Can Sleep Apnea Cause Cancer? New Research Points to a Significant Risk

By Annette Pinder
We keep hearing about it – sleep apnea. More than 28 million Americans have it, and many are undiagnosed. It is a disorder that disrupts breathing, causes snoring, and is linked to low oxygen levels. It can be serious, and lead to depression, obesity, heart disease, strokes, high blood pressure, diabetes, and death.
Two studies presented in June to the American Thoracic Society indicate people who suffer from sleep apnea also have a higher risk of developing cancer. Researchers say low oxygen levels associated with sleep apnea can trigger the development of tumors. The study, conducted by researchers at University of Wisconsin School of Medicine and Public Health over 22 years, revealed severe breathing problems at night increase the likelihood of dying from cancer by 4.8 times, compared to people who did not have breathing issues. They also found people with moderate apnea had twice the risk of dying.
Similar findings by the Spanish Sleep Network were also presented at the conference. Researchers there assessed the incidence of cancer, rather than the mortality rate, and followed 5,200 people over seven years tracking oxygen depletion. They found that people whose oxygen levels dipped below 90 percent, for up to 12 percent of the total time asleep, had a 68 percent greater likelihood of developing cancer, than people who did not have breathing difficulties at night.
Sleep apnea is already confirmed to be related to diabetes, obesity, high blood pressure, heart attacks and strokes. And, according to the National Cancer Institute, all of these conditions also linked to cancer. “But this is the first time researchers have found a definite link between sleep apnea and cancer, and the findings seem to be well-documented,” says Dr. Daniel I. Rifkin, M.D., President of Sleep Medicine Centers of Western New York. Dr. Joseph Golish, former chief of medicine at the Cleveland Clinic, said, “Even if future studies reveal the cancer link is not as strong as the proven relationship between sleep apnea and cardiovascular disease, it is one more reason to get your apnea diagnosed and treated,” and Dr. Rifkin agrees.

The Wisconsin study also showed that when people who were being treated with CPAP (continuous positive airway pressure) were removed from the analysis, the cancer association became stronger. This is consistent with the connection between low levels of oxygen and cancer. Meanwhile, Dr. F. Javier Nieto, one of the study’s authors and chairman of the department of population health sciences at the University of Wisconsin, says, “It could be something else, but it’s hard to imagine something we didn’t control for is causing this.”
Meanwhile, Dr. Rifkin says, regardless of future findings, “It is clear that sleep apnea can have a profound impact people’s health, and not breathing while you’re sleeping is a serious problem. People who suspect they have sleep apnea should contact their physician.”
To learn more about the Wisconsin and Spanish Sleep Network studies visit  www.medpagetoday.com/MeetingCoverage/ATS/32936#.
Western NY Resource:
Dr. Rifkin sees patients in Amherst, Buffalo, Dunkirk, Kenmore, Lockport, West Seneca, Women’s and Children’s Hospital, and Niagara Falls. Home sleep study kits are also available. Learn more at www.sleepmedicinecenters.com or call 716-923-7326.