The skin lesions called early
beginnings of skin cancer are those with a proven ability to evolve into
skin cancer. Actinic keratoses are one of a group of keratinocyte
lesions that are early beginnings of skin cancer, which includes:
- Keratoses
associated with exposure to arsenic, tar or chemical carcinogens;
- Keratoses
associated with chronic exposure to ionizing (x-ray) or infrared
(heat) radiation;
- Keratoses
associated with human papillomavirus infection (Bowenoid papulosis);
- Keratoses
that develops at the site of a scar; and,
- Leukoplakia, a premalignant plaque
on mucosal surfaces—e.g., the tongue.
Of this group of lesions that are early
beginnings of skin cancer, actinic keratoses are by far the most common.
The skin cancer into which AKs can
progress to is invasive squamous cell carcinoma
(SCC), a cancer
of the keratinocytes and the second most common cancer of the epidermis.
The frequency of SCC varies in different geographic areas of the world
and the United States, but is strongly associated with (1) sunny
climate, and (2) large populations of fair-skinned people. The most
significant causative and predisposing factors for SCC are the same as
for actinic keratoses—long-term exposure to sunlight and fair skin.
