained cannabis use may increase the risk of testicular cancer, but overall, the association of cannabis use and cancer development remains uncertain.»

And this study?

Let's dive into the 2009 study. A population of 369 men aged 18 to 44 diagnosed with testicular tumors (TGCT) between 1999 and 2006 were asked about their past cannabis use. A healthy control group of the same size and from the same counties was surveyed over the same period. Men with a TGCT were more likely to be current cannabis smokers at baseline than controls, with a coefficient of 1.7 (Le Figaro not lacking titrate that cannabis doubles the risk of testicular cancer, which neither the study nor its authors state).

A another study from 2009 focuses on the etiological factors involved in the development of this type of cancer. It notes that «the incidence of testicular cancer is highest in men of Northern European ancestry and lowest in men of Asian and African descent» and that ’a growing body of evidence suggests that testicular cancer occurs in the fetal stage. Perinatal factors, including exposure to endocrine-disrupting chemicals, have been suggested to be linked to risk«. This does not exonerate cannabis, but it does add a little depth to the analysis.

In 2017, a study magazine on TGCT also notes that «the only risk factor that has been consistently associated with a histological subtype (non-seminoma) is cannabis use. The prevalence of cannabis use in the U.S. has been increasing in the general population and among Hispanics. While it is possible that the positive association between cannabis use and non-seminoma explains some of the increase in TGCT rates, this interpretation must be made with caution because existing studies of cannabis use and TGCT are limited in study design (all are case-control studies) and rely on self-reports.»

What do we learn in the end? That the need for research is greater than current knowledge about cannabis, for its benefits as for his misdeeds. And that the cliché of cannabis causing cancer is still alive and well in some media.