Impact of previous diverticulitis on oncological outcomes after colorectal cancer. A nationwide Swedish cohort study
Hannah Sahli, Valentinus Valdimarsson, Marie-Louise Lydrup, Caroline Nordenvall, Mirna Abraham Nordling, Sol Erika Boman, Ida Hed Myrberg, Pamela BuchwaldAbstract
Introduction
Previous diverticulitis may complicate diagnostic work-up and surgical management of colorectal cancer (CRC), but its impact on long-term oncological outcomes is unclear. We investigated the association between prior diverticulitis and oncological outcomes after curative resection for stage I-III CRC in a nationwide cohort.
Methods
This retrospective study included adults undergoing curative resection for stage I-III CRC in Sweden between 2007–2021, identified through the Swedish Colorectal Cancer Database (CRCBaSe). Previous diverticulitis was defined using ICD-10 codes and classified as uncomplicated (UD) or complicated (CD). No prior diverticulitis served as comparators. Primary outcome was Overall Survival (OS) and secondary outcome was Time To Recurrence (TTR). Associations were analyzed with multivariable Cox proportional hazards models, adjusted for confounders.
Results
Among 57240 patients, 5893 (10.3%) had previous diverticulitis, including 5362 (9.4%) with UD and 531 (0.9%) with CD. Prior diverticulitis, particularly CD, was associated with adverse tumor characteristics and complex clinical presentation. Prior diverticulitis was associated with lower mortality rate (adjusted HR 0.935, 95% c.i. 0.891–0.981) and recurrence rate (adjusted HR 0.867, 95% c.i. 0.805–0.935) versus no prior diverticulitis. These associations were confined to UD. CD was not statistically significantly associated with OS or TTR compared to no prior diverticulitis.
Discussion
Prior diverticulitis was not associated with worse oncological outcomes after curative resection for stage I-III CRC, despite less favorable tumor characteristics at presentation. This suggest that despite being a vulnerable group, a history of diverticulitis is not a negative prognostic factor in CRC management possibly due to existing post-diverticulitis colonic evaluation.