What is Cutaneous Squamous Cell Carcinoma?
Squamous cell carcinoma is the second most frequently occurring skin cancer in the United States. Factors that increase the risk of developing this type of cancer include a weakened immune system, persistent wounds, light skin color, being male, old age, certain genetic conditions, exposure to environmental factors like UV radiation, and having had squamous cell carcinoma before.
Though it’s rare for this cancer to spread to other parts of the body, if it does, the lymph nodes are usually the first place it will show up. The frequency of squamous cell carcinoma is on the rise, which is a significant public health concern. To reduce the risk of serious health problems and death, it’s crucial to monitor for any signs of this cancer, diagnose it as early as possible, and begin treatment promptly.
Protecting oneself from the sun and undergoing regular full-body skin checks are recommended prevention practices. Treatment typically involves surgically removing the cancer, but new treatment methods continue to be developed. For those with more severe cases, cancer drug therapy and radiation therapy may be needed.
What Causes Cutaneous Squamous Cell Carcinoma?
Cutaneous squamous cell carcinoma, a type of skin cancer, can develop due to several risk factors and causes:
* UV radiation: The main risk factors are two types of rays from the sun, known as UVA and UVB.
* Exposure to other environmental factors: These can include substances like arsenic, certain hydrocarbons, nitrosamines, alkylating agents, and radiation not from the sun.
* Personal characteristics: People with fair skin, men, and older individuals have a higher risk.
* A weakened immune system: This can be a result of medical treatment, leukemia, or AIDS.
* Genetic conditions: Certain genetic syndromes, such as Huriez syndrome, xeroderma pigmentosa, and others, can increase the risk.
Existing skin conditions or wounds can also increase the risk, including chronic wounds (known as Marjolin ulcer), human papillomavirus, actinic keratosis, and others. Certain medications, such as BRAF inhibitors, vismodegib, and voriconazole, as well as immunosuppressive drugs, can also raise the risk of this type of skin cancer.
Risk Factors and Frequency for Cutaneous Squamous Cell Carcinoma
Squamous cell carcinoma is the second most common skin cancer in the United States. The number of people getting this cancer has been increasing since the 1970s. In 2012, for every 100,000 men, 140 were diagnosed with this cancer, and 50 out of every 100,000 women were diagnosed. The death rate is around 1% to 2%. In certain parts of the United States, this cancer is as deadly as melanoma (another skin cancer) and kidney and throat cancers. It is more common in men, people with fair skin, and older adults.
- Squamous cell carcinoma is the second most common type of skin cancer in the US.
- Since the 1970s, the number of cases has tripled.
- In 2012, 140 out of every 100,000 men, and 50 out of every 100,000 women were diagnosed with it.
- About 1% to 2% of cases result in death.
- In certain regions, the death rate matches that of melanoma, and kidney and throat cancers.
- this cancer is more common in men, people with fair skin, and older people.
Signs and Symptoms of Cutaneous Squamous Cell Carcinoma
Cutaneous squamous cell carcinoma is a type of skin cancer that usually appears as a scaly, red, or dark-colored raised spot or flat area on the skin. Some cases might show signs of ulcers, protruding features, or discomfort. Since it is often linked to exposure to UV radiation, this type of cancer is commonly found on skin that has been damaged by the sun. This skin tumor can also come from pre-existing skin conditions or lesions, such as the following:
- Actinic keratosis (sun spots)
- Chronic wounds (known as Marjolin ulcer)
- Human papillomavirus infection (HPV)
- Porokeratosis
- Lichen sclerosus et atrophicus
- Hypertrophic or oral lichen planus
- Discoid cutaneous lupus erythematosus
Testing for Cutaneous Squamous Cell Carcinoma
To confirm the diagnosis of cutaneous squamous cell carcinoma, which is a type of skin cancer, a skin biopsy is required. This means a small piece of the affected skin is removed and examined under a microscope for any signs of cancer.
If the diagnosis is established and the disease is classified as stage T2B-T3 in the Brigham and Women’s Hospital (BWH) staging system or stage T4 in the American Joint Committee on Cancer 8th edition (AJCC-8) staging system, additional tests are recommended. These may include a sentinel lymph node biopsy (a procedure to check if cancer has spread to the lymph nodes) and/or radiological evaluation with either a computed tomography scan, often known as a CT scan, or an ultrasound. Both are imaging techniques used to look for signs of the disease spreading.
If the cancer is rated as stage T2-3 according to the AJCC-8 system, further decisions on testing should be made on a patient-by-patient basis. Other tests, like a fine-needle aspiration or biopsy of the lymph node(s), can be done when any swelling in these areas is felt. This procedure involves using a thin needle to remove a small sample of tissue for examination.
