Extrapulmonary small cell carcinoma: Single center experience with 61 patients

Abstract

Extrapulmonary small-cell carcinoma (EPSCC) is a clinicopathological entity distinct from small-cell carcinoma (SCC) of the lung. The aim of this study was to review the clinico-pathologic features, treatment modalities, and factors prognostic for survival in patients with EPSCC. We retrospectively reviewed the medical records of patients with EPSCC diagnosed between January 1995 and July 2004 at the Asan Medical Center. We identified 61 patients with EPSCC, 37 with limited disease (LD) and 24 with extensive disease (ED). The most common primary sites were the gastrointestinal (GI) tract (56%) and uterine cervix (18%). Overall survival (OS) at 1 and 3 years was 59% and 29%, respectively, with a median survival of 16 months (range, 1∼56 months). Treatment information was available for 51 patients, 34 with LD and 17 with ED. Of the 34 LD patients, 25 underwent surgery. Surgery was the only treatment modality in five patients, two of whom remained alive and disease free at last follow-up, 27 and 47 months after surgery, respectively. Adjuvant chemoradiotherapy was administered to 11 patients, nine of whom (82%) had distant failure with a median overall survival of 23 months. Of the eight patients who received adjuvant chemotherapy, four (50%) had distant failure, with a median survival of 21.7 months. In univariate analysis, advanced disease status, as measured by VALSG (LD vs. ED) stage, was a significant prognostic factor for OS (p<0.001). Interestingly, there were no statistically significant differences in progression-free survival or OS between patients with pure (n=45) and mixed (n=16) EPSCC. Overall, the response to various treatment modalities and the median survival time observed were discouraging. Patients with GI primary tumors had poorer prognoses than those with primary tumors at other locations. Fifty six percent of patients with a GI primary tumor had ED at the time of diagnosis, whereas 100% of patients with SCC of the uterine cervix had LD at the time of diagnosis and showed a favorable clinical course. The majority of patients with LD SCC who underwent surgery, followed by adjuvant chemotherapy or chemoradiotherapy, showed tumor recurrence and/or systemic metastases. Clinical trials are needed to define adequate treatment strategies for EPSCC.