What is the primary risk factor for developing squamous cell carcinoma?

The primary risk factor for developing squamous cell carcinoma is cumulative sun exposure. This type of skin cancer is strongly associated with ultraviolet (UV) radiation from the sun, which damages the DNA in skin cells. Over time, repeated and prolonged exposure to UV rays contributes significantly to skin alterations that can lead to the development of cancerous cells.

While other factors such as genetic predisposition, exposure to chemicals, and skin type do play a role in increasing the risk of skin cancers, they are not as universally impactful as cumulative sun exposure. Individuals with fair skin, for example, are at higher risk due to their lower levels of melanin, which offers some protection against UV damage. However, the overarching factor remains the total amount of sun exposure one has experienced throughout their life, making it the most significant risk factor for squamous cell carcinoma.