Extrapulmonary small‐cell carcinoma compared with small‐cell lung carcinoma

Abstract

The study was conducted with the aim of reviewing the clinical features, therapy, and natural course of patients with extrapulmonary small-cell carcinoma (EPSCC) and small-cell lung carcinoma (SCLC) to better define current concepts regarding EPSCCs. The medical records of patients with proven diagnosis of small-cell carcinoma (SmCC) between January 1999 and May 2006 were retrospectively reviewed. A total of 65 SmCC cases were included in the study (11 [17%] cases of EPSCC and 54 [83%] cases of SCLC). Progression-free survival of all patients with EPSCC and patients with extensive EPSCC disease was 7 months (95% confidence interval [CI], 0.58-13.42) and 7 months (95% CI, 4.71-13.29), respectively. Overall survival of all patients with EPSCC and patients with extensive EPSSC disease was 32 months (95% CI, 18.74-45.26) and 28 months (95% CI, 12.24-43.76), respectively. Progression-free survival and overall survival for all patients with SCLC were 5 months (95% CI, 2.26-7.74) and 10 months (95% CI, 5.95-14.05), respectively. Progression-free survival and overall survival for patients with extensive disease were 3 months (95% CI, 4.71-13.29) and 5 months (95% CI, 3.33-6.67), respectively. Overall survival was significantly better in all patients with EPSCC and in patients with extensive EPSCC disease compared with all patients with SCLC and patients with extensive SCLC disease (P = .014, P = .004, respectively). Early death and brain metastasis were observed in a higher number of patients with SCLC compared with EPSCC; however, these results were not statistically significant (P = .33 and P = .076, respectively). Smoking history was significantly less in the EPSCC group (P < .0001). EPSCC is usually treated similarly to SCLC. However, this study suggests some differences such as etiology, clinic course, survival, frequency of brain metastases, and early death between these entities. These possible differences may influence the choice of therapeutic approach.