This prospective study aimed to evaluate the usefulness of squamous cell carcinoma antigen (SCCA) as a clinical marker of sinonasal inverted papilloma (IP). The potential benefit of SCCA in the diagnosis of unilateral nasal pathology and as a marker of hidden recurrence was evaluated as well.

Blood samples from patients with sinonasal IP were examined to determine serum SCCA levels before surgery, the day after surgery, and every 6 months during follow-up. Preoperative and postoperative levels of SCCA were compared.

INTRODUCTION Squamous cell carcinoma antigen (SCCA) is a protein with a strong homology to the family of protease inhibitors known as serpins. SCCAs are cytoplasmic proteins: they are found in normal squamous epithelia, and in elevated levels in the serum of patients with squamous cell carcinomas, especially in cases of uterine cervix carcinoma, lung carcinoma, and head and neck squamous cell carcinoma. SCCA is clinically useful, especially for the staging of uterine cervix carcinoma (risk of lymph node metastasis). It is also a useful marker for monitoring during follow-up and therapy, and increasing SCCA levels may predict carcinoma relapse. Recent studies have shown a close relationship between SCCA and sinonasal inverted papilloma (IP).

IP is a relatively infrequent, benign sinonasal tumour. Careful long-term follow-up after radical surgery is necessary when treating IP, owing to its malignant potential and high recurrence rate. Distinguishing between inflammatory changes and recurrence of IP can sometimes be difficult. The purpose of this study was to determine the benefit of SCCA serum level evaluation in patients with IP.

MATERIAL AND METHODS Study design This prospective study was performed in accordance with the Declaration of Helsinki, the criteria of good clinical practice, and all applicable regulatory requirements. Written informed consent was obtained from all participants before the initiation of any procedure.

Patients with IP treated at the Department of Otolaryngology, Faculty of Medicine, University of Ostrava were included in the study. At least three years of follow-up after surgery was required for inclusion of a patient in the study.

Blood samples from enrolled patients were examined to determine serum SCCA levels before surgery, the day after surgery, and every 6 months during follow-up. Preoperative and postoperative SCCA levels were compared. The changes in SCCA levels during follow-up were evaluated.

Biochemical analysis Serum SCCA levels were assayed using an immunofluorescence assay with monoclonal antibodies (B.R.A.H.M.S SCC KRYPTOR kit, Hennigsdorf, Germany). The normal serum level of SCC antigen is 0-1.5 µg/l.

Statistical analysis Statistical analysis of the correlation between preoperative and postoperative serum SCCA levels was performed using Student's t-test for paired data. Differences with p < 0.05 were considered statistically significant.

Inclusion Criteria:

• at least three-year follow-up following the surgical procedure
• signed Informed Consent

Exclusion Criteria:

• patient lost during follow-up
• patients in critical condition (ASA IV)