Prediction of sentinel lymph node metastasis using the platelet-to-lymphocyte ratio in T1 breast cancer

Abstract

Background/Aim: The host's systemic inflammatory response is thought to affect the progression of cancer and the antitumor effects of chemotherapy. Meta-analyses have reported that the peripheral blood platelet-to-lymphocyte ratio (PLR) is a prognostic indicator of this effect. Therefore, we hypothesized that PLR may differ, depending on sentinel lymph node metastasis (SLNM) in patients diagnosed with cT1N0M0 breast cancer by preoperative imaging. This study investigated the ability of preoperative PLR to predict SLNM in patients diagnosed with cT1N0M0 breast cancer. Patients and Methods: This study included 475 patients with cT1N0M0 breast cancer diagnosed by preoperative imaging. Peripheral blood was obtained at diagnosis, i.e., before surgery. PLR was calculated from preoperative blood tests, by dividing the absolute platelet count by the absolute lymphocyte count. Results: The probability of SLNM was significantly higher (p=0.002) in cases where the tumor diameter was larger than 10 mm. The incidence of SLNM was significantly high in the high (preoperative) PLR group (p=0.031). Multivariate analysis revealed that high PLR [compared to low PLR, p=0.021, odds ratio (OR)=1.815, 95% confidence interval (CI)=1.093-3.090] and large tumor size (compared to small tumor size, p=0.001, OR=2.688, 95%CI=1.524-4.997) were independent factors influencing SLNM. Conclusion: PLR may act as a predictor of SLNM in cT1N0M0 breast cancer.