The Sun Conundrum

The Sun Conundrum: Balancing Known Risk With Possible Benefit

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Overexposure to the sun’s ultraviolet rays is associated with the development of melanoma, a potentially fatal malignancy. However, data continue to suggest that exposure to sunlight increases vitamin D synthesis, which may help prevent heart disease and cancers of the prostate, colon, and breast. How can you help your patients balance the risk of sun exposure with the benefits of obtaining adequate vitamin D? It’s easier than you think!

Skin cancer is the most common of all cancer types, with more than 2 million skin cancers diagnosed each year in the United States. That’s more than cancers of the prostate, breast, lung, colon combined.[1]

Basal cell and squamous cell cancers are the most common cancers of the skin, and 90% of them are associated with exposure to ultraviolet (UV) radiation from the sun.[1] These cancers usually develop on parts of the body typically exposed to the sun, such as the head and neck, and are more likely to occur in people who accumulate a great deal of sun exposure over their lifetime. If left untreated, these cancers can grow quite large and invade nearby tissues, causing scarring, disfigurement, or even loss of function in some parts of the body.

Melanoma, the third type of skin cancer, is the most difficult to treat and most likely to metastasize. Melanomas can occur anywhere on the body, but are more likely to develop in the trunk (men) or the legs (women). This may occur because these sites are not regularly exposed to sun year-round and are more likely to burn on initial exposure to the sun each year.[2] Although melanoma accounts for less than 5% of skin cancers, it is responsible for almost 75% of deaths from skin cancer.[1]

The incidence of melanoma has more than tripled in the white population during the last 20 years, making it the sixth most common cancer in the United States.[1] The American Cancer Society estimates that approximately 76,250 Americans (44,250 men and 32,000 women) developed invasive melanoma in 2009, with an estimated additional 55,120 or more cases of melanoma in situ.[1,3] The incidence may actually be higher due to underreporting to cancer registries, particularly for tumors that are managed in the outpatient setting.[4] Overall, the lifetime risk of developing melanoma is about 1 in 50 for whites, 1 in 200 for Hispanics, and 1 in 1000 for blacks.[1] However, when skin cancer does occur in black patients, they often present with an advanced stage and a worse prognosis than white patients.[5]

Although the median age at diagnosis is 61, melanoma is the most common cancer in women younger than 39 years and is second only to breast cancer.[1] As of 2009, the most rapid increases in melanoma occurrence are among young white women (3% annual increase since 1992 in those between 15 and 39 years of age) and older white men (5.1% annual increase since 1975 in those 65 and older).[1]

Melanoma is one of the most costly cancers to diagnose, follow, and treat, with care for a patient with stage IV melanoma estimated to cost approximately $11,500 per month.[6] There is a significant cost decrement when melanoma is diagnosed at an earlier stage, with a late-stage lesion being approximately 2200% more expensive to diagnose and treat than an early in situ melanoma and 1000% more expensive than a stage I tumor.[7]

Treatments for melanoma range from surgical excision (stage I) to adjuvant treatment with interferon, chemotherapy, radiation therapy, and, at times palliative surgery, at more diffuse stages.[8]  Ipilimumab and vemurafenib are two newer  FDA-approved drugs that may extend survival rates.[1]

Who’s at Risk?

Two major contributing factors place patients at high risk of developing melanoma. The first is prolonged exposure to UV radiation, which is estimated to cause 30% of malignant melanomas.[10] In addition to sun exposure, however, other factors also confer a high risk. These include a fair complexion, excessive childhood sun exposure and blistering childhood sunburns, a family history of melanoma, the presence of a changing mole or evolving lesion on the skin, and, importantly, older age (Box 1).[11,12]

Compared with any other age group, patients older than 65 are more likely to be diagnosed with, and to die from, melanoma. Therefore, elderly patients should be targeted for melanoma prevention, as treatment options in this age group are often limited because of comorbid medical conditions, an inability to tolerate adverse medication effects or toxicity, and the increased likelihood of drug interactions.[13,14]

