Prognosis of metastatic gastric and gastroesophageal junction cancer by HER2 status: a European and USA International collaborative analysis
A partir d'échantillons tumoraux prélevés sur 381 patients atteints d'un cancer métastatique de l'estomac ou de la jonction gastro-oesophagienne, cette étude internationale évalue, du point de vue de la survie globale, la valeur pronostique du niveau d'expression tumorale du gène HER2
Background To 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 methods Formalin-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.Results Seventy-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).Conclusions Approximately 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.
Annals of Oncology , résumé, 2012