People with sleep apnea may be at cancer risk, study finds

Almost all people may face the problem of snoring at some point in their lives. Because snoring affects breathing, it also has a bad impact on sleep quality.

It was known before that snoring may cause some diseases, but recently a group of scientists from various universities suggested that snoring could lead to another disease: Cancer.

A study — presented on September 5 at the European Respiratory Society (ERS) International Congress in Barcelona, Spain — found that people with obstructive sleep apnea (OSA) have a higher chance of developing cancer.

People with OSA frequently experience partial or total obstruction of their upper airway while they sleep, which results in frequent breathing pauses. This frequently leads to daytime lethargy, loud snoring, gasping, and choking.

The disorder is particularly common in those who are overweight or obese, have diabetes, smoke, or drink a lot of alcohol. Although not all people who snore have OSA, snoring is considered one of the symptoms of OSA.

“It is known already that patients with obstructive sleep apnea have an increased risk of cancer but it has not been clear whether or not this is due to the OSA itself or related risk factors for cancer, such as obesity, cardiometabolic disease, and lifestyle factors," said Dr. Andreas Palm, who presented the first study from Uppsala Univerity, Sweden.

"Our findings show that oxygen deprivation due to OSA is independently associated with cancer."

They matched 2093 patients with OSA and cancer diagnosis

As per ERS, Dr. Andreas Palm and colleagues looked at data from 62,811 patients five years before the start of treatment for OSA in Sweden. The scientists considered factors that could influence the results, such as body size, other health issues, and socioeconomic status,

They matched 2,093 patients with OSA and a cancer diagnosis up to five years before OSA diagnosis with 2,093 patients with OSA but no cancer.

The apnoea hypopnea index (AHI), which measures the number of breathing disturbances during sleep, or the oxygen desaturation index (ODI), which measures how many times per hour levels of oxygen in the blood fall by at least 3 percent for 10 seconds or longer, were used to assess the severity of OSA.

“We found that patients with cancer had slightly more severe OSA, as measured by an apnea-hypopnea index average of 32 vs. 30, and an oxygen desaturation index of 28 vs. 26,” Dr. Palm said.

“In further analysis of subgroups, ODI was higher in patients with lung cancer (38 versus 27) prostate cancer (28 vs. 24), and malignant melanoma (32 vs. 25).

The study will be expanded in the future

“The findings in this study highlight the need to consider untreated sleep apnea as a risk factor for cancer and for doctors to be aware of the possibility of cancer when treating patients with OSA. However, extending screening for cancer to all OSA patients is not justified or recommended by our study results.”

Dr. Palm and his colleagues intend to expand the number of patients and follow them over time to investigate the potential effects of CPAP treatment on cancer incidence and survival.

Presentation abstract

Purpose Chronic hypoxic and hypercapnic respiratory failure and obstructive sleep apnoea (OSA) are chronic diseases associated with decreased quality of life and increased mortality. The rationale behind the set up of the retrospective nationwide DISCOVERY cohort was to study several questions including disease course and risk factors for incident disease, impaired quality of life, hospitalization risk, and mortality in patients with chronic respiratory failure with long-term oxygen therapy (LTOT), long-term mechanical ventilation (LTMV) and obstructive sleep apnoea (OSA) on treatment with continuous positive airway pressure (CPAP).