Temporal trends in small cell lung cancer: Analysis of the national Surveillance, Epidemiology, and End-Results (SEER) database

Abstract

7082 Background: Research interest in small cell lung cancer (SCLC) has waned over the past 10 years due to the lack of significant therapeutic advances and a presumed decline in the incidence of SCLC. Methods: We analyzed data on all patients with primary bronchogenic carcinoma registered in the national SEER database from 1973–2002. To identify temporal trends, the study period was divided into three decades: 1973–1982 (D1), 1983–1992 (D2), and 1993–2002 (D3). Results: Of 318,584 eligible patients, 59,704 (18.7%) had SCLC. The proportional incidence of SCLC relative to non-SCLC was higher in Caucasians than African-Americans (19.6% vs 13.9%), women vs men (21% vs 17.4%), and patients ≥ 50 yrs old vs < 50 yrs old (18.9% vs 16%). By decade, the proportional incidence of SCLC was: D1, 18.4%; D2, 19.8%; D3, 17.9%. The overall incidence rates for both SCLC and non-SCLC initially rose and then declined during the study period. The incidence rates for SCLC were similar in both Caucasians and African-Americans throughout the study period, while those for non-SCLC were significantly higher in African-Americans. The gap between incidence rates in men and women has narrowed to a similar degree for both SCLC (M/F: D1, 2.6/1 to D3 1.4/1) and NSCLC (M/F: D1, 3.3/1 to D3, 1.7/1). Only 0.8% of SCLC patients underwent surgical resection from 1988–2002. The use of radiotherapy decreased during the study period (D1, 53% to D3, 43%) with greater use in younger patients and African-Americans. Stage-specific 2- and 5-year survival rates for SCLC improved over time (regional 2-yr/5-yr: D1, 15%/6.8% to D3, 22%/11%; distant 2-yr/5-yr: D1, 3.4%/1.3% to D3, 5.6%/1.9%). In multivariate analysis, significant favorable prognostic factors included: younger age, Caucasian race, female gender, limited stage, and later year of diagnosis. Conclusions: The proportional incidence of SCLC has declined only slightly over the past three decades. While overall survival has modestly improved, SCLC remains a major public health problem. No significant financial relationships to disclose.