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.
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 10&sup5; 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.