HER2 PROGNOSTIC ROLE IN GASTRIC CANCER

Ann Oncol. 2012 Jun 11. [Epub ahead of print]

Prognosis of metastatic gastric and gastroesophageal junction cancer by HER2 status: a European and USA International collaborative analysis.

Janjigian YY, Werner D, Pauligk C, Steinmetz K, Kelsen DP, Jäger E, Altmannsberger HM, Robinson E, Tafe LJ, Tang LH, Shah MA, Al-Batran SE.

Source

Department of Medicine, Memorial Sloan-Kettering Cancer Center, Weill Cornell Medical College of Cornell University, New York, USA.

Abstract

BackgroundTo determine whether human epidermal growth factor receptor 2 (HER2) status is an independent prognostic factor in metastatic gastric and gastroesophageal junction (GEJ) adenocarcinoma.Patients and methodsFormalin-fixed paraffin-embedded tumor samples from 381 metastatic gastric/GEJ cancer patients enrolled at Krankenhaus Nordwest and Memorial Sloan-Kettering Cancer Centers on six first-line trials of chemotherapy without trastuzumab were examined for HER2 by immunohistochemistry (IHC) and in situ hybridization (ISH). IHC 3+ or ISH-positive tumors were considered HER2 positive.ResultsSeventy-eight of 381 patients (20%) had HER2-positive disease. In the multivariate logistic model, there were significantly higher rates of HER2 positivity in patients with liver metastasis (liver metastasis 31%; no liver metastasis 11%; P = 0.025) and intestinal histology (intestinal 33%; diffuse/mixed 8%; P = 0.001). No significant differences in HER2 positivity were found between resections and biopsies or primaries and metastases. Patients with HER2-positive gastric cancer had longer median overall survival compared with HER2-negative gastric cancer patients (13.9 versus 11.4 months, P = 0.047), but multivariate analysis indicated that HER2 status was not an independent prognostic factor (hazard ratio 0.79; 0.44-1.14; P = 0.194).ConclusionsApproximately 20% of Western patients with metastatic gastric cancer are HER2 positive. Unlike breast cancer, HER2 positivity is not independently prognostic of patient outcome in metastatic gastric or GEJ.