Immunohistochemical markers of prolonged survival in small cell carcinoma of the lung. An immunohistochemical study.

Abstract

To investigate the association of a variety of cell surface and cytoplasmic antigens in small cell carcinoma of the lung with long-term survival (greater than 2 years). Using immunohistochemical analysis of small cell carcinomas, the tissue expression of corticotropin, bcl-2, p-glycoprotein, cathepsin B, cathepsin D, CD44, carcinoembryonic antigen, collagenase IV, Leu-7, neu oncoprotein, p53, S100, and synaptophysin was assessed. Compared with the control group of short-term survivors, tumors from prolonged survivors were unique in their relative absence of staining for cathepsin B (0/13 vs 3/13 [23%], P = .037), cathepsin D (5/13 [38%] vs 13/15 [87%], P = 0.006), carcinoembryonic antigen (5/13 [38%] vs 11/15 [73%], P = .047), and neu oncoprotein (5/13 [38%] vs 14/15 [93%], P = .0014). A variety of histologic characteristics were also compared, and none were shown to be associated with differences in survival in this study. Negative immunohistochemical staining for cathepsin B, cathepsin D, carcinoembryonic antigen, and neu oncoprotein is associated with prolonged survival in small cell carcinoma of the lung. Evaluation of these antigens should be considered in future attempts to stratify patients with small cell carcinoma of the lung for prognostic or therapeutic purposes, as this study is limited by the small size of the study group and the large number of clinical and pathologic variables.