Small cell lung cancer survival disparities by socioeconomic status

Background: Little research exists on survival disparities by socioeconomic status (SES) for patients with small cell lung cancer (SCLC), a less prevalent form of lung cancer. The goal of our study was to determine if there are survival disparities among SCLC patients by SES using a large and comprehensive population-based dataset. Methods: Data from the 1996-2007 Florida Cancer Data System Registry were linked with the Agency for Health Care Administration, a database of diagnoses and procedural information. Survival was defined as the elapsed time from dates of diagnosis to death or last follow-up. SES was categorized by percent of the neighborhood living in poverty: lowest (≥20%), middle-low (≥10%-<20%), middle-high (≥5%-<10%), highest (<5%). Univariate and multivariate Cox regression models were fit to determine the association of SES with survival. Multivariate models were adjusted with demographics, clinical and pathological characteristics and individual comorbidities. Results: Among 20,593 SCLC patients in our sample the majority were White (94.4%), non-Hispanic (94.3%), and possessed more than 4 comorbidities (87.9%). In the univariate model, compared to lowest SES, independent predictors of better survival were middle-low (hazard ratio [HR] .88), middle-high (HR .87), and highest SES (HR .81; P<.001 for all) and the multivariate model maintained better survival for middle-low (HR .92), middle-high (HR .89), and highest SES (HR .84; P<.001 for all). Conclusion: To the best of our knowledge, this was the first study of its kind in SCLC patients. After adjusting for extensive confounders we have confirmed that SES remains an important predictor of SCLC survival.