WS3-5 - Practice and Problems in Conducting HER2-Testing and Trastuzumab-Combined Chemotherapy for Advanced/Recurrent Gastric Cancer

Abstract

ABSTRACT Background Approval of trastuzumab (Her) following ToGA trial was a milestone of chemotherapy for advanced/recurrent gastric cancer. In this presentation, we report the practice, in Kyushu Cancer Center, of HER2 screening, safety and efficacy of Her-combined chemotherapy, and discuss on the problems of clinical practice. Methods We examined HER2-immunohistochemistry (IHC) on 90 cases of advanced/recurrent gastric cancer which were under chemotherapy on March 2011 or initiated chemotherapy until January 2012 at Kyushu Cancer Center. HER2 fluorescent in situ hibridization (FISH) was tested when IHC result was 2+. Her-combined chemotherapy was planned to HER2-high cases (IHC 3+ or IHC2+ and FISH positive). Results IHC results of 90 cases were 3 + : 12, 2 + : 6, 1 + : 11 and 0: 61 cases, respectively. Five positive FISH results were obtained out of six IHC 2+ cases. We experienced 17 HER2-high cases (18.9%). Her-combined chemotherapy was planned as first-line therapy (11 cases) or subsequent lines (3 cases), gaining 6 PR. Only three cases were started initial therapy as Her-combined, and others were started with chemotherapy alone and added Her later. As adverse events, three infusion reactions and no cardiac toxicity was observed. Conclusions An equivalent HER2-high rate as previous reports was observed in our practice. Many cases did not allow delay in initiation of chemotherapy during HER2 testing, and chemotherapy was often started without HER2 results. Further practical experiences and new evidences were needed in the point of chemotherapy initiation. Her-combined chemotherapy was safely carried out, and its efficacy must be confirmed by further accumulation of trials and practical experiences.