Treatment Options for Cutaneous Squamous Cell Carcinoma
The preferred treatment for skin squamous cell carcinoma, a type of skin cancer, is usually surgical removal. A type of surgery known as Mohs micrographic surgery is especially recommended for more difficult cases. This might include situations where the skin lesion is bigger than 2 cm, has high-risk characteristics under the microscope, has come back after previous treatment, is located in sensitive or high-risk areas like the ears, lips, nose, and areas around the eyes, or if the patient has a weakened immune system.
Studies have shown that the recurrence rate (or the chance of the cancer coming back) after 5 years is around 3.1% for Mohs surgery, and around 8.1% for a standard surgical removal (where they remove the lesion with a 4 to 6 mm clear margin around it). Therefore, Mohs surgery offers a significantly better chance of preventing the cancer from coming back, especially for high-risk cases.
For cases where the cancer has already been treated but has come back, the recurrence rate was found to be 10% for Mohs surgery, and 23.3% for standard surgical removal. For very early skin cancers, treatment options like electrodessication and curettage (where the doctor scrapes away the lesion and then uses electricity to kill the remaining cancer cells) can be considered, although these have slightly higher recurrence rates than Mohs surgery and standard excision.
For patients who are not suitable for surgery, other treatments can be used. These might include surface-level radiation therapy, creams with 5-fluorouracil or imiquimod, freezing with cryotherapy, light treatment with photodynamic therapy, or a type of laser treatment. However, these treatments often have higher recurrence rates compared to surgery and they don’t allow for a lab test to confirm that all the cancer has been removed.
If the lymph nodes are involved, the recommended treatment often includes a lymphadenectomy, where the affected lymph nodes are removed. Radiation therapy is typically considered for more serious cases, like those with large nerves involved, invasion of lymph vessels, multiple involved lymph nodes, or cancer spread beyond the lymph nodes. Additional treatments for advanced cases can include chemotherapy, drugs that target specific proteins in the cancer cells, or drugs that boost the body’s immune response against the cancer cells. Recently, new immunotherapy drugs have been shown to offer better results compared to traditional treatments.
What else can Cutaneous Squamous Cell Carcinoma be?
When a patient presents with skin lesions or abnormalities, doctors may consider several possible conditions before reaching a final diagnosis. These possibilities include:
- Basal cell carcinoma (a type of skin cancer)
- Melanoma (another, more serious type of skin cancer)
- Extramammary Paget’s Disease (a rare skin condition)
- Actinic keratosis (sun-related skin damage)
- Seborrheic keratosis (benign skin growths)
- Porokeratosis (a rare, inherited skin disorder)
- Lichen planus-like keratosis (a benign, solitary, often itchy skin lesion)
- Verruca (warts)
- Psoriasis (a chronic autoimmune skin disease)
- Nummular dermatitis (another chronic skin condition characterized by coin-shaped spots on the skin)
- Lichen planus (an inflammatory skin condition)
- Lichen sclerosus et atrophicus (a rare skin condition primarily affecting genital skin)
- Discoid cutaneous lupus erythematosus (a chronic skin condition that appears as sores with inflammation and scarring)
Accurately diagnosing these conditions usually involves a thorough examination and possibly further tests.
What to expect with Cutaneous Squamous Cell Carcinoma
The overall outlook for localized diseases is generally very good. For skin cancer known as cutaneous squamous cell carcinoma, the death rate is about 1% to 2%. In approximately 3% of the cases, the cancer cells spread to other parts of the body, a process called metastasis. The lymph nodes are the most common places where this type of cancer spreads.
Cases where the cancer has spread to a single lymph node and the node is up to 3 cm in size, there is a 90% chance of surviving for at least 5 years post-diagnosis. Therefore, the chances of survival are high in such scenarios.
Possible Complications When Diagnosed with Cutaneous Squamous Cell Carcinoma
Common complications of cutaneous squamous cell carcinoma entail:
- Metastases: This refers to spreading of the cancer to other parts of the body.
- Local invasion: It means cancer cells invading nearby healthy tissues.
- Pain: Affected individuals may experience discomfort or pain.
- Loss of function: Depending on where the cancer is, it may affect the normal function of that body part.
- Poor cosmesis: This implies a less pleasant aesthetic outcome following treatment.
- Death: In advanced or untreated cases, this type of cancer may lead to death.
Preventing Cutaneous Squamous Cell Carcinoma
The American Academy of Dermatology (AAD) offers the following tips to help protect your skin:
* Try to stay out of the sun during times when UV radiation is at its highest.
* Regularly use sunscreen with an SPF of at least 30. Make sure to reapply it every two hours, as well as after swimming or getting sweaty.
* Always wear protective clothing and sunglasses when you’re in the sun.
* Adults should get a full-body skin checkup every year. If you’re at a higher risk for skin issues, you might need to get checked more often.
