['To evaluate response to radiation and clinical outcome of uterine cervical cancer patients with tumor-related leukocytosis (TRL) at initial diagnosis and during definitive radiotherapy.', 'We retrospectively analyzed 2456 patients with stage IA-IVA uterine cervical cancer who received definitive radiotherapy with (37.4%) or without (62.6%) platinum-based chemotherapy between 1986 and 2012. TRL was defined as two or more occurrences of leukocytosis over 9000/μl at the time of diagnosis and during the course of treatment. Locoregional failure-free survival (LFFS) and overall survival (OS) were compared between patients with or without TRL.', 'The median age of all patients was 55 years, and the median follow-up time was 65.1 months. TRL was observed in 398 patients (16%) at initial diagnosis; TRL (+) patients were younger and had larger tumors, advanced stage, and more frequent lymph node metastases (all P < 0.05). TRL (+) patients showed a significantly lower rate of complete remission than TRL (-) patients (89.9% versus 96.3%, respectively, P = 0.042). Ten-year LFFS and OS for all patients were 84% and 78%, respectively. LFFS and OS were significantly lower in TRL (+) patients than TRL (-) patients (10-year LFFS: 69% versus 87% respectively, P < 0.001; 10-year OS: 63% versus 81% respectively P < 0.001). After propensity score matching, LFFS and OS rates in TRL (+) patients remained significantly lower than for TRL (-) patients; this significant difference was also observed on multivariate analysis. Twenty-six percent of patients with locoregional failure (n = 345) were TRL (+) and had significantly poorer median OS (6 versus 12 months, P = 0.001).'] Is tumor-related leukocytosis associated with poor radiation response and clinical outcome in uterine cervical cancer patients?