Neoadjuvant Chemotherapy Effect on Predictive Value of Sentinel Lymph Node Biopsy using Single Method Methylene Blue in Breast Cancer Patients at Low-resource Country

Abstract

AIM: This study aimed to examine the application of neoadjuvant chemotherapy (NAC) effect on sentinel lymph node biopsy (SLNB) using single method methylene blue 1% in breast cancer patients at low-resource country. METHODS: This analytical observational study employed a retrospective case–control approach. The total sampling method was used by involving the entire population of Stage-I and -II breast cancer patients after performed core biopsy or open biopsy with clinically negative axillary lymph nodes that had performed SLNB and axillary lymph nodes dissection at several hospitals in Surakarta from January to May 2020. The descriptive data were presented in the frequency table. Sensitivity, specificity, positive predictive value, negative predictive value (NPV), and diagnostic values were reported with 95% confidence of interval (CI). RESULTS: From a total of 161 patients, 100 patients were given NAC. The identification rate of the non-NAC was 91.3% and the NAC group 80.6%. Non-NAC group obtained a false-negative rate of 24.4% with NPV of 94.4% (95% CI 85–100), while the false-negative rate of the NAC group was 10.8% with NPV of 74% (95% CI 65–80). CONCLUSIONS: NAC with single method methylene blue 1% injection in SLNB can reduce the identification and false-negative rates in breast cancer patients.