- Greater exposure to sunlight is associated with lower incidence of renal cancer.
- This association is also seen when latitude is used as an index of exposure to sunlight and vitamin D.
The two studies by Grant were based on the Atlas of Cancer Mortality Rates in the United States4. Kidney cancer mortality rates are highest in the northeast and the upper Midwest and lowest in the southeast and southwest. The elevated rates in the upper Midwest are very likely related to widespread herbicide use5.
There are also two multi-country ecological studies36. The geographical variation of July solar UVB dose was used in the U.S. This index is highly asymmetrical7, being high in the southwest and low in the northeast due to variations in surface elevation and stratospheric ozone layer. In Europe, latitude was used as the index of vitamin D3.
In the global multi-country study, calculated solar UVB doses and cloud cover were used for the vitamin D index. Indices for other risk modifying factors, such as smoking, alcohol consumption were also used in the United States and dietary factors were added to the multi-country studies in order to rule out well-known cancer risk factors that might affect the geographical variation and interpretation of the results. In all of these studies, significant inverse correlations between the vitamin D indices and kidney cancer incidence and/or mortality rate were found.
There has been one reported case-control study of occupational UV and kidney cancer incidence reported. A significant reduction (24%-38%) in the risk of kidney cancer was observed with increasing occupational UV exposure among men who participated in the study. No association between UV exposure and kidney cancer risk was observed among women who participated. When the analyses were stratified by latitude as another estimate of sunlight intensity, a stronger reduction (71%-73%) in the risk of RCC was observed between UV exposure and cancer risk among men who resided at the highest latitudes8.
Non-melanoma skin cancer (NMSC) is often an index of high personal solar UVB irradiance. Thus, it can be used as a long-term vitamin D index in sunnier countries, where people tend to expose sufficient skin to produce a reasonable amount of vitamin D. A study in England found a significant inverse correlation between incidence of NMSC and incidence of kidney cancer among male outdoor workers9.
A cancer registry study using data from Australia, Singapore and Spain found statistically insignificant reduced incidence of kidney cancer after incidence of basal cell or squamous cell carcinoma10. The same result was also found in an ecological study of cancer mortality rates with respect to NMCS mortality rates11.
Page last edited: 01 July 2011
- Boscoe, F. P. Schymura, M. J. Solar ultraviolet-B exposure and cancer incidence and mortality in the United States, 1993-2002. BMC Cancer. 2006; 6264.
- Grant, W. B. An estimate of premature cancer mortality in the U.S. due to inadequate doses of solar ultraviolet-B radiation. Cancer. 2002 Mar 15; 94 (6): 1867-75.
- Grant, W. B. Garland, C. F. The association of solar ultraviolet B (UVB) with reducing risk of cancer: multifactorial ecologic analysis of geographic variation in age-adjusted cancer mortality rates. Anticancer Res. 2006 Jul-Aug; 26 (4A): 2687-99.
- Devesa, S. S. Grauman, D. J. Blot, W. J. Pennello, G. A. Hoover, R. N. Fraumeni, J. F. Jr. Atlas of Cancer Mortality in the United States, 1950-1994. NIH Publication No. 99-4564. 1999 November 8, 2008;
- Hu, J. Mao, Y. White, K. Renal cell carcinoma and occupational exposure to chemicals in Canada. Occup Med (Lond). 2002 May; 52 (3): 157-64.
- Mohr, S. B. Gorham, E. D. Garland, C. F. Grant, W. B. Garland, F. C. Are low ultraviolet B and high animal protein intake associated with risk of renal cancer?. Int J Cancer. 2006 Dec 1; 119 (11): 2705-9.
- Leffell, D. J. Brash, D. E. Sunlight and skin cancer. Sci Am. 1996 Jul; 275 (1): 52-3, 56-9.
- Karami, S. Boffetta, P. Stewart, P. Rothman, N. Hunting, K. L. Dosemeci, M. Berndt, S. I. Brennan, P. Chow, W. H. Moore, L. E. Occupational sunlight exposure and risk of renal cell carcinoma. Cancer. 2010 Apr 15; 116 (8): 2001-10.
- Newton, R. Roman, E. Fear, N. Carpenter, L. Non-Hodgkin’s lymphoma and solar ultraviolet radiation. Data are inconsistent. BMJ. 1996 Aug 3; 313 (7052): 298.
- Tuohimaa, P. Pukkala, E. Scelo, G. Olsen, J. H. Brewster, D. H. Hemminki, K. Tracey, E. Weiderpass, E. Kliewer, E. V. Pompe-Kirn, V. McBride, M. L. Martos, C. Chia, K. S. Tonita, J. M. Jonasson, J. G. Boffetta, P. Brennan, P. Does solar exposure, as indicated by the non-melanoma skin cancers, protect from solid cancers: vitamin D as a possible explanation. Eur J Cancer. 2007 Jul; 43 (11): 1701-12.
- Grant, W. B. An ecologic study of cancer mortality rates in Spain with respect to indices of solar UVB irradiance and smoking. Int J Cancer. 2007 Mar 1; 120 (5): 1123-8.