Tumor angiogenesis predicts recurrence in invasive colorectal cancer when controlled for Dukes staging

Tumor angiogenesis is associated with metastasis in several types of solid tumors, including melanoma, breast. prostate, lung, bladder, and oral-cavity tumors, The purpose of this study was to determine whether tumor angiogenesis could predict recurrence following curative surgery for colorectal cancer, Thirty-five patients were studied, including 13 patients with recurrent tumor and 22 without. Representative formalin-fixed, paraffin-embedded sections of invasive colorectal cancers from these patients were sectioned. The endothelial cells of microvessels within the tumors were highlighted by immunohistochemical staining for CD31. The most active areas were identified and the microvessels counted in a x400 field (0.152 mm(2)) by two observers in a blinded fashion. Tumor microvessel count (p = 0.0062), Dukes' staging (p = 0.0004), vascular invasion (p = 0.0280), and tumor grade (p = 0.0559)were all significantly associated with tumor recurrence, Tumor microvessel counts greater than or equal to 65 per x400 field were associated with tumor recurrence (p 0.0035, relative risk [RR] = 11.3), Controlling for Dukes' stage, a multivariate logistic regression model revealed that a tumor microvessel count greater than or equal to 65 is an important predictor of tumor recurrence (p = 0.0783, RR = 6.0). A backwards elimination proportional hazards model revealed that a microvessel count greater than or equal to 65 shows a trend toward independent prediction of time to tumor recurrence (p = 0.1303, RR = 2.967) when controlled fur Dukes staging (p = 0.0029, RR = 9.089). Despite the small number of patients studied, these results suggest that the number of microvessels in sections of invasive colorectal adenocarcinoma immunohistochemically stained with CD31 may be an important independent predictor of tumor recurrence and time to recurrence.