Squamous cell carcinoma antigen (SCC)

General Information

Squamous cell carcinoma (scc) antigen is a glycoprotein belonging to the group of serine/cysteine ​​protease inhibitors.

SCC antigen is a serological marker for squamous cell tumors localized in: cervix, vulva, lung, esophagus and head and neck region.

The usefulness of the study depends on the location of the tumor:

1. Cervical carcinoma

Sensitivity is 45-85% in case of primary tumor, and 66-84% in case of recurrent tumor. Serum SCC antigen concentration correlates with disease severity, lymph node involvement, and presence of metastases. The pre-treatment index is an indicator of the post-treatment prognosis. As a rule, SCC antigen levels normalize within 2-7 days after surgery or radiotherapy.

Maintaining a high pre-treatment score for 2-6 weeks after starting therapy indicates a high risk of relapse. After normalization of indicators after treatment, returning to a high level again, despite the absence of clinical signs, may indicate a relapse of the disease. In terms of clinical sensitivity, carcinoembryonic antigen is inferior to squamous cell carcinoma antigen by a ratio of 2:3.

2. Lung carcinoma

In squamous cell tumors of the lung, the sensitivity of determination of squamous cell antigen is 39-78% and is correlated with the stage of the disease and TNM classification (T- primary tumor size and spread, N - involvement of lymph nodes, M- metastases).

Within 2 days after tumor resection, SCC antigen levels should return to normal. In the case of residual tumors, it is much more difficult to normalize SCC antigen markers. 4-5 months after tumor treatment, an increase in SCC antigen indicators is an indication of tumor recurrence. According to clinical studies, the combined determination of SCC and CEA (carcinoembryonic) antigens increases the clinical sensitivity from 35% to 50-82%.

3. Carcinomas of the head and neck

The clinical sensitivity of SCC antigen in these tumors is 34-78% and depends on the disease stage and TNM classification.

The detection rate of SCC antigen in head and neck tumors is as follows: in upper jaw tumors - 49%, in oral cavity tumors 34%, in tongue tumors 23%, in salivary tumors 19%, in throat tumors 11-33%.

In the case of recurrent obesity, the sensitivity is 60-75%.

4. Esophageal tumors

The clinical sensitivity of SCC antigen in esophageal tumors is 30-39%, taking into account the stage of the disease. After a successful surgical intervention, the SCC antigen level returns to normal. Prolonged elevation of antigen levels in residual tumors and increases after initial normalization indicate tumor recurrence.

5. Other genitourinary (urinary) tumors

The sensitivity of squamous cell carcinoma antigen research in endometrial tumors is 8-30%, in ovarian tumors - 4-20%, in vulvar tumors - 19-42%, in cervical vaginal tumors - 17%.

Increased levels of SCC antigen are observed in metastatic squamous cell tumors of the genital tract and urethra, approximately 45%.

Preparation of the patient: No prior preparation is required.

Material for examination: Venous blood

Possible reason for sample rejection:

• hemolytic material
• Violation of the temperature regime of the sample
• sample contamination

Reference norms:  < 2.7 ng/mL 

LIMITATIONS AND INTERPRETATION

SCC antigen is included in normal flat epithelium, so its increase may be observed in such skin pathologies as processes with hyperkeratosis: psoriasis, eczema. An increase in SSC antigen is also observed in infectious lung diseases, liver and kidney failure.

Determination of SCC antigen is not a screening test in asymptomatic patients.