Simultaneous Expression of Epidermal Growth Factor Receptor (EGFR) and Cellular Apoptosis Susceptibility Protein (CAS) in Serous Ovarian Carcinoma: Relation with High Grade in a Two-Tier Grading System and Outcome
H Brustmann. Landesklinikum Thermenregion, Moedling, Lower Austria, Austria
Background: This study investigated the simultaneous expression of epidermal growth factor receptor (EGFR) and cellular apoptosis susceptibility protein (CAS) in a cohort of ovarian serous carcinomas with regard to grade in a two-tier grading system (Malpica A et al., Am J Surg Pathol 2004; 496-504) and outcome. The main ligands of EGFR are epidermal growth factor (EGF) and transforming growth factor- (TGF-). The CAS gene maps at 20q13.1, is related with TGF- mediated apoptosis and plays a role at the G1 checkpoint of the cell cycle.
Design: Formalin-fixed, paraffin-embedded archival tissues of 41 ovarian serous carcinomas were stained with antibodies to EGFR and CAS by immunohistochemistry. At first, immunostaining of both factors was scored with regard to quantity and intensity. Subsequently, cases were classified into two different groups of negative or weak (group 1, scores 0 and 1+), and moderate or strong factor coexpression (group 2, scores 2+ and 3+). Grading was based on nuclear atypia and frequency of mitotic figures.
Results: Patients with high EGFR/CAS coexpression (scores 2+ and 3+) had frequently a high tumor grade. One out of 18 grade 1 tumors and 17 out of 23 grade 2 cancers were categorized in group 2 (P<0.0001, Fisher's exact test). A trend for poor outcome was noted in group 2 patients (P=0.0232, logrank test), with a median survival of 20.5 months.
Conclusions: This study indicates that evaluation of dual marker immunoexpression for EGFR and CAS in serous ovarian carcinomas provides further support for the recently proposed two-tier grading system and that multiple marker testing may be an adjunct in the identification of high-risk ovarian serous cancers.
Wednesday, March 11, 2009 9:30 AM
Poster Session V # 141, Wednesday Morning