Cutaneous squamous cell carcinoma (SCC) is a prevalent form of skin cancer that originates in the outer layers of the skin. It develops from squamous cells, which are flat cells found in the epidermis. Early detection of this condition is highly beneficial for successful treatment outcomes.
Understanding Cutaneous Squamous Cell Carcinoma
Cutaneous SCC is a type of cancer that begins in the squamous cells, which form the middle and outer layers of the skin. These cells continuously shed as new ones form, but DNA damage can disrupt this process, leading to abnormal cell growth and the formation of cancerous lesions. It is the second most common skin cancer, following basal cell carcinoma. Although it can be serious, cutaneous SCC is highly treatable when identified early.
The incidence of cutaneous SCC has shown a steady increase, with a nearly threefold rise reported from the 1970s to the early 2000s. In 2012, the estimated incidence in the United States was 140 per 100,000 men and 50 per 100,000 women. The prevalence of this condition is higher among men, individuals with fair skin, and older age groups.
Recognizing Cutaneous SCC
Cutaneous SCC often appears as a firm, red bump or nodule, which may be skin-colored or have a different hue like pink, red, black, or brown. It can also present as a flat sore with a scaly crust that may bleed or itch. Sometimes, it resembles a wart-like growth that crusts and occasionally bleeds.
Suspicious growths may also appear as an open sore that does not heal, or one that heals only to return. These lesions frequently develop on sun-exposed areas of the body, including the face, ears, lips, scalp, neck, shoulders, and the backs of the hands and forearms. It is important to note that SCC can also develop in other areas, such as inside the mouth or on the genitals. Any new, changing, or unusual skin lesion should be promptly evaluated by a healthcare professional.
Factors Increasing Risk
The primary risk factor for cutaneous SCC is prolonged and unprotected exposure to ultraviolet (UV) radiation from sunlight and artificial sources like tanning beds. Cumulative lifetime sun exposure increases the likelihood of developing this skin cancer, with approximately 90% of non-melanoma skin cancers linked to UV radiation.
Other factors also contribute to increased risk. Individuals with fair skin, light-colored hair, blue or green eyes, or skin that freckles or burns easily have a heightened susceptibility. A history of multiple severe sunburns, especially in earlier life, also raises the risk. A weakened immune system, whether due to illness or certain medications, can increase vulnerability. Certain genetic conditions, chronic infections, and long-term skin inflammation from burns or scars are also recognized risk factors for cutaneous SCC.
Diagnosis and Treatment Approaches
Diagnosis of cutaneous SCC begins with a physical examination by a healthcare professional, who will inquire about your medical history and examine any suspicious skin areas. To confirm cancer, a skin biopsy is performed. This procedure involves removing a small tissue sample, by cutting, shaving, or punching out part of the unusual area, which is then examined under a microscope. The biopsy helps classify the cancer as low or high risk, influencing treatment decisions based on factors like size, depth, and location.
Treatment options for cutaneous SCC vary depending on the tumor’s characteristics, such as its size, location, and depth, and the patient’s overall health. Surgical removal is a common approach, including excisional surgery where the cancer and a margin of healthy skin are cut out. Mohs micrographic surgery is another precise method, especially for high-risk or cosmetically sensitive areas, removing and examining layers of skin microscopically until no cancer cells remain.
For smaller, superficial skin cancers, less invasive treatments may be considered:
- Curettage and electrodessication: Scraping off the cancer and searing the base with an electric needle.
- Cryosurgery: Using extreme cold to destroy cancerous tissue.
- Laser therapy: Utilizing an intense beam of light to destroy growths.
- Topical medications: Creams or gels like 5-fluorouracil or imiquimod, used for superficial cases to target cancerous or precancerous cells.
- Radiation therapy: Often used for tumors difficult to treat surgically, or in conjunction with surgery for advanced cases.
Prevention and Prognosis
Preventing cutaneous SCC largely centers on minimizing exposure to ultraviolet (UV) radiation. Consistent sun protection practices are highly recommended, which include applying sunscreen with an SPF of 30 or higher, wearing protective clothing such as long-sleeved shirts and wide-brimmed hats, and seeking shade during peak sun hours. Avoiding tanning beds entirely is also an important preventive measure, as they emit harmful UV radiation.
Regular self-skin exams are encouraged to monitor for new or changing growths. Professional skin screenings by a dermatologist are also beneficial for early detection. When detected early, the prognosis for cutaneous SCC is favorable, with a five-year survival rate of approximately 99%. While rarely fatal, timely diagnosis and treatment prevent the cancer from growing or spreading.
Even if the cancer has spread to nearby lymph nodes, a combination of surgery and radiation treatment can still be effective. Lifelong monitoring and follow-up care are advised for individuals who have had cutaneous SCC, due to the possibility of recurrence.