Severe OSA associated with higher risk of mortality in stage III and IV lung cancer.

STUDY OBJECTIVES

OSA has been associated with increased cancer incidence and mortality. The aim of this study was to investigate cancer-related mortality, overall survival, and progression-free survival in patients with suspected OSA and lung cancer.

METHODS

This was a case series analysis of lung cancer from a sleep cohort with suspected OSA between 2009 and 2014. The AHI, hypoxia index, and survival outcome were recorded. Immunohistochemistry was used to analyze hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor expression in tumor pathology.

RESULTS

In the sleep cohort comprising 8,261 patients, a total of 23 patients had lung cancer. The incidence of lung cancer was significantly higher in the sleep cohort than in the entire adult population in Taiwan (crude incidence rate: 242.1 vs 51.5 per 10⁵ persons, P < .01). The 3-year cancer-related mortality was 25% in AHI < 15 events/h, 50% in AHI 15-29 events/h, and 80% in AHI ≥ 30 events/h (χ² test for trend, P = .03). In Kaplan-Meier survival analysis, patients with stage III-IV lung cancer and AHI < 30 events/h exhibited significantly better overall survival (P = .02) and progression-free survival (P = .02) than patients with severe OSA. Overexpression of HIF-1α and vascular endothelial growth factor was shown in 63% and 45% of lung tumor samples. Overexpression of HIF-1α was positively associated with AHI (P = .04).

CONCLUSIONS

In this preliminary case series, severe OSA is associated with an increased risk of cancer mortality in patients with stage III-IV lung cancer. AHI was significantly associated with HIF-1α overexpression.