678P - Clinical significance of HER2 overexpression in gastric and gastroesophageal junction cancers

Date 30 September 2012
Event ESMO Congress 2012
Session Poster presentation II
Topics Oesophageal Cancer
Biomarkers
Gastric Cancer
Presenter Meltem Baykara
Authors M. Baykara1, M. Benekli2, O. Ekinci2, U. Coskun3, E.P. Eser3, O. Polat4, U. Demirci5, A. Üner3, A. Ozet3, S. Buyukberber3
  • 1Medical Oncology, Gazi University Medical Faculty, 06500 - Ankara/TR
  • 2Medical Oncology, Gazi University Faculty of Medicine, 090 - Ankara/TR
  • 3Medical Oncology, Gazi University Faculty of Medicine, Ankara/TR
  • 4Internal Medicine, Gazi University Medical Faculty, 06500 - Ankara/TR
  • 5Medical Oncology, Ataturk Education and Research Hospital, ankara/TR

Abstract

Objectives

In this study, we investigated the rate of HER2 overexpression in gastric and gastroesophageal junction cancers (GC, GEJC), and the relationship with HER2 expression and clinical, pathological parameters and prognosis.

Materials and methods

Surgery or biopsy specimen of 285 (202 male, 83 female) patients with GC or GEJC, the presence of HER2 overexpression by immunohistochemistry (IHC) and silver insitu hybridization (SISH) were evaluated. The relationship between HER2 positivity and tumor size (TS), histopathology (H), grade (G), serosal invasion (SI), lenfovascular invasion (LVI), perineural invasion (PNI), Lauren and Borrmann type, tumor location (TL), TNM stage, local recurrence (LR) and metastasis (M) and survival (OS) were investigated.

Results

HER2 IHC scores were; 194 (68.1%) IHC 0, 34 (11.9%) IHC +1, 30 (10.5%) IHC +2, 27 (9.5%) IHC +3. Twelve of 30 (4.2%) patients with IHC +2, SISH positive, and 18 patients SISH negative. The number of patients evaluated with IHC +3 or IHC +2 and SISH positive, HER2 positivity was 13.7%. There was no relationship between HER2 positivity and the age, gender, TNM stage, TS, TL, LR, M, LVI, PNI, and Borrmann type. HER2 positivity was higher in intestinal type tumors than in diffuse type (16.7% vs 6.9%, p = 0.075). HER2 positivity was significantly higher in well-moderately diferantiated tumors than poorly diferantiated tumors (24.3% and 23.4% vs 7.3%, p = 0.001). HER2 positivity was higher in adenocarcinomas than the other histologic subtypes; 19.4% of adenocarcinomas, 4.2% of signet-ring cell carcinomas were HER2-positive (p = 0.013). HER2 pozitivity was no significant effect on median OS (22.7 vs 18.4 months, p = 0.81). But in the early stage median OS of HER2-positive patients was shorter than HER2-negative patients (54.9 months vs not reach, p = 0.022). However patients with advaced stage HER2-positive and –negative there was no significant difference between the median OS rates.

Conclusion

HER2 positivity is associated with the degree of tumor differantiation and histopathology in GC and GEJC. Patients with early-stage, HER2 positivity is related to poor prognosis.

Disclosure

All authors have declared no conflicts of interest.