[Factors associated with identification of lymph node detected by axillary reverse mapping for breast cancer]

Objective: To investigate the different tracer materials in identifying the axillary reverse mapping(ARM) lymph nodes. Methods: A retrospective analysis of clinical and pathological data of 478 breast cancer female patients(mean age: 50.5±8.0) under axillary lymph node dissection(ALND) with ARM technique was conducted between March 2019 and November 2020 in Wuhan University Zhongnan Hospital. Of the 478 patients, methylene blue was applied in 147 patients, indocyanine green in 119, and indocyanine green plus methylene blue in 212 patients. Wilcoxon rank-sum test, Chi-squire test or Fisher test, and binary logistic regression were carried out to identify the factors associated with identifying ARM lymph nodes. Results: The recognition rates of ARM lymph nodes were 73.5%, 79.0%, and 83.0%(P=0.091), and the recognition rate of ARM lymphatic vessels was 62.6%, 92.4%, 89.6%(P<0.001), respectively. The coincidence rate of ARM lymph node and SLN was 8.1%(12/148), and the metastasis rate was 16.1%(61/378). Supplemental injection of 1 ml of methylene blue or indocyanine green can improve the identification of ARM lymph nodes. The larger BMI and the performance of neoadjuvant therapy were associated with the lower recognition rate of ARM lymph nodes. Neoadjuvant therapy was an independent factor for the identification rate of ARM lymph nodes. Conclusions: Indocyanine green combined with methylene blue can improve the recognition rate of ARM lymph nodes. Obese patients have a lower recognition rate of ARM lymph nodes, and the supplemental injection tracer can be injected to improve the recognition rate. In breast cancer patients whose ARM lymph nodes are not successfully identified during operation, it may be that the ARM lymph nodes are not located in the axilla.