NEUROENDOCRINE DIFFERENTIATION IS AN INDEPENDENT PROGNOSTIC FACTOR INCHEMOTHERAPY-TREATED NONSMALL CELL LUNG-CARCINOMA

BACKGROUND, Neuroendocrine differentiation can be identified in 10-30% of patients with nonsmall cell lung carcinoma (NSCLC) by immunohistoc hemical or electron microscopic techniques. However, its clinical sign ificance is not well established. METHODS. Tumors from 107 patients wi th Stage IIIA, IIIB, and IV NSCLC treated with cisplatin/etoposide wit h or without hydrazine in the North Central Cancer Treatment Group and Mayo Clinic protocols were analyzed immunohistochemically with antibo dies to chromogranin A (CGA), Leu 7 (CD 57), and synaptophysin (SY). T hese results were compared with clinical outcomes. RESULTS, Keratin AE 1/AE3, used as a control, was positive in 99.1% of cases; 34.6% had po sitive staining for at least 1 neuroendocrine marker, and 11.3% had po sitive staining for 2 or more markers. CGA was positive in 4.7%, Leu 7 in 18.7%, and SY in 24.3% of cases. A significant increase in surviva l was seen in patients with tumors expressing any one neuroendocrine m arker or any combination of neuroendocrine markers (P less than or equ al to 0.01). There was no correlation between the presence of neuroend ocrine differentiation and either response to chemotherapy or time to disease progression (P > 0.3), nor was there any correlation between c hemotherapy response, time to progression, or survival with staining i ntensity or percent of cells positive per case. CONCLUSIONS. Neuroendo crine differentiation may be of prognostic significance in patients wi th advanced stage NSCLC treated with chemotherapy. (C) 1996 American C ancer Society.