The Importance of Screening

Melanoma is classified using the American Joint Committee’s TNM system: “T” stands for tumor; “N” for the cancer has spread to the lymph nodes; and “M” for metastasized to distant organs.  The T rating also has numbers (0-4) to describe the tumor’s thickness. The N rating also assigns numbers (0-3) based on if the cells have spread to any lymph nodes or are in the lymphatic channels.[15] This helps the cancer care team determine the patient’s prognosis more accurately.  The good news is that when melanoma is detected and treated in its early stages, the chances for long-term, disease-free survival are excellent. But if left untreated, melanoma is much more likely than basal or squamous cell cancer to metastasize and can be very difficult to treat.

Approximately 40% of medical office visits in the United States are to a family clinician or internist,[16] so primary care practitioners (PCPs) are in a unique position to perform cancer screenings and to provide prevention counseling. Encouragingly, PCPs do find most melanomas at an early stage, although not quite as often or as accurately as dermatologists.[17] Unfortunately, the rate of skin examinations in primary care falls far behind screening for breast, cervical, and colorectal cancer.[16]

In 1985, the acronym ABCD was released as a tool to help both nondermatologists and the public identify the characteristics of early, superficial melanomas.[19] In the years since 1985, the ABCD acronym has changed to ABCDE (Box 2).[19] Since their introduction, some debate has emerged over the chosen criteria; however, they are still strongly supported by the literature.[20] You may find it helpful to go over these criteria with your higher-risk patients as you perform a skin examination and encourage them to look for the “ABCDE” at home between visits. See How to Perform a Skin Self-Exam.

Prevention

The American Cancer Society continues to state that aside from a full-body examination, the best melanoma prevention tools are sun protection and sun avoidance. However, according to data published by St. Louis University, less than one-third of people routinely use sun protection.[20] Emphasize to patients the importance of avoiding unprotected exposure to the sun and other sources of UV light, such as sunlamps and tanning beds. Stress the importance of “Slip! Slop! Slap! Wrap!”—a catch phrase reminding them to “slip on a shirt, slop on sunscreen, slap on a hat, and wrap on sunglasses.” The Skin Cancer Foundation recommends using a sunscreen with an SPF 15 or higher as one important part of a complete sun protection regimen. Sunscreen alone is not enough, however (Box 3).[21] See Facts About Sunscreens.

In addition to ABCDE screening, patient education is key to decreasing the morbidity and mortality associated with melanoma. Data suggest that when PCPs provide patients with photos of suspicious lesions, show them what to look for at home, and offer written guidelines for avoiding excess sun exposure, patients are more likely to examine their skin at home and practice sun-protective behavior.[22] And it’s important to start the message early. By 20 years of age, people have experienced more than half of their lifetime of sun exposure. Try placing posters and handouts [Free Materials Link] in the waiting and examination rooms and distributing these tools as patients leave the office. Run a sun-safety video in the waiting room. Use the outdoor activities of a particular season as an opportunity to reinforce the message (skiing, walking, swimming). Your staff can help you reach a large number of patients in this way, leaving you to focus on the patients who are at particularly high risk.

Higher-risk patients can also be referred to genetic counseling and/or screening. According to guidelines published in 2009, families or individuals with a hereditary pattern of melanoma should see a genetics counselor.[23] Such patients might also wish to be tested for mutations of cyclin-dependent kinase inhibitor 2A (CDKN2A). Up to 40% of patients with hereditary melanoma have CDKN2A mutations, which are also associated with an increased risk for pancreatic cancer. The indicators of a hereditary pattern are 3 or more primary melanomas, or at least 1 case of melanoma and 2 or more other diagnoses of melanoma and/or pancreatic cancer among first- or second-degree relatives on the same side of the family.

