title: Is the seasonal variation in cancer prognosis caused by sun-induced folate degradation?
abstract: Recently, we have documented that the season of diagnosis affects the prognosis of Hodgkin's lymphoma, colon-, breast- and prostate-cancer patients in Norway. The relative risk of death was lower for the patients diagnosed during summer and autumn when compared with the winter diagnosis. We here hypothesise that UV (ultraviolet) induced degradation of folate may be the reason for the observed seasonal variations in cancer prognosis. It is known that folic acid, a synthetic form of folate, is degraded by UV radiation. We have also found that the most common folate derivative in the human body, 5-methyltetrahydrofolate, is UV sensitive.
authors.affiliation: Department of Radiation Biology, Institute for Cancer Research, Health Enterprise, Rikshospitalet - Radiumhospitalet, Montebello, N-0310 Oslo, Norway. arnfinn.hykkerud.steindal@rr-research.no
authors.forename: Arnfinn Hykkerud
authors.initials: AH
authors.lastname: Steindal
authors.forename: Alina Carmen
authors.initials: AC
authors.lastname: Porojnicu
authors.forename: Johan
authors.initials: J
authors.lastname: Moan
mesh_terms: D005492:Folic Acid / Q000378:metabolism*; D006801:Humans; D015994:Incidence; D008657:Metabolic Clearance Rate / Q000528:radiation effects; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology* / Q000378:metabolism*; D009664:Norway / Q000453:epidemiology; D011379:Prognosis; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012621:Seasons; D013472:Sunlight
chemical_list: D005492:Folic Acid