Squamous cell cancer antigen (SCC) is a group of glycoproteins that belong to the family of inhibitors of serine / cysteine proteases. SCC is a serological marker for squamous cell carcinomas localized in the cervix, vulva, lung, esophagus and head-neck area.
The utility of the marker depends on the location of squamous cell carcinoma:
A. Cervical Cancer
Clinical sensitivity is of 45-85% in SCC primary cancer and 66-84% in recurrent cancer.
SCC serum correlates with extent of disease (clinical manifestations and nodal). Pre-treatment level is an early indicator of prognosis. After radical surgery or radiation therapy SCC serum usually normalizes in 2-7 days. Persistency of abnormal levels after 2-6 weeks of treatment correlates with a high rate of recurrence. Increased levels recurrence after initial normalization is associated with disease relapse, even in the absence of clinical manifestations, thus the marker being useful for early detection of tumor recurrence. In terms of clinical sensitivity, CEA marker is inferior to SCC Ag in cervical squamous cell.
B. Lung cancer
In squamous cell lung cancer prevalence of increased SCC concentrations ranges between 39 and 78%. SCC levels are increased in direct correlation with disease stage and TNM classification. After 2 days after tumor resection SCC values should be normalized; values decline in residual tumors occur more slowly. If after 4-5 months the SCC will increase significantly, it indicates tumor recurrence. According to some studies the combination of SCC and CEA increases susceptibility to this cancer clinic from 35 to 50-82%.
C. Carcinomas of the head-neck area
In these cancers SCC clinical sensitivity ranges from 34 to 78%, being dependent on disease stage and TNM classification. In various tumor detection rate is 49% in maxillary sinus lesions, 34% in lesions of the mouth, tongue lesions 23%, 19% and 11-33% in lesions of the larynx in the throat lesions. Regarding the detection of tumor recurrence describes a clinical sensitivity of 60-75%.
D. Esophageal cancer
In esophageal cancer clinical sensitivity SCC average is 30-39%, which is dependent on the stage of the disease. After a successful surgery SCC levels normalize. The persistence of elevated levels are associated with the presence of residual tumor and increased values after normalization, indicates tumor recurrence.
Method – ELISA :
Reference values -1.2 -5.6 mg / L
Limits and interference SCC antigen is present in normal squamous epithelia so elevated levels may be found in skin disorders associated with hyperkeratosis (psoriasis, eczema). Elevated concentrations can occur pulmonary inflammatory disorders, hepatic or renal impairment.
SCC should not be used in cancer screening in asymptomatic patients.
SCC antigen is present in skin, sweat and saliva, is easily distributed in aerosols (as a result of sneezing). To avoid falsely elevated results due to contamination it is mandatory to use protective barriers (ie. Gloves, mask) during the test.