The prognostic value of angiogenesis by Chalkley counting in a confirmatory study design on 836 breast cancer patients.

This study addresses the prognostic value of estimating angiogenesis by Chalkley counting in breast cancer. A population-based group consisting of 836 patients with operated primary, unilateral invasive breast carcinomas was included from a predefined region and period of time. The median follow-up time was 11 years and 4 months. The microvessels were immunohistochemically stained by antibodies against CD34. The Chalkley count was obtained by a 25-point grid within three, subjectively selected, vascular tumor areas of highest microvessel density. The Chalkley count was analyzed in three categories using predefined Chalkley cutoff points at five and seven. There were significant correlations between high Chalkley counts and axillary lymph node metastasis, large tumor size, high histological malignancy grade, and histological type. A high Chalkley count showed lower probabilities of recurrence-free survival (P < 0.0001) and overall survival (P < 0.0001). In the Cox multivariate analysis, the hazard ratio (and 95% confidence interval) showed that the increased risk to die were: 1.55 (1.19-2.03) with Chalkley counts between 5 and 7; 2.26 (1.72-2.98) with counts > or =7 compared with counts < or =5; and 1.46 (1.14-1.87) with counts > or =7 compared with counts between 5-7. The study confirmed that estimation of angiogenesis by Chalkley counting had independent prognostic value in breast cancer patients. The Chalkley count could be useful to stratify node-negative patients for adjuvant treatment.