Extrapulmonary small cell carcinoma: the University of Kansas experience and review of literature

Abstract

Though extrapulmonary small cell carcinoma was first described over 80 years ago, definitive treatment recommendations are lacking. The treatment strategies commonly utilized are extrapolated from pulmonary small cell carcinoma experience. A better understanding of this entity is needed to improve management approach. The University of Kansas tumor registry was reviewed from 1990 to 2013. Thirty-five cases met the inclusion and exclusion criteria for review. Age, gender, smoking status, weight loss, metastatic disease-related data, stage, performance status (PS), treatment received, and survival data were collected. Patients were evaluated with a variety of primary locations of disease including GI tract (29 %), GU tract (35 %), Gyn organs (17 %), head and neck (14 %), and unknown primary (9 %). Several sites of metastatic disease were noted, with 57 and 43 % of patients meeting criteria for limited disease (LD) and extensive disease (ED), respectively. Chemotherapy, surgery, and radiation were used in several different regimens, with small cell lung cancer-type regimens incorporating a platinum and etoposide being the most common (74 %). Patients with LD had a median survival of 36 months compared with 5 months in patients with ED (p < 0.0001). Among different primary sites, patients with GU and Gyn LD tumors had best median survival of 36 months. Among other variables that were examined with respect to their poor prognostic significance, PS >2 (p = 0.001) and one or fewer number of treatment modalities especially in LD (p = 0.0005) were found to be associated significantly with mortality. GI and GU tract tumors were the most common primary sites of disease in our retrospective review. Survival varied according to stage, PS, site of primary disease, use of chemotherapy, and number of treatment modalities used. Further studies are needed to better understand this rare disorder and optimize management approach.