Basal cell carcinoma (BCC) is the most frequently diagnosed form of skin cancer, originating from basal cells in the outermost layer of the skin. While most BCC cases are detected early and successfully treated, some can progress to “advanced” basal cell carcinoma. This progression signifies a more complex stage of the disease, requiring specialized approaches.
Defining Advanced Basal Cell Carcinoma
Advanced basal cell carcinoma refers to cancer that has grown beyond its typical, easily treatable stage. It manifests in two primary ways: locally advanced BCC or metastatic BCC. Locally advanced BCC involves tumors that have grown significantly, invading deeply into surrounding tissues like muscle, bone, or cartilage, or recurring multiple times in the same area after initial treatment. These lesions can be disfiguring and challenging to remove with standard surgical methods.
Metastatic BCC occurs when cancer cells break away from the primary tumor and travel through the bloodstream or lymphatic system to establish new tumors in distant parts of the body, such as lymph nodes, lungs, or bones. This form is rarer than locally advanced BCC, accounting for a small percentage of all BCC cases. Factors contributing to a BCC becoming advanced include delayed diagnosis, leading to prolonged growth of the tumor, or aggressive histological subtypes. Tumors in high-risk areas, such as the head and neck, particularly around the eyes, nose, or ears, may also have a higher propensity to become advanced due to proximity to delicate structures.
Signs and Symptoms of Advanced BCC
Recognizing the signs and symptoms of advanced basal cell carcinoma is important for timely intervention. A persistent, non-healing sore that bleeds easily, crusts, or oozes, especially if present for several weeks or months, can indicate advanced BCC. Large lesions growing rapidly or with an unusual appearance, such as a rolled border or central ulceration, also raise concern. Pain or tenderness within the lesion or surrounding tissue may suggest deeper invasion.
Nerve involvement can manifest as numbness, tingling, or muscle weakness in the affected area, indicating cancer spread along nerve pathways. Visible invasion of underlying structures, such as erosion into bone or cartilage, is a clear sign of locally advanced disease. For rare metastatic BCC, general symptoms may include unexplained weight loss, persistent fatigue, or specific symptoms related to the site of metastasis, such as bone pain or breathing difficulties.
Treatment Options for Advanced BCC
Treatment strategies for advanced basal cell carcinoma are individualized and often involve a multidisciplinary team. Targeted therapies represent a significant option, particularly Hedgehog pathway inhibitors like vismodegib and sonidegib. These oral medications block the Hedgehog signaling pathway, which is active in most BCCs. They are often used for locally advanced BCC not amenable to surgery or radiation, or for metastatic BCC.
Immunotherapy, specifically PD-1 inhibitors such as cemiplimab, is another option. Cemiplimab works by blocking the PD-1 protein on immune cells, allowing the immune system to recognize and attack cancer cells. This intravenous therapy is administered every few weeks and is approved for locally advanced BCC after Hedgehog inhibitor therapy or for metastatic BCC. Advanced surgical techniques, including Mohs micrographic surgery, are sometimes used for select locally advanced cases, especially those with ill-defined borders or in cosmetically sensitive areas, to precisely remove cancer while preserving healthy tissue. For larger or more invasive locally advanced tumors, wide local excision with complex reconstruction may be necessary to ensure clear margins and repair the affected area.
Radiation therapy is frequently used for advanced BCC, either as a primary treatment when surgery is not feasible, or in combination with other therapies. It can be effective for palliative care, managing symptoms like pain or bleeding, or as adjuvant therapy after surgery to reduce recurrence risk. While less common, chemotherapy may be considered when other targeted therapies or immunotherapies have not been effective, or in aggressive subtypes. The overall treatment plan is tailored to the individual patient, considering disease extent, tumor characteristics, and overall health.
Living with Advanced Basal Cell Carcinoma
While advanced basal cell carcinoma presents a serious challenge, treatment progress has improved outcomes. Many patients achieve disease control or long-term remission with current therapies. Ongoing monitoring and regular follow-up appointments are important to detect any recurrence or new lesions. Surveillance typically involves routine skin exams by a dermatologist, and sometimes imaging studies, depending on disease extent and metastasis risk.
Patients should continue practicing sun protection, including wearing protective clothing, seeking shade, and using broad-spectrum sunscreen with an SPF of 30 or higher. Limiting sun exposure, especially during peak hours, reduces the risk of new BCCs and other skin cancers. Adopting a healthy lifestyle, including a balanced diet and regular physical activity, can support overall well-being during treatment. Emotional and psychological support, whether through support groups, counseling, or connecting with others facing similar challenges, can also benefit patients and their families.