Skin Cancer Risk Factor Summary Tables

Skin cancer is usually associated with a limited set of risk factors connected to ultraviolet (UV) radiation. These include excessive sun exposure (especially during adolescence), **red or blonde hair,** and **fair (easily sunburned) skin**. These skin cancer risk factors are pillars in the campaign to educate everyone that **sun avoidance** and **sunscreen** are the best measures for prevention. More than 1.3 million skin cancers are diagnosed yearly in the United States. About 1 in 5 of all Americans and 1 in 3 of Caucasians will develop skin cancer in their lifetime (2006, Skin Cancer Foundation).

Although UV exposure from the sun usually plays an important role in basal cell carcinoma and squamous cell carcinoma, it is only part of the story. This web site explores other causes of skin cancer in addition to excessive sun exposure, borrowing from modern research and older theories. If skin cancer is considered to be a "real" cancer, it expands the list of possible risk factors to take into account. At worst, this does no harm because no one wants to have any type of cancer. At best, it can help us to improve our health, discover ways to treat and cure skin cancer, and enjoy a little sunshine.

It is appropriate to be concerned about cancer. **The lifetime risk of developing any invasive cancer is about 42%.** This does not include skin cancer except melanoma. (2006, American Cancer Society). Persons with a history of non-melanoma skin cancer are at increased risk of cancer mortality. Previous basal cell or squamous cell cancer statistically increases the likelihood of dying from any cancer by 30%, according to a 1998 study. Having previous squamous cell or basal cell cancer increases the risk of dying from malignant melanoma by about 3.4 times. These statistics, and the fact incidence levels have rather consistently risen for the past fifty years, highlight that skin cancer is not an isolated disease of excessive ultraviolet radiation exposure.

The tables are based on material presented in the 2002 book How to Prevent and Treat Cancer with Natural Medicine by Dr. Michael Murray, Dr. Tim Birdsall, Dr. Joseph E Pizzomo, and Dr. Paul Reilly. Please see the book (about $12 paperback, easy to find, highly recommended) for references and detailed discussion. The numbers at the right show the associated relative risk and are a help in determining what is most important. For example, smoking is clearly indicated in the first table to be one of the most significant cancer risk factors.

**Table I: Factors Resulting in** **Increased** **Cancer Risk**
Activity	Condition	Relative Risk Factor
1. Smoking	Active ever active high exposure to smoke, especially as a child	10 2 4.5
2. Family history of cancer	Grandparent, parent, sibling	2.5
3. Strong electromagnetic field exposure	occupational, e.g., linesmen	2.0
4. No fish in diet	1 or less serving / week	2.0
5. Red meat consumption	Servings / week: 1 more than 4 Smoked or well done	1.5 2 3
6. Low fruit and vegetable consumption	1 or less serving / day	1.65
7. Obesity		1.5
8. Above average sugar consumption	5 ounces per day is average	1.6
9. Depression		1.4
10. High diesel fume exposure	occupational	1.4
11. Dairy consumption	more than 1 serving / day	1.4
12. Refined flour consumption	more than 1 serving / day	1.3
13. Use omega 6 polyunsaturated oils (especially for cooking)	Corn, safflower, sunflower, sesame	1.4
14. High alcohol consumption	Men >21 drinks /week Women >10 drinks / week	1.2

Scientifically established risk factors for cancer are important because they provide objective evidence of the nature of the disease. This evidence can be used to develop an explanation or model to help understand how to best fight cancer. Risk factors can also directly lead to effective treatment and prevention strategies.

All types of cancer require three factors in order to thrive: cell damage, stimulating hormones, and insufficient immune system defenses. These factors can be modified to effectively fight any type of cancer. The influence of hormones and optimizing immune defenses are strongly influenced by diet and nutrition. In the case of skin cancer, the option of using topical treatments is also feasible because the tumor is accessible. It is also relatively easy to check the progress of treatment strategies with skin cancer.

The next table shows factors that decrease cancer risk. For skin cancer prevention, supplementing folic acid would appear be one of the most effective measures. Increased folate consumption is associated with reduced sun sensitivity and propensity for sunburns, and therefore should result in reduced skin cancer risk. Somewhat surprising is that a simple thing like supplementing selenium appears to be more effective than exercise or consuming large amounts of vegetables. It makes sense to implement the most effective and easiest lifestyle changes first. Of course, using every advantage is even better.

**Table II: Factors Resulting in** **Decreased** **Cancer Risk**
Activity	Condition	Relative Risk Factor
1. Multivitamin with folate (folic acid)	for more than 14 years 5-14 years	0.25 0.8
2. Fluid consumption	more than 2.5 liters / day	0.5
3. Selenium supplement	200 mcg / day	0.5
4. Fish	3 or more servings / week	0.5
5. Cruciferous vegetables (cross shaped leaves)	Broccoli, cabbage family	0.5
6. Legumes, soy milk	more than 5 servings / week	0.5
7. Zinc supplement	RDA=15 mg / day	0.55
8. Exercise	more than 5 hours / week	0.7
9. Vegetables	28 servings / week or more	0.7
10. Vitamin E supplement	400 IU / day	0.7
11. Green tea	3 or more servings / day or 300mg or more extract / day	0.7
12. Garlic	more than 20 grams (5 cloves) / week	0.6
13. Olive oil	1 or more tablespoon / day	0.75
14. Wine	3 - 18 drinks / week	0.8
15. Whole grains	instead of refined flours	0.85
16. Fruit	2 or more / day	0.85

Do these risk factors apply to skin cancer? I think the answer is yes, although the relative risk for each identified factor may be different for skin cancer. Smoking is sometimes cited as a skin cancer risk factor although it has been shown to be a relatively minor one. The common health advice to replace saturated fats in the diet with polyunsaturated oils to lower cholesterol levels probably results in a higher risk for skin cancer more than for other cancers. This is because unstable polyunsaturated fats are easily damaged by sun exposure when incorporated into skin cell structures.

These tables are useful but are not comprehensive, especially for skin cancer. For example, the well established link between excessive sun exposure and skin cancer is missing. Also left out is the beneficial mitigating effect on cancer risk from vitamin D that results from sun exposure. Still other factors sometimes speculated to increase skin cancer incidence include smog, cosmetics, modern farming practices, fluorescent lights, parasites, antibiotics, chlorinated water, mercury amalgam dental fillings, carcinogens, hormones in foods, ozone depletion, various medicines, AM/FM and TV broadcasting signals, cell phones, sunscreens, and airplane travel. The skin cancer overview page provides insights to explain the mechanisms of many of these risk factors. Many of these risk factors have been turned into skin cancer treatment and prevention strategies.

Cancer Risk Factor Tables