Real-world prevalence of microsatellite instability testing and related status in women with advanced endometrial cancer in Europe

Sneha S Kelkar; Vimalanand S Prabhu; Jingchuan Zhang; Yoscar M Ogando; Kyle Roney; Rishi P Verma; Nicola Miles; Christian Marth

doi:10.1007/s00404-024-07504-3

Real-world prevalence of microsatellite instability testing and related status in women with advanced endometrial cancer in Europe

Arch Gynecol Obstet. 2024 Apr 18. doi: 10.1007/s00404-024-07504-3. Online ahead of print.

Authors

Sneha S Kelkar¹, Vimalanand S Prabhu², Jingchuan Zhang³, Yoscar M Ogando¹, Kyle Roney¹, Rishi P Verma¹, Nicola Miles⁴, Christian Marth⁵

Affiliations

¹ OPEN Health, Bethesda, MD, USA.
² Merck & Co., Inc., 126 East Lincoln Ave, P.O. Box 2000, Rahway, NJ, 07065, USA. vimalanand.prabhu@merck.com.
³ Eisai Inc., Nutley, NJ, USA.
⁴ M3 (EU) Ltd., Abingdon, UK.
⁵ Department of Obstetrics and Gynecology, Medical University Innsbruck, Innsbruck, Austria.

PMID: 38634898
DOI: 10.1007/s00404-024-07504-3

Abstract

Purpose: To assess the real-world prevalence of microsatellite instability (MSI)/mismatch repair (MMR) testing and related tumor status in recurrent/advanced endometrial cancer patients in Europe.

Methods: Data were from two multi-center, retrospective patient chart review studies conducted in the United Kingdom, Germany, Italy, France and Spain: The Endometrial Cancer Health Outcomes-Europe-First-Line (ECHO-EU-1L) study and the ECHO-EU-Second-Line (ECHO-EU-2L) study. ECHO-EU-1L included recurrent/advanced endometrial cancer patients who received first-line systemic therapy between 1/JUN/2016 and 31/MAR/2020 after recurrent/advanced diagnosis. ECHO-EU-2L included patients with recurrent/advanced endometrial cancer who progressed between 1/JUN/2016 and 30/JUN/2019 following prior first-line systemic therapy. Data collected included patient demographics, MSI/MMR tumor testing and results, and clinical/treatment characteristics.

Results: ECHO-EU-1L included 242 first-line patients and ECHO-EU-2L included 475 s-line patients. For all patients, median age at recurrent/advanced diagnosis was 69 years, roughly half had endometrioid carcinoma histology and over 75% had Stage IIIB-IV disease at initial diagnosis. The prevalence of MSI/MMR testing in the first-line and second-line cohorts was similar (36.4 and 34.9%, respectively). Among those tested, a majority had non-MSI-high/MMR proficient tumors (80.7 and 74.7% among first- and second-line patients, respectively). About 15% had MSI-high/MMR deficient tumors in both cohorts, and a few patients had discordant results (3.4 and 10.8% among first- and second-line patients, respectively).

Conclusion: Prior to the approvals of biomarker-directed therapies for recurrent/advanced endometrial cancer patients in Europe, there were low MSI/MMR testing rates for these patients of just over one-third. Given the availability of biomarker-directed therapies, increased MSI/MMR testing may help inform treatment decisions for recurrent/advanced endometrial cancer patients in Europe.

Keywords: Biomarkers; Gynecology; Mismatch repair; Oncology; Recurrent; Retrospective.