Independent prognostic value of hypoxia-inducible factor 1-alpha expression in small cell lung cancer

Hypoxia is an important factor in tumor angiogenesis, metastasis, and resistance to chemotherapy or radiotherapy, and may be an indicator of poor prognosis. The transcription factor hypoxia-inducible factor 1 (HIF-1) is the key regulator of the hypoxic state. This study was designed to evaluate the prognostic value of HIF-1α expression in small cell lung cancer (SCLC). Forty-three paraffin-embedded biopsy materials were examined using immunohistochemistry. Our results indicated that the expression of HIF-1α was high in males, and patients with poor Eastern Cooperative Oncology Group (ECOG) performance status and metastases. To elucidate the prognostic value of HIF-1α expression, Kaplan-Meier analysis was carried out and the results showed that patients with high HIF-1α expression had a poorer prognosis than patients with low expression of HIF-1α. After adjusting clinical parameters by the Cox proportional hazards model, our results demonstrated that high HIF-1α expression is an independent prognostic factor for SCLC with a 39.2-fold risk of death (p<0.003). In conclusion, we have provided evidence that HIF-1α expression has significant value in predicting survival of patients with SCLC and is an independent prognostic factor beyond ECOG performance and metastasis status.