Prognostic benefit of conversion surgery for HER2 positive stage IV gastric cancer; a case series study of eleven patients treated with trastuzumab-based chemotherapy

Abstract

Background Since the ToGA trial, trastuzumab-based chemotherapy is the standard treatment for HER2 positive stage IV gastric cancer. However, it is not yet clear whether surgical resection after trastuzumab-based chemotherapy (conversion surgery) can improve survival of HER2 positive stage IV gastric cancer. The purpose of this study is to evaluate the prognostic benefit of conversion surgery in HER2 positive stage IV gastric cancer patients. Case presentation We retrospectively investigated the medical records of the patients with HER2 positive (IHC3(+) or IHC2(+)/FISH(+)) stage IV gastric cancer treated with trastuzumab-based chemotherapy as the first line treatment. Overall survival (OS) was compared between patients with conversion surgery and without. Eleven HER2 positive stage IV gastric cancer patients treated with trastuzumab-based chemotherapy as the first line treatment were evaluated. Response rate was 63.6%, and 6 of 11 patients could receive conversion surgery. R0 resection was achieved in four patients. In Kaplan–Meier analysis, patients who received conversion surgery showed significantly better OS than those without surgery (3-year survival rate, 66.7% vs. 20%, P = 0.03). The median OS of patients who achieved R0 resection is 51.8 months. Conclusions Conversion surgery might have a survival benefit for HER2 positive stage IV gastric cancer patients. If curative surgery is technically possible, conversion surgery could be a treatment option for HER2 positive stage IV gastric cancer.

A prognostic scoring system for conversion surgery after trastuzumab-based chemotherapy for human epidermal growth factor receptor 2-positive advanced gastric cancer

“…Surprisingly, in the present study, the 5-year OS rate in the conversion surgery group with HER2-positive AGC was 68.6%. Hayano et al [ 18 ] examined prognostic data retrospectively in six patients with HER2-positive AGC, who underwent conversion surgery after trastuzumab-containing chemotherapy, and found that the 3-year survival rate was 66.7%. These findings imply that patients with HER2-positive AGC may be more suitable candidates for conversion surgery after trastuzumab-based chemotherapy, with greater improvements in prognosis, than those with HER2-negative AGC.…”

Trastuzumab in combination with chemotherapy for HER2-positive metastatic gastric cancer patients underwent conversion therapy

“…Hence, the feasibility and survival benefit of conversion surgery for patients who respond to chemotherapy plus trastuzumab should be urgently addressed (11). Some case reports have shown that trastuzumab has a beneficial effect on tumor regression, R0 resection rate, and long-term survival (12,13). Nevertheless, any role of trastuzumab played in the context of conversion surgery have not been reported on a larger scale.…”