Also known as epidermoid carcinoma, squamous cell carcinoma mainly affects elderly patients. Sun exposure, scars, precancerous local skin lesions as well as immunosuppression, toxins, genetic diseases, and tobacco all play a major role in the development of squamous cell carcinoma.
Squamous Cell Carcinoma: Definition
Carcinoma is the most common form of cancer in humans. This skin condition is different from melanoma. Contrary to melanoma, which spreads from melanocytes (pigment-containing skin cells), carcinoma stems from keratinocytes, which correspond to epidermal skin cells.
Squamous cell carcinomas can appear anywhere on the body. In most cases, they develop on the areas most exposed to the sun, particularly on:
- the mucous membranes and lips;
- the face (nose and ear squamous cell carcinomas are the most frequent);
- the neck and back of the neck;
- the head, especially when it is bald;
- the back of the hands;
- the arms and legs.
Squamous cell carcinoma tends to spread, which means it causes nodal and visceral metastases. Ulcerated, burgeoning lesions are quite common.
Squamous cell carcinoma vs. basal-cell carcinoma: How are they different?
Basal-cell carcinoma and squamous cell carcinoma are two types of cancer that develop from the spinous cells responsible for the production of keratin. The difference between basal-cell carcinoma and squamous cell carcinoma resides the prognosis and in how these two cancers behave:
- Basal-cell carcinomas: These are the most widespread skin cancers. Basal-cell carcinomas come in different forms, namely superficial, nodal, and sclerodermiform. These carcinomas remain superficial and never metastasise. Contrary to squamous cell carcinoma, basal-cell carcinoma mostly tends to develop after sudden or repeated sun exposure. The main kind of treatment for this type of carcinoma consists in excision surgery.
- Squamous cell carcinomas: These are on average 4 times less prevalent than basal-cell carcinomas. However, squamous cell carcinomas can cause nodal, and sometimes pulmonary metastases.
Although there is a difference between basal-cell and squamous cell carcinomas, they do also have things in common. Both types of carcinomas develop as the patient ages (starting at 50 for the basal-cell carcinoma, and around 60 to 65 for the squamous cell carcinoma). Both skin cancers affect men and women alike, even if the proportion of men is greater.
What are the risk factors for squamous cell carcinoma?
The most prominent risk factor – which is also the one we can counter the most easily – is UV radiation exposure. Squamous cell carcinoma on the skin indeed tends to develop primarily in people who have been exposed to the sun chronically and consistently throughout their life. This is especially true for people who work outdoors such as farmers, nautical sports instructors, builders, or road workers.
UV radiation from the sun can cause abnormalities inside the nucleus of keratinocytes and lead to the cells becoming cancerous. As a patient ages, their body is no longer capable of repairing these lesions as effectively. This is why skin cancers tend to develop later in life, usually after 50.
Several other factors can amplify the risk of a squamous cell carcinoma appearing:
- Skin phototype: A patient’s skin phototype plays an important part. Individuals with fair skin, a lighter eye colour, and light hair are at a higher risk.
- Genetics: a family history of carcinoma also constitutes a risk factor.
- Skin damage: Carcinoma can spread more easily where the skin sustained X-ray or ulcer damage, burns, or chronic wounds.
- Tobacco: Tobacco is an important factor which promotes the appearance of lip squamous cell carcinomas.
- Human papillomavirus-type viruses: Some infections connected to papillomavirus-type viruses could cause squamous cell carcinomas, particularly on the genital mucosa and in immunocompromised patients.
As a preventive measure, protect your skin from UV rays, be they natural or artificial, as they are in tanning booths. Applying the right kind of sun cream for your skin phototype constitutes the first precautionary action. To stop any development or progression of squamous cell carcinoma, check your skin regularly and report any change to your doctor or dermatologist.
How to recognise squamous cell carcinoma?
The appearance of squamous cell carcinoma depends on the area where it is developing and on how much it has already spread. Generally speaking, one can recognise this type of carcinoma as a small-shaped pimple, pink or red and covered with a scaly crust. When the crust comes off, an ulcerated skin lesion appears, and the edges swell up and often tend to bleed. In some rather rare cases, it can look like a nodule. If it is placed on the lips, squamous cell carcinoma may also be a white, scaly patch that is likely to get gradually bigger.
Squamous cell carcinoma may occur anywhere on the body. With that said, it is primarily recommended to check areas most frequently exposed to the sun. These include the head, face, neck, shoulders, and limbs such as arms and legs, along with the back of the hands.
Any skin lesion should be shown to a doctor or dermatologist. Only a healthcare professional will be able to make a diagnosis and guide the patient towards the appropriate care.
Squamous cell carcinoma: Which exams?
To detect squamous cell carcinoma in Paris, your dermatologist performs an in-depth clinical examination using a dermatoscope. This medical magnifying glass makes it possible to diagnose squamous cell carcinoma and, in some cases, its histologic subtype.
To confirm the diagnosis, a sample of the tumour is obtained through a skin biopsy and analysed under the microscope. A dermatologist collects the sample and sends it to an anatomic pathology laboratory.
An extension assessment (X-ray, ultrasound, and scan) is often necessary to look for a metastatic lesion. In the case of squamous cell carcinoma, an analysis of the lymphatic nodes is also required. Your doctor will perform an in-depth clinical exam and ultrasound to find out whether the lymph nodes themselves are affected.
How to treat squamous cell carcinoma?
The recovery rate for squamous cell carcinoma is very good. When it is detected early on and treated quickly, patients almost always make a complete recovery. However, the prognosis is less certain if the metastases have reached the lymph nodes.
Treatment depends on a patient’s age, their family history, and the nature of the tumour.
In most cases, treatments rely on surgery, and sometimes on radiotherapy and chemotherapy. Other kinds of procedures are usually reserved for specific types of tumours. Many surgical techniques are available, though they all consist in:
- Removing the tumour along with a security margin to reduce the risk of relapse. This margin can go from 5 mm to 10 mm or even 20 mm. This precaution allows medical professionals to eliminate any potential abnormal or cancerous cells that could be located around the lesion. This surgical procedure is usually carried out by a doctor who knows their way around tumours and skin surgery, typically a dermatologist or a plastic surgeon.
- Removing potential metastatic lymph nodes. Lymph node dissection is given consideration when lymph node metastases can be observed.
- Resorting to radiotherapy if surgery is not possible. This is the case when lymph nodes are affected or when there is a concern for squamous cell carcinoma relapse.
- Compensating for the resulting loss of substance. This is where a cosmetic surgeon plays a major role, as reconstructive surgery calls for wide local excision, skin grafts, and sometimes flaps.
In cases where squamous cell carcinoma has metastasised, additional chemotherapy may be necessary. Some less malignant squamous cell carcinomas may also be treated by applying medication onto the skin.
What to expect from post-treatment reconstruction?
If the skin lesions are mild, the doctor operating on a squamous cell carcinoma in Paris will typically use simple stitches, allowing the wound to heal rapidly and lessening cosmetic damage. However, when the lesions are too extensive, reconstructive surgery will be necessary. Following a squamous cell carcinoma operation in Paris, skin flaps or skin grafts will minimise its cosmetic impact.