Prognostic significance of microvascular counts in rectal carcinoma

Numerous studies of many tumor types have demonstrated that microvessel quantitation as a measure of angiogenesis is a powerful prognostic tool. Vascular enumeration has been claimed to be an independent prognosticator for several human tumors, including breast carcinoma, melanoma or bladder carcinoma; however, the studies of colorectal cancer have rendered variable results. To test the prognostic influence of this factor in our patients, we selected 39 patients with rectal carcinoma Dukes' stages A to C treated only with curative surgery, with no further adjuvant therapy. The minimal follow-up time was 5 years (60 months). After immunostaining with CD34, we performed a manual count of the vessels following Gasparini's criteria. In our series, vascular enumeration has been a prognosticator for OS (overall survival) but not for RFS (relapse-free-survival) at all Dukes' stages in the univariate analysis. This prognostic influence was lost in the multivariate analysis, in which only stage as well as vascular and neural invasion behaved as significant independent prognosticators. The presence of hypervascularization did not show any significant association with histologic grade, tumor staging, and vascular or neural invasion.