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

## TL;DR

This study found that patients who had mesh implants or were readmitted after hernia surgery may have a higher cancer risk compared to the general population.

## Contribution

The study explores the link between hernia repair methods and cancer risk in a nationwide cohort.

## Key findings

- Mesh repair in ventral hernia surgery was associated with a higher cancer risk compared to the general population.
- Readmission within 30 days after hernia surgery was linked to an increased cancer risk for both mesh and sutured repairs.
- Inguinal hernia mesh repair did not show a significant increase in cancer risk compared to the general population.

## Abstract

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.