Retrospective study regarding the efficacy of second- or higher-line chemotherapy (CT) of patients in advanced or recurrent gastric cancer (ARGC) after the failure of S-1 or S-1 combination chemotherapy (S+α).

Abstract

129 Background: At the 2007 ASCO meeting, two RCTs from Japan showed that S-1 (S) and S-1/CDDP (S+P) therapy now are an accepted standard 1st-line chemotherapeutic regimens for ARGC. Today in Japan, S+α are the mainstay CTs for ARGC. However, it is important to acquire a longer survival for ARGC and therefore development of a 2nd or higher line CT after S+α failure is thus required. At the 2012 ASCO meeting, WJOG4007G trial showed that weekly PTX was regarded as a temporary standard 2nd-line CT for ARGC after the failure of S+P. However, some clinical questions to appropriate 2nd-line CT have been unsolved. The present study set out to identify the factors, which make it appropriate to perform the CT after S+α failure, and to examine the validity of this treatment. Methods: Sixty-one pts with ARGC who failed to sufficiently respond to S+α therapy between Dec. 2004 and May 2010 were retrospectively reviewed. Results: The patient characteristics were: mean age, 63.8 y.o.; sex, M/F=42/19; patient status: unresectable: 35, non-curative operation: 17 and postoperative recurrence: 9. The initial CT regimens consisted of S: 32, S+α: 29. The 2nd-line CT regimens included Taxanes (TA): 40, CPT-11 (IRI): 20, S+α: 1. The median number of 2nd or higher treatment courses was 2 (1-6). The RR of 2nd-line CT was 24.6%. The mTTF and MST since the 2nd-line CT was administered were 112 days and 311 days, respectively. The transition rate to 3rd-line was 65.6%. The OS since the S+α administration significantly correlated with the TTF of S+α (p<0.001), while the OS since the 2nd-line CT administration (2nd OS) was independent of the TTF of S+α. The 2nd OS did not correlate with either the specific type of 2nd-line CT. However, the 2nd OS of pts receiving both TA and IRI was significantly longer than ones only either TA or IRI (p=0.0012). Conclusions: The findings of this study suggest that the addition of a 2nd or higher line CT is expected to result in a longer survival for pts with ARGC, even when the anti-tumor effect was deemed to be insufficient following the S+α therapy, and that the strategy of using all available agents in the treatment course of ARGC might be needed.