Dr. David Samadi gives his expert opinion on a recent study linking lack of sleep to be associated with an increased risk of death from prostate cancer in men under the age of 65.
Men younger than age 65 who sleep less than 7 hours per night have a significantly higher risk for prostate cancer death according to data presented at the American Association for Cancer Research Annual Meeting in Washington, DC.
“We’ve known for some time now that men who lack sleep do appear to have a higher risk of prostate cancer,” said Dr. David Samadi. “A 2012 study looked at the risk of cancer among men who worked night shift hours, who often don’t get in sufficient sleep, and there was clearly a link suggesting that working odd hours of the day appeared to influence tumor development. So the findings from this study do seem to make sense.”
The information for the study was conducted by analyzing data from the Cancer Prevention Study-I (CPS-I) and Cancer Prevention Study-II (CPS-II). Both are large, long-term cohort studies of the American Cancer Society. CPS-I included 407,649 men who were followed from 1950 through 1972 and CPS-II which included 416,649 men followed from 1982 through 2012. All men participating in the studies were cancer-free at baseline and each self-reported their sleep-related behaviors such as sleep duration, shift work, and insomnia. During the follow-up periods, 1,546 men in CPS-I and 8,704 men in CPS-II died of prostate cancer.
Findings from the study showed that in relation to deaths from prostate cancer, men under the age of 65 and who got three to five hours of sleep per night had a 55 percent greater risk of dying from prostate cancer than men sleeping seven hours a night. If a man got six hours of sleep each night, he had a 29 percent higher risk than men sleeping more hours a night.
For men over the age of 65, it appeared that no matter what number of hours they slept each night, there was no difference shown in the risk of death from prostate cancer. It is not entirely clear the reason for this but it may be related to the natural decline in nocturnal melatonin as one ages, making sleep deprivation not as critical.
“Right now we don’t know specifically why sleep deprivation appears to increase prostate cancer death but it reiterates the importance of a good night’s sleep,” explained Dr. Samadi. “Prior studies have shown that insufficient sleep and particularly for anyone who works a night shift, that the body’s biological clock is disrupted because of the inhibition of the production of melatonin. People who are exposed to light at night will have a suppressed release of the hormone melatonin, which typically is at its highest in the middle of the night.”
The study authors also speculated that when the production of melatonin is low this can lead to an increase in genetic mutations, greater oxidative damage, reduced DNA repair, and immune suppression. Ultimately, these factors together could contribute to the dysregulation of a number of genes involved in tumor suppression.
“It is very compelling to see how this study mirrors results from previous studies suggesting that our body’s internal clock known as circadian rhythm and the lack of production of melatonin may have a role of increasing risk of prostate cancer and how it progresses,” exclaimed Dr. Samadi. “We know sufficient sleep is vital for all of us with the recommendation from the National Sleep Foundation that adults get at least seven hours of sleep every night. But at this time, it is important to remember that the findings from this study should be considered preliminary. In the meantime, younger men with prostate cancer should make it a priority to get at least seven hours of sleep to possibly increase their odds of lowering prostate cancer mortality.”
Patients newly diagnosed with prostate cancer can contact world renowned prostate cancer surgeon and urologic oncologist, Dr. David Samadi. For a free phone consultation and to learn more about prostate cancer risk, call 212-365-5000.