Prognostic significance of microvascular counts in rectal carcinoma

Numerous studies of many tumor types have demonstrated that microvessel qua ntitation as a measure of angiogenesis is a powerful prognostic tool. Vascu lar enumeration has been claimed to be an independent prognosticator for se veral human tumors, including breast carcinoma, melanoma or bladder carcino ma; however, the studies of colorectal cancer have rendered variable result s. To test the prognostic influence of this factor in our patients, we sele cted 39 patients with rectal carcinoma Dukes' stages A to C treated only wi th curative surgery, with no further adjuvant therapy. The minimal follow-u p time was 5 years (60 months). After immunostaining with CD34, we performe d a manual count of the vessels following Gasparini's criteria. In our seri es, vascular enumeration has been a prognosticator for OS (overall survival ) but not for RFS (relapse-free-survival) at all Dukes' stages in the univa riate analysis. This prognostic influence was lost in the multivariate anal ysis, in which only stage as well as vascular and neural invasion behaved a s significant independent prognosticators. The presence of hypervasculariza tion did not show any significant association with histologic grade, tumor staging, and vascular or neural invasion.