Conversion Surgery for Patients With Stage IV HER2-Positive Gastric Cancer: A Report of 3 Patients
Gastric cancer is a common malignancy and remains potentially lethal. The prognosis of patients with stage IV gastric cancer is thought to be poor, but new molecular targeted therapy may benefit patients with advanced gastric cancer. Currently, conversion surgery after chemotherapy with a trastuzumab-containing regimen is reported to be effective in these patients. We present 3 patients with human epidermal growth factor receptor 2 (HER2)–positive advanced gastric cancer who underwent conversion surgery after receiving a trastuzumab-containing chemotherapy regimen. Interestingly, the primary lesion acquired resistance to the trastuzumab-containing regimen, although the metastatic lesions maintained a complete response. The reason why the primary lesions became resistant to trastuzumab remains unclear. More studies are needed to clarify the mechanism of resistance. Conversion surgery, made possible by the use of molecular-targeted therapy, may improve the prognosis of patients with stage IV gastric cancer, particularly if metastatic lesions show a complete response to therapy.