Postoperative surveillance recommendations for early-stage colon cancer based on results from the clinical outcomes of surgical therapy trial

Abstract

4013 Background: Intensive postoperative surveillance is associated with improved survival and recommended for patients with late stage (stage IIB & III) colon cancer. We hypothesized that stage I & IIA colon cancer patients would experience similar benefits. Methods: Secondary analysis of data from the Clinical Outcomes of Surgical Therapy trial was performed by analyzing results according to TNM stage; early (stage I & IIA; 537 patients) and late (stage IIB & III; 254 patients) stage disease. Five-year recurrence rates were higher in patients with late (35.7%) versus early stage disease (9.5%). Early and late stage salvage rates, recurrence patterns and methods of first detection were compared by χ2 test. Results: Salvage rates for early and late stage disease patients with recurrence were the same (35.9% versus 37%, p=0.9 respectively). Median survival following second surgery after recurrence was 35.8 months late stage and 51.2 months for early stage patients respectively. Sites of first recurrence did not significantly differ between late and early stage disease: liver (37.4% vs. 27.2%); lung (29.7% vs.23.6%); intraabdominal (24.2% vs.10.9%); and locoregional (12.1% vs.10.9%). Methods of first detection of recurrence were also not significantly different: CEA (37.4% vs. 29.1%); CT scan (26.4% vs. 23.6%); chest X-ray (12.1% vs. 7.3%); and colonoscopy (8.8% vs. 12.7%), for late versus early stage disease, respectively. Conclusions: Patients with early stage colon cancer have similar sites of recurrence, and receive similar benefit from post-recurrence therapy as later stage patients; implementation of existing surveillance guidelines for early stage patients is appropriate. No significant financial relationships to disclose.