Differences in Presentation and Prognosis of Early versus Late Diagnosis of Locoregional Recurrences after Colon Cancer Resection: A Nationwide Cohort Study

BACKGROUND: Despite advances in treatment of primary colon cancer, approximately 5 to 10% of patients will develop a locoregional recurrence of colon cancer. Early recurrences diagnosed within 1 year have been associated with worse outcomes, but evidence is limited and conflicting. OBJECTIVE: This study aimed to evaluate the prognostic impact of timing of locoregional recurrence detection. DESIGN: This is a cross-sectional multicenter cohort study. SETTINGS: Multicenter collaborative study involving 50 Dutch hospitals. PATIENTS: Patients with locoregional recurrence after colon cancer resection between January 2014 and December 2015, stratified by timing of locoregional recurrence diagnosis (early < 1 year, late ≥ 1 year). MAIN OUTCOME MEASURES: Overall survival stratified by treatment intent. RESULTS: Among 9,523 patients, 676 (7.1%) developed locoregional recurrence (291 early, 385 late). Median time to locoregional recurrence diagnosis was 13.7 months (IQR 8.6-23.4). Late diagnosis of locoregional recurrence was independently associated with higher probability of overall survival (median 18.0 vs 9.1 months; HR 0.83, 95% CI 0.69-0.99) and was more often treated with curative intent (34.6 vs 24.0%, p = 0.01). In patients treated with curative intent, overall survival did not differ between early and late locoregional recurrence (median 40.1 vs 40.7 months; HR 1.05, 95% CI 0.73-1.51, p = 0.79). In palliatively treated patients, late locoregional recurrence was associated with longer overall survival compared to early locoregional recurrence (median 10.1 vs 6.8months; HR 0.70, 95% CI 0.58-0.84, p < 0.001). LIMITATIONS: This study is limited by its retrospective design. CONCLUSIONS: Late diagnosis of locoregional recurrence was associated with better survival, but survival from the moment of locoregional recurrence was not different between patients with early and late recurrences who were treated with curative intent. See Video Abstract.