Reduced risk of axillary lymphatic spread in triple-negative breast cancer

Abstract

We examined the association between the hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status of women with primary breast cancer and the risk of axillary lymph node (ALN) involvement at the time of diagnosis. Information on 20,009 women diagnosed with primary breast cancer between 2008 and 2012 was retrieved from the Danish Breast Cancer Cooperative Group database. The associations between clinical and pathological variables and ALN involvement at the time of diagnosis were evaluated in univariate and multivariate regression analyses, as well as the significance of tumor subtypes in ALN involvement. The risk of ALN metastases at the time of diagnosis was significantly reduced in HR-negative patients compared to HR-positive patients [adjusted odds ratio (OR) 0.69; 95 % CI 0.63-0.76; P = 0.0009]. A HER2-positive status was associated with an increased risk of ALN involvement at diagnosis compared to a HER2-negative status (OR 1.37; 95 % CI 1.24-1.50; P < 0.0001). An interaction between HER2 and HR was observed, with a HER2-positive status significantly associated with ALN involvement at the time of diagnosis only in HR-negative patients (P < 0.0001). The triple-negative breast cancer (TNBC) patients showed a significantly reduced risk of ALN involvement at the time of diagnosis compared to patients with HR-positive/HER2-negative tumors (OR 0.55; 95 % CI 0.49-0.62; P < 0.0001). The HR and HER2 statuses are significantly associated with ALN involvement at the time of diagnosis. Despite the poor prognosis, TNBC patients have a reduced risk of ALN involvement at the time of diagnosis compared to patients with other subtypes, when adjusting for other risk factors. This may indicate that TNBC tends to spread hematogenously rather than lymphogenously.

Expression of Nestin associates with BRCA1 mutations, a basal-like phenotype and aggressive breast cancer

“…We also observed that Nestin was significantly associated with activated angiogenesis and blood vessel invasion, as a potential reflection of early haematogenous spread, whereas there was no association with lymphatic involvement. It has been reported by others that basal-like tumours are associated with lymph node negative breast cancer 23 , which was observed in one of our cohorts, and increased presence of brain metastasis 24 .…”

Tumour cell invasion into blood vessels is significantly related to breast cancer subtypes and decreased survival

“…It has been suggested that the basal-like phenotype may be related to non-lymphatic spread,20 and recent findings indicate a reduced risk of axillary lymphatic spread in triple-negative breast cancer 21. Here, 11% of the cases with negative lymph nodes showed presence of BVI, indicating the possibility of direct haematogenic spread in some patients.…”

Axillary lymph node micrometastases decrease triple-negative early breast cancer survival

“…Some authors described that TNBC showed a significantly lower risk of ALNI than HR-positive or HER2-positive tumours (Holm-Rasmussen et al , 2015). We have previously explored the prognostic value of microscopic ALNI for 8001 BC patients with SLNB without molecular selection (Houvenaeghel et al , 2006).…”