HER-2 and EGFR: Possible Targets for Vulvar Carcinoma
Rafael M Rocha, Beatriz Maia, Andre Rocha, Iara Rodrigues, Fernando Soares. A C Camargo Cancer Hospital, Sao Paulo, Brazil
Background: Vulvar carcinoma is a rare disease. Being radical surgery the standard treatment approach, often accompanied by considerable morbidity, knowledge on prognostic and predictive factors is criticaly necessary. The aim of this study was to identify alterations in EGFR and HER-2 oncogenes and its protein expression in order to determine prognostic and predictive values of new therapies for vulvar cancer.
Design: 140 invasive squamous cell carcinoma of the vulva were selected for this study, confirmed by pathologist and collected in two TMAs, in which immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) were performed for HER-2 and EGFR. All results were associated with clinical data of patients and with well-established prognostic factors in anatomic pathology.
Results: A 100% correlation between FISH and IHC for HER-2 and EGFR was observed in our cases. HER-2 and EGFR overexpression (3+) by IHC were present in 1,6% and 3,9% respectively (A, Negative; B, 1+; C, 2+; D, 3+).
Amplification was present in 2,1% for HER-2 and 6,4% for EGFR. Overexpression of HER-2 corresponded to poorly differentiated tumors (p=0,0221), presence of vascular invasion (p=0,0314), recurrence (p=0,05) and death by cancer (p=0,0349). Lower survival rates were observed in tumors scored as 3+ for HER-2 (p=0,0445), but it was not significant for EGFR. EGFR expression showed no association with the analyzed clinical and histological data.
Conclusions: Our study shows a novel data regarding the 100% correlation between FISH and IHC for HER-2 and EGFR in vulvar carcinoma which allows the distinction between two entities of negativity (score 0, 1+ and 2+) and positivity (3+) of these oncogenes in vulvar cancer. Despite of the rare overexpression found for HER-2, it can possibly be associated with a more aggressive phenotype of the tumors. The lack of association between EGFR expression with the analyzed clinical and histological data may be due to the heterogeneity of the vulvar carcinomas. Still, the overexpression of both membrane receptors, although rare, could benefit a small group of patients with therapy against these tyrosine kinase receptors.
Category: Gynecologic & Obstetrics
Wednesday, March 21, 2012 1:00 PM
Poster Session VI # 184, Wednesday Afternoon