The Skin Cancer Foundation Journal recently published an article which compiled an ever-growing list of surprising things that increase our risk for skin cancer other than the sun. In their article they explain how some studies show a cause and effect relationship, such as smoking and lung cancer, and others show what is called “association” of two or more behaviors. This is where a behavior may not singularly cause a disease, but it may contribute towards the tendency for the disease.
They discuss the difference between an “absolute risk” and a “relative risk.” Absolute risk means there is a chance of developing a condition over a time period, such as your lifetime. Relative risk is the chance of a group of people or person who has a certain characteristic—such as a person who eats chocolate every day—in developing a disorder or condition in contrast to a group or person who never eats chocolate. If 8 in 100 chocolate eaters develop a particular disease, that’s an absolute risk of 8%. If a study found that eating no chocolate reduced the relative risk of that disease by 50%, then 4 of 100 no-chocolate eaters would develop it, reducing the absolute risk from 8% to 4%.
In determining the risk for skin cancer, we understand that most skin cancers are caused by ultraviolet radiation (UVR). But this article describes a host of other things besides the sun that may increase your chances of getting skin cancer also. So far, many of those things have already been well publicized, such as indoor tanning, family history of skin cancer, previous skin cancers, genetic traits, immunosuppressants, and exposure to certain chemicals. Let’s look at the new risk promoters:
- Drinking White Wine: A 2016 study published in Cancer Epidemiology, Biomarkers & Prevention reported an association between white wine intake and an increase in the risk of invasive melanoma in white men and women. Drinking white wine daily carried a 13% increased risk for skin cancer and in individuals who drank greater than 20 grams of ethanol/day had an increased risk of 50% or higher than non-drinkers. The cancer component in alcohol is called acetaldehyde, a byproduct of alcohol metabolism created when the liver breaks down alcohol. Currently, the National Cancer Institute has listed other cancers in association with alcohol, but melanoma at this time has not yet been added.
- Hydrochlorothiazide (HCTZ): This medication is a diuretic or water pill that helps to lower blood pressure numbers by ridding extra salt and water. A recent study of 80,000 cases of skin cancer in Denmark found that the longer duration a person was taking the medication, the stronger the risk for squamous cell carcinoma (SCC). This risk was 7 times greater than if the person had never taken the drug at all. In conclusion, these scientists stated that eliminating the use of HCTZ could prevent 1 in 10 cases of SCC.
- Endometriosis: This condition is when the uterus isn’t shed during the menstrual cycle but becomes trapped and grows elsewhere in the body. Women with this condition already have an increased risk for certain cancers such as ovarian and non-Hodgkin’s lymphoma. Add to the list skin cancer, especially melanoma. The scientists observed genetic factors that are associated with both endometriosis and melanoma, including red hair, freckles and skin sensitivity to sun exposure. This study of 100,000 French women is an additional study to several others showing a positive association between endometriosis and melanoma.
We’ll look at more skin cancer risk promoters in part two.
References:
- Singer J. Beyond the sun. The Skin Cancer Foundation Journal. 2018;36: 80-83.
