How do chemical peels work to treat skin cancer?

Chemical peels act both on the outer skin and the inner layer. The epidermis is exfoliated while the superficial layer of the inner layer (dermis) has increased collagen and elastin formation from fibroblastic activity. Chemical peels work both on reducing fine lines and wrinkles and reversing the effects of sun damaged skin. The actinic keratosis considered premalignant for squamous cell cancer is also greatly reduced.

Many precancers, such as actinic keratosis, are in the epidermis. Because they are on the surface of the skin, fairly invasive chemical peels such as a 30% trichloracetic acid (TCA) peel and also fractionated laser or CO2 laser resurfacing of the skin can take them off. These methods literally burn off the damaged cells, along with the top surface of the skin. (Laser resurfacing is more expensive and not often used as a treatment for AKs.) Both treatments have been shown to decrease the incidence of squamous cell precancers. TCA is also melanotoxic, which means it decimates melanosomes (tiny balloons containing melanin), so it works well on pigment problems such as melasma. Frequently, doctors treat a section of sun-damaged actinic keratosis with a TCA peel spot treatment, rather than treating the entire face and neck. After a peel like this, the patient's skin becomes red and irritated, and after a day or two the damaged stratum corneum starts to peel off. Ironically, it looks and feels like a horrible sunburn.