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

ABSTRACT

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.