Barrios-Rodríguez R, García-Esquinas E, Pérez-Gómez B, et al. - The findings highlight the importance of including the aggressiveness and susceptibility of prostate cancer (PCa) and type 2 diabetes mellitus (T2DM) treatments in the study of the relationship between the two diseases.

• For the population-based MCC-Spain case-control study, the authors studied 1,047 incident PCa cases and 1,379 randomly selected controls recruited in 7 Spanish provinces.

• Overall, the findings revealed an inverse relationship between T2DM and overall PCa limited to grade 1 tumours, which could be explained by a detection bias.

• However, PCa risk varied with diabetes treatment duration - inversely with metformin and positively with insulin - with no differences by aggressiveness.

• T2DM was more strongly associated with lower PCa risk in those with a lower polygenic risk score, regardless of the International Society of Urological Pathology grade, when genetic susceptibility was considered.