Predictive factors for response to neoadjuvant chemotherapy: inflammatory and immune markers in triple-negative breast cancer

Background Tumor-infiltrating lymphocytes (TILs) predict response to neoadjuvant chemotherapy (NAC) in triple-negative breast cancer (TNBC) patients. However, the TIL level can be determined at a few facilities. By contrast, neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are easily and objectively determined from the results of full blood counts. We conducted a retrospective study to investigate whether TILs, NLR, and PLR predict NAC efficacy and whether NLR and PLR could be surrogate markers for TILs in TNBC. Methods Of the 266 patients diagnosed with TNBC between 2013 and 2019, 66 who underwent radical surgery after sequential administration of anthracycline and taxane as NAC were included in the study. TILs, NLR, and PLR were evaluated as predictors of pathologic complete response (pCR) using cutoff values determined from receiver operating characteristic curves. Results The cutoff values of TILs, NLR, and PLR were 20%, 2.6, and 180, respectively. High TIL level was associated with low NLR ( P = 0.01) and low PLR ( P = 0.01). High TIL level (odds ratio [OR] 4.28 [95% CI 1.40–13.1]; P = 0.01), low NLR (OR 5.51 [95% CI 1.60–18.9]; P = 0.01), and low PLR (OR 3.29 [95% CI 1.13–9.57]; P = 0.03) were associated with pCR. Low NLR predicted pCR independently (OR 6.59 [95% CI 1.45–30.0]; P = 0.01). Conclusions TILs, NLR, and PLR predicted NAC efficacy against TNBC. TIL level was associated with NLR and PLR. NLR was an independent predictive factor and may be a useful surrogate marker for TILs when predicting pCR.