Mediastinal small cell carcinoma: a unique clinical entity?

Abstract

Mediastinal small cell carcinoma (MSCC) is a rare tumor with limited published literature. In view of diagnostic confusion pertaining to this tumor, we investigated its origin, clinical features, management and survival. Clinical data of MSCC patients were retrospectively reviewed. Eligible patients showed pathologically proven small cell carcinoma (SCC) with the primary lesions confined to the mediastinum. Survival information was collected through follow-up studies. Among 25 MSCC patients identified, 22 were classified to have limited disease (LD), while 3 were with extensive disease (ED). The 5 patients (20%) underwent surgery and 20 patients (80%) underwent non-surgical treatment. The 4 patients with LD MSCC received chemotherapy alone, while 13 of them received chemoradiotherapy. Overall median survival time (MST) of all patients was 22 months, and the 1-, 3- and 5-year overall survival rates were 67.4, 16.8, and 8.4%, respectively. The MST of LD and ED patients separately was 23 and 8 months, respectively, with significant difference (P = 0.005). But, the MST of patients who received surgical and non-surgical treatment was 25 and 21 months, respectively, with no significant difference (P = 0.757). The MST of LD patients receiving chemotherapy and chemoradiotherapy was 12 and 29 months, respectively, but somehow did not show significant difference (P = 0.482). Our data suggested that MSCC may be a separate clinical entity like extrapulmonary small cell carcinomas (EPSCCs). Despite, multimodal treatment is currently the main treatment option, but for patients with LD MSCC, chemoradiotherapy is recommended to be preferred treatment modality.