ASO Visual Abstract: Locoregionally Recurrent Colon Cancer: How Far Have We Come? A Population-Based, Retrospective Cohort Study

Background The reported outcomes of locoregionally recurrent colon cancer (LRCC) are poor, but the literature about LRCC is scarce and aged. Recent population-based studies to provide current insight into LRCC are warranted. This study aimed to provide an overview of the incidence, risk factors, treatment, and overall survival (OS) of patients with LRCC after curative resection of stage I–III primary colon cancer. Methods Data on disease recurrence were collected for all patients with a diagnosis of non-metastasized primary colon cancer in the Netherlands during the first 6 months of 2015. Patients who underwent surgical resection (N = 3544) were included in this study. The 3-year cumulative incidence, risk factors, treatment, and OS for patients with LRCC were determined. Results The 3-year cumulative incidence of LRCC was 3.8%. Synchronous distant metastases (LRCC-M1) were diagnosed in 62.7% of the patients. The risk factors for LRCC were age of 70 years or older, pT4, pN1-2, and R1-2. Adjuvant chemotherapy was associated with a decreased risk of LRCC for high-risk stage II and stage III patients [hazard ratio (HR), 0.47; 95% confidence interval (CI) 0.31–0.93]. The median OS for the patients with LRCC was 13.1 months (95% CI 9.1–18.3 months). Curative-intent treatment was given to 22.4% of the LRCC patients, and the subsequent 3 years OS was 71% (95% CI 58–87%). The patients treated with palliative treatment and best supportive care showed 3-year OS rates of 15% (95% CI 7.0–31%) and 3.7% (95% CI 1.0–14%), respectively. Conclusions The cumulative incidence of LRCC was low, and adjuvant chemotherapy was associated with a decreased risk for LRCC among targeted patients. Curative-intent treatment was given to nearly 1 in 4 LRCC patients, and the OS for this group was high.