Clinical Characteristics and Survival Outcomes in Patients With Small Cell Lung Cancer in Spain: An Analysis of the...

Small cell lung cancer (SCLC) represents approximately 15% of all lung cancers and is characterized by poor survival. This study describes SCLC cases diagnosed in Spain and analyzes differences in patient characteristics and outcomes according to tobacco use.

A cross-sectional study was conducted using data from the Thoracic Tumor Registry of the Grupo Español de Cáncer de Pulmón. All SCLC cases diagnosed between 2016 and 2025 were included. Sociodemographic and clinical variables were described and compared according to tobacco use (never smoker, former smoker, current smoker) and sex. Survival was assessed using Kaplan-Meier curves and multivariable Cox regression models.

A total of 4920 cases were analyzed: 91 never smokers (1.8%), 1872 former smokers (38.1%), and 2957 current smokers (60.1%). Men accounted for 78.9% of cases, and the median age was 66 years. At diagnosis, 68.2% of patients had extensive-stage SCLC. Current smokers were more frequently female and younger. The most common symptoms were cough (36.7%) and dyspnea (36.0%). Five-year survival was 9.4% (95%CI, 8.3-10.5): 15.4% in never smokers, 10.8% in former smokers, and 8.2% in current smokers. Survival was higher in women than in men regardless of tobacco use. Higher mortality was associated with male sex (HR, 1.10; 95%CI, 1.01-1.20), current smoking (HR, 1.30; 95%CI, 1.01-1.68), older age (HR, 1.03 per year; 95%CI, 1.02-1.03), and extensive-stage disease (HR, 2.96; 95%CI, 2.72-3.22).

The clinical characteristics and survival outcomes of SCLC differ according to tobacco use and sex. Current smokers have a poorer prognosis than never smokers, and women have higher survival across all groups.