Actinic keratosis is a precursor to which type of cancer?

Actinic keratosis is a skin condition that arises from prolonged sun exposure and is characterized by the presence of rough, scaly patches on sun-exposed areas of the skin. It is considered a precursor to squamous cell carcinoma (SCC), which is a type of skin cancer.

The lesions of actinic keratosis are dysplastic, harboring mutations in the keratinocytes due to UV radiation, leading to abnormal growth. If left untreated, these lesions can progress to invasive squamous cell carcinoma, which is a more aggressive form of skin cancer.

While basal cell carcinoma is also associated with sun exposure, actinic keratosis does not directly progress to it; therefore, it is not considered a precursor to basal cell carcinoma. Melanoma has different risk factors and development pathways that do not include actinic keratosis as a precursor. Similarly, Merkel cell carcinoma is also distinct in its etiology and is not linked to actinic keratosis. Thus, squamous cell carcinoma is the type of cancer most closely associated with actinic keratosis.