Background: Current staging system for small cell lung cancer (SCLC) categorizes patients into limited- or extensive-stage disease groups according to anatomical localizations. Even so, a wide-range of survival times has been observed among patients in the same staging system. This study aimed to identify whether endobronchial mucosa invasion is an independent predictor for poor survival in patients with SCLC, and to compare the survival time between patients with and without endobronchial mucosa invasion.
Methods: We studied 432 consecutive patients with SCLC based on histological examination of biopsy specimens or on fine-needle aspiration cytology, and received computed tomography and bone scan for staging. All the enrolled patients were assessed for endobronchial mucosa invasion by bronchoscopic and histological examination. Survival days were compared between patients with or without endobronchial mucosa invasion and the predictors of decreased survival days were investigated.
Results: 84% (364/432) of SCLC patients had endobronchial mucosal invasion by cancer cells at initial diagnosis. Endobronchial mucosal involvement (Hazard ratio [HR], 2.01; 95% Confidence Interval [CI], 1.30-3.10), age (HR, 1.04; 95% CI, 1.03-1.06), and extensive stage (HR, 1.39; 95% CI, 1.06-1.84) were independent contributing factors for shorter survival time, while received chemotherapy (HR, 0.32; 95% CI, 0.25-0.42) was an independent contributing factor better outcome. The survival days of SCLC patients with endobronchial involvement were markedly decreased compared with patients without (median 145 vs. 290, p<0.0001). Among SCLC patients of either limited (median 180 vs. 460, p<0.0001) or extensive (median 125 vs. 207, p<0.0001) stages, the median survival duration for patients with endobronchial mucosal invasion was shorter than those with intact endobronchial mucosa, respectively.
Conclusion: Endobronchial mucosal involvement is an independent prognostic factor for SCLC patients and associated with decreased survival days.