Squamous cell carcinoma of the skin

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at February 5, 2016
StartDiseasesSquamous cell carcinoma of the skin

Squamous cell carcinoma of the skin or SCC is a cancer that affects the skin. It can remain on the topmost layer of the skin – the epidermis - or sometimes spread deep into skin tissue. It may also metastasize or spread to other parts of the body.

Contents

Definition & Facts

Squamous-cell carcinoma of the skin is a category of skin cancer that develops from the squamous cells on the skin. Squamous cell carcinoma in general affects many areas of the body that contain squamous cells, including the lungs, the esophagus, prostate, oral cavity, anus, and genitalia.

Squamous cells form the outer layer of the skin, and SCC of the skin causes red scaly patches that look like warts and which are usually open sores. They often crust and bleed causing lots of discomfort. In the U.S alone, over 700,000 new cases crop up each year.

Mortality rates of the disease range between 3,000 and 4,000 yearly from the disease. Statistically, the prevalence rates of SCC have grown exponentially by a whopping 200 percent in the past thirty years making it the second most common form of skin cancer.

Symptoms & Complaints

Squamous cell carcinoma of the skin occurs on the exposed areas of the skin like the hands, ears and the legs. This cancer exhibits the following signs:

  • Scaly red patches which may bleed
  • Raised lumps with a depression at the center
  • Open sores that usually do not heal, but if they improve, they come back
  • A firm red inflammation

It is prudent to make an appointment with a doctor when such signs appear and persist longer than two months.

Causes

Squamous cell carcinoma develops when cells in the epidermis multiply uncontrollably. Persistent exposure to ultraviolet light over an extended period, for example, during hot summer months may cause skin cancer. Other than the sun, some variables predispose people to SCC.

Some precancerous conditions arising from prolonged sun exposure and resultant sun damage increase a person's risk to developing SCC. These include actinic keratosis or AK. Affecting the elderly mostly, AK exhibits itself as a scaly, rough, raised growth and has red and brown pigmentation. These lesions occur on sun-exposed areas of the body. If left untreated, about two to ten percent of those affected with AK later develop squamous cell carcinoma.

Another risk factor is a form of actinic keratosis called actinic cheilitis or AC which affects the lower lip, causing it to crack and become scaly and pale. The lips also experience a burning sensation and dryness.

Leukoplakia also increases the risk of developing SCC and is a condition that occurs in the mucous membrane of the oral cavity. A person will notice white patches on the tongue, the cheeks, the gums and other areas. Tobacco use is the leading cause of leukoplakia though it can also be caused by irritation from rough teeth and dentures. Sun damage causes leukoplakia on the lips.

Bowen’s disease is a noninvasive early stage of SCC. It shows itself as a persistent red-brown patch. It arises from arsenic exposure and prolonged sun exposure. Carcinogenic elements, radiation, and trauma may cause Bowen's disease. When Bowen's disease appears on the genitalia, it may be caused by human papilloma virus (HPV) which is a sexually transmitted disease.

Diagnosis & Tests

A doctor will first perform a physical examination. He or she will examine the skin for any signs of SCC. He will try to find out about past health history. In the event that the doctor suspects the existence of SCC, he or she will conduct a biopsy where suspicious tissue from the skin is sampled and taken to the laboratory for examination.

Treatment & Therapy

It is imperative for early detection of SCC so that it may not develop into full blown cancer. If not treated early, it may penetrate nearby tissues and spread. As it stands, several treatments exist. Each treatment depends on the size, shape, and extent of cancer. The patient’s age and health also determine the type of treatment.

Mohs surgery involves using a scalpel to cut away the tumor. The doctor checks the sample under a microscope, and if he or she finds that cancer has spread beyond the neighboring tissue, the practitioner repeats the same procedure until the surrounding tissue is free of cancerous cells.

During excision surgery the doctor removes the tumor together with the surrounding area as a safety margin. The sample goes through a microscopic examination to determine the extent of cancerous cells. In the case of recurrence, a repeat excision may need to take place.

Electrodesiccation and curettage is a treatment for small lesions. The doctor scrapes the growth with a curette, a small instrument with a sharp ring-shaped tip. The doctor uses an electronically heated needle to burn the cancerous tissue. The procedure occurs repeatedly to ensure subsequent layers lack malignant cells. Doctors do not recommend it for areas near the eye for it leaves scars.

Cryosurgery is another treatment option which utilizes freezing temperatures to kill cancerous cells. It is appropriate for shallow cancers. Usually, redness, blistering, and swelling occur. For people with dark skin, loss of pigmentation occurs. The treatment is suitable for people with bleeding disorders and those averse to anesthesia.

Radiation is another option which uses high-energy beams like X-rays to kill cancer cells. It is appropriate in treating deep-seated cancers. No incisions or anesthesia happens. The patient needs multiple visits and runs the risk of radiation side effects.

With photodynamic therapy, doctors combine photosensitizing drugs and light to kill skin cancer cells. Medical practitioners apply the drug to the skin then shine the light on it which activates the drug to kill the cancer cells. Minimal damage happens to the adjacent cells. Photosensitivity, swelling, and redness are common side-effects.

Laser surgery involves doctors using a laser beam to vaporize the skin's outer layer and deeper affected areas with minimal destruction of the surrounding tissue. Topical medications like fluorouracil and imiquimod drugs exist for the treatment of cancer. Imiquimod activates the immune system to produce a chemical—interferon—that attacks cancerous and precancerous cells. Fluorouracil finds its use in chemotherapy as it is toxic to malignant cells.

Prevention & Prophylaxis

Some methods for preventing squamous cell carcinoma of the skin include:

  • Avoid prolonged exposure to the sun, especially between 10 am and 4 pm
  • Use broad spectrum (UVA/UVB) sunscreen with a sun protection factor (SPF) of 15 and if it is on an extended physical activity, let it be 30 or higher.
  • Avoid tanning. Keep away from tanning beds.
  • Keep newborns out of the sun
  • Visit your doctor annually for professional advice.