The Conundrum

Many of your patients already practice good sun protection when they swim, golf, or sit out on the deck. But how can you reinforce these practices when patients come to you with questions about the link between vitamin D, sunshine, and disease prevention? While it’s too early to draw any definitive conclusions, adequate amounts of vitamin D do appear to be associated with the prevention of certain cancers and heart disease. Unfortunately, data from the National Health and Nutrition Examination Survey (NHANES) showed that at least 40% of men and women in the United States have lower-than-optimal levels of vitamin D for at least part of the year.[24] As vitamin D is partially activated when the sun’s UV rays help convert cholesterol compounds in the skin to active vitamin D, it seems intuitive that the more time patients spend exposed to UV light, the more vitamin D they’ll produce! However, as vitamin D synthesis is dependent on geography, season of the year, and skin color, prolonged sun exposure may never produce sufficient vitamin D. In fact, North Americans who live north of 42 degrees latitude—which would include Boston, Seattle, and Milwaukee—don’t ever absorb enough UVB to produce vitamin D, regardless of how much time they spend outdoors.[25] But if they are high-risk for melanoma, they could absorb enough UVB to add to the melanoma burden.

When it comes to sun exposure and vitamin D, there is a very fine line between enough sun and too much sun. People should be encouraged to get outside and be active as long as they recognize the dangers of overexposure to the sun. The American Academy of Dermatology is emphatic in its advice that everyone avoids unprotected sun exposure and obtains their vitamin D from foods and supplements.[26] The Office of Dietary Supplements at the National Institutes of Health concurs,[27] as does the American Cancer Society.[28] You might emphasize to patients that while prolonged exposure to UV light is one [albeit dangerous] way to obtain vitamin D, there is a better and safer route. Try reminding them that in the United States, there are no seasonal or geographic limitations on natural and fortified food sources of vitamin D, which include salmon, mackerel, and other fish; fish oils; and egg yolks, as well as fortified milk, cereals, and juices.

Patients who insist on sunbathing for aesthetic purposes may be more difficult to sway. While expecting patients to willingly give up all recreational sun exposure is draconian and unrealistic, perhaps you can strike a compromise that balances their need for tanning with a liberal dose of common sense—and sunscreen!

Jill Shuman, MS, ELS
Updated on May 8, 2012
Published on May 10, 2010

 

