Platelet-to-lymphocyte ratio as a predictive factor of complete pathologic response to neoadjuvant chemotherapy in breast cancer

Response to neoadjuvant chemotherapy in breast cancer patients is of prognostic value in determining short- and mid-term outcomes. Inflammatory biomarkers, such as platelet-to-lymphocyte ratio (PLR) and neutrophil to lymphocyte ratio (NLR), have been proposed as predictive factors of response to neoadjuvant chemotherapy. Currently, there are no studies in Colombian patients reporting the role of inflammatory biomarkers as response predictors in patients receiving neoadjuvant chemotherapy. Therefore, in this study we performed a cross-sectional study and analyzed the association between inflammatory biomarkers and pCR (pathological complete response) in patients diagnosed with breast cancer–of different molecular subtypes- and treated with neoadjuvant chemotherapy. A total of 288 patients were included in the study, with a median age of 51 years old. Disease was locally advanced in 83% of the participants, and 77.7% had compromised lymph nodes. In our cohort, the most frequent tumor molecular subtype was luminal B/Her2- (27.8%) followed by triple negative [TN] (21.5%), luminal B/Her2+ (19.8%), Her2-enriched (16%) and luminal A (13.5%). PLR was not associated with age, menopausal status, baseline tumor size, histologic grade, axillary lymph node involvement, disease stage, estrogen receptor status, or Ki67; however, complete pathological response was significantly higher in the low PLR group (PLR<150) compared with the high PLR group (35.1% Vs. 22.2%, p = 0.03). In addition, Her2-enriched tumors achieved the highest pCR rates (65%), followed by TN (34%) tumors. Our results suggest that breast cancer patients with low platelet-to-lymphocyte ratio (PLR <150), treated with neoadjuvant chemotherapy achieve higher complete pathological response, independently of primary tumor molecular subtype.