Incidence and risk factors of internal mammary lymph nodes metastases in breast cancer patients

Internal mammary lymph node (IMLN) metastasis forms the part of the N-staging of breast cancer, and affects the treatment program and prognosis. At present, IMLN metastasis is clinically diagnosed by anatomical imaging, functional imaging and postoperative pathology. Anatomical imaging includes ultrasound, CT and MRI. Functional image includes positron emission computed tomography (PET-CT), PET-MRI, single photon emission computed tomography (SPECT) and SPECT-CT. Because of the special location of the internal mammary region and the complex anatomical structure around it, the imaging diagnosis rate and pathological diagnosis rate of IMLN are often different. Therefore, it is important to identify the relevant factors of IMLN metastasis for guiding the local treatment of internal mammary region, including the scope of surgery and radiotherapy. Key words: Breast neoplasms; Internal mammary lymph node; Metastasis rate