Objective: To investigate the prognostic values of HIF-1α, APE1, VEGF, and COX-2 protein expressions and their predictive value of tumor necrosis rate and prognosis in osteosarcoma, as well as their interrelationships.
Methods: Formalin-fixed paraffin-embedded tissue samples were obtained from patients with osteosarcoma. Immunohistochemical assay was performed in pre-chemotherapy samples to determine the HIF-1α, VEGF, APE1, and COX-2 protein expression levels. Hematoxylin-eosin staining was used in post-operative samples to determine the tumor necrosis rate. Univariate and multivariate analyses were used to assess the impact of protein expression on prognosis.
Results: Tumor tissues were obtained from 49 patients. Their median follow up was 29 months. HIF-1α was significantly correlated to every protein we tested: VEGF (P = 0.032), APE1 (P < 0.001), and COX-2 (P < 0.001). HIF-1α protein expression had a significant impact on disease free survival (P = 0.006). Expression of HIF-1α had a sensitivity of 64.7% and a specificity of 71.9% for poor pathological response (< 90% of tumor necrosis) versus good pathological response to chemotherapy (≥ 90% necrosis).
Conclusion: Expression of HIF-1α is a predictor of tumor response to neoadjuvant chemotherapy and outcome in osteosarcoma and is correlated with VEGF, APE1, and COX-2 expression.