Transcript Kara Travis

Sun Exposure May
Help Prevent Cancer
Author: Kara Travis
Advisors: Professor Vandyke and Dr. Weaver
Background on Sun Exposure
• During the 19th and early 20th centuries the sun
was avoided by the upper class
• In the late 1900’s sun exposure became very
popular
• Several years later it was discovered that sun
exposure caused skin cancer
Current Thoughts on Sun Exposure
• New research has established that people who
are following current sun avoidance guidelines
are becoming vitamin D deficient.
• Vitamin D deficiency increases risks for several
types of cancers
• The cancers caused by vitamin D deficiency are
far more deadly, than skin cancers
Scientific Studies
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2002 study by the American Cancer Society
2004 study about prostate cancer
2004 study on non-Hodgkin lymphoma
Numerous additional studies on lung, breast,
and colon cancer
Grant WB. An estimate of premature cancer mortality in the U.S. due to
inadequate doses of solar ultraviolet-B. Cancer 2002; 94:1867-75.
• Estimated the number and types of cancers affected
by sun exposure and the number of premature deaths
due to a lack of UV exposure
• Analyzed cancer mortality rates and UV-B exposure
in geographic locations
• Results: 13 types of cancers are statistically inversely
correlated with sun exposure and an estimated 21,700
premature deaths occur annually
John EG, Dreon DM, Koo J, Schwartz GM. Residential sunlight exposure is
associated with a decreased risk of prostate cancer. J of St Biochem and Mol
Bio. 2004; 89-90 (1-5):549-52.
• Supported the hypothesis that sun exposure
reduces the risk of prostate cancer
• Conducted detailed surveys that adjusted for
age, family history, and dietary intake
• Concluded that the risk of prostate cancer was
reduced by as much as 50% for men who
resided in the southernmost states
Hughes AM, Armstrong BK, Vajdic CM, Turner J, Grulich AE, Fritschi L, et
al. Sun exposure may protect against non-Hodgkin lymphoma: a case-control
study. Int J Cancer. 2004; 112:865-71.
• Discovered that sun exposure provided
protection against non-Hodgkin's lymphoma
• Also a group comparison survey
• This association was strongest in women and
children
The Role of Vitamin D
• 2 ways to get vitamin D (skin synthesis and
diet)
• Sunlight is the major source of vitamin D for
most people
• Vitamin D supplements are not as effective
The Role of Vitamin D
• Deficiency has been reported in 36% of
healthy young adults and 57% of hospital
inpatients
• Vitamin D deficiency is also linked to rickets
in children and osteoporosis and secondary
hyperparathyroidism in adults
How Does Vitamin D Decrease Cancer Risk?
• Vitamin D has been proven to have anti-tumor
activity
• Possible link to inhibition of angiogenesis in
tumors
• Current phase I and II clinical trials for use of
vitamin D in various cancer treatments
The Bottom Line
• Most individuals are not receiving enough
vitamin D
• Sun exposure is the easiest and most efficient
way to produce enough vitamin D
• Sun exposure still causes skin cancers
• Skin cancer has a low mortality rate
Is the sun exposure worth the
risk of skin cancer?
Site of Cancer Est. New Cases
Est. Deaths
% Mortality
Lung and
Bronchus
172.570
163,510
94.7%
Colorectal
149,280
56,910
38.1%
Breast
212,930
40,870
19.2%
Prostate
232,090
30,350
13.1%
NHL
56,390
19,200
34.0%
Melanoma
59,580
7,770
13.0%
What do I tell my patients?
• 5-10 minutes of sun exposure daily on hands
and face
• Still use sunscreen after the 5-10 minutes
• Avoid sunburns, especially in childhood
• Pay close attention to specific groups of
patients (elderly, African Americans, certain
religious backgrounds)
Conclusion
• It is time for clinicians to rethink their harsh
recommendations on sun exposure
• Watch for more published articles and research
studies in the near future
Questions?
References
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Affleck P. Sun exposure and health. Nursing Standard. 2005 Feb 24; 19(47):50-4.
Albert MR, Ostheimer KG. The evolution of current medical and popular attitudes toward
ultraviolet light exposure: part 1. J Am Acad Dermatol. 2002; 47(6): 930-7.
Albert MR, Ostheimer KG. The evolution of current medical and popular attitudes toward
ultraviolet light exposure: part 3. J Am Acad Dermatol. 2003 Dec; 49(6): 1096-1106.
Allen J. Ultraviolet Radiation: How it Affects Life on Earth. NASA. September 6, 2001.
Available at: http://earthobservatory.nasa.gov/Library/UVB/.
American Cancer Society. Cancer Facts and Figures. 2005. Available at
http://www.cancer.org.
BC Decker Inc. Cancer Medicine 5. 2000. Available at:
http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=cmed.section.31749.
Bernardi R, Jonson CS, Modzelewski RA, Trump DL. Antiproliferative effects of 1-alpha,25dihydroxyvitaminD(3) and vitamin D analogs on tumor derived endothelial cells.
Endocrinology. 2002; 143:2508-14.
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Cholecalciferol Council. Understanding Vitamin D. 2005. Available at:
http://www.cholecaciferol-council.com
Craig CR, Stitzel RE. Modern Pharmacology with Clinical Applications. 6th edition.
Baltimore: Lippincott Williams & Wilkins; 2004.
Egan KM, Sosman JA, Blot WJ. Sunlight and reduced risk of cancer: Is the real story vitamin
D? J Nat Cancer Inst. 2005 Feb 2; 97(3):161-3.
Grant WB. An estimate of premature cancer mortality in the U.S. due to inadequate doses of
solar ultraviolet-B. Cancer 2002; 94:1867-75.
Homeier B. Sun Safety. Kids Health for Parents. 2004. Available at:
http://kidshealth.org/parent/firstaid_safe/outdoor/sun_safety.html.
Hughes AM, Armstrong BK, Vajdic CM, Turner J, Grulich AE, Fritschi L, et al. Sun exposure
may protect against non-Hodgkin lymphoma: a case-control study. Int J Cancer. 2004;
112:865-71.
John EG, Dreon DM, Koo J, Schwartz GM. Residential sunlight exposure is associated with a
decreased risk of prostate cancer. J of St Biochem and Mol Bio. 2004; 89-90 (1-5):549-52.
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Kumar V, Abbas AK, Fausto N. Pathologic Basis of Disease. 7th edition. Penn: Elsevier Inc.;
2005.
Senne S. Vitamin D research may have doctors prescribing sunshine. USA Today. 2005.
Available at http://usatoday.com/news/nation/2005-05-21-doctors-sunshine-good_x.htm
Tung RC, Vidimos AT(a). Non-Melanoma Skin Cancer. The Cleveland Clinic. May 30,
2002. Available at:
http://www.clevelandclinicmed.com/diseasemanagment/dermatology/nonmelanoma/nonmela
nomas.htm.
Tung RC, Vidimos AT(b). Non-Melanoma Skin Cancer. The Cleveland Clinic. May 30,
2002. Available at:
http://www.clevelandclinicmed.com/diseasemanagment/dermatology/nonmelanoma/nonmela
nomas.htm.