Disparities in Survival Outcomes Between Locally Advanced Cervical Squamous Cell Carcinoma and Adenocarcinoma Treated with Chemoradiotherapy.

Purpose: To determine the disparities in survival outcomes between stage IIB-IVA cervical squamous cell carcinoma (SCC) and adenocarcinoma (AC) treated with chemoradiotherapy.

Methods: Patients diagnosed between 2004 and 2015 were retrospectively included from the Surveillance, Epidemiology, and End Results databases. Propensity score matching (PSM) was used in this study. The primary endpoints were cervical cancer-specific survival (CCSS) and overall survival (OS).

Results: A total of 2752 patients were identified, including 87.5% (n=2408) were SCC and 12.5% (n=344) were AC. Patients with AC had inferior 5-year CCSS (67.5% vs 54.8%, P<0.001) and OS (58.4% vs 47.2%, P<0.001) compared to those with the SCC subtype. The hazard curve of cervical cancer-related death in AC peaked at 2 years (19%) and still small peaks in the 7 and 11 years of follow-up. Regarding SCC, cervical cancer-related deaths peaked at 2 years (15%) and the hazard rate was 2.0% during the six years of follow-up. The multivariate Cox regression analyses indicated that histology was an independent prognostic factor associated with survival outcomes. Patients with AC had significantly poor CCSS (P<0.001) and OS (P<0.001). Similar results were found after PSM.

Conclusion: Our study demonstrates a significantly better prognosis for cervical SCC patients compared to those with cervical AC undergoing chemoradiotherapy. These results highlight the importance of histological subtyping in predicting treatment outcomes and tailoring therapeutic strategies.