Peripheral blood cell count ratios are predictive biomarkers of clinical response and prognosis for non‐surgical esophageal squamous cell carcinoma patients treated with radiotherapy

BACKGROUND: Peripheral blood cell count ratios, including the neutrophil‐to‐lymphocyte ratio (NLR), platelet‐to‐lymphocyte ratio (PLR), and lymphocyte‐to‐monocyte ratio (LMR), have been reported to be prognostic factors in many malignancies as markers of inflammation and immune status. The aim of this study was to determine whether NLR, PLR, or LMR can be clinical response and prognostic biomarkers of non‐surgical esophageal squamous cell carcinoma (ESCC) patients treated with radiotherapy. METHODS: 193 non‐surgical ESCC patients who underwent radiotherapy were retrospectively analyzed. The peripheral blood cell count ratios were obtained before, during (weekly) and at the end of the treatment. Then, we compared the subsequent results with the corresponding pretreatment values and computed the rates of change, which were defined as cNLR, cPLR, and cLMR. Univariate and multivariate Cox regression analyses were used for overall survival (OS). Ordinal logistic regression was used to analyze the clinical response. RESULTS: In multivariate analysis, cNLR at week 4(P = .026) and week 5(P = .025) during radiotherapy were significantly associated with OS, along with BMI, tumor stage, tumor length, tumor location, and grade of adverse events. Besides, BMI, tumor stage, tumor length, adverse event grade, cNLR at week 4(P = .044) and week 5(P = .013), and cPLR at week 4(P = .034) and week 5(P = .015) were significantly associated with the clinical response in the multivariate logistic regression analysis. CONCLUSIONS: The cNLR at weeks 4 and 5 was negatively correlated with the OS and clinical response of non‐surgical ESCC patients treated with radiotherapy. The elevated cPLR at weeks 4 and 5 was only related to poor clinical response.