ERCC1 expression and survival in small cell lung cancer

Abstract

e19080 Background: The excision repair cross-complementation group 1 (ERCC1) protein expression has been suggested as both predictive or prognostic according to the administration or not of cisplatin-based chemotherapy in non-small cell lung cancer. It's role in small cell lung cancer (SCLC) is still uncertain. Methods: Forty four patients (pts) with diagnosis of SCLC were retrospectively analyzed. Paraffin blocks were reviewed to reconfirm a SCLC diagnosis and submitted to semi-quantitative immunohistochemical (ICH) method to detect the ERCC1 protein. The criteria for ERCC1 IHC evaluation was based on the percentage of cells with positive staining. Medical charts were reviewed and findings correlated to the IHC expression. All pts were treated with standard cisplatin-based chemotherapy and concomitant radiotherapy when appropriate according to stage. We report the correlation of ERCC1 expression with the overall survival of the population. Results: The group of pts had 59% (n=26) men with a median age of 60,8 years (±10). Staging revealed limited disease (LD) in 41% (n=18), extensive disease (ED) in 55% (n=24) and was not available from the chart review in 7% (n=3). The median survival time (MST) was 15.84 (±9.73) months (mo) in LD; 8.39 (±8.53) mo in ED. ERCC1 was positive in 50% (n=22) of the pts. From these, 54% (n=12) had ≥50% of the cells with positive staining. The overall median survival of this group was 10.8 (±8.6) mo. The 45% (n=10) of cases presenting with <50% of cells with positive staining had an overall survival of 13 (±10) mo. In the group with positive ERCC1 expression, 45%(n=10) had LD and median survival of 17.1 (±7.8) mo [≥50% staining (n=6): median survival 12.1 (±3.9) mo; <50% staining (n=4): median survival 24.4 (±6.1) mo]. The 11 pts with ERCC1 expression and ED had a median survival of 7.9 (±8.7) mo. [≥50% staining (n=6): median survival 9.4 (±12) mo; <50% staining (n=5): median survival 6.1 (±1.5) mo]. The group with no ERCC1 expression (n=22)] had an overall survival of 9.7 (±10.1) mo. Of these pts 7 had LD and a median survival of 14.03 (±12.4) mo, while 13 pts had ED and a median survival of 8.76 (±8.73) mo. Conclusions: In this group of SCLC pts ERCC1 expression by IHC does not seem to correlate with survival. No significant financial relationships to disclose.