A population-based cohort study examining the risk of abdominal cancer after endovascular abdominal aortic aneurysm repair.

Abstract

Endovascular aneurysm repair (EVAR) has increasingly been used as the primary treatment approach for abdominal aortic aneurysm (AAA). This study examined the hypothesis that EVAR leads to an increased risk of abdominal cancer within the radiation field compared with open AAA repair. The nationwide English Hospital Episode Statistics database was used to identify all patients older than 50 years who received an AAA repair in 2005 to 2013. EVAR and open AAA repair groups were compared for the incidence of postoperative cancer using inverse probability weights and G-computation formula to adjust for selection bias and confounding. Among 14,150 patients who underwent EVAR and 24,645 patients who underwent open AAA repair, follow-up was up to 7 years. EVAR was associated with an increased risk of postoperative abdominal cancer (hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.03-1.27) and all cancers (HR, 1.09; 95% CI, 1.02-1.17). However, there was no difference between the groups in the risk of lung cancer (HR, 1.04; 95% CI, 0.92-1.18) or obesity-related nonabdominal cancer (HR, 1.12; 95% CI, 0.69-1.83). Within the EVAR group, use of computed tomography surveillance was not associated with any increased risk of abdominal cancer (HR, 0.94; 95% CI, 0.71-1.23) or all cancers (HR, 0.97; 95% CI, 0.81-1.17). This study suggests an increased risk of abdominal cancer after EVAR compared with open AAA repair. The differential cancer risk should be further explored in alternative national populations, and radiation exposure during EVAR should be measured as a quality metric in the assessment of EVAR centers.