Impact of HER2 expression on outcome in gastric cancer patients with liver metastasis

We aim to investigate the correlation of HER2 expression with liver metastasis and the impact of HER2 status and trastuzumab therapy on the prognosis of gastric cancer with liver metastasis (GCLM) patients.

This prospective observational study was carried out in Shanghai Zhongshan Hospital, Fudan University, from January 2012 to June 2015. HER2 status and baseline characteristics were collected from the patient record. GCLM patients were divided into three groups according to HER2 status and trastuzumab therapy.

A total of 290 patients were included, and94 patients were diagnosed with liver metastasis. The HER2 positivity was 37.2 % (35/94) in GCLM patients and 21 % (61/290) in the overall GC patients. Among 94 GCLM patients, 28 HER2-positive patients received trastuzumab-based therapy (group A), 7 HER2-positive patients received chemotherapy alone (group B) and the other 59 patients were HER2 negative (group C). The median progression-free survival (PFS) for groups A, B and C was 7.83, 6.30 and 5.33 months, respectively (P = 0.007). The median overall survival (OS) for groups A, B and C was 12.00, 10.47 and 8.67 months, respectively (P = 0.056). Further Cox analysis showed that there was no significant difference in OS (P = 0.917) and PFS (P = 0.456) between group B and C.

HER2 positivity was higher in GCLM patients. HER2 status itself was not an independent prognostic factor in GCLM patients. Trastuzumab-based therapy could significantly improve survival in HER2-positive GCLM patients.