08 Aug No Close Link Between Cancer and Obstructive Sleep Apnea
MedicalResearch.com Interview with:
Dr. Tetyana Kendzerska
Institute for Clinical Evaluative Science
Women’s College Research Institute
Women’s College Hospital
Department of Medicine
University of Toronto
Medical Research: What are the main findings of the study?
Dr. Kendzerska: In a large cohort with varying degrees of obstructive sleep apnea (OSA), severity of obstructive sleep apnea was not found to be independently associated with either prevalent or incident cancer, except in one subgroup analysis in smoking-related cancer.
Medical Research: Were any of the findings unexpected?
Dr. Kendzerska: Because the longitudinal evidence on this relationship is very limited, and the mechanism of an association is unclear (only chronic intermittent hypoxemia was postulated as a potential link), there were no expected or unexpected findings. This is the new area to explore.
Medical Research: What should clinicians and patients take away from your report?
Dr. Kendzerska: We were not able to confirm previous hypotheses that obstructive sleep apnea is a cause of overall cancer development through intermittent hypoxemia. However, sleep apnea has been shown to be associated with adverse long-term consequences such as cardio-vascular events, diabetes and all-cause mortality. Thus, identifying and treating obstructive sleep apnea (including in patients with cancer) may be a worthwhile strategy to reduce the risk of these adverse long-term consequences, particularly in subjects with other known risk factors.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Kendzerska: As we stated in our manuscript: “there is a need for a sufficiently large cohort study with a long enough follow-up to allow for the potential development of cancer, that adjusts for important potential confounders, examines common cancer subtypes, and has a rigorous assessment of both obstructive sleep apnea and cancer”. As such, additional studies are needed to elucidate whether there is an independent effect of obstructive sleep apnea on specific types of cancer. In a light of results found in our subgroup analyses, potentially smoking-related cancer should be in a focus of further studies.
Obstructive sleep apnea and the prevalence and incidence of cancer
Tetyana Kendzerska, Richard S. Leung, Gillian Hawker, George Tomlinson, and Andrea S. Gershon
CMAJ cmaj.140238; published ahead of print August 5, 2014, doi:10.1503/cmaj.140238