Treatment patterns and prognosis of patients with clear cell adenocarcinoma of the cervix: a population-based cohort study

Objectives: To describe treatment patterns and prognoses for clear cell adenocarcinoma of the cervix (CCAC), a poorly understood rare tumor. Methods: A retrospective case-control study was conducted using the Surveillance, Epidemiology, and End Results (SEER) database, focusing on females diagnosed with CCAC between 2000 and 2019. Kaplan-Meier analysis, propensity score matching, Cox regression analysis, and subgroup analysis were used to assess treatment outcomes and risk factors. Results: Of the 52 153 patients with cervical cancer in the SEER database, 528 had CCAC. Overall survival (OS) was worse for patients with early-stage and locally advanced CCAC disease, although no differences in survival were observed for patients with stage IVB disease compared to those with other histologies. In our investigation into treatment patterns, we have discovered that surgical treatment was the preferred choice for the majority of patients with locally advanced CCAC (58.5%). Further, Kaplan-Meier analysis revealed that surgery improved OS in CCAC patients (65.6 vs. 25.3%, P=0.000), with similar results in locally advanced-stage patients (57.9 vs. 26.7%, P=0.000). Moreover, multivariate Cox regression analysis revealed that surgery was significantly associated with a more favorable prognosis in CCAC patients with locally advanced disease (HR 0.299, 95% CI: 0.153-0.585, P=0.000). Consistent findings were observed following propensity score matching (HR 0.283, 95% CI: 0.106-0.751, P=0.011). According to the subgroup analyses, surgical intervention continued to show a beneficial effect on CCAC patients with locally advanced disease (HR=0.31, 95% CI: 0.21-0.46, P<0.001). In particular, we also found that compared to patients who received primary radiotherapy (RT), those who underwent radical surgery exhibited a significantly prolonged OS in locally advanced CCAC patients. Furthermore, multivariate Cox regression analysis revealed that surgery was associated with better outcomes in patients with stage IB3-IIA2 and locally resectable stage IIIC patients (HR 0.207, 95% CI=0.043-0.991, P=0.049). However, this trend was not observed for patients with stage IIB-IVA (except locally resectable stage IIIC) CCAC. Conclusions: Surgery should be considered the preferred treatment option for patients with locally advanced CCAC at stage IB3-IIA2 and locally resectable stage IIIC.