Many people with obstructive sleep apnea use a CPAP machine every night, hoping it does more than just help them breathe. Some have wondered if treating this serious sleep disorder might also lower the risk of developing cancer. A fresh look at the data from three large clinical trials aimed to find out.
The analysis combined results from thousands of patients with sleep apnea who were randomly assigned to use CPAP or not. When researchers tracked who developed cancer, they found no statistically significant difference between the two groups. The numbers showed a wide range of possibilities—from a potential reduction in risk to a potential increase—but the most honest takeaway is that the effect, if there is one, remains unclear.
It's important to understand what this result means. These trials weren't originally designed to study cancer; they were looking at heart and stroke risks. The cancer data came from tracking side effects, which isn't the most precise way to measure this outcome. The confidence interval, a statistical measure of certainty, crossed the line of 'no difference.' So, for now, we can't say CPAP prevents cancer. The best reason to use your CPAP is still the proven one: to treat your sleep apnea and protect your heart.