Risk Factors for Peritoneal Recurrence in Stage II to III Colon Cancer.

ABSTRACT

BACKGROUND: Most previous reports to analyze risk factors for peritoneal recurrence in patients with colon cancer have been observational studies of a population-based cohort. OBJECTIVE: This study aimed to determine the risk factors for peritoneal recurrence in patients with stage II to III colon cancer who underwent curative resection. DESIGN: This was a pooled analysis using a combined database obtained from 3 large phase III randomized trials (N = 3714). SETTINGS Individual patient data were collected from the Japanese Foundation for Multidisciplinary Treatment of Cancer clinical trials 7, 15, and 33, which evaluated the benefits of postoperative 5-fluorouracil-based adjuvant therapies in patients with locally advanced colorectal cancer. PATIENTS We included patients who had stage II to III colon cancer and underwent curative resection with over D2 lymph node dissection. MAIN OUTCOME MEASURES: Main outcomes measured were risk factors for peritoneal recurrence without other organ metastasis after curative surgery. RESULTS: Peritoneal recurrence occurred in 2.3% (86/3714) of all patients undergoing curative resection. Mean duration from operation to peritoneal recurrence was 17.0 ± 10.3 months. Of these patients with peritoneal recurrence, 29 patients (34%) had recurrence in ≥1 other organ. Multivariate analysis showed that age (≥60 y HR = 0.531; p = 0.0182), pathological T4 (HR = 3.802; p < 0.0001), lymph node involvement (HR = 3.491; p = 0.0002), and lymphadenectomy (D2 HR = 1.801; p = 0.0356) were independent predictors of peritoneal recurrence. The overall survival was lower in patients who developed peritoneal recurrence than in those with other recurrence (HR = 1.594; p = 0.002). LIMITATIONS: The regimens of adjuvant chemotherapy were limited to oral 5-fluorouracil. CONCLUSIONS: Our findings clarified the risk factors for peritoneal recurrence in patients who underwent curative resection for colon cancer. See Video Abstract at http//links.lww.com/DCR/A609.