Lack of prognostic significance of intratumoral angiogenesis in nonmetastatic osteosarcoma

Background: A need exists to stratify patients with nonmetastatic osteosarc oma into risk subcategories to administer risk-adapted therapy. Intratumora l angiogenesis determined at diagnosis may have a prognostic significance i n this malignancy. Patients and Methods: The authors performed a retrospective immunohistochem ical study on archival pathologic material from patients with nonmetastatic osteosarcoma, excluding patients with purely chondroblastic tumors associa ted with hypovascularity of the cartilaginous stroma. Representative sectio ns from the diagnostic biopsies were stained with a murine monoclonal antib ody directed against CD34, an endothelial cell marker. Two pathologists una ware of the patients' long-term outcome counted microvessels in 10 microsco pic fields from the most active areas of neovascularization. Results: Between March 1988 and December 1996, 15 girls and 14 boys (median age 12.6 y, range 4.3-18.3) were identified. Seven patients had died of me tastatic disease at a median of 3.4 years (range 0.8-7.4) after diagnosis; 22 were alive with no evidence of disease at a median follow-up of 6.8 year s (range 2.7-11.4). There was no significant difference in the number of mi crovessels per field (pathologist 1, median 19 vs. 18.5; pathologist 2, med ian 15 vs. 10) between survivors or patients who died of metastatic disease . The correlation between the measurements of the two pathologists was exce llent (correlation coefficient 0.87). Conclusions: Intratumoral neovascularization determined at diagnosis does n ot correlate with long-term outcome in patients with nonmetastatic osteosar coma. A prospective study is necessary to confirm these results.