Squamous cell carcinoma is a health condition that often affects areas of the skin that are regularly exposed to ultraviolet (UV) radiation in sunlight, although there are several other risk factors. Areas that are affected by severe burns, infections or other damage, particularly on a chronic basis, are more likely to be affected by squamous cell carcinoma.
Other risk factors include:
- Fair complexion and light-colored hair
- Regular exposure to the sun over long period of time
- Severe sunburn in early life
- Chemical exposure
- Family History
- Xeroderma pigmentosum
- Immune system suppression
- Human papillomavirus (HPV) infection
These risk factors are linked to squamous cell carcinoma and thought to be involved in the pathogenesis of the condition. Exposure to ultraviolet radiation, in particular, has been exposed as a cause of the condition.
Ultraviolet Light Exposure
The primary risk factor for squamous cell carcinoma is exposure to ultraviolet radiation, which is present in sunlight and the radiation used in tanning beds. The UV radiation can damage the DNA of the skin cells that can affect the cell replication and growth over time.
Some individuals are more susceptible to the damage from UV radiation than others. The color of the skin is an important factor and people with fairer skin are much more likely to be affected than people with darker skin. This is because the level of melatonin in the skin differs and offers more protection for people with darker skin.
It is this concept that accounts for the high incidence of squamous cell carcinoma in Australia and New Zealand. The population is largely of Caucasian origin with predominantly fair skin, which is susceptible to the high level of UV radiation from sunlight in these regions, increasing the risk of skin cancer.
Exposure to some chemicals such as arsenic can increase the risk of developing squamous cell carcinoma. Additionally, people with workplace environments that cause them to be exposed to coal tar, paraffin and particular types of oil can increase the risk of skin cancer development.
Individuals that have been exposed to radiation as a medical treatment have a higher risk of developing squamous cell carcinoma. This is a prominent concern for children that require radiation therapy as a treatment for cancer.
In particular, patients that require psoralen and ultraviolet radiation (PUVA) treatments in the management of severe psoriasis are more likely to be affected by skin cancer.
Some health conditions may be involved in the pathogenesis of squamous cell carcinoma. For example, individuals with the rare congenital condition, basal cell nevus syndrome, also known as Gorlin syndrome, are much more likely to suffer from squamous cell carcinoma and many patients develop several skin tumors over their lifetime.
Immune System Suppression
The immune system plays an important role in the regulation of cells in the body and helps to eradicate abnormal cells with cancerous properties.
For this reason, individuals with a weakened immune system, due to a medical condition or pharmaceutical medication, are more likely to develop squamous cell carcinoma and other skin cancers.