Horizontal tumor extent (HZTE) has limited prognostic significance in 2018 FIGO stage I endocervical adenocarcinoma (ECA): a retrospective study of 416 cases

Purpose The 2018 International Federation of Gynecology and Obstetrics (FIGO) update on cervical cancer staging eliminated horizontal tumor extent (HZTE) as a staging parameter in stage IA (microscopic) disease. We aimed to determine whether HZTE correlates with outcomes in early stage ECAs and FIGO should reinstate HZTE as a staging parameter in futures updates. Methods We retrospectively analyzed 416 FIGO 2009 stage I ECAs from 17 institutions and re-assigned stage using FIGO 2018. Correlation between HZTE, overall (OS) and recurrence free survival (RFS) was performed using univariable and multivariable analyses. Results Re-staging 416 cases resulted in 126 (30.3%) IA and 290 (69.7%) IB cases; 85 (67.5%) IA tumors had HZTE ≤ 7 mm, while 41 (32.5%) were > 7 mm; 32 (11%) IB tumors had HZTE ≤ 7 mm, while 258 (89%) were > 7 mm ( p = 0.0001). Four (3.2%) IA (1 IA1, 3 IA2) patients developed recurrence (3 ≤ 7 mm, 1 > 7 mm) compared to 41 (14.1%) IB patients ( p = 0.002). Fourteen IB and no IA patients died of disease (8 IB1, 1 ≤ 7 mm). Cox univariate analysis demonstrated that only RFS is significantly influenced by HZTE ( p = 0.01), while OS and RFS were not influenced by HZTE on multivariate analysis. Conclusion HZTE has limited prognostic value in early stage ECAs and is only associated with RFS on univariate but not multivariate analysis. HZTE does not improve prognostication of patients with stage I ECAs as per 2018 FIGO staging. Consequently, the rationale to remove this variable from FIGO staging is justified for ECAs.