Extrapulmonary small cell carcinoma: epidemiology and response to treatment

Extrapulmonary small cell carcinoma (EPSCCA) represents a clinicopathologic entity distinct from small cell lung carcinoma (SCLC). To further analyze the epidemiology and response of these uncommon neoplasms to treatment, we studied the records of all patients (pts) with EPSCCA treated in our institution between 1974 and 1993. All pts had a normal chest radiograph, CT scan, sputum cytology, and/or negative bronchoscopy. Pts with neuroendocrine tumors were excluded. There were 81 pts: 47 M and 34 F. 51/81 pts were smokers. The primary sites of the EPSCCA were: GI-29, GU-12, HEENT-19, GYN-10, thymus-3, lymph nodes-5, Peritoneum1, unknown primary-2. After the initial surgical procedure or evaluation, follow-up was lost in 11/81 pts. Of the remaining 70 pts, 39 had curative resection of the primary tumor. 9/39 pts ( 15%) remained alive and disease free at least 3 yr after surgery. Of these 9, 3 had EPSCCA of the salivary glands, 3 of the LNs, i of the pancreas, 1 of the bladder, and 1 of the pelvis: 4/9 had adjuvant platinum-based chemotherapy (CT) and 3/9 had adjuvant radiation therapy (RT). The remaining 31 pts relapsed with a median of 5 mo, despite the use of adjuvant CT or RT in most cases. From the pts with inoperable or recurrent disease, 17 had RT. 16/17 pts progressed with a median of 6 mos. Platinum-based CT was employed in the majority of pts with metastatic disease (22 pts): 16 (72%) had a regression with a median duration of 8.5 mo, 3 (9%) remained stable with a median duration of 6 mo, and 3 (9%) progressed. In summary, EPSCCA is a fatal disease in the majority of the pts (15% 3-yr survival, 8% 5-yr survival). Even when feasible, surgical resection is of limited benefit in most cases. Although EPSCCA is responsive to commonly employed agents for SCLC, the response is brief. Any advances in therapy await development of new systemic agents.