Trastuzumab combined with chemotherapy in patients with HER2-positive chemo-refractory advanced gastric or gastro-esophageal junction adenocarcinoma

Abstract

To evaluate the efficacy and safety of trastuzumab combined with chemotherapy in the treatment for HER-2-positive chemo-refractory advanced gastric or gastro-esophageal junction adenocarcinoma. Twenty consecutive cases of chemo-refractory advanced gastric or gastro-esophageal junction adenocarcinoma treated in Peking University Cancer Hospital between 2009 June and 2013 August were included in this study. The patients with adenocarcinoma were previously confirmed and were eligible if their tumor showed overexpression of HER-2+++ by immunohistochemistry or HER-2 gene amplification-positive by FISH, and if they failed to at least one previous chemotherapy. Response and toxicities were evaluated with RECIST 1.0 and CTC AE 3.0 criteria. The twenty patients received trastuzumab plus second- or later-line chemotherapy, consisting of nine platinum with fluoropyrimidines, five paclitaxel with fluoropyrimidines, three fluoropyrimidines monotherapy, two irinotecan monotherapy, and one docetaxel monotherapy. In these 20 cases, 3 PR (15.0%) and 10 SD (50.0%) were achieved, with a disease control rate of 65.0%. The median PFS was 6.1 months (95%CI 3.0-9.2) and median OS was 11.1 months (95%CI 8.4-13.7). The median cycle number of Trastuzumab administration was 6.5. The patients treated with Trastuzumab ≥ 6 times had a median OS of 13.8 months, significantly longer than that of 9.5 months in the patients treated <6 times (P < 0.001). The patients treated with Trastuzumab ≥ 6 times had a median PFS of 7.8 months, significantly longer than that of 3.7 months in patients treated <6 times (P = 0.029). Among the 20 cases, loss of appetite (13 cases of grade 1-2), neutropenia (12 cases of grade 1-2 and 3 cases of grade 3-4) and fatigue (9 cases of grade 1-2 and 3 cases of grade 3-4) were the most frequent adverse events. No cardiac events including asymptomatic decreases in LVEF ≥ 10% and no treatment-related death were recorded. Combination of trastuzumab with chemotherapy is effective and safe in patients with HER2-positive advanced chemo-refractory gastric or gastro-esophageal junction adenocarninoma. However, prospective studies are warranted to further confirm its efficacy and safety.