Role of squamous cell carcinoma antigen in prognostication, monitoring of treatment response, and surveillance of locally advanced cervical carcinoma

Introduction: Squamous cell carcinoma antigen (SCC Ag) is a sub-fraction of the tumor antigen TA-4, first isolated by Kato and Torigoe, the most commonly used tumor marker in cervical cancer. It can be used as a serum marker to detect residual disease, early local recurrence, or distant metastasis in locally advanced cervical cancer even before the clinical symptoms of recurrence or metastasis. Methods and Materials: Between January 2018 and August 2018, 30 patients with squamous cell carcinoma cervix (FIGO) stages IB2-IVA, who received concurrent chemoradiation, followed by brachytherapy, were included in the study. Serum SCC Ag levels were collected at four time points during the course of the treatment, and their correlation with tumor and treatment factors were analyzed. Results: As the FIGO stage increases, mean pre-treatment SCC Ag also increases. Node-positive patients had higher pre-treatment SCC Ag as compared to those who were negative (P = 0.05). There was a statistically significant decreasing trend in the mean SCC Ag at the end of EBRT (P = 0.015). After completion of treatment, 78% had a complete response, 8% had a partial response, and 14% had progressive disease with statistically significant elevation of SCC Ag at 6 weeks of follow-up (P = 0.01). Patients who progressed or had the residual disease at follow-up were found to have high pre-treatment SCC Ag values. Conclusion: SCC Ag can be potentially used as a reference indicator of biological behavior of cervical cancer, to monitor the treatment response, and as a prognostic marker, especially in those with node-positive disease.