BACKGROUND: We have earlier found that the prognosis for several cancers is dependent on season of diagnosis. More recently, both prostate cancer incidence and mortality have been shown to increase with increasing latitude, which probably relates to photosynthesis of vitamin D. METHODS: The 3 year survival of prostate cancer patients has been analyzed with the Cox regression method for two age groups at different latitudes in Norway. RESULTS: Patients diagnosed during the summer and autumn had the best prognosis (Ralative risk (RR) death 0.8; 95% CI 0.75-0.85). Similar results were observed in three regions of the country that differ with respect to annual fluences of solar UV radiation, incidence rates of squamous cell carcinoma (SCC) and intake of fish. Furthermore, similar relationship between the season and survival was seen among patients </=65 years and >65 years old, although the younger group had a slightly larger advantage of summer and autumn diagnosis. CONCLUSIONS: The seasonal effect on prognosis may be related to the seasonal variations of calcidiol (the marker of vitamin D status). The lack of latitude effect and the similarity of prognosis for different age groups may be related to higher consumption of vitamin D in food in the north region and to increase of such consumption with age.
BACKGROUND: We have earlier found that the prognosis for several cancers is dependent on season of diagnosis. More recently, both prostate cancer incidence and mortality have been shown to increase with increasing latitude, which probably relates to photosynthesis of vitamin D. METHODS: The 3 year survival of prostate cancerpatients has been analyzed with the Cox regression method for two age groups at different latitudes in Norway. RESULTS:Patients diagnosed during the summer and autumn had the best prognosis (Ralative risk (RR) death 0.8; 95% CI 0.75-0.85). Similar results were observed in three regions of the country that differ with respect to annual fluences of solar UV radiation, incidence rates of squamous cell carcinoma (SCC) and intake of fish. Furthermore, similar relationship between the season and survival was seen among patients </=65 years and >65 years old, although the younger group had a slightly larger advantage of summer and autumn diagnosis. CONCLUSIONS: The seasonal effect on prognosis may be related to the seasonal variations of calcidiol (the marker of vitamin D status). The lack of latitude effect and the similarity of prognosis for different age groups may be related to higher consumption of vitamin D in food in the north region and to increase of such consumption with age.
Authors: Sarah K Holt; Erika M Kwon; Joseph S Koopmeiners; Daniel W Lin; Ziding Feng; Elaine A Ostrander; Ulrike Peters; Janet L Stanford Journal: Prostate Date: 2010-09-15 Impact factor: 4.104
Authors: Adam B Murphy; Yaw Nyame; Iman K Martin; William J Catalona; Courtney M P Hollowell; Robert B Nadler; James M Kozlowski; Kent T Perry; Andre Kajdacsy-Balla; Rick Kittles Journal: Clin Cancer Res Date: 2014-05-01 Impact factor: 12.531
Authors: Katherine D Crew; Elizabeth Shane; Serge Cremers; Donald J McMahon; Dinaz Irani; Dawn L Hershman Journal: J Clin Oncol Date: 2009-04-06 Impact factor: 44.544
Authors: Christine M Barnett; Carrie M Nielson; Jackie Shannon; June M Chan; James M Shikany; Douglas C Bauer; Andrew R Hoffman; Elizabeth Barrett-Connor; Eric Orwoll; Tomasz M Beer Journal: Cancer Causes Control Date: 2010-04-10 Impact factor: 2.506