Treatment and outcomes of small cell neuroendocrine carcinoma of the cervix (SCCC).

5531 Background: Extrapulmonary small cell carcinoma is rare. SCCC represent 2% of cervical cancers and can portend a poor prognosis. Treatment standardization is challenging given its rarity. We describe management of limited stage (LS; disease could be encompassed within one radiation port) at a large tertiary referral center and the characteristics and outcomes in a cohort of patients (pts) with LS and extensive stage (ES) SCCC. Methods: Pts with SCCC diagnosed from 1/1990-1/2016 were identified following IRB approval. Clinicopathologic, treatment, and follow-up data were recorded. Descriptive statistics were provided. Median PFS/OS or PFS/OS rate were estimated using Kaplan-Meier method. Results: 39 pts were identified, 29 with LS. Select characteristics are shown in table. Tumor molecular profiling revealed MYC amplifications, TP53 mutations, PIK3CA mutation among the small subset of pts who had this performed. LS SCCC was treated with whole pelvic radiation therapy (RT) (4500-5040cGy) and concurrent IV cisplatin (60mg/m2) on day 1 and etoposide (120mg/m2) on days 1, 3, and 5 during RT and days 1-3 post RT to complete a total of 4 cycles. 26 pts, all had LS, underwent initial surgical management. No pt had prophylactic cranial RT. 3 pts (8%), all had LS, developed brain metastases. Median follow-up was 59.5 months (1.9-234.1). Median PFS (95%CI) for LS pts was 39.2 months (15.1-not estimable) vs 2.9 months (0.9-4.6) for ES. Median OS(95%CI) was 31.8 months (16.3-56.0) for the whole cohort, 52.8 months (31.8-not estimable) for LS and 5.9 months(1.8-16.3) for ES. Conclusions: In the LS SCCC cohort treated with concurrent cisplatin/etoposide chemo/RT and outback cis/etoposide +/- post initial radical hysterectomy the 5-year PFS (95%CI) was 37.5% (19.2-55.9%). Clinicopathologic characteristics and risk factors for SCCC appear distinct to cervical cancers and lung small cell cancers. Further investigation of molecular alterations and treatment of this rare tumor is needed to improve pt outcomes. [Table: see text]