Recent study from february:
Characteristics of finasteride users in comparison with nonusers: A Nordic nationwide study based on individual-level data from Denmark, Finland, and Sweden
Methods: In total, 246 508 finasteride users (≥35 years) were identified in the prescription registries of Denmark (1995-2014), Finland (1997-2013), and Sweden (2005-2014). An equal number of nonusers were sampled. The directed acyclic graph (DAG) methodology was used to identify potential confounders for the association between finasteride and male breast cancer. A logistic regression model compared finasteride users and nonusers with regard to potential confounders that were measurable in registries and population surveys.
Results: Finasteride users had higher odds of testicular abnormalities (odds ratio [OR] 1.40; 95% confidence interval [CI] 1.36-1.44), obesity (1.31; 1.23-1.39), exogenous testosterone (1.61; 1.48-1.74), radiation exposure (1.22; 1.18-1.27), and diabetes (1.07; 1.04-1.10) and lower odds of occupational exposure in perfume industry or in high temperature environments (0.93; 0.87-0.99), living alone (0.89; 0.88-0.91), living in urban/suburban areas (0.97; 0.95-0.99), and physical inactivity (0.70; 0.50-0.99) compared to nonusers.
Conclusions: Systematic differences between finasteride users and nonusers were found emphasizing the importance of confounder adjustment of associations between finasteride and male breast cancer.
Systematic differences between finasteride users and nonusers were found emphasizing the importance of confounder adjustment of associations between finasteride and male breast cancer.
pubmed.ncbi.nlm.nih.gov
So a study of 246,508 finasteride users age 35 and over by Kjaerulff et al;
Finasteride users were 1.4x more likely to have testicular abnormalities compared to non-users