Lymphatic and blood vessels in basal and triple-negative breast cancers: characteristics and prognostic significance

摘要

Basal and triple-negative breast cancer phenotypes are characterised by unfavourable biological behaviour and outcome. Although certain studies have examined their pathological and molecular profile, the vascular characteristics of lymphatic and blood vessels have not been examined. Immunohistochemical staining with podoplanin, CD34 and CD31 was used to examine lymphatic and microvessel density, as well as vascular invasion in 197 basal-like and in 99 triple-negative breast tumours and compared against 200 non-basal and 334 non-triple-negative cases. All specimens were lymph node negative. Vascular invasion was identified as blood or lymphatic vascular invasion by the differential expression of markers. All measurements were correlated with clinicopathological features and prognosis. No significant difference was detected between the basal and triple-negative groups in terms of lymphatic or microvessel density or vascular invasion. However, both the basal and the triple-negative groups showed significantly higher microvessel density than did the non-basal and non-triple-negative groups (P=0.017 and PP=0.012), and 46% in triple-negative vascular invasion-positive compared with 79% in vascular invasion-negative tumours (P=0.001). Basal-like vs non-basal-like and triple-negative vs non-triple-negative tumours have similar vascular characteristics in terms of lymphatic vessel density and vascular invasion but higher microvessel density, suggesting that such groups may preferentially benefit from anti-angiogenic therapy. Vascular invasion was, in all phenotypes, almost entirely lymphatic vessel invasion and could stratify basal-like and triple-negative phenotypes into distinct prognostic groups.