What is Squamous Cell Carcinoma?
Squamous cell carcinoma (SCC) is one of the most common cancers in the world but, fortunately, it is not as common as basal cell carcinomas. It is most commonly seen in light-skinned individuals on the sun-exposed areas such as the head and neck.
Just like basal cell carcinoma, squamous cell carcinoma presents as a slowly growing spot or bump that sometimes bleeds when easily traumatized by every day activities such as toweling or washing. Some patients describe it as a spot that looks like a pimple that does not go away.
When looked at closely, squamous cell carcinoma can have small scales or flakes and can sometimes look like a wart. Warts are not usually located on the head and neck regions, the most common regions for SCC. At the same time we need to remember that squamous cell carcinoma can be located on the whole body and have almost any color from white to red/pink to dark brown. Although light-skinned individuals (with light hair and eye color) are the most susceptible to SCC, patients with all skin types and colors can develop a squamous cell carcinoma. Dermatologists who specialize in skin cancer, have been treating patients of all skin types including Caucasians, Native Americans and Canadians, Inuits, Asians as well as Persians and East Indians among others. This list alone points to the fact that no patient group is immune to this most common form of cancer.
Squamous cell carcinoma can destroy tissues locally as well as it can spread to the lymph nodes and other parts of the body. SCCs are dangerous as they can kill the person if not treated.
It is very important that any new and persistent spot (e.g. more than three months) be assessed by a family doctor or a dermatologist. When detected early, SCC can be treated successfully. Depending on the treatment method, the success of the therapy can vary but, with the most effective methods, can approach 99% cure rate.
The abnormal growth (cancer) originates in the uppermost layer of the skin. The cancer then grows downward, forming root and fingerlike projections under the surface of the skin. Unfortunately, at times these roots are so subtle they cannot be seen without the aid of a microscope. Therefore, what you see on your skin is sometimes only a small portion of the total tumor.
What does Squamous Cell Carcinoma look like?
There are many ways that a squamous cell carcinoma can look. In most cases it is a red, scaly (flaky) bump that is slightly elevated, can develop ulceration, change over time into firm or fragile nodule and are located on the sun exposed areas such as on the face and scalp, ears, neck, forearms, backs of hands, and legs. In most instances, it is solitary but in rare cases, there can be more than one SCC in the similar area.
In some cases, SCC can be mistaken for other skin conditions that look very similar such as psoriasis, eczema, fungal infection or other red, scaly conditions. For proper diagnosis, a skin biopsy is needed. If you are concerned that you may have a squamous cell carcinoma or another skin cancer, please see your doctor or a dermatologist
Are there any precursors to full blown Squamous Cell Carcinoma?
YES – Actinic Keratoses are the earliest form of Squamous Cell Carcinomas and as such need to be treated. We have a whole section on our website dedicated to actinic keratoses , as their importance can not be overemphasized.
What causes Squamous Cell Carcinomas?
There are several well known reasons why SCC forms:
ExposureExcessive exposure to Ultraviolet radiation from the sun and other artificial sources. This is why skin cancers develop most often on the face and the arms (sun-exposed body parts). Squamous cell carcinoma is most commonly seen in fair skinned individuals who are unable to tan and is associated with an accumulated lifetime exposure to sun. PUVA (Psoralen and Ultraviolet A radiation), which is used mostly for psoriasis, has an increased risk of squamous cell carcinomas.
Radiation TreatmentsWhen patients are treated with radiation (for skin cancers or for other reasons), it can cause development of further skin cancers in the distant future (20 or more years later).
Chemicalsit is well known that exposure to arsenic (sometimes found in contaminated water) can cause the development of skin cancer many decades later.
Cigarette SmokingCigarette smoking increases the risks of squamous cell carcinoma by a factor of two.
HPVHuman Papilloma Viruses (warts) are associated with squamous cell carcinoma in the genital area as well as around the nails.
Genetic ProblemsSome patients have rare genetic syndromes that greatly predispose them to the development of skin cancers. Some of these syndromes include: Xeroderma Pigmentosum or Gorlin’s Syndrome.
Prior InjuryPatients who had injury in the distant past, such as burns or non-healing ulcers, have an increased risk of developing skin cancers.
ImmunosuppressionPatients who are immunosuppressed such as those following organ transplant or some cancers of the blood or bone marrow have their immunity reduced allowing some of the skin cancers to grow.
How can Squamous Cell Carcinomas be treated?
The treatment of squamous cell carcinomas depends on many factors including the type of SCC, its location and size, general health of the patient as well as the observation regarding its borders (when the borders of the cancer are not easily determined more sophisticated methods need to be used).
The following list represents some of the available treatments for squamous cell carcinomas:
- Mohs Micrographic Surgery (the most successful method)
- Surgical excision – surgical removal and stitching
- Curettage and electrodesiccation (scraping and burning with an electric needle)
- Radiation therapy (“deep X-ray”)
The method chosen depends upon several factors, such as the microscopic type of tumor, the location and size of the cancer, and previous therapy. For example, small squamous cell carcinomas on the legs, arms, back, chest or abdomen can be treated with curettage and electrodesiccation (scraping and burning with an electric needle), surgical excision or radiation therapy. Sometimes these methods can be combined increasing the chances of the cure rate.
The success rate for Mohs surgery , even in treating recurrent lesions, is about 95 – 99%. Mohs surgery is very time consuming and requires a highly trained team of medical personnel.
Since Mohs Micrographic surgery is the most successful and most tissue spearing (it strives to preserve as much of the normal tissue as possible and yet remove the cancer successfully), it is intended for skin cancers on the head and neck areas, the cancers that have poorly defined edges, recurrent cancers, cancers in patients with decreased immune system (such as patients with kidney, liver or heart transplants) and cancers in areas of the body when preservation of the normal tissues is important (such as hands and feet).