Association of angiogenesis in lymph node metastases with outcome of breast cancer

Angiogenesis: pathological, prognostic, and growth-factor pathways and their link to trial design and anticancer drugs

Angiogenesis is essential for tumour growth, invasion, and metastasis. Tumour blood vessels show many differences from normal vessels and are not genetically unstable, so they form a potentially key area for therapy of all types of cancer including leukaemias. Here we review current knowledge on the multiple pathways controlling tumour angiogenesis and assess which are the most clinically relevant. We also review the clinical evidence that angiogenesis affects the behaviour of cancer. Retrospective studies on intratumoral vascularisation suggest that it is an independent prognostic factor that merits prospective validation. Also, the presence of vascular endothelial growth factor in high concentrations in primary cancers is associated with poor prognosis. Key targets for drug development, current clinical trials, and the problems of developing drugs that do not have direct cytotoxic effects are reviewed. Recommendations are made on organising and monitoring antiangiogenic trials.

Microvessel density and p53 overexpression in young women with breast cancer: a case-control study

Several reports have indicated that young women (less than 40 years of age) with breast cancer have a worse prognosis than older women. We performed a case-control study in order to confirm this observation and to determine whether this was attributable to increased microvessel density (MVD) or p53 expression. Twenty-six young women (cases) with stage I-III breast cancer that had adequate paraffin-embedded archival tissue were identified by the Montefiore Medical Center Tumor Registry over a 24-year period. For each case, two or three control subjects at least 40 years of age or older were selected from the registry and matched for nodal status and tumor size. Immunohistochemistry was performed for MVD and p53 overexpression. A Cox proportional hazard model was performed to examine the influence of age, MVD, p53 overexpression, and recognized prognostic factors on disease-free and overall survival. There were 26 cases (median age, 36 years) and 72 controls (median age, 64 years). The groups were well matched for known prognostic variables. There was no significant difference in p53 overexpression or MVD in the cases and controls. In multivariate analysis, the only features associated with an increased risk of recurrence included young age (hazard ratio [HR] = 2.49; 95% confidence interval [CI]: 1.18-5.25; P = 0.02) and positive lymph nodes (HR = 2.44; 95% CI: 1.12-5.30; P = 0.02). We have confirmed previous reports demonstrating a worse prognosis for women younger than 40 years with invasive breast cancer but found no correlation between young age and MVD or p53 overexpression when adjusted for other variables.

Anti-angiogenesis therapy:concepts and importance of dosing schedules in clinical trials

The biological control of angiogenesis is critical to the clinical control of cancer. Understanding the mechanism of formation and regulation of new blood vessel development would open a new avenue for cancer treatment. Intense research effort has revealed a variety of factors which initiate, control and terminate the multi-stage process of angiogenesis, as well as target structures which interfere with this process. Protease inhibitors, inhibitors of the endothelial cell proliferation, suppressors of angiogenic growth factors, copper chelators, and other compounds interfering with the process of angiogenesis were screened for inhibition of tumor angiogenesis and some of them are in clinical trials. Very recently, a new term, 'metronomic dosing regimen' has been introduced, which implicates the use of the old cytostatic anticancer agents as anti-angiogenic agents. Results from recent studies will be discussed briefly and the prospects of inhibition of tumor angiogenesis as a new treatment modality will be outlined. Copyright 2000 Harcourt Publishers Ltd.