Among men younger than 65 years, sleeping only 3 to 5 hours per night significantly increases the risk of dying from prostate cancer, according to research presented at the American Association for Cancer Research (AACR) Annual Meeting in Washington, D.C.1

No such association between sleep and prostate cancer mortality was found among older men, reported lead study author Susan M. Gapstur, PhD, MPH, of the American Cancer Society in Atlanta, Georgia, in a press release.

Analyzing self-reported sleep data from the Cancer Prevention Study-I (CPS-I) and CPS-II cohort studies, representing 407,649 and 416,040 men, respectively, the research team found that men younger than age 65 years who got 3 to 5 hours of sleep per night had a 55% increased risk of dying of prostate cancer compared to men who slept 7 hours per night.

Even only seemingly slightly-shorter sleep durations increased the risk of dying from prostate cancer, Dr Gapstur noted: men under age 65 who got 6 hours of sleep nightly saw a 29% higher risk of death from prostate cancer than those who got 7 hours of sleep nightly.

The biological mechanisms linking sleep deprivation and cancer are not yet known, Dr Gapstur reported. Sleep deprivation and artificial light at night can both affect melatonin production, and impaired melatonin production is linked to oxidative stress, gene mutations, impaired DNA repair, and immune suppression, all of which can contribute to tumorigenesis and tumor progression. Sleep disruption might also lead to dysregulation of tumor-suppressor genes.

RELATED: Prostate Cancer: Treatment Choices and Patient-reported Outcomes

The findings are the latest evidence that circadian rhythm factors are involved in prostate carcinogenesis, Dr Gapstur said.

The CPS-I cohort was followed from 1950 through 1972; the CPS-II cohort was followed from 1982 through 2012. All of the men in both cohorts were cancer-free at baseline.


  1. Shorter sleep duration is associated with increased risk of fatal prostate cancer in younger men [news release]. Washington, DC: American Association for Cancer Research; April 3, 2017. Accessed April 4, 2017.