Definitive pelvic radiation therapy improves survival in stage IVB neuroendocrine cervical carcinoma: A NeCTuR study

Objective: To evaluate the survival impact of adding definitive pelvic radiation therapy (RT) to chemotherapy among patients with stage IVB neuroendocrine cervical carcinoma (NECC). Methods: We retrospectively studied patients with FIGO 2018 stage IVB NECC diagnosed during 1998–2020 who received chemotherapy with or without definitive whole pelvic RT (concurrent or sequential). Demographic, oncologic, and treatment characteristics were summarized. Progression-free (PFS) and overall survival (OS) were plotted using the Kaplan-Meier method, and hazard ratios (HRs) were calculated using Cox regression. Results: The study included 71 patients. Median age was 43 years (range, 24–75). Fifty-nine patients (83%) had pure neuroendocrine histology, and 57 (80%) had pretreatment tumor size >4 cm. Fifty-six patients (79%) received chemotherapy alone with (n = 15) or without (n = 41) palliative pelvic RT, and 15 (21%) received chemotherapy and definitive pelvic RT (chemo+RT). Median follow-up time was 20.1 months (range, 11.3–170.3) for the chemo+RT group and 13.5 months (range, 0.9–73.6) for the chemotherapy-alone group. Median PFS was 10.3 months (95% CI, 7.5-∞) for the chemo+RT group vs 6.6 months (95% CI, 6.1–8.7) for the chemotherapy-alone group (p = 0.0097). At 24 months, the PFS rate was 24% for chemo+RT vs 7.8% for chemotherapy alone. Median OS was 20.3 months (95% CI, 18.5-∞) for the chemo+RT group vs 13.6 months (95% CI, 11.3–19.2) for the chemotherapy-alone group (p = 0.0013). At 24 months, the OS rate was 49.2% for chemo+RT vs 21.5% for chemotherapy alone. In a Cox regression model, definitive RT was associated with improved PFS (HR, 0.44; 95% CI, 0.23–0.83; p = 0.0119) and OS (HR, 0.31; 95% CI, 0.14–0.65; p = 0.0022). Conclusions: Addition of definitive pelvic RT to chemotherapy may improve survival in patients with stage IVB NECC.