"Meta" Study: Cannabis Tends to Reduce Risk of Cancer

This is a research meta analysis (which means they reviewed LOTS of other research) and determined "The hypothesis that Cannabis use increases cancer risk is not supported by the available data. The data instead show a trend toward a negative association between Cannabis use and cancer risk".

This is a detailed study published in August, 2020 and if you like "getting into the weeds" a bit, you can find the full paper and results here.