Treatment and subsequent prognosis in locally recurrent rectal cancer: a multicenter retrospective study of 498 patients.

Purpose Locally recurrent rectal cancer (LRRC) has a tremendous impact on prognosis as well as the quality of life. Because of the low incidence and various recurrence patterns, the treatment outcome of LRRC is not fully elucidated. The current study aimed to evaluate the prognosis and identify the prognosticators in patients with LRRC. Methods We conducted a multicenter study at 24 hospitals in Japan. Patients with primary rectal cancer who underwent curative resection between 1997 and 2012 and developed local recurrence only as a first recurrent event were recruited. The primary outcome of our study was overall survival (OS) after a diagnosis of LRRC. Results Four hundred and ninety-eight patients were included in the study. Of these, 213 (42.8%) underwent surgical resection; this was associated with the best 5-year OS rate of 52%, followed by carbon ion/proton therapy (44%). Among LRRC patients, undifferentiated type, T4, high CEA level, and high CA19-9 level were independent prognosticators of OS (hazard ratio (HR) = 1.83, P = 0.008, HR = 1.54, P = 0.004, HR = 1.35, P = 0.03, and HR = 1.58, P = 0.003, respectively). Conclusions This large-scale cohort study showed that surgical resection led to a favorable prognosis compared to other treatments for LRRC. Therefore, surgical resection should be considered whenever feasible for LRRC patients. In addition, undifferentiated type, T4, and tumor marker (CEA and CA19-9) elevation were identified as independent prognostic factors for OS among patients with LRRC.