Life course sun exposure and risk of prostate cancer: population-based nested case-control study and meta-analysis.
There is currently no means of primary prevention for prostate cancer. Increased exposure to ultraviolet-radiation may be protective, but the literature is inconclusive. We investigated associations of life course exposure to sunlight with prostate cancer. The study design was a UK-wide nested case-control study, based on 1,020 prostate specific antigen-detected cases and 5,044 matched population controls and a systematic review with meta-analysis. Men with olive/brown skin (OR = 1.47; 95% CI: 1.00 to 2.17), men who burnt rarely/never (OR = 1.11; 0.95 to 1.29) and men with the lowest levels of intense sun exposure in the 2 years prior to diagnosis (OR = 1.24; 1.03 to 1.50) had an increased prostate cancer risk. However, amongst men with prostate cancer, spending less time outside was associated with a reduced risk of advanced cancer (OR = 0.49; 0.27 to 0.89) and high Gleason grade (OR = 0.62; 0.43 to 0.91), and men who burnt rarely/never had a reduced risk of advanced cancer (OR = 0.71; 0.47 to 1.08). The meta-analysis provided weak evidence that men with the lowest (versus highest) sunlight exposure had an increased prostate cancer risk (4 studies, random-effects pooled relative risk = 1.13; 0.98 to 1.29) and higher advanced or fatal prostate cancer risk (6 studies, random-effects pooled relative risk = 1.14; 0.98 to 1.33). Our data and meta-analyses provide limited support for the hypothesis that increased exposure to sunlight may reduce prostate cancer risk. The findings warrant further investigation because of their implications for vitamin D chemoprevention trials.
Gilbert
Rebecca
R
Department of Social Medicine, University of Bristol, Bristol, United Kingdom. becky.gilbert@bristol.ac.uk
Metcalfe
Chris
C
Oliver
Steven E
SE
Whiteman
David C
DC
Bain
Chris
C
Ness
Andy
A
Donovan
Jenny
J
Hamdy
Freddie
F
Neal
David E
DE
Lane
J Athene
JA
Martin
Richard M
RM
D000367:Age Factors; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology*; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000453:epidemiology*; D012307:Risk Factors; D013472:Sunlight
D017430:Prostate-Specific Antigen