Extrapulmonary small cell carcinoma: An indication for prophylactic cranial irradiation?

Abstract

e12040 Background: Extrapulmonary small cell carcinoma (EPSCC) accounts for 2.5-4% of small cell carcinomas. Information about disease presentation, prognosis and treatment is limited. Prophylactic cranial irradiation (PCI) has been adopted in small cell lung cancer (SCLC), but its role in EPSCC remains uncertain. Methods: We retrospectively analyzed all EPSCC at our Hospital between 1990 and 2009. Demographics, stage, therapy, response, recurrence patterns and survival were assessed. Results: Of 30 EPSCC 20% were mixed type carcinomas. Median age was 71years (32–80). Male/female ratio was 58%/42%. Seventeen (57%) had limited disease (LD), 13 (43%) extensive disease (ED). The majority were ex-/never-smokers (73%) in performance status (PS) 0-2 (83%). Location of primary: Gastrointestinal (8), unknown (6), gynaecological (6), urogenital (5) and ear nose throat (ENT) (5). Sites more likely to present as ED: Stomach (1), gall bladder (1), pancreas (1), colon (1) and anal canal (1). Primarily LD: ENT (5), rectal (2), bladder (3), endometrial (2), prostate (1), cervix (1), vagina (1) and breast (1). No patient presented with brain metastases. Four (13%) developed brain metastases (2 ED, 2 LD), including one isolated brain recurrence. Eighty-five percent of ED patients received first-line chemotherapy (CT). Response rate was 91%. Platinum/etoposide was most commonly used (64%). Most LD patients with resection only (5 out of 7) relapsed. Combination of CT and radiotherapy (RT) ± resection resulted in persistent remissions in 67% of LD patients (n = 6). Median survival was 16 months (1-108 months), 18 months (1-108 months) and 9 months (1-25 months) for LD+ED, LD and ED, respectively. Weight loss > 5 kg and PS 3+4 were significantly associated with worse survival (p < 0.001 and p < 0.01). Conclusions: In LD, resection alone results in frequent systemic relapse, but long term survivors exist. Best outcomes result from combined modality treatment including CT and RT. Prognosis is poor in ED with no long-term survivors. PCI should not be applied routinely, because brain metastases, - isolated ones in particular -, seem less frequent than in SCLC. No significant financial relationships to disclose.