Prevalence of Sleep Apnea in Lung Cancer

Obstructive sleep apnea hypopnea syndrome (OSAHS) is an important medical condition which causes significant morbidity and mortality. The prevalence of OSAHS in Spain is 4-6% in men and 2-4% in women and rises steadily with age. Snoring and smoking have been independently linked, and smoking may be a risk factor for developing OSAHS. This is particularly true of heavy smokers (> 2 packs/day), those at greatest risk for LC. Associations between OSAHS and some forms of cancer have been described in humans, especially in those experiencing nocturnal hypoxemia, and intermittent hypoxia has been linked to the progression of cancer in animal models. LC is currently the leading cause of cancer deaths in developped nations. A link between OSAHS and LC, therefore, is plausible.

Sleep disordered breathing may be common among patients recently diagnosed of lung cancer and may contribute to tumor progression.

Objectives: a) To perform home sleep testing in patients recently diagnosed with lung cancer in order to determine the prevalence of sleep disordered breathing in this patient population. b) To include biological samples obtained from all participants, including surgically treated patients with stage I / IIp LC through the program in the CIBERES Pulmonary Biobank Platform. Biological samples will be preserved under different storage conditions for subsequent determination of molecular biomarkers. c) To follow-up lung cancer patients with and without sleep disordered breathing in order to determine the potential influence OSAHS might have on their prognosis.

Prospective screening for sleep disordered breathing will be performed by home sleep testing in 100 subjects diagnosed with lung cancer, irrespective of stage at diagnosis, who give their consent. A modified epidemiologic questionnaire for sleep disordered breathing will also be administered. Patients identified as suffering from OSAHS will be referred to sleep clinic. Biologic samples and lung function studies will be obtained in all participating patients.

All patients with lung cancer will undergo follow-up for at least three years or until their demise, and those identified with OSAHS will also be followed in sleep clinic. The prevalence of OSAHS in this patient population will be determined. A link between OSAHS, and especially intermittent nocturnal hypoxemia, and tumor progression will be sought.