Skin cancer involves the uncontrolled growth of abnormal skin cells. Non-melanoma skin cancers are the most common types, primarily basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Both originate in the outermost layer of the skin.
Basal Cell Carcinoma Explained
Basal cell carcinoma (BCC) is the most frequently diagnosed skin cancer, accounting for approximately 75% to 80% of all non-melanoma types. It arises from basal cells in the deepest layer of the epidermis. BCC typically grows slowly and rarely spreads, making it the less aggressive of the two main non-melanoma types.
BCC often appears on sun-exposed areas like the face, head, and neck, but can also occur on the back or lower legs. Its appearance can vary, commonly presenting as a pearly or waxy bump, a flat, flesh-colored or brown scar-like lesion, or a bleeding sore that heals and then returns. Early detection and treatment are important to prevent local tissue damage.
Squamous Cell Carcinoma Explained
Squamous cell carcinoma (SCC) is the second most common non-melanoma skin cancer, making up about 20% of diagnoses. It originates from squamous cells in the upper epidermis. SCC can be more aggressive than BCC, with a higher potential for local invasion and a greater, though still relatively low, risk of spreading to distant organs or lymph nodes if untreated.
Like BCC, SCC frequently develops on sun-exposed areas, including the face, ears, lips, and hands. However, it can also emerge in areas of chronic inflammation, scars, or on mucous membranes. SCC may manifest as a red, scaly patch, an open sore that does not heal, or a wart-like growth. These lesions might be tender to the touch and can sometimes bleed or crust over.
Understanding the Differences in Severity
The primary distinction in severity between BCC and SCC is their potential to spread beyond the original tumor site. While BCC rarely metastasizes, with spread occurring in less than 0.5% of cases, SCC carries a higher risk of metastasis, estimated at 2% to 5%, and a higher risk of recurrence, especially if treatment is delayed or incomplete.
Factors influencing severity for both types include tumor size, location, and aggressive subtypes. Lesions on the head and neck, particularly around the eyes, nose, lips, or ears, can be more challenging to treat and may indicate a higher risk of local recurrence or spread. A patient’s immune status also plays a role, with compromised immune systems facing a greater risk of more aggressive disease for both BCC and SCC.
Treatment Approaches and Outlook
Treatment for both BCC and SCC primarily focuses on removing cancerous cells. Surgical excision is a common approach, involving the removal of the tumor along with a margin of healthy tissue. Mohs micrographic surgery is often used for tumors in cosmetically sensitive areas or for more aggressive types, as it allows for precise removal of cancerous tissue while preserving healthy skin. Other treatment options include curettage and electrodesiccation, which involve scraping away the tumor and then burning the base with an electric needle.
Less common treatments, depending on the tumor’s characteristics and patient factors, may include radiation therapy or topical medications. The outlook for both BCC and SCC is generally excellent when detected and treated early. Consistent follow-up care is important to monitor for any recurrence or the development of new skin cancers.