Pretreatment Squamous Cell Carcinoma Antigen (SCC-Ag) as a Predictive Factor for the Use of Consolidation Chemotherapy in Cervical Cancer Patients After Postoperative Extended-Field Concurrent Chemoradiotherapy

Objective: The goal of this study was to confirm the clinical value of pretreatment serum squamous cell carcinoma antigen (SCC-Ag) in the administration of consolidation chemotherapy in patients with cervical cancers undergoing postoperative extended-field radiotherapy (EFRT) and concurrent chemotherapy (CCRT). Methods: Between 2007 and 2018, a total of 113 patients were treated with postoperative extended-field intensity-modulated radiotherapy (EF-IMRT) and CCRT. There were 63 patients receiving extended-field concurrent chemoradiotherapy (EF-CCRT) and consolidation chemotherapy, while another 50 patients underwent EF-CCRT alone. For the planning target volume, the prescribed dose was 45 to 50.4Gy/25 to 28 fractions. The consolidation chemotherapy regimen contained docetaxel and cisplatin. Results: For the patients with high pretreatment SCC-Ag, the addition of consolidation chemotherapy significantly improved their treatment outcomes and they had better 5-year overall survival (OS) (81.02% vs 63.44%, P = .018) and disease-free survival (DFS) (76.95% vs 61.12%, P = .007) than those without it. Meanwhile, the patients with consolidation chemotherapy had a lower rate of distant metastasis (8.8% vs 34.8%, P = .001). For the patients with low pretreatment SCC-Ag, there was no difference in prognosis between patients receiving consolidation chemotherapy and those not receiving consolidation. In multivariate analysis, consolidation chemotherapy was found to be a factor significantly associated with DFS (P = .035, 95% confidence interval (CI): 0.304-0.977) and distant metastasis (P = .009, 95% CI: 0.125-0.841). Conclusion: The patients who received consolidation chemotherapy showed significantly better DFS. Furthermore, pretreatment serum SCC-Ag > 6.5 ng/mL may be a predictive factor for the use of consolidation chemotherapy in cervical cancer patients treated with postoperative EF-CCRT.