Squamous cell carcinoma antigen (SCCA)

Why this test? 

For the complex diagnosis of squamous cell carcinoma with an assessment of the probable tumor process spread and the metastases presence,

for monitoring patients with squamous cell neoplasms of various locations, 

to predict survival in squamous cell carcinoma, 

for planning treatment tactics for patients with squamous cell carcinoma,

to evaluate the effectiveness of squamous cell cancer treatment. 

In what cases is it prescribed? 

If an epithelial neoplasm of various organs and tissues is suspected,

when planning a treatment regimen for patients with squamous cell carcinoma and selecting patients for more aggressive treatment tactics, 

before and after surgical removal of a squamous neoplasm of different localization,

during periodic examination of patients in whom squamous cell carcinoma has been removed.

Test information 

Squamous cell carcinoma is a malignant epithelial tumor that can develop in the cervix, mouth, esophagus, head and neck, lungs, anus, and skin. Squamous cell carcinoma antigen is a glycoprotein from the family of serine protease inhibitors. The molecular weight of this protein is 45-55 kilodaltons. Normally, a small amount of antigen is produced inside the epithelial cells of the skin, cervix, and anal canal and is not released into the extracellular space.

In squamous cell carcinoma, an increase in antigen secretion by tumor cells is noted, which may play a role in the processes of carcinoma invasion and metastasis. The half-life of antigen in blood serum is 2.2 hours. There is a correlation between the concentration of antigen in the blood and the stage of cancer, the size of the tumor, its progression, the aggressive nature of the growth and the presence of metastases in the lymph nodes and other organs. 

Antigen of squamous cell carcinoma is detected in 60% of patients with cervical cancer at various stages. In stage I cervical cancer, the sensitivity of this marker is 10%, in stage IV - 80%. After the removal of the tumor, a decrease in the antigen level to normal levels is noted within 96 hours.

A persistently elevated level of squamous cell carcinoma antigen or an increase in its concentration after surgical removal of the tumor indicates relapse or progression of the disease. In 46-92% of cases, an increase in the level of antigen allows to detect tumor recurrence a few months before the first clinical manifestations of the pathology. 

Numerous studies have shown the relationship between the level of antigen, the stage of cancer and the survival of oncological patients, which is important for the choice of treatment tactics, the appointment of neoadjuvant and adjuvant therapy, radiotherapy, prognosis and assessment of a possible recurrence of the disease. 

However, a normal antigen level does not exclude the possibility of metastases, just as an increased concentration of squamous cell carcinoma antigen in the blood is not an absolute indicator of the presence of a tumor and cannot be the basis for making a diagnosis. To evaluate the results of this analysis, it is important to compare the test results before and after the radical treatment of the neoplasm.