ncident invasive breast cancer, geographic location of residence, and reported average time spent outside.
Millen AE, Pettinger M, Freudenheim JL, Langer RD, Rosenberg CA,
Mossavar-Rahmani Y, Duffy CM, Lane DS, McTiernan A, Kuller LH, Lopez AM, Wactawski-Wende J.
Cancer Epidemiol Biomarkers Prev. 2009 Feb;18(2):495-507. Epub 2009 Feb 3.
PMID: 19190147
doi: 10.1158/1055-9965.EPI-08-0652
In conclusion, region of residence and geographic solar irradiance are not consistently related to risk of breast cancer and may not be sufficient proxy measures for sunlight/vitamin D exposure. The observed association between time spent outside and breast cancer risk support the hypothesis that vitamin D may protect against breast cancer.
The association of solar ultraviolet B (UVB) with reducing risk of cancer: multifactorial ecologic analysis of geographic variation in age-adjusted cancer mortality rates.
Grant WB, Garland CF.
Anticancer Res. 2006 Jul-Aug;26(4A):2687-99.
PMID: 16886679
CONCLUSION: These results provide additional support for the hypothesis that solar UVB, through photosynthesis of vitamin D, is inversely-associated with cancer mortality rates, and that various other cancer risk-modifying factors do not detract from this link. It is thought that sun avoidance practices after 1980, along with improved cancer treatment, led to reduced associations in the latter period. The results regarding solar UVB should be studied further with additional observational and intervention studies of vitamin D indices and cancer incidence, mortality and survival rates.