Reproducibility of microvessel counts in breast cancer specimens

Assessment of tumour vascularity in core biopsy specimens may be a useful predictor of response to primary therapy. This study addresses practical methodological issues regarding accuracy of tumour vascularity assessments in different breast cancer specimens. Issues addressed in the study are variation caused by (i) inherent observer variation in the method, (ii) tumour heterogeneity and (iii) previous surgical manipulation of tumours. Microvessel counts were performed by two observers on separate occasions and by two different observers. Counts were performed on core biopsies and tumour sections taken simultaneously (n = 16) and with an intervening time interval (n = 21). In addition core biopsies were obtained from the same tumour on two separate occasions (n = 10). A highly significant correlation was found in counts performed by the same observers at different times and between two different observers. No significant correlation was found in counts of core biopsies and tumour sections taken either simultaneously or subsequently. No correlation was found between counts of sequential core biopsies. Study findings suggest that, although microvessel counts may be assessed reproducibly by the same and different observers, counts performed in core biopsies do not accurately reflect those of overall tumour, limiting their potential as predictive or prognostic markers. © 1999 Cancer Research Campaig

Prognostic significance of microvessel density and other variables in Japanese and British patients with primary invasive breast cancer

The purpose of this study is to investigate the associations of microvessel density (MVD) and other pathological variables with survival, and whether they accounted for survival differences between Japanese and British patients. One hundred seventy-three Japanese and 184 British patients were included in the study. British patients were significantly older (56.3±11.4 years vs 52.5±12.9 years; P<0.01) and had smaller tumours (2.2±1.3 vs 2.7±1.8 cm; P<0.01), which were more frequently oestrogen receptor positive (78.8 vs 57.2%, P<0.01), had more grade III tumours (29.9 vs 21.4%, P=0.04) and more infiltrating lobular carcinomas (13.6 vs 4.0%, P<0.01) and a higher MVD compared with Japanese patients (57.9±19.8 vs 53.2±18.6; P=0.01). However, no difference in the prevalence of lymph-node metastasis was found between them (39.1 vs 37.5%, P=0.75). Younger British patients (age <50 years) had the highest MVD compared with Japanese and older British patients (P<0.01). Japanese patients were proportionately more likely to receive chemotherapy than endocrine therapy (P<0.01). British patients had a significantly worse relapse-free survival and overall survival compared with Japanese patients, after statistical adjustment for variables (hazard ratio=2.1, 2.4, P<0.01, P<0.01, respectively), especially, in T2 stage, low MVD and older subgroup (HR: 3.6, 5.0; 3.1, 3.3; 3.2, 3.9, respectively), but only in ER negative cases (P=0.04, P=0.01, respectively). The present study shows that MVD contributes to the Japanese–British disparity in breast cancer. However, the MVD variability did not explain the survival differences between Japanese and British patients

Fully automated microvessel counting and hot spot selection by image processing of whole tumour sections in invasive breast cancer.

BACKGROUND: Manual counting of microvessels is subjective and may lead to unacceptable interobserver variability, which may explain conflicting results. AIMS: To develop and test an automated method for microvessel counting and objective selection of the hot spot, based on image processing of whole sections, and to compare this with manual selection of a hot spot and counting of microvessels. METHODS: Microvessels were stained by CD31 immunohistochemistry in 10 cases of invasive breast cancer. The number of microvessels was counted manually in a subjectively selected hot spot, and also in the same complete tumour sections by interactive and automated image processing methods. An algorithm identified the hot spots from microvessel maps of the whole tumour section. RESULTS: No significant difference in manual microvessel counts was found between two observers within the same hot spot, and counts were significantly correlated. However, when the hot spot was reselected, significantly different results were found between repeated counts by the same observer. Counting all microvessels manually within the entire tumour section resulted in significantly different hot spots than manual counts in selected hot spots by the same observer. Within the entire tumour section no significant differences were found between the hot spots of the manual and automated methods using an automated microscope. The hot spot was found using an eight connective path search algorithm, was located at or near the border of the tumour, and (depending on the size of the hot spot) did not always contain the field with the largest number of microvessels. CONCLUSIONS: The automated counting of microvessels is preferable to the manual method because of the reduction in measurement time when the complete tumour is scanned, the greater accuracy and objectivity of hot spot selection, and the possibility of visual inspection and relocation of each measurement field afterwards