What is the primary cause of skin cancer associated with UV exposure?

The primary cause of skin cancer associated with UV exposure is DNA damage in skin cells. Ultraviolet (UV) radiation from the sun or artificial sources can penetrate the skin and cause mutations in the DNA of skin cells. These mutations can disrupt normal cellular processes, including those that regulate cell growth and division, potentially leading to uncontrolled cell proliferation, which is characteristic of cancer.

When skin cells are damaged by UV radiation, their ability to repair itself is compromised, making it easier for mutations to accumulate. Over time, these genetic changes may lead to the development of certain types of skin cancer, such as melanoma, basal cell carcinoma, or squamous cell carcinoma.

Increased melanin production is a response of the skin to UV exposure, acting as a natural defense mechanism by darkening the skin to absorb and dissipate UV radiation. However, while this can provide some protection, it does not address the underlying risk associated with DNA damage. Excessive moisture in the skin and hyperkeratosis, which refers to thickening of the outer layer of the skin, are not direct causes of skin cancer related to UV exposure. Instead, they are conditions that may occur as a result of other factors unrelated to the DNA-damaging effects of UV radiation.