The value of prognostic factors in Chinese patients with small cell lung cancer: A retrospective study of 999 patients.

INTRODUCTION: Little is known about the prognostic factors for small cell lung cancer (SCLC) in Chinese patients. OBJECTIVE: The aim of this retrospective study was to improve our understanding of overall survival (OS) and progression-free survival (PFS) prognostic factors in Chinese patients with SCLC. METHODS: A retrospective analysis of 999 SCLC cases was performed. Patient characteristics, treatments, and laboratory data, including platelet counts and serum lactate dehydrogenase (LDH) and serum sodium levels, were collected. Potential prognostic factors for OS and PFS were evaluated by univariate and multivariate analyses. RESULTS: The median OS and PFS were 10.6 and 7.0 months, respectively. The multivariate Cox proportional hazards model was used to identify stage, serum LDH, and several therapy-relevant factors, including the initial chemotherapy regimen, number of initial chemotherapy cycles, and combination therapy, as independent prognostic factors for OS. Furthermore, female sex, normal LDH levels, a response to therapy, receiving six cycles of initial chemotherapy, and receiving chemotherapy combined with radiotherapy and/or surgery were favorable prognostic factors for PFS. In addition, patients with hyponatremia had a worse OS; therefore, hyponatremia could not influence survival when a good response to therapy was achieved, and it failed to predict PFS. CONCLUSIONS: This study demonstrated that several factors, including patient, tumor, and treatment characteristics and serum LDH levels are independent prognostic factors for OS and PFS in Chinese patients with SCLC. The identification of such factors will help physicians compare different populations and to interpret the contribution of treatment to differences in survival among groups.