EXPRESSION OF BCL-2 PROTEIN IN STAGE T1NOMO NON-SMALL-CELL LUNG-CARCINOMA

The bcl-2 gene product (bcl-2 protein, BCLP) prevents apoptotic cell d eath. Via a 14;18 chromosomal translocation, BCLP is overexpressed in most follicular lymphomas as well as some other non-Hodgkin's lymphoma s, and it has also been documented in other nonlymphomatous malignanci es. To address the possible prognostic value of this marker in predefi ned subsets of non-small cell lung carcinoma (NSCLC), the authors stud ied 126 T1NOMO cases seen between the years 1986 to 1991 at our instit ution. Patients were treated by lobectomy (105 cases) or wedge excisio n (21 cases) with negative margins; neuroendocrine carcinomas of all g rades were specifically excluded. The mean follow-up period was 39 mon ths. Immunostaining for BCLP was done using a monoclonal antibody (clo ne no. 124; DAKO, Carpinteria, CA), and the complex (ABC) technique. T he study cases included 73 adenocarcinomas (ACs) as well as 40 squamou s cell (SCC), five adenosquamous (ASC), and eight large cell/poorly di fferentiated (LCC) carcinomas. As assessed with the Kaplan-Meier metho d, overall survival was 64% at 5 years (66% AC vs 59% SC). BCLP was de tected in 47 of 126 cases (37%) including 32 AC (44%), 10 SCC (25%), t wo ASC (40%), and three LCC (38%). No significant difference in ii-yea r survival was noted in a comparison of all cases with BCLP expression (63%) and those without (59%). There was, however, a significant diff erence in the survival of grade 1 BCLP(+) cases, when compared with gr ade 2 or 3 BCLP(+) cases (P =.01). A nonstatistically significant tren d toward increased survival was observed in BCLP(+) SCC cases (66% 5-y ear survival in BCLP[+] vs 45% in BCLP[-] [P =.11]). Proportional haza rds analysis failed to disclose significant independent risk factors. These data suggest that bcl-2 protein immunoreactivity has limited pro gnostic value in the pathological evaluation of NSCLC. Copyright (C) 1 995 by W.B. Saunders Company