AUTHOR=Kato Mayumi Kobayashi , Yoshida Hiroshi , Tanase Yasuhito , Uno Masaya , Ishikawa Mitsuya , Kato Tomoyasu 

TITLE=Loss of ARID1A Expression as a Favorable Prognostic Factor in Early-Stage Grade 3 Endometrioid Endometrial Carcinoma Patients

JOURNAL=Pathology and Oncology Research

VOLUME=Volume 27 - 2021

YEAR=2021

URL=https://www.por-journal.com/journals/pathology-and-oncology-research/articles/10.3389/pore.2021.598550

DOI=10.3389/pore.2021.598550

ISSN=1532-2807

ABSTRACT=Introduction: It is unclear which high-risk patients with grade 3 endometrioid endometrial carcinoma (G3EEC) require adjuvant therapy. Therefore, the current study aimed to investigate the prognostic impact of ARID1A, p53, and mismatch repair (MMR) protein expressions—previously reported as prognosticators in some gynecological cancers—in patients with early-stage G3EEC. 
Methods: A total of 67 patients with pathologically confirmed early-stage G3EEC diagnosed between 1997 and 2020 were identified. None of them received adjuvant chemotherapy. The recurrence-free survival (RFS) and overall survival (OS) were estimated using the Kaplan-Meier method and compared with a log-rank test. The protein expressions of ARID1A, p53, and MMR were examined via immunohistochemistry, and the associations between these biomarkers and clinical outcomes were evaluated.
Results: Recurrence was observed in 9 (13%) of the 67 patients with early-stage G3EEC. The 5-year RFS and OS rates were, respectively, 87.7% and 93.7% for Stage I, and 68.6% and 85.7% for Stage II patients. Multivariate analysis showed significantly longer RFS among patients with ARID1A loss (hazard ratio= 8.7; 95% CI, 1.09-69.6, p=0.04). No significant differences were observed in RFS and OS of patients according to p53 and MMR expression status.
Conclusion: ARID1A expression status was a prognosticator for patients with early-stage G3EEC without adjuvant therapy, whereas p53 and MMR expression status showed no impact on survival outcomes. ARID1A may become a useful biomarker for stratification of adjuvant treatment for early-stage G3EEC patients.