A study in the May issue of Sleep is the first to report a significant positive association between long sleep duration and the development of colorectal cancer, especially among individuals who are overweight or snore regularly. According to the authors, the results raise the possibility that obstructive sleep apnea may contribute to cancer risk. Sleep disruption caused by OSA may reduce sleep quality and increase sleepiness, resulting in longer reported sleep durations.  The authors also noted that intermittent hypoxemia similar to that which occurs in OSA has been shown in animal models to promote tumor growth.