Risk factors associated with febrile neutropenia in patients with esophageal cancer receiving 5-fluorouracil plus cisplatin combination chemoradiotherapy

Purpose To identify risk factors for febrile neutropenia (FN) in patients with esophageal cancer receiving the first cycle of definitive chemoradiotherapy with 5-fluorouracil plus cisplatin and concurrent radiotherapy (FP + R therapy). Methods We conducted a retrospective single-center cohort study of patients who started FP + R at Oita University Hospital between April 2011 and June 2023. The primary outcome was FN onset in cycle 1. Univariate tests and multivariable logistic regression [forced entry: age, C-reactive protein (CRP), prognostic nutritional index (PNI), dysphagia) were used to evaluate association with FN development. Receiver operating characteristic (ROC) analysis was conducted to evaluate the predictive performance of baseline CRP for FN. Results Among 120 patients studied, grade ≥ 3 neutropenia occurred in 37 (30.8%) and FN in 14 (11.7%) during the first cycle. In multivariable analysis, higher baseline CRP was independently associated with increased FN risk [odds ratio (OR) 1.790; 95% confidence interval (CI) 1.120–2.850; p  = 0.014), whereas dysphagia showed a non-significant association (OR 2.890; p  = 0.145). Age and PNI were not independent predictors. ROC analysis for baseline CRP yielded area under the ROC curve of 0.699 (95% CI 0.520–0.877; p  = 0.021) with optimal cut-off value of 0.68 mg/dL (sensitivity 61.54%; specificity 70.65%). Conclusion Baseline systemic inflammation, indicated by elevated CRP, is an independent risk factor for FN development during FP + R therapy. Despite the regimen having an intermediate FN risk, patients with elevated pre-treatment CRP may need closer monitoring and consideration of intensified supportive care including primary prophylaxis with granulocyte colony-stimulating factor.