Aim: To evaluate the value of pretreatment blood biomarkers in predicting pathologic responses to neoadjuvant chemoradiotherapy (neo-CRT) in patients with locally advanced rectal cancer. Materials & methods: We conducted logistic regression analysis and receiver operating characteristic to assess the predictive value of blood biomarkers. The outcome was defined by the pathologic complete response and good response. Results: Carcinoembryonic antigen (CEA) (p < 0.001), neutrophil-to-lymphocyte ratio (p = 0.024), platelet-to-lymphocyte ratio (p = 0.006) and lymphocyte-to-monocyte ratio (LMR) (p < 0.001) were significant predictors of pathologic complete response, with area under the curve of 0.785, 0.794, 0.740 and 0.913, respectively; CEA (p = 0.007) and LMR (p < 0.001) correlated significantly with good response, with area under the curve of 0.743 and 0.771, respectively. Conclusion: Lower LMR and higher CEA, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio before treatment could predict poorer pathologic response to neo-CRT in patients with locally advanced rectal cancer.
Keywords: carcinoembryonic antigen; lymphocyte-to-monocyte ratio; neoadjuvant chemoradiotherapy; neutrophil-to-lymphocyte ratio; pathologic response; platelet-to-lymphocyte ratio; predictor; rectal cancer.