Squamous cell carcinoma (SCC) is a common cancer originating in squamous cells, found in the outer skin layer and lining internal organs. While many SCCs are detected early and are localized, some can become more aggressive. When these cancer cells spread from their original location to distant parts of the body, it is referred to as metastatic squamous cell carcinoma.
What is Metastatic Squamous Cell Carcinoma
Squamous cell carcinoma is a type of cancer that begins in the squamous cells. These flat, thin cells are present on the surface of the skin and in the lining of certain organs, such as the lungs, head, and neck. Most cutaneous (skin) SCCs are curable with local treatments, but a small percentage can spread.
Metastasis occurs when cancer cells break away from the primary tumor, travel through the bloodstream or lymphatic system, and form new tumors elsewhere. For SCC, common sites of metastasis include regional lymph nodes, particularly in the neck, and distant organs like the lungs, bones, and liver. This spread signifies a more advanced stage of the disease.
Factors Affecting Survival Rates
Several factors influence survival rates for metastatic squamous cell carcinoma. The original site of the tumor plays a role, with SCC originating in areas like the head and neck, or on the ear, potentially having different outcomes compared to cutaneous SCC. The extent of metastasis, meaning the number and locations of secondary tumors, also significantly impacts survival; patients with a single metastasis generally have a better prognosis than those with multiple sites of spread.
The patient’s overall health, including their age and immune system status, can affect how well they respond to treatment and their ability to withstand the disease. For instance, individuals with weakened immune systems, such as organ transplant recipients, face a higher risk of metastasis and may have different survival outcomes. Additionally, characteristics of the primary tumor, such as its size, depth of invasion, and whether it has recurred previously, are important indicators.
Understanding Survival Statistics
Survival rates in cancer refer to the percentage of people who are still alive for a certain period, typically five years, after their diagnosis. These statistics are derived from large population studies and provide a general benchmark, but they do not predict individual outcomes due to variations in patient health and disease characteristics.
For cutaneous SCC that has metastasized, the five-year disease-specific survival rate has been reported to be approximately 79.1% in some studies. However, when considering all forms of metastatic SCC, including those from other primary sites, the five-year survival rate can drop to less than 50 percent. For metastatic head and neck squamous cell carcinoma, the five-year overall survival rate for distant metastatic disease is around 39%. If there is a single metastasis, the five-year overall survival can be higher, approximately 35%, compared to patients with multiple metastases, where it may be as low as 4%.
Treatment Options and Their Impact
Treatment for metastatic squamous cell carcinoma aims to control the disease and improve outcomes. Surgical removal of resectable metastases is a common approach, and it often leads to better survival rates. Radiation therapy is often employed, sometimes after surgery or in combination with other treatments, especially for tumors difficult to remove surgically or in patients for whom surgery is not suitable.
Chemotherapy is used to target cancer cells throughout the body. While it can induce responses, its impact on overall survival for metastatic head and neck SCC has been limited, though it can help control symptoms. Targeted therapies, which focus on specific molecular pathways involved in cancer growth, and immunotherapies, which boost the body’s immune response against cancer. Immunotherapies like cemiplimab-rwlc and pembrolizumab have received approval for treating advanced cutaneous SCC and have shown promising results in improving survival for some patients, particularly in head and neck SCC.
Living with Metastatic Squamous Cell Carcinoma
Navigating a diagnosis of metastatic squamous cell carcinoma involves ongoing management and a focus on quality of life. Regular follow-up care is important, as relapse can occur even after treatment.
A multidisciplinary care team is beneficial for developing a comprehensive care plan. Supportive care can help address the emotional and physical challenges associated with the disease. The goal of treatment often extends beyond survival statistics to encompass symptom control and maintaining the best possible quality of life.