Timing of relapse and outcome after curative resection for colorectal cancer: A japanese multicenter study

Background: The aim of this multicenter study was to clarify the influence of timing of relapse after curative resection for colorectal cancer on prognosis. Methods: We enrolled 5,230 consecutive patients who underwent curative resection for colorectal cancer at 14 hospitals from 1991 to 1996. All patients were intensively followed up. Time to relapse (TR) was classified into three groups as follows: group A, TR ≤1 year; group B, TR >1 year and ≤3 years, and group C, TR >3 years. The prognoses after relapse were compared among the three groups. Results: Of the 5,230 patients, 906 experienced relapse (17.3%). The curative resection rates for recurrent tumors were 35.2% in group A, 46.6% in group B, and 45.1% in group C (p = 0.0045). There were significant differences in the prognoses after relapse among the three TR groups in patients with relapse to the liver (p = 0.0175) and in those with local relapses (p = 0.0021), but not in those with pulmonary or anastomotic recurrence. There were no differences in prognoses after relapse in any recurrence site among the three groups in patients who underwent curative resection for relapse. Conclusion: If patients can undergo curative resection for relapse, they receive a survival benefit regardless of the timing of relapse.