What Is Squamous Cell Carcinoma?

Squamous Cell Carcinoma (SCC) is a common form of skin cancer that develops in the squamous cells, which make up the middle and outer layers of the skin. While not typically life-threatening, SCC can become aggressive and spread to other parts of the body if left untreated. It is second only to basal cell carcinoma in frequency among skin cancers.

Understanding the Causes of Squamous Cell Carcinoma

The primary cause of SCC is prolonged exposure to ultraviolet (UV) radiation from the sun or tanning beds. UV rays damage the DNA in skin cells, leading to abnormal cell growth and ultimately, cancer. Other contributing factors include:

Chronic skin injuries or inflammation
Immunosuppression, especially in organ transplant patients
Exposure to carcinogenic substances, like arsenic or industrial chemicals
History of precancerous skin lesions such as actinic keratosis
Human papillomavirus (HPV) infection, particularly with mucosal SCC

Recognizing the Symptoms of Squamous Cell Carcinoma

SCC often presents itself as a scaly red patch, open sore, thickened skin, or wart-like growth that may crust or bleed. It most commonly appears on sun-exposed areas like:

Face
Ears
Neck
Lips
Backs of the hands

Symptoms to watch for include:

Persistent rough or scaly patch
Raised growth with a central depression
Sore that does not heal or heals and returns
Pain or tenderness at the site

Early detection significantly improves the prognosis, making regular skin checks essential.

Types and Variants of Squamous Cell Carcinoma

SCC can take on multiple forms and histological variants:

In situ SCC (Bowen’s Disease) – Confined to the epidermis and highly treatable
Invasive SCC – Has penetrated deeper layers of the skin and can spread
Keratoacanthoma – A fast-growing but usually benign variant
Acantholytic SCC – Shows loss of cell-to-cell adhesion, often more aggressive
Desmoplastic SCC – A rare, fibrotic type with high metastatic potential

Understanding the specific type helps guide treatment decisions and predict outcomes.

Diagnosis of Squamous Cell Carcinoma

Diagnosis begins with a clinical examination followed by a skin biopsy. There are different biopsy methods including:

Shave biopsy
Punch biopsy
Excisional biopsy

A histopathological examination confirms the presence of cancerous cells. In cases where SCC is suspected to have spread, imaging tests like CT scans or PET scans may be ordered.

Staging of Squamous Cell Carcinoma

Staging is crucial for treatment planning and is typically based on the TNM system:

T (Tumor): Size and extent of the tumor
N (Nodes): Spread to nearby lymph nodes
M (Metastasis): Spread to distant organs

Stages range from 0 (in situ) to Stage IV (advanced, metastatic disease).

Treatment Options for Squamous Cell Carcinoma

Surgical Treatments

Excisional Surgery: The tumor and a margin of healthy tissue are removed.
Mohs Micrographic Surgery: Offers the highest cure rate; ideal for high-risk or facial tumors.
Curettage and Electrodessication: Often used for small, superficial SCCs.

Nonsurgical Treatments

Cryotherapy: Freezes and destroys abnormal tissue.
Topical Chemotherapy: Creams like 5-fluorouracil (5-FU) for in situ lesions.
Photodynamic Therapy (PDT): Uses light-sensitive drugs and laser to target cancer cells.

Advanced Treatment Options

Radiation Therapy: Used for patients who are not surgical candidates.
Systemic Chemotherapy: Typically reserved for metastatic SCC.
Immunotherapy: Drugs like cemiplimab or nivolumab that boost the immune system to fight cancer.
Targeted Therapy: Inhibits molecular pathways involved in tumor growth.

Prognosis and Survival Rates

The prognosis for SCC is generally excellent when detected early. The five-year survival rate for localized SCC is over 95%. However, if the cancer metastasizes, the survival rate drops significantly.

Risk factors for poor outcomes include:

Tumor size greater than 2 cm
Depth of invasion
Perineural invasion
Immunocompromised status
Tumors located on high-risk areas (ears, lips, genitalia)

Prevention of Squamous Cell Carcinoma

Prevention strategies are critical in reducing risk:

Avoid excessive sun exposure, especially between 10 a.m. and 4 p.m.
Use broad-spectrum sunscreen with SPF 30 or higher.
Wear protective clothing, hats, and sunglasses.
Avoid tanning beds completely.
Perform regular skin self-exams and schedule annual dermatologic checkups.
Treat precancerous lesions like actinic keratoses promptly.

SCC in High-Risk Populations

Certain individuals are more prone to SCC:

Organ transplant recipients
People with xeroderma pigmentosum
Elderly individuals
Those with chronic inflammatory skin conditions
Workers exposed to carcinogens, such as outdoor laborers

These populations require more frequent screening and proactive preventive care.

Living with Squamous Cell Carcinoma

A diagnosis of SCC can be emotionally and physically challenging. However, with prompt treatment and proper lifestyle changes, most people recover completely. Key steps include:

Following up regularly with dermatologists
Monitoring for recurrence
Adopting sun-safe habits
Reporting any new or changing lesions immediately

Conclusion

Squamous Cell Carcinoma is a highly treatable cancer when caught early. By understanding its causes, symptoms, risk factors, and available treatments, individuals can take charge of their skin health. Early detection, professional care, and preventive strategies are the pillars of successful SCC management.