Prognostic Factors for Survival in Extensive Stage Small Cell Lung Cancer (ED-SCLC): The Importance of Smoking History, Socioeconomic and Marital Statuses, and Ethnicity

Background:We investigated whether independent prognostic factors for overall survival (OS) in non-small cell lung cancer such as ethnicity, smoking history, socioeconomic, and marital statuses are also applicable to extensive stage small cell lung cancer (ED-SCLC).Methods:SCLC patients diagnosed from 1991 to 2005 from 3 Southern California counties were identified. Prognostic factors for ED-SCLC patients were evaluated by univariate and multivariate analysis.Results:Of the 4782 SCLC patients analyzed, only 2.5% of the patients were never-smokers and 71.7% of patients presented with ED-SCLC. By multivariate analysis, a positive smoking status was a statistically significant poor prognostic factor for OS in ED-SCLC patients (versus never-smoker; hazard ratio [HR] = 1.310; p = 0.0125), in addition low socioeconomic status (SES) (from the lowest to the highest SES score; ptrend = 0.0128) and being unmarried (versus married; HR = 1.179; p < 0.0001). Asian ethnicity was a favorable prognostic factor in ED-SCLC (versus Caucasian; HR = 0.785; p = 0.0076). Female gender was another independent favorable prognostic factor (versus male; HR = 0.823; p < 0.0001).Conclusions:A positive history of smoking, low SES, and being unmarried are independent unfavorable prognostic factors for OS in ED-SCLC while Asian ethnicity and female gender are independent favorable prognostic factors for OS in ED-SCLC by multivariate analysis.