IMMUNOHISTOCHEMICAL MARKERS OF PROLONGED SURVIVAL IN SMALL-CELL CARCINOMA OF THE LUNG - AN IMMUNOHISTOCHEMICAL STUDY

Objective.-To investigate the association of a variety of cell surface and cytoplasmic antigens in small cell carcinoma of the lung with lon g-term survival (greater than 2 years). Design.-Using immunohistochemi cal analysis of small cell carcinomas, the tissue expression of cortic otropin, bcl-2, p-glycoprotein, cathepsin B, cathepsin D, CD44, carcin oembryonic antigen, collagenase IV, Leu-7, neu oncoprotein, p53, S100, and synaptophysin was assessed. Results.-Compared with the control gr oup of shortterm survivors, tumors from prolonged survivors were uniqu e 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), c arcinoembryonic 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 histol ogic characteristics were also compared, and none were shown to be ass ociated with differences in survival in this study. Conclusions.-Negat ive immunohistochemical staining for cathepsin B, cathepsin D, carcino embryonic antigen, and neu oncoprotein is associated with prolonged su rvival in small cell carcinoma of the lung. Evaluation of these antige ns should be considered in future attempts to stratify patients with s mall cell carcinoma of the lung for prognostic or therapeutic purposes , as this study is limited by the small size of the study group and th e large number of clinical and pathologic variables.