Squamous Cell Carcinoma

Squamous Cell Carcinoma (SCC) is a type of skin cancer that begins in the squamous cells, which are the flat, scale-like cells found in the outer layer of the skin (the epidermis). SCC is the second most common type of skin cancer after basal cell carcinoma. While it is generally less aggressive than melanoma, SCC can still be dangerous, particularly if left untreated, as it has the potential to spread (metastasize) to other parts of the body.

Key Features of Squamous Cell Carcinoma (SCC):

• Appearance:
  • Lesion Characteristics: SCC typically appears as a firm, red nodule or a scaly, crusted lesion. It may start as a rough, thickened patch of skin or a wart-like growth that becomes more prominent over time.
  • Color: The lesion may be flesh-colored, pink, red, or have a brown or gray hue, especially if it's associated with previous sun damage.
  • Texture: The surface of the lesion can be scaly, crusted, or ulcerated. Sometimes, it may bleed or become tender.
  • Size: SCC lesions may range from small to several centimeters in size and may grow rapidly.
• Common Locations:
  • Sun-Exposed Areas: SCC is most often found on areas of the skin that have been frequently exposed to the sun, such as the face, ears, neck, scalp, hands, forearms, shoulders, back, and lips. It can also occur in areas that are not typically sun-exposed, like the genitals, inside the mouth, and on mucous membranes (especially in those with compromised immune systems).
  • Chronic Wounds: SCC can also arise from chronic wounds, burn scars, or areas of skin irritation that have been exposed to repeated trauma or infection.
• Risk Factors:
  • Sun Exposure: The most significant risk factor for developing SCC is exposure to ultraviolet (UV) radiation from the sun or tanning beds. Long-term, repeated exposure to UV rays damages the skin cells and increases the likelihood of cancerous changes.
  • Fair Skin: Individuals with fair skin, blonde or red hair, and blue or green eyes are more prone to developing SCC because they are more sensitive to sun damage.
  • Age: SCC is more common in older adults, particularly those aged 50 years or older, as the cumulative sun exposure over time increases the risk.
  • Immunosuppression: People with weakened immune systems, such as those undergoing organ transplantation or HIV/AIDS, are at a higher risk. Immunosuppressive medications can also increase the likelihood of SCC.
  • Previous Skin Cancer: A history of basal cell carcinoma or other skin cancers increases the risk of developing SCC.
  • Human Papillomavirus (HPV): Certain strains of HPV can increase the risk of developing SCC, particularly in mucosal regions like the mouth, throat, or genital area.
  • Chronic Skin Conditions: Conditions like actinic keratosis (AK), a precancerous lesion caused by sun damage, can increase the likelihood of developing SCC. Additionally, scar tissue from burns or chronic inflammation is a risk factor.
• Symptoms:
  • Changes in Skin Lesions: SCC may appear as a growing, scaly, or crusted bump that doesn’t heal over time. It may bleed, crust over, and then reopen.
  • Pain or Tenderness: The tumor can become painful as it grows or ulcerates, and it may cause bleeding or itching.
  • Ulceration: In some cases, SCC lesions may become ulcerated and have a central crater with a firm border.
  • Swelling: If the cancer spreads to nearby lymph nodes, swelling may be noted.
• Diagnosis:
  • Clinical Examination: An oncodermatologist or healthcare provider will examine the suspicious lesion, looking for features of SCC such as scaliness, firmness, irregular borders, and possible bleeding.
  • Skin Biopsy: A skin biopsy is the most reliable way to confirm the diagnosis. A small sample of the suspicious lesion is taken and examined under a microscope for signs of cancerous changes in the squamous cells.
  • Imaging: If the tumor is suspected to have spread beyond the skin, imaging tests such as X-rays, CT scans, or MRI may be used to check for lymph node involvement or metastasis to other organs.
• Staging:
  • Stage 0 (Carcinoma in Situ): The cancer is confined to the epidermis (the outermost layer of skin) and has not spread deeper.
  • Stage I-III: The cancer has grown deeper into the skin and may have spread to nearby lymph nodes or other tissues, but has not yet spread to distant organs.
  • Stage IV: The cancer has spread to distant organs such as the liver, lungs, or bones.
• Treatment Options:
  • Surgical Excision: Wide Local Excision (WLE): The most common treatment for SCC involves surgically removing the tumor along with a margin of healthy tissue to ensure clear edges and reduce the risk of recurrence.
  • Mohs Micrographic Surgery: This technique is particularly useful for SCCs located on areas with a high risk of recurrence or in cosmetically sensitive areas like the face. The tumor is removed layer by layer, with each layer examined under a microscope to ensure that all cancerous cells have been excised.
  • Radiation Therapy: Radiation may be used in cases where surgery is not feasible or if the tumor is inoperable (for example, in high-risk locations or for advanced disease). It can also be used post-surgery to treat remaining cancerous cells and reduce the risk of recurrence.
  • Cryotherapy: Cryotherapy (freezing the tumor) may be an option for small, superficial SCCs, especially those found on the surface of the skin.
  • Topical Treatments: Topical chemotherapy (e.g., 5-fluorouracil) or immune-modulating treatments (such as imiquimod) may be used for superficial SCC or precancerous lesions like actinic keratosis.
  • Chemotherapy: For advanced or metastatic SCC, chemotherapy may be employed, though it is typically reserved for cases where the cancer has spread to distant areas and is not amenable to surgery or radiation.
  • Immunotherapy: Immunotherapy agents, like checkpoint inhibitors (e.g., pembrolizumab or nivolumab), may be used for advanced SCC that has spread to other parts of the body. These drugs work by stimulating the body's immune system to recognize and fight the cancer.
• Prognosis:
  • Prognosis for SCC depends on factors such as the size, location, and depth of the tumor, as well as whether it has spread to lymph nodes or distant organs.
  • Localized SCC (confined to the skin) has a high cure rate, especially if treated early. The 5-year survival rate for localized SCC is generally high.
  • Metastatic SCC, where the cancer has spread to distant organs, is more difficult to treat and has a poorer prognosis.
• Prevention:
  • Sun Protection: Protecting your skin from UV radiation is the most effective way to prevent SCC. This includes wearing broad-spectrum sunscreen with SPF 30 or higher, wearing protective clothing (e.g., hats, sunglasses), and seeking shade during peak sun hours.
  • Avoid Tanning Beds: Tanning beds are a known risk factor for skin cancer and should be avoided to reduce the risk of developing SCC and other skin cancers.
  • Regular Skin Checks: Routine skin self-exams and regular visits to an oncodermatologist are essential, especially for people at higher risk (those with a history of sunburns, fair skin, or other skin cancers). Early detection of SCC can improve treatment outcomes.

Summary:

Squamous Cell Carcinoma (SCC) is a type of skin cancer that arises from the squamous cells in the skin's epidermis. It's often caused by sun exposure, but other risk factors such as immunosuppression and HPV infection can also contribute. SCC typically appears as a scaly, firm, red nodule or ulcerated lesion and is often found on sun-exposed areas of the skin. Surgical excision is the primary treatment, and radiation and chemotherapy may be used for more advanced cases. Early detection and treatment are key to preventing SCC from spreading and improving outcomes.