Keratinocyte cancer triggering factors

Ultraviolet (UV) radiation from sunlight is the most significant preventable risk factor for KC. The skin accumulates UV damage over a lifetime. This includes sunburn in childhood and regular daily exposure, both of which can encourage harmful changes in skin cells. People who live in very sunny regions, work outdoors or spend long periods outside without protection face an increased risk.

The use of devices that emit artificial UV radiation, such as sunbeds, tanning booths and sunlamps, raises the risk of KC. Use at young ages appears to be particularly harmful. People who have used these devices should be especially attentive to sun protection and regular skin checks.

Smoking is linked with an increased risk of SCC. It can contribute to chronic skin inflammation, impair skin healing and reduce the body’s ability to repair DNA damage. Where smoking and UV exposure occur together, the combined effect further increases risk.

Individuals with naturally fair or pale skin, light hair and light-coloured eyes have less melanin, which provides some natural defence against UV radiation. As a result, they are more likely to develop KC. Although people with darker skin tones have a lower risk overall, they are not fully protected and should still take steps to avoid UV damage.

People who have had a previous skin cancer or precancerous lesion, such as actinic keratosis, face a higher chance of developing KC in the future. Earlier cell damage can create areas of vulnerability where further abnormal changes may occur.

KC becomes more common with age. This is partly due to the cumulative effects of UV exposure and partly because the skin’s ability to repair DNA damage weakens over time. While young adults can develop KC, older adults represent the majority of cases.

Some examples are long-term use of immunosuppressants, specific anticancer medicines and certain antifungal treatments which may increase the skin’s sensitivity to light.

Men have higher rates of KC than women. This may relate to greater lifetime sun exposure, particularly through outdoor work or recreational activities, and differences in protective behaviours. Regardless of the cause, being male is recognised as a contributing factor.

A weakened immune system reduces the body’s ability to detect and remove abnormal cells. People who have had organ transplants, those taking long-term immunosuppressive medicines and individuals with certain medical conditions that impair immunity have a significantly higher risk of KC. In some cases, cancers may behave more aggressively.

Exposure to certain chemicals can also raise the risk of KC. Long-term contact with arsenic, tar, soot, creosote and other aromatic hydrocarbons is of particular concern. Occupations involving industrial chemicals, mining or smelting may carry elevated exposure risks and require additional protective measures.

Ionising radiation can cause lasting changes in skin cells even decades after treatment. This is why long-term monitoring for people who received radiation therapy in the past is important.

Areas of the skin that have been severely damaged, for example through burns, long-standing wounds or chronic inflammation, may become more prone to cancerous change. Repeated cell turnover and persistent irritation increase the likelihood of abnormal cell development.

There are certain types of HPV which can contribute to the development of KC, particularly SCC. This link is more noticeable in immunocompromised individuals or in skin areas where infection persists. HPV is not usually the sole cause, but may add to the risk in combination with other factors.

Individuals with naturally fair or pale skin, light hair and light-coloured eyes have less melanin, which provides some natural defence against UV radiation. As a result, they are more likely to develop KC. Although people with darker skin tones have a lower risk overall, they are not fully protected and should still take steps to avoid UV damage.

Some examples are long-term use of immunosuppressants, specific anticancer medicines and certain antifungal treatments which may increase the skin’s sensitivity to light.