Objective To investigate the risk factors of internal mammary lymph node (IMLN) metastasis in breast cancer patients, and to provide evidence for clarifying the TNM stage of tumors and formulating precise treatment plans. Methods  The female patients who were admitted to the First Affiliated Hospital of Chongqing Medical University from February 2019 to January 2020 and diagnosed with breast cancer by tissue biopsy pathology based on the new tracer technology were retrospectively collected. All IMLNs were dissected. The associations of IMLN metastasis with patients’ age, tumor size (long diameter), tumor location, tumor grade, estrogen and progesterone receptor statuses, human epidermal growth factor receptor-2 (HER2) status, number of axillary lymph node (ALN) metastasis, and pathological molecular typing were analyzed. Results A total of 28 patients were included in this study. The visualization rates in the ALN and IMLN by the new tracer technique were 96.4% (27/28) and 35.7% (10/28), respectively. The pathological results of IMLN biopsy confirmed that 6 patients (The 6 cases were all displaying) had IMLN metastases, with an IMLN metastasis rate of 21.4%. The IMLN metastasis was related to the tumor location and ALN metastasis number of patients with breast cancer (P<0.05). That is to say, when the tumor located in the medial quadrant and the number of ALN metastasis was 4 or more, the IMLN metastasis rates were higher than those in the lateral quadrant (57.1% vs. 10.0%, P=0.028) and in the patients with ALN metastasis number <4 (50.0% vs. 11.1%, P=0.038). It was not found that IMLN metastasis was related to age, tumor size, tumor grade, estrogen and progesterone receptor statuses, HER2 status, and pathological molecular typing of patients with breast cancer (P>0.05). And the area of the receiver operating characteristic curve of the number of ALN metastasis for assessing IMLN metastasis was 0.697. Conclusion From the summarized results of cases in this study, the visualization rate of IMLN is higher based on the new tracer technology. When breast cancer locates in the medial quadrant and the number of ALN metastasis is 4 or more, it is recommended to actively carry out IMLN biopsy to clarify the results of pathological diagnosis, so as to accurately assess the tumor stage and formulate appropriate individualized treatment plan.

Citation： CHEN Yan, SHI Yihan, XING Lei, YANG Guanglun. Detection of internal mammary lymph node metastasis in breast cancer based on new tracer technology and evaluation of risk factors. CHINESE JOURNAL OF BASES AND CLINICS IN GENERAL SURGERY, 2023, 30(6): 698-702. doi: 10.7507/1007-9424.202301004 Copy