The impact of hematological and radiation parameters on clinical prognosis of esophageal cancer patients treated with definitive chemoradiotherapy

Abstract

Abstract Purpose: The aims of the study were to conduct a survival analysis of thoracic esophageal squamous cell carcinoma (ESCC) patients treated with radical chemoradiotherapy and to identify prognostic variables from among the hematological and radiotherapy parameters. Methods: Cases of ESCC receiving definitive chemoradiotherapy at Jiangsu Cancer Hospital between January 2018 and September 2020 were screened. Cox proportional hazards model was used to assess the impact of hematologic and dosimetric parameters on overall survival (OS). The neutrophil-to-lymphocyte ratio (NLR) was calculated by dividing absolute neutrophil count (ANC) by absolute lymphocyte count (ALC) in the week prior to radical radiotherapy. Variables associated with radiation were gathered according to dose-volume histograms (DVH). X-tile software was used to determine the optimal cut-off values for pre-treatment NLR and post-treatment ALC nadir. Associations between lymphopenia and dose-volume parameters were analyzed using multivariate logistic regression. Results: The study comprised a total of 100 ESCC patients. The median follow-up of surviving patients was 33.9 months (interquartile range, 29.2-41.1), with 1-year and 3-year OS rates of 87% and 62.5%, respectively. Multivariate Cox regression analysis demonstrated a significant survival benefit in patients with lower baseline NLR (≤2.2), higher ALC nadir (>0.24*109/L), lighter lymphopenia (value dropped<1.82*109/L), and lower mean lung dose (<10.75Gy). Dose-volume parameters of the heart and lungs were correlated with radiation-induced lymphopenia (RIL) (p < 0.05). Conclusion: In ESCC patients treated with definitive radiotherapy, baseline NLR, ALC nadir, degree of lymphopenia and mean lung dose (MLD) are independent prognostic factors for OS. Optimization of radiation parameters in the heart and lungs can be effective in avoiding RIL.