Introduction This study aims to evaluate mismatch repair defect (MMRd) in placental trophoblastic tumors (PSTTs) and epithelial trophoblastic tumors (ETTs).
Methods This study was performed in three academic hospitals retrospectively. Serial histology sections from 15 patients diagnosed with a PSTT or ETT were immunohistochemically stained using the MLH1/MSH2/MSH6/PMS2 to test MMRd. MMRd was determined by one pathologist. Less than 10% of expression in IHC was considered as MMRd.
Results We obtained IHC stain of MLH1/MSH2/MSH6/PMS2 from 15 patients’ samples. There were nine PSTT and six ETT patients. Sample from PSTT patients showed one MLH1 defect and one PMS2 defect. Sample from ETT patients showed PMS2 defect in five out of six samples. One sample showed defects in MLH1, MSH6, and PMS6.
Conclusion/Implications Gestational trophoblastic tumors especially in ETT showed high MMRd. This study explains the high response rate in PSTT and ETT to immune checkpoint inhibitors. This type of tumor may be a good target of immune checkpoint inhibitors.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.