Platelet-Lymphocyte Ratio in Positive Sentinel Lymph Node in Early Breast Cancer

Platelets promote tumour progression, while lymphocytes are critical for cancer immune surveillance, suggesting that the platelet-to-lymphocyte ratio (PLR) may reflect malignant tumour behaviour. This is a single-centre, cross-sectional study aimed to evaluate the association between preoperative PLR and positive sentinel lymph node biopsy (SLNB) in early breast cancer. Secondary objectives included assessing the relationship between positive SLNB and clinico-pathological features. Preoperative PLR was calculated as the absolute platelet count divided by the absolute lymphocyte count, with a cut-off value of 127.1, determined by receiver operating characteristics (Area under the curve = 0.53). Statistical analysis was performed using the Pearson Chi-Square test. Among 271 women with early breast cancer who underwent SLNB, 17.7% (n = 48) had positive SLNB. No significant correlation was found between PLR and SLNB positivity (p = 0.193). However, high PLR was significantly associated with Chinese ethnicity (OR 2.524, 95% CI 1.05-6.069, p = 0.039). In conclusion, preoperative PLR does not predict SLNB positivity in early breast cancer and may not be suitable as an independent preoperative tool for assessing sentinel lymph node metastasis. Further research is required to explore alternative predictive markers.