Association of Circadian Rhythm and Prostate Cancer

Association of Circadian Rhythm and Prostate Cancer

The International Agency for Research on Cancer (IARC) designated night shift work involving circadian disruption as a probable (group 2A) human carcinogen in 2007. The report was based primarily on data on breast cancer, and to date there is little epidemiological data – although strong biologic rationale – for associations of circadian rhythm and prostate cancer. The overarching goal of our projects is to investigate circadian disruption as a risk factor for prostate cancer, and particularly lethal cancer, as well as to explore mechanisms underlying the association. Specifically, our primary aims are to:

1) Assess the association of genetic variation in core circadian rhythm genes with risk of prostate cancer and with urinary levels of melatonin, under the hypothesis that genetic susceptibility to prostate cancer may be in part due to common variation in the core circadian rhythm genes.

2) Evaluate the association between first morning void urinary 6-sulfatoxymelatonin levels and risk of prostate cancer, particularly aggressive forms of the disease defined by advanced stage or prostate cancer death. Our hypothesis is that men with lower levels of urinary 6-sulfatoxymelatonin levels have a higher risk of lethal prostate cancer.

3) Investigate the association between sleep disruption and sleep duration and risk of prostate cancer, under the hypotheses that men with more disrupted sleep patterns or fewer hours of sleep per night have an increased risk of prostate cancer.

4) Evaluate the size and calcification of the pineal gland and risk of prostate cancer. This aim will test the hypothesis that men with pineal glands that are reduced or have extensive calcifications, have lower levels of 6-sulfatoxymelatonin, and thus are at increased risk of prostate cancer, particularly aggressive forms of the disease.