Intermittent Chemotherapy In Advanced Unresectable Colorectal Cancer. An Option For Our Patients?

3703 Background: Chemotherapy (CT) improves overall survival and quality of life in advanced unresectable colorectal cancer (auCRC) and CT has better outcome when administered early. Several schedules are active in auCRC, but optimal duration remains uncertain and general practice results in administering CT until progression, toxicity or patient’s decision. The purpose of this study is to identify which auCRC patients (pts) could benefit from stopping first line CT although no progressive disease has been observed without detriment in overall survival. Methods: all pts with CRC are prospectively recorded in our single institution-data base and are included in the same assistance protocol. 358 pts (224 M; 134 F) with auCRC have been analysed. Median age 61y (23,83);67% presented as auCRC at diagnosis and 33% appeared in the follow up; 46 pts had locoregional (LR) disease, 220 pts had distant metastasis (M) and 92 pts had LR + M. Number of metastatic sites: one, 64.7%; two, 26.3% and >two, 9%. All pts received CT. CT lines: Group 1, one line with 5FU: 150 pts (42%); group 2, one line with either CPT-11 or Oxaliplatin: 67 pts (19%); group 3, two or more lines: 141 pts (39%). CT was stopped between two lines for at least 3 months (m) in 80/148 pts (141 pts of group 3 + 7 pts of groups 1 and 2) with a median interval of 9 m (3–56). CT was stopped due to maintained response in 57/80 pts (71.3%), and 12 pts (15%) restarted the same CT scheme.Kaplan-Meier survival curves were compared with log rank test. We used X2 tests to determine association between continuous or intermittent CT with certain prognostic variables. Results: With a median follow-up of 24.7 m (3.5; 72.4), the median survival (MS) of all pts was 16.7m (14.7;18.6); MS of group 1: 12.5 m; MS of group 2: 14.5m; MS of group 3: 27.9m (p<0.0001). MS of initial auCRC: 13.3m; MS for progressive auCRC: 21.53m (p<0.01). MS of pts with continuous CT: 16.5 m; MS of pts that stopped CT for at least 3 months: 36.9m (p50y in the group of intermittent CT (p<0.05). Conclusions: there is a group of pts with auCRC that could benefit from interrupting CT and restarted CT when they progress even with the same schedule. Randomised trials are warranted in order to establish the optimal duration of CT in auCRC. No significant financial relationships to disclose.