Clinical use of trastuzumab combined with different chemotherapy regimens in multi‑line treatment of advanced human epidermal growth factor receptor 2‑positive gastric cancer: A case report

It is generally acknowledged that gastric cancer requires comprehensive treatment approaches to be adopted. For patients with human epidermal growth factor receptor-2 (HER2)-overexpressing gastric cancer, targeting HER2 with trastuzumab in first-line therapy combined with standard chemotherapy significantly improves the prognosis. However, there is a lack of international guidance for second-line treatment if a patient experiences disease progression. There is also no accepted conclusion regarding the efficiency of cross‑line therapy with trastuzumab. The present study reports the case of a 55-year-old male with gastric cancer who underwent radical gastrectomy. Immunohistochemistry indicated that samples were EGFR(+) and HER-2(3+), with Ki-67 (20%). From abdominal computed tomography scanning and contrast-enhanced ultrasound following surgery, hepatic metastasis was identified and the patient was administered microwave thermocoagulation therapy. Since December 2012, the patient received multi-line chemotherapy regimens as follows: i) Oxaliplatin, tegafur/gimeracil/oteracil and trastuzumab; ii) paclitaxel liposome and S-1 plus trastuzumab; iii) apatinib; iv) epirubicin/oxaliplatin/xeloda; and v) irinotecan plus trastuzumab. During the course of therapy, the trastuzumab served an important function in multi-line therapy and the patient benefited from the combined therapy. The application of trastuzumab in the multi-line treatment of a patient with HER2-positive advanced gastric cancer may be worthy of investigation for use in the clinic.