Abstract
OBJECTIVE: The authors' objective was to quantitatively assess angiogenesis or neovascularity within node-negative colon cancers and to determine if increased angiogenesis correlated with higher recurrence and lower survival rates. SUMMARY BACKGROUND DATA: Neovascularization promotes rapid tumor growth by facilitating nutrient and metabolite exchange. Recent work with breast and nonsmall cell lung cancers has shown that low angiogenic activity imparts a lower risk of recurrence and metastasis. Although adjuvant therapy is beneficial for patients with node-positive colon cancers, no such benefit has been demonstrated for patients with node-negative lesions. Nevertheless, up to 30% of this latter group will experience recurrence. We sought to identify a subset of patients with node-negative colon cancers at high risk for recurrence who might benefit from such therapy. METHODS: One hundred five node-negative colon cancers were immunostained for endothelial cell factor VIII-related antigen. Blood vessels within three microscopic fields at 100X magnification were counted, the mean calculated, and an angiogenesis score assigned. A subjective angiogenesis grade (1-4) was assigned after each slide was surveyed in its entirety. Score and grade were then assessed with respect to cancer recurrence and patient survival. RESULTS: Mean patient age was 71 years (range, 41-90 years) and mean tumor size, 5.6 cm (range, 2-12 cm). Mean follow-up was 6.5 years; mean angiogenesis score, 27.9 (range, 4-50); and mean grade, 2.0 (range, 1-4). Patients living 5 years had significantly lower angiogenesis scores than did nonsurvivors (22.8 vs. 43.2, p = 0.0004). Each 10-vessel increase in score imparted a 2.0-fold greater hazard of death and a 2.7-fold greater hazard of recurrence. The probability of surviving 5 years is estimated by: [formula: see text] and the probability of recurrence is estimated by: [formula: see text] CONCLUSIONS: Angiogenesis within colon cancer is an important predictor of tumor behavior and may identify patients at higher risk for recurrence and early death.