According to the Skin Cancer Foundation, there have been a lot of people affected by skin cancer than all other types of cancer combined over the past three decades. Melanoma is the most common cancer which affect Americans. However, recent statistics showed that these statistics may be skewed.
There was a study published in 2009 in the British Journal of Dermatology which discovered that sun exposure may not be the sign of skin cancer. Well, not in the way that we understand it. According to them, the lesions of skin cancer in the USA does not correspond truly malignant lesions and was discovered that health professionals are quick to diagnose patients with cancer even if the moles are non-cancerous. The distribution of the lesions did not correspond to the sites of the lesions which care caused by solar exposure. The findings led to a reconsideration of the ‘early’ lesions treatment, a search for better diagnostic methods to distinguish them from malignant melanomas, re-evaluation of the UV radiation, as well as the recommendations for protection. A new direction in the search for its cause also led to rethinking. Moreover, the stable cases of deaths which have been caused by cancer didn’t correspond to the increasing number of patients who suffered from the disease.
There was a review of 4,000 cases which discovered that there has been an increase of .39 to 13.91 cases annually per 100,000 between 1991 and 2004. The increase was because of over-diagnosis of non-cancerous lesions. There has not been changes in the combined incidence of the other stages of the disease, and the mortality raised from 2.16 to 2.54 cases per 100,000 annually. The great increase is due to diagnostic drift that classifies the benign lesions as stage 1 melanoma.
The connection between melanoma and sun exposure
Research groups have been explaining how sun exposure causes skin cancer. However, this is not completely true. Sunburns cause damage which can contribute to skin abnormalities and melanoma, but researches have shown that the high skin rates affect a specific population, and those are indoor workers with light skin. There is almost no evidence which can support the claim of melanoma being caused by sunburns. There were couple of studies which discovered that sun exposure allows the body adapt to the harsh effects of the sun while boosting the levels of vitamin D. it is a vitamin which fight cancer and it is produced by the body when the skin catches some rays.
One article published in a prestigious journal named The Lancet said that the risks of melanoma are decreased with greater exposure to sun and can be increased by sunscreens. The indoor workers receive 3-9 time less UV exposure than the workers who work outside, and the indoor workers have increasing rates of melanoma.
The sun produces UVA and UVB rays and they both cause burning and tanning of the skin. The UVB rays allow the body produce vitamin D, but burn the skin more quickly, compared to the UVA rays which penetrate the skin deeply and lead to photoaging, wrinkles, and skin cancer. Most of the windows block the UVB rays, but allow the UVA rays penetrate through them.
The researchers from the latest skin cancer and sun exposure studies hypothesized that one factor involves indoor exposure to UVA (321-400nm) passing through the windows and it can cause mutations and can even break down vitamin D3 which has been formed after outdoor UVB (290-320nm) exposure, while the other factor involves low levels of cutaneous vitamin D3.
When vitamin D3 is formed, the melanoma cells convert to a hormone called 1,25-dihydroxyvitamin D3, or calcitiol. It causes growth inhibition as well as apoptotic cell death in vivo and in vitro.
The researchers actually agree that intermittent outdoor overexposure to UV and sunburns can initiate CMM, or cutaneous malignant melanoma, but they propose that increase exposure to UVA and inadequately maintained cutaneous levels of vitamin D3 promote CMM.
Use the sun for your advantage
The aim is to spend time on sun exposure as much as possible and never get burned. If your sin is light, then you should be exposed only 10-20 minutes during the peak hours of UVB rays, between 10 am and 1 pm. In case your skin is darker, then your body will need more time to reach the peak of vitamin D production.
The rays are stopped from penetrating in the skin with sunscreen and long-sleeved clothing, thus make sure you give the sun some real estate and expose your arms and/or shoulders when you are outside. If you are going to be exposed to the sun for a longer period of time, then soak it up for a bit, cover up, or apply a homemade sunscreen in order to protect it from burning.