To Örebro University

Aim: To investigate whether androgen deprivation therapy (ADT) for prostate cancer increases the risk for inguinal hernia.

Material and Methods: A population-based nested case-control study based on data from the Prostate Cancer Database Sweden. The cohort included men with prostate cancer who had not received curative treatment. Men who had been diagnosed with inguinal hernia or had undergone inguinal hernia repair (n ¼1324) were cases and controls were men, not diagnosed, nor operated on for inguinal hernia, matched on birth year (n ¼13 240). Conditional multivaria te logistic regression models were used to assess any temporal association between ADT and inguinal hernia, adjusting for confounders.

Results: Odds Ratio [OR] for repair of inguinal hernia 0-1 years from start of ADT was 0.5 (95% confidence Interval (CI)) 0.38-0.68), between 1 and 3 years after, the OR was 0.35 (95% CI 0.26-0.47), 3-5 years after, the OR was 0.39 (95% CI 0.26-0.56), 5-7 years after, the OR was 0.6, (95% CI: 0.41-0.97), and >9 years after, the OR was 3.68 (95% CI 2.45-5.53).

Conclusions: The marked increase in OR for inguinal hernia after 9 years of ADT supports the hypothesis that low testosterone levels increase the risk for inguinal hernia. The low risk for inguinal hernia during the first eight years on ADT is likely caused by selection of men with advanced cancer unlikely to be diagnosed or treated for inguinal hernia. This finding may support the hypothesis that sex hormones plays a crucial role in inguinal hernia development.