194P Efficacy of second line chemotherapy following first line triplet chemotherapy in advanced colorectal cancer (ACRC)

Abstract

Background: The efficacy of second line therapy after first line triplet in advanced colorectal cancer has not been extensively explored. Methods: Medical records of patients (pts) with ACRC treated on prospective phase I-II study with the combination of oxaliplatin, irinotecan, capecitabine and bevacizumab were retrospectively reviewed. The following data were recorded: Demographics, response to first line chemotherapy, organs involved, type of second line chemotherapy, response to second line chemotherapy, progression free survival (PFS), overall survival (OS), K-ras status, and baseline lab results at second line chemotherapy. Results: Fifty three pts received first line triplets, out of which 28 (52%) received second line chemotherapy. Median survival for pts who received second line vs no second line was 28.0 months (95% CI 22.8-33.2) vs 23.0 months (95% CI 13.2-32.8) (Log-rank P ¼ 0.693). Of the 28 pts who received second line chemotherapy, 13 were male, 8 had colon primary, 10 had mutant K-tas with 3 unknown, ECOG performance status 1/2/3/ unknown was in 16/3/2/7 pts, organs involved: liver/lung/peritoneum: in 17/16/8 pts. Second line chemotherapy was Xelox/FOLFOX in 13, Xeliri/FOLFIRI in 12 and irinotecan þ cetuximab in 3 pts. Best response was partial in 6 (21.43%), stable disease in 11 (39.29%) and progressive disease in 11 (39.29). Median PFS and OS was 4.8 mo (95% CI 2.4-9.6) and 15 mo (95% CI 9.6-20.4). Univariate analysis of above prognostic factors for survival including type of chemotherapy showed no significance except for elevated CEA (Log-rank P ¼ 0.0074) Conclusions: Second line chemotherapy following first line triplet in ACRC shows equal efficacy compared to reported results following doublets, regardless of the agent used. Elevated CEA at second line chemotherapy confer poor prognosis.