Which type of skin cancer is the most common and least severe?

Basal cell carcinoma is the most common and least severe type of skin cancer. It originates in the basal cells, which are found in the lower part of the epidermis, the outer layer of the skin. This type of cancer typically arises due to prolonged exposure to ultraviolet (UV) radiation from the sun or tanning beds. While basal cell carcinoma can cause local damage and disfigurement if left untreated, it rarely metastasizes or spreads to other parts of the body, making it less severe than other forms of skin cancer.

In contrast, squamous cell carcinoma, while still generally treatable, has a higher risk of metastasis than basal cell carcinoma. Melanoma is the most aggressive and dangerous type of skin cancer due to its potential for rapid spread. Adenocarcinoma primarily affects glandular tissues and is unrelated to skin cancer, thus making it an outlier in this context. Understanding the severity and behavior of these cancers is crucial for effective diagnosis and treatment strategies.