Introduction Small cell neuroendocrine carcinoma of cervix (SMNEC) is associated with poor prognosis on account of high incidence of nodal and systemic spread at diagnosis. Trimodality treatment often required if primary treatment was surgery even for early-stage disease. This study aims to investigate the survival and patterns of failure in immuno-histologically confirmed SMNEC treated with chemoradiotherapy-based primary treatment.

Methods Thirty patients with FIGO 2009 1b-3b SMNEC treated consecutively with curative intent between 1997–2017 were identified from a prospectively collected institutional ethics-approved Gynaecology Unit database. Five patients had surgery as primary treatment whilst the remainder 25 who underwent primary radiotherapy were eligible for analysis. All patients had staging Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET). Treatment consisted of external beam radiotherapy and brachytherapy in combination with sequential and/or concurrent platinum-etoposide (EP)-based chemotherapy. Kaplan-Meier method and descriptive statistics were used to estimate survival and patterns of relapse.

Results Twenty-five SMNEC patients followed-up for a median (IQR) of 69.5(20.8–120.0) months. Five-year overall survival was 55.5% (34.1%-72.4%). For node-negative patients (n=14) it was 76.9% (44.2%-91.9%) and for node-positive patients(n=11), it was 31.2% (8.5%-57.8%). Eleven patients (44%) relapsed, all of whom had distant failure. In addition, relapses in the primary(n=3), pelvic(n=6) and para-aortic(n=6) sites concomitantly. Primary and pelvic sites were controlled in 22(88%) and 19(76%) patients respectively. There were no primary site failures in the node-negative patients up to stage 2a.

Conclusion/Implications Loco-regional control was obtained in 76% patients. However, distant failure rate was 39% and 58% in node-negative and node-positive patients respectively.