Chronic inflammation following hernia repair and cancer risk: A nationwide study

Implantation of mesh in patients undergoing hernia surgery or prolonged inflammation due to postoperative complication may be associated with increased risk of cancer.We aim to test whether implementation of mesh or complicated postoperative course with readmittance was associated with increased risk of cancer.

This register-based nationwide observational cohort study included 48,392 and 127,756 patients undergoing ventral and inguinal hernia surgery, respectively, during 1996-2004, with follow-up until Dec. 2014. In total, 16,909 patients undergoing ventral hernia repair with mesh, and 31,483 undergoing sutured repair, as well as 106,342 patients undergoing inguinal hernia repair with mesh and 21,414 undergoing sutured repair were included. Patients were matched with a reference cohort from the general Danish population and were followed in the Danish Cancer Registry.

For ventral hernia surgery, there was a significant association between mesh repair and risk of cancers, [(vs general population), HR 1.09 (95%CI, 1.00-1.18)]. Thirty-day readmission after mesh and sutured repair was associated with developing cancer [HR 1.15 (0.99-1.34) and 1.14 (1.00-1.31), respectively]. However, the association for suture repair (HR 1.14) did not reach statistical significance (p = 0.055). For inguinal hernia surgery, mesh repair was not associated with increased risk of cancer [(vs. general population), HR 1.00 (95%CI, 0.97-1.02)]. For both mesh and sutured repair, there was an increased risk for developing cancer after 30-day readmission, [HR 1.21 (1.12-1.31) and 1.24 (1.07-1.43), respectively].

Patients undergoing ventral hernia repair with mesh and patients readmitted after inguinal or ventral hernia repair may have higher risk of developing cancer than the general population.These exploratory findings do not establish causality, but the association warrants further investigations in other populations.