References

  1. American Cancer Society. Cancer Facts and Figures 2012. Atlanta: American Cancer Society. http://www.cancer.org/acs/groups/content/@epidemiologysurveilance/documents/document/ acspc-031941.pdf. Accessed May 7, 2012.
  2. Whiteman DC, Watt P, Purdie DM, et al. Melanocytic nevi, solar keratoses, and divergent pathways to cutaneous melanoma. J Natl Cancer Inst. 2003;95(11):806-812.
  3. Jemal A, Siegel R, Ward E, et al. Cancer statistics, 2009. CA Cancer J Clin. 2009;59(4):225-249.
  4. Cockburn M, Swetter SM, Peng D, et al. Melanoma underreporting: why does it happen, how big is the problem, and how do we fix it? J Am Acad Dermatol. 2008;59(6):1081-1085.
  5. Hu S, Sora-Vento RM, Parker DF, Kirsner RS. Comparison of stage at diagnosis of melanoma among Hispanic, Black, and White Patients in Miami-Dade County, Florida. Arch Derm. 2006;142:704-708.
  6. Davis KL, Mitra D, Kotapati S, et al. Direct economic burden of high-risk and metastatic melanoma in the elderly: evidence from the SEER-Medicare linked database. Appl Health Econ Health Policy. 2009;7(1):31-41.
  7. Alexandrescu DT. Melanoma costs: a dynamic model comparing estimated overall costs of various clinical stages. Dermatol Online J. 2009;15(11):1.
  8. Melanoma skin cancer. American Cancer Society Website. http://www.cancer.org/Cancer/SkinCancer-Melanoma/DetailedGuide/melanoma-skin-cancer-treating-by-stage.  Updated January 11, 2012. Accessed May 7, 2012.
  9. Triesman J, Garlie N. Systemic therapy for cutaneous melanoma. Clin Plast Surg. 2010;37(1):127-146.
  10. Torrens R, Swan BA. Promoting prevention and early recognition of malignant melanoma. Dermatol Nurs. 2009; 21(3):115-122.
  11. Cho YR, Chiang MP. Epidemiology, staging (new system), and prognosis of cutaneous melanoma. Clin Plast Surg. 2009;37(1):47-53.
  12. Amercian Cancer Society. Why you should know about Melanoma.
    http://www.cancer.org/acs/groups/content/documents/document/acspc-024621.pdf. Updated July 2008. Accessed May 7, 2012.
  13. Geller AC, Miller DR, Annas GD, et al. Melanoma incidence and mortality among US whites, 1969-1999. JAMA. 2002;288(14):1719-1720.
  14. Swetter SM, Geller AC, Kirkwood JM. Melanoma in the older person. Oncology (Williston Park). 2004;18(9):1187-1196.
  15. Detailed Guide: Skin Cancer – Melanoma: How is melanoma staged? American Cancer Society Web site. http://www.cancer.org/Cancer/SkinCancer-Melanoma/DetailedGuide/melanoma-skin-cancer-staging. Updated January 11, 2012. Accessed May 7, 2012.
  16. Geller AC, O’Riordan DL, Oliveria SA, et al. Overcoming obstacles to skin cancer examinations and prevention counseling for high-risk patients: results of a national survey of primary care physicians. J Am Board Fam Pract. 2004;17(6):416-423.
  17. Chen SC, Pennie ML, Kolm P, et al. Diagnosis and managing cutaneous pigmented lesions: primary care physicians versus dermatologists. J Gen Int Med. 2006;21:678-682.
  18. Friedman RJ, Rigel DS, Kopf AW. Early detection of malignant melanoma: the role of physician examination and self-examination of the skin. CA Cancer J Clin. 1985;35(3):130-151.
  19. Abbasi NR, Shaw HM, Rigel DS, et al. Early diagnosis of cutaneous melanoma: revisiting the ABCD criteria. JAMA. 2004;292(22):2771-2776.
  20. Sun Protection Outreach Teaching by Students. Statistics and facts on skin cancer. St. Louis University School of Medicine Web site. http://dermatology.slu.edu/spots/files/SPOTS%20Manual%203%20Statistics.pdf. Accessed May 7, 2012.
  21. Prevention Guidelines. Skin Cancer Foundation Web site. http://www.skincancer.org/prevention-guidelines.html. Accessed May 7, 2012.
  22. Hay JL, Oliveria SA, Dusza SW, et al. Psychosocial mediators of a nurse intervention to increase skin self-examination in patients at high risk for melanoma. Cancer Epidemiol Biomarkers Prev. 2006;15(6), 1212-1215.
  23. Leachman SA, Carucci J, Kohlmann W, et al. Selection criteria for genetic assessment of patients with familial melanoma. J Am Acad Dermatol. 2009;61(4):677.e1-e14.
  24. Looker AC, Dawson-Hughes B, Calvo MS, et al. Serum 25-hydroxyvitamin D status of adolescents and adults in two seasonal subpopulations from J Am Acad Dermatol NHANES III. Bone. 2002;30(5):771-777.
  25. Cranney C, Horsely T, O’Donnell S, et al. Effectiveness and safety of vitamin D in Relation to Bone Health. Evidence Report/Technology Assessment No. 158 prepared by the University of Ottawa Evidence-based Practice Center under Contract No. 290-02.0021. AHRQ Publication No. 07-E013. Rockville, MD: Agency for Healthcare Research and Quality, 2007.
  26. Position statement on Vitamin D. American Academy of Dermatology and AAD Association. http://www.aad.org/forms/policies/uploads/ps/ps-vitamin%20d.pdf. Updated November 14, 2009. Accessed May 7, 2012.
  27. Dietary Supplement Fact Sheet: Vitamin D. Office of Dietary Supplements Website. http://dietary-supplements.info.nih.gov/factsheets/vitamind.asp#en5. Accessed May 7, 2012.
  28. Common questions about diet and cancer. American Cancer Society Website. http://www.cancer.org/docroot/PED/content/PED_3_2X_Common_Questions_About_ Diet_and_Cancer.asp. Updated January 11, 2012. Accessed May 7, 2012.