Predictive parameters for internal mammary node drainage in patients with early breast cancer.

INTRODUCTION: Breast cancer treatment currently represents one of the biggest challenges in clinical oncology. The gold standard for axillary lymph node management is to perform sentinel node biopsy to avoid axillary dissection and its sequelae. The detection of radiocolloid flow outside the axillary nodes is a diagnostic and therapeutic challenge.

METHODS: A database search at the Department of Oncology of Palacky University, Olomouc, Czech Republic, identified 127 patients who underwent breast cancer resection with a sentinel node procedure and had radiocolloid flow into the internal mammary nodes. Sentinel node lymphoscintigraphy was performed after intraparenchymal injection. Clinical and pathological data were collected to identify possible risk factors.

RESULTS: Ten clinical and pathological parameters including age, tumor histology, axillary lymph node status, estrogen receptor expression, progesterone receptor expression, tumor grade, Ki-67 expression, Her-2 status, tumor size and tumor location were analyzed with regard to internal mammary node drainage. A cohort of 127 patients with detected drainage into the internal mammary nodes was compared with 135 patients without such drainage. Six significant risk factors, including age <50 years ( P <0.0313), tumor location in central and inner quadrants (P <0.012), larger tumor size (P <0.017), positive Her-2 status (P <0.025), progesterone receptor expression (P <10-4) and axillary lymph node involvement (P <0.01) were found to predict radiocolloid flow into the internal mammary nodes.

CONCLUSION: Six parameters (patient age, tumor location, hormone receptor status, tumor size, Her-2 status and axillary lymph node status) should be considered in the management of breast cancer patients and help in the selection of patients for locoregional procedures encompassing the internal mammary nodes.