Pretreatment blood biomarkers predict pathologic responses to neo-CRT in patients with locally advanced rectal cancer.

To evaluate the value of pretreatment blood biomarkers in predicting pathologic responses to neoadjuvant chemoradiotherapy (neo-CRT) in patients with locally advanced rectal cancer. 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. 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. 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.