Angiogenesis is an independent prognostic factor in malignant mesothelioma

Angiogenesis is essential for tumour growth beyond 1 to 2 mm in diameter. T he clinical relevance of angiogenesis, as assessed by microvessel density ( MVD), is unclear in malignant mesothelioma (MM). Immunohistochemistry was p erformed on 104 archival, paraffin-embedded, surgically resected MM samples with an anti-CD34 monoclonal antibody, using the Streptavidin-biotin compl ex immunoperoxidase technique. 93 cases were suitable for microvessel quant ification, MVD was obtained from 3 intratumoural hotspots, using a Chalkley eyepiece graticule at x 250 power. MVD was correlated with survival by Kap lna-Meier and log-rank analysis. A stepwise, multivariate Cox model was use d to compare MVD with known prognostic factors and the EORTC and CALGB prog nostic scoring systems. Overall median survival from the date of diagnosis was 5.0 months. Increasing MVD was a poor prognostic factor in univariate a nalysis (P = 0.02). Independent indicators of poor prognosis in multivariat e analysis were non-epithelial cell type (P = 0.002), performance status > 0 (P = 0.003) and increasing MVD (P = 0.01). In multivariate Cox analysis, MVD contributed independently to the EORTC: (P = 0.006), but not to the CAL GB (P = 0. 1), prognostic groups. Angiogenesis, as assessed by MVD, is a po or prognostic factor in MM, independent of other clinicopathological variab les and the EORTC prognostic scoring system. Further work is required to as sess the prognostic importance of angiogenic regulatory factors in this dis ease. (C) 2001 Cancer Research Campaign.