Be careful about sunbath

Skin cancer is the most common form of cancer in the United States. More than 3.5 million skin cancers in over two million people are diagnosed annually. In Asians, skin cancer represents approximately two to four percent of all cancers.

There are 3 types of skin cancer - basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and melanoma.

Basal cell carcinoma is the most common form of skin cancer, an estimated 2.8 million are diagnosed annually in the US. BCCs are rarely fatal, but can be highly disfiguring if allowed to grow.

Squamous cell carcinoma is the second most common form of skin cancer. An estimated 700,000 cases of SCC are diagnosed each year in the US.

Amongst the three, melanoma has the lowest incidence, accounts for less than five percent of skin cancer cases. But from 1970 to 2009, the incidence of melanoma increased by 800 percent among young women and 400 percent among young men in the US. And it is also the most dangerous. It is easy to spread to other organs and has the highest mortality. Although melanoma accounts for less than five percent of skin cancer cases but the vast majority of skin cancer deaths.

The overall 5-year survival rate for patients whose melanoma is detected early, before the tumor has spread to regional lymph nodes or other organs, is about 98 percent in the US. The survival rate falls to 62 percent when the disease reaches the lymph nodes, and 15 percent when the disease metastasizes to distant organs.

More than 85 percent of skin cancers are associated with exposure to ultraviolet (UV) radiation from the sun. The sun's ultraviolet rays can induce skin cells undergo gene mutations. And the longer the exposure to UV, the higher the chance of suffering from skin cancer. One or more blistering sunburns in childhood or adolescence can cause more than double a person's chances of developing melanoma later in life.

There are two wavelengths for UV, UVA and UVB. UVA can cause skin aging, wrinkles skin tanning and also inducing skin cancer while absorbing excess UVB can burn skin and this is also one of the main causes of skin cancer. In short, more than 90 percent of the visible changes commonly attributed to skin aging are caused by the sun. And so be careful when you are sunbathing!