Third line chemotherapy in metastatic colorectal cancer: A single institution experience.

Abstract

e14706 Background: The median overall survival for metastatic colorectal cancer (mCRC) has been increasing over the past two decades and is very common to see longer survivals with a good performance status. They may benefit from treatment after progression to second line chemotherapy. In this context, raltitrexed is an active and simple-administration drug that appears to be a convenient treatment. Our objetive was to determine if there is benefit in patient retreated with oxaliplatin based chemotherapy (OBCT), CPT 11 based-chemotherapy (CBCT) or raltitrexed every 21 days in a third line chemotherapy (3L CT) setting. Methods: We conducted an analytical epidemiological study, using descriptive analysis and Long Rank test. Between 2009 and 2012, were treated 28 mCRC with a 3L CT and 11 of which recieved adyuvant chemotherapy. All were treated previously with OBCT and CBCT. Treatment consisted in OBCT, CBCT or raltitrexed in monotherapy. Results: Male predominance in proportion of cases (67.9%) with a median of 62 years old (range 27-79 and 90% between 45-75) and 78.6% had aceptable clinical condition (ECOG 0-1). Median CEA level before 3L CT was 61.1 ng/dL. Sixteen patient had rectal cáncer, mostly male (75%). In our sample, the mCRC overall survival was 30.4 months (95% confidence interval(CI), 14.3 to 46.4) . Patients retreated with OBCT or CBCT had the same survival than treated with a particular sequence that includes OBCT, CBCT and raltitrexed in monotherapy (7.5 months (CI, 5.81 to 9.2) vs 7.4 months (CI, 2.5 to 12.3); p<,598). Raltitrexed in monotherapy tends to have better survival in comparison with OBCT or CBCT, no reaching statistical significance (14.3 months (CI, 3.6 to 24.9) vs 7.5 months (CI, 5.9 to 9.1) vs 7.4 months (CI, 0.0 to 18.1); p<,755). The most common toxicity with raltitrexed was asthenia grade 1 (32,1%), with OBCT was neurotoxicity grade 1 (75%) and with CBCT was abdominal pain grade 1 (55.5%). Conclusions: In our serie, there was a male predominance and median mCRC survival is better than reported in the literature. There is a trend for a better survival with raltitrexed in monotherapy with a good toxicity profile in a 3L CT setting. Future studies are needed to verify these findings.