Subtype of breast cancer influences sentinel lymph node positivity

Introduction: The purpose of the study was to determine the correlation between biological subtype of breast cancer and the risk of its metastasis to a sentinel lymph node.Material and methods: In the analysed group there were 1018 women with breast cancer, clinically node negative, untreated previously. Luminal A subtype was recognised in 57% of patients. A positive sentinel lymph node was detected in 26.5% of women.Results: In the multivariate analysis only age and tumour size proved to be significant for the entire group, respectively: OR = 0.59, p = 0.0004; OR = 1.96; p < 0.0001. For Luminal A subtype values were OR = 0.51, p = 0.0007; OR = 1.78, p = 0.0045, respectively. For Luminal B patients, in women over 61 years, the risk of sentinel node metastasis probability decreases by 67% and for tumours over 21 mm the probability of positive sentinel node metastasis increases by 117%. Conclusions: According to our analysis luminal breast cancers are most numerous subtypes, and in these cases we expect more frequent instances of metastasis to a sentinel node. Following the most updated and modern procedures of breast cancer patients' treatment a procedure of sentinel lymph node biopsy is used, replacing an aggressive treatment in the axilla region. In regards to our analysis we should be more vigilant in estimation of regional lymph nodes in luminal patients under sixty with high grade tumours and the tumour diameter more than 20 mm.