Definition

Squamous Cell Carcinoma (SCC) is the second most common form of skin cancer. It usually appears in areas of the body that are exposed to Ultraviolet (UV) radiation from the sun or sunbeds. Sun-exposed skin includes the head, neck, ears, lips, legs and feet.

Squamous cell carcinoma grows quite slowly contrary to other types of skin cancer, it may spread through metastases to the tissues, the bones and nearby lymph nodes, where it could be difficult to treat. When the diagnosis is made early, it is easy to treat it.

The following people are more likely to develop squamous cell carcinoma:

  • Older age
  • Male gender
  • With fair skin
  • With blue, green or grey eyes
  • With blonde or red hair
  • Spending time outdoors, exposed to the solar UV radiation
  • Tanning beds and bulbs
  • Long-term exposure to chemical substances, such as arsenic in the water
  • With Bowen’s disease, HPV, HIV, or AIDS
  • Exposed to radioactivity
  • With an inherited DNA condition

Symptoms

Squamous cell carcinoma usually begins as a dome-shaped, red, scaly bump. It is usually rough and crusty, and can bleed easily when scraped. Large growths may cause itching or hurt. It may also pop through scars or chronic skin sores, so check for any changes and report them to your doctor.

What are the causes of Squamous Cell Carcinoma?

The majority of invasive cutaneous squamous cell carcinomas are caused by chronic exposure to ultraviolet radiation, which destroys the DNA of the skin’s cells, especially in people with fair skin. Squamous cell carcinoma most often results from actinic keratoses and less often from Bowen’s disease. Other risk factors for developing invasive squamous cell carcinoma include:

  • Genetic predisposition for skin cancer.
  • Smoking – especially in the case of squamous cell carcinoma on the lip.
  • Thermal burn marks.
  • Long-term leg ulcers.
  • Immunosuppression from drugs, such as cyclosporine or azathioprine, especially in organ transplant recipients.
  • High risk types of Human Papillomavirus Infection (HPV)

Precancerous lesions that are the first step in SCC

Presence of cutaneous tumours or precancerous lesions, most of them resulting from cumulative sun damage, can are associated with the later development of squamous cell carcinoma (SCC).

Actinic or Solar Keratoses

These lesions are more common among older people. The colour of these lesions is red or brown, with a maximum diameter of 1 cm. They are found on sun-exposed areas of the body. Many specialists support that they represent the initial form of squamous cell carcinoma. According to studies, up to 10% of untreated actinic keratoses advance to cancer within ten years. It has been estimated that 40% to 60% of squamous cell carcinomas (SCCs) begin as actinic keratoses (AKs).

Actinic Cheilitis

Actinic cheilitis is a form of dangerous actinic keratosis that occurs on the lower lip, which is characterised by dryness, cracks and pale or white scaly lips. Its location is related to the areas of maximum sun exposure. If not treated promptly, actinic cheilitis can lead to squamous cell carcinoma (SCC) on the lip, which is actually aggressive and has poor prognosis.

Leukoplakia

Arising in the mucous membranes of the mouth, as white patches on the tongue, gums, the buccal mucosa or elsewhere inside the mouth cavity have the potential to develop into squamous cell carcinoma. Chronic irritation is a common cause, inflammatory diseases of the oral cavity, tobacco and alcohol, frequent injuries from dentures, etc. Sometimes they may even be caused by a long-time habit of biting the inside of the lips. However, leukoplakias on the lips are mainly caused by long-term exposure to solar radiation.

Bowen’s Disease

Today it is considered an early, non-invasive stage of squamous cell carcinoma. It appears as a persistent patch resembling psoriasis or eczema, a red, scaly, and dry patch. If untreated, it may progress. Bowen’s disease is caused by exposure to the sun or to arsenic, but other factors, including chemical carcinogens, radiation, genetic factors, and trauma may also play a role. The human papillomavirus (HPV), which is mainly transmitted through sexual contact, is one of the manifestations of the disease affecting the genitals. HPV can also arise in the mucous membranes of the nose and mouth as well as on the skin. It has been demonstrated that the HPV vaccination is particularly effective in preventing and thus reducing genital warts, cervical cancer, and Bowen’s disease.

Treatment

The type of treatment a patient will receive depends on where the tumour is and how far the cancer has spread. Squamous cell carcinoma is often treated with:

  • Excision: This is a surgical procedure that can be performed by the doctor during a visit at the medical office. It includes local anaesthesia of the area and removal of the tumour and part of the skin surrounding the tumour. If cancer cells are identified in nearby tissues through biopsy, more skin will have to be removed. This is a common method to treat squamous cell carcinoma, and it is often the first therapeutic choice.
  • Radiation: This treatment is typically reserved for cases of squamous cell carcinoma in which surgical excision cannot be performed or it is not the best option. A patient may require 15 to 30 radiation therapy sessions.

When squamous cell carcinoma is identified in a very early stage, it can be treated with:

  • Electrodesiccation and curettage (Electrosurgery): This treatment method consists of two steps. Initially the dermatologist removes – scrapes off the tumour. Following this, electric energy is used to destroy any remaining cancer cells. These two steps are repeated.
  • Photodynamic therapy (PDT): This treatment uses light to remove skin cancers at the initial stages. PDT is a two-stage procedure. Firstly, a chemical substance is applied to the skin until absorbed. Then the skin is exposed to a special light that eliminates cancer cells.
  • Laser Treatment: Laser can be used to remove squamous cell carcinoma located on the surface of the skin. This treatment is only recommended for the initial stage of squamous cell carcinoma.
  • Chemotherapy Cream: A cream with a chemotherapeutic agent 5-Fluorouracil (5-FU), can be used to treat squamous cell carcinoma at an early stage.