Treatment with curative intent for locoregional recurrent colon cancer - a systematic review

Locoregional recurrence of colon cancer (LRCC) might still be amenable to treatment with curative intent with high survival outcomes, but little is known about patient selection, treatment strategy and corresponding long-term outcomes. This study aimed to review the literature on intentional curative treatment of LRCC and related long-term outcomes. MEDLINE, Embase, Web of Science Core Collection, Cochrane Central Register of Controlled Trials and Google Scholar were searched for publications in any language from 2010 to August 27th 2024. Studies reporting on treatment and survival of uni- or multifocal LRCC without peritoneal spread to another abdominal region after initial curative resection of colon cancer were included. This study was conducted according to the PRISMA and MOOSE recommendations and included independent study selection and data extraction by two reviewers. Of 2843 studies identified, 54 were included, which consisted of 2 consecutive population-based studies, 10 selected cohorts and 42 case studies. The latter were pooled into a case series. In the two consecutive series, treatment intention was curative in 22% and 81%, R0-resection 75% and 50%, and median overall survival 13 and 29 months, respectively. From all 12 cohorts, 495 of 635 (78%) were curatively treated (56% males) with time to LRCC ranging from 15 to 42 months. Neoadjuvant chemotherapy was administered in 6-100% and resection was multivisceral in 40-67%. Adjuvant chemotherapy was provided in 17-88% of the cases. Survival time was heterogeneously reported, limiting possibilities for pooled analysis. Within the pooled case series of 46 unique cases, 83% underwent R0-resection and 5-year overall survival was 86%. Literature regarding treatment and outcomes of LRCC is scarce with limited interpretability and generalizability. Treatment with curative intent can result in high survival rates, but selected cohorts and cases are at high risk of bias.