Assessment of tumour vascularity as a prognostic factor in lymph node negative invasive breast cancer

The association between tumour vascularity and relapse was examined in 93 patients with lymph node negative (LNN) invasive breast cancer. Factor VIII-related antibody was used to stain the microvessels. Vascularity was defined by the number of vessels per field counted in the area of highest vascular density at 100 x magnification. These vascular counts were divided into three groups of vascular density (group I: < 67, group 2: 68-100, group 3: > 101 vessels/field). Cross-tabulation analysis revealed a significant relationship between vascular density and tumour grade (P = 0.027). No association was found between vascularity and tumour size, tumour type, age or menopausal status. Survival analysis showed no association between vascularity and relapse-free (P = 0.92) or overall survival (P = 0.99). Significant associations between tumour grade and relapse-free (P = 0.0048) and overall survival (P = 0.0064) and between tumour size at the cut off of 15 mm diameter and relapse-free (P = 0.0097) and overall survival (P = 0.0271) were found. When grade was taken into account the effect of tumour size became non-significant (P = 0.059). Our results suggest that assessment of vascularity is not an independent prognostic factor in LNN invasive breast cancer.