Neuroendocrine and cytokeratin serum markers as prognostic determinants of small cell lung cancer

Abstract

This retrospective study aimed at determining the prognostic significance of neuroendocrine markers chromogranin A (CgA), pro-gastrin releasing peptide (ProGRP) and neuron-specific enolase (NSE), together with the cytokeratin 19 marker CYFRA 21-1 in small cell lung cancer (SCLC). A total of 148 histologically proven and previously untreated SCLC patients were included. Among them 118 patients received a cisplatin-etoposide combination or cisplatin-etoposide-cyclophosphamide-4'-epidoxorubicin combination. All tumour markers were tested using immunoradiometric assays except for ProGRP which was tested using an enzyme-linked immunosorbent assay. The thresholds for marker serum titrations were 53 pg/ml, 65, 17, and 3.6 ng/ml for ProGRP, CgA, NSE and CYFRA 21-1 respectively. Univariate analysis showed that patients affected by one of the following characteristics proved to have a significant shorter survival in comparison with the opposite status of each variable: age over 63 years, extensive-stage, serum LDH level higher than 600 U/l, serum NSE level higher than 17 ng/ml, serum CgA level higher than 65 ng/ml and serum CYFRA 21-1 level higher than 3.6 ng/ml. In addition, there was a trend towards a statistical significance for a high serum alkaline phosphatase level and a performance status equal to or worse than two. The following variables were independent determinants of a poor outcome: a poor performance status (hazard ratio [95% confidence interval]: 1.51 [1.02-2.22]), a high CgA level (HR: 1.61 [1.06-2.45]), a high CYFRA 21-1 level (HR: 2.10 [1.40-3.14]) and an age older than 63 years (HR: 1.68 [1.14-2.48]). When the multivariate analysis was restricted to patients receiving a cisplatin-etoposide-based chemotherapy, the same variables were prognostic determinants with nearly similar hazard ratios. In conclusion, aside classical variables such as age and performance status, high serum CYFRA 21-1 and high serum CgA level in SCLC are both prognostic determinants of prognosis, in particular in patients receiving conventional chemotherapy consisting of cisplatin and etoposide-based combinations.