The Good News: Colon Cancer Update

The Good News: Colon Cancer Update

by Patricia E. Reykdal and Donald L. Smith

Colon cancer is the third most common cancer in the United States and the second deadliest with 57,000 Americans expected to die from it this year. Only lung and prostate cancer in men, and lung and breast cancer in women have a higher incidence rate. Only lung cancer has a higher mortality rate.

The human colon is a tube-shaped organ approximately 4 feet in length extending from the end of the small bowel to the anus. The colon’s three main functions are to digest and absorb nutrients from food, concentrate fecal material by absorbing the fluid from it, and store and control evacuation of fecal material.

The majority of colon cancers begin with an adenomatous polyp, which is a cluster of abnormal cells in the glands covering the inner wall of the colon. Over time, these growths enlarge and become adenocarcinomas—colon cancers. Tragically, colon cancers usually occur before age 40, and most experts historically believe that the death rate from this disease can be significantly reduced by the following:

• Better and earlier screening, especially of individuals with a family history of colon cancer, with programs utilizing FOBT (Fecal Ocult Blood Testing), rectal exams and colonoscopy.
• Adopting a low-fat, high-fiber diet.
• Maintaining an optimal weight level because being overweight is a significant risk factor.
• Eliminating smoking because there is a proven link between cigarette smoking and colon cancer.
• Eliminating overuse of NSAIDs (nonsteroidal anti-inflammatory drugs such as aspirin).

A recent British Medical Journal article titled “Sunlight and Mortality from Breast, Ovarian, Colon, Prostate, and Non- Melanoma Skin Cancer; A Composite Death Certificate Based Case-Control Study” by Freedman, et al of the National Cancer Institute showed that individuals who lived in high-sunlight areas of the United States and had occupations that allowed them to be outside during part of the day had 20 percent to 30 percent less mortality from colon cancer (verified by death certificates) than individuals who lived in low-sunlight areas of the country and had occupations that required them to work inside. [Note: The reduction in colon cancer mortality was attributed to the “link” between sunlight exposure and vitamin D levels.]

The authors concluded that “In this exploratory study, unlike mortality from non-melanoma skin cancer, mortality from female breast cancer and colon cancer were negatively associated with both residential and occupational sunlight.”

Since the number of deaths (1,000 per year) from non-melanoma skin cancer—basal cell carcinoma and squamous cell carcinoma—was positively associated with overexposure to residential and occupational sunlight, let’s take a look at whether the benefits associated with more sunlight exposure outweighs the risks.

The table below shows there would be a net savings of 11,200 lives each year if there was a 20-percent reduction in colon cancer and 16,800 lives saved each year if there was a 30-percent reduction. Thus, there would be 56 lives saved each year from death due to colon cancer as a result of more sunlight (UVR) exposure for every one life lost due to non-melanoma skin cancer as a result of sunlight (UVR) overexposure each year-trade-off that definitely would appeal to most people.

The data clearly shows that individuals who live in low-sunlight areas of the United States have a much higher relative risk of death due to colon cancer; however, changing the odds doesn’t require moving their residences or changing their occupations. Individuals who live in low-sunlight areas and work indoors can gain the same advantage as those who live in high-sunlight areas and work outdoors by simply visiting their friendly and convenient local indoor tanning salon once or twice each week year-round.

The bottom line is that this information supports the premise that the incontrovertible benefits of sensible, moderate and responsible exposure to ultraviolet radiation in the controlled and consistent environment of an indoor tanning salon outweigh the minimal and manageable risks involved. Moreover, the advice given to the American public by the sunscreen industry, the dermatology community and state and federal regulatory agencies to reduce UVR exposure, slather on a sunscreen every day of the year and avoid patronizing an indoor tanning salon can be seen to play a significant role in increasing the risk of premature death due to colon cancer each year.

The indoor tanning industry can take pride in the fact that we are the only entity telling the American public the truth about both the risks associated with overexposure and underexposure to ultraviolet radiation. We must insist that we be allowed to administer exposure schedules that neither overexpose nor underexpose clients to ultraviolet radiation. Additionally, we must point out that attaining and maintaining optimal vitamin D levels— >80 nmol/L— can best be accomplished by ingesting 1,000 IU of vitamin D (food or supplements) each day and patronizing an indoor tanning salon once or twice each week year-round.