Neutrophil-to-lymphocyte ratio: a hidden gem in predicting neoadjuvant treatment response in locally advanced rectal cancer?

Purpose: The link between the pro-inflammatory status, tumor aggressiveness and treatment response has been well established in multiple cancers. Various hematologic and biochemical variables representing surrogates for inflammation have been used as predictive markers. Our primary aim was to assess the prognostic value of neutrophil-to-lymphocyte ratio (NLR) in evaluating neoadjuvant treatment response in locally advanced rectal cancer (LARC).

Methods: We included 60 consecutive patients with LARC, admitted for surgery, after completing a standard full-course neoadjuvant radio-chemotherapy regimen. NLR and other hematologic parameters were collected one day prior to surgery. Treatment response was assessed on the resection specimens.

Results: On univariate analysis, poor responders had a significantly higher NLR value when compared with good responders: 5.81 (5.40-7.28) vs. 3.51 (2.36-4.04), p<0.0001. NLR retained its significance on multivariate analysis, with an OR of 3.51 (1.54-6.57), p=0.001. A NLR cut-off value of 4.50 had the best predictive value for poor response, with an area under the curve (AUC) of 0.85, sensitivity of 83.3% and specificity of 83.3% (p<0.001). Other hematologic ratios, such as the derived NLR (dNLR) and platelet-to-lymphocyte ratio (PLR) were also significant predictors for poor response, although to a lesser extent when compared to NLR.

Conclusion: NLR is a simple and cost-effective predictor for neoadjuvant treatment response in LARC. As more data is generated, clear cut-off values could provide valuable insight regarding the management of LARC.