Expression of hypoxia-inducible factor-1 alpha and its prognostic significance in small-sized adenocarcinomas of the lung.

OBJECTIVE

To analyze the prognostic value of hypoxia-inducible factor-1 (HIF-1) alpha expression and its correlation with clinicopathologic variables and the expression of vascular endothelial growth factor-A and -C in patients with lung adenocarcinomas of small size.

METHODS

The expression of hypoxia-inducible factor-1 alpha was immunohistochemically determined in 78 cases of small-sized adenocarcinoma (maximum dimension < or = 2 cm) using antibody against a recombinant protein corresponding to amino acids 575-780 of hypoxia-inducible factor-1 alpha. Data regarding patient survival, clinicopathologic factors, and immunohistochemical studies of vascular endothelial growth factors were also collected.

RESULTS

Strong expression of hypoxia-inducible factor-1 alpha was observed in 23 of 78 cases; absent or minimal expression was found in the localized bronchioloalveolar carcinomas. Strong expression of hypoxia-inducible factor-1 alpha was significantly higher in cases with vascular invasion, lymph node involvement, and vascular endothelial growth factor-A expression. The 5-year survival rate was 63.2% if expression of hypoxia-inducible factor-1 alpha was strong and 85.1% if expression was weak (p < 0.05).

CONCLUSION

Immunohistochemical staining of HIF-1 alpha, along with examination of metastatic potential via vascular pathways, may be valid defining a subpopulation of patients with small-sized adenocarcinoma of the lung whose tumors have aggressive angiogenesis potential.