CORRELATION OF MISMATCH REPAIR DEFICIENCY WITH CLINICOPATHOLOGICAL PARAMETERS IN ENDOMETRIAL CARCINOMA

Abstract

Objective: To estimate the incidence of mismatch repair deficiency in endometrial carcinoma and to refine its association with clinic-pathological parameters, in view of its emerging role in prognostication and therapeutic decision making. Study design: This cross-sectional study was conducted on 80 histologically proven cases of endometrial carcinoma over a period of 18 months in a tertiary care centre. Representative tumour sections were immunohistochemically analysed for expression of key mismatch repair proteins. Nuclear expression loss in tumour cells was taken as an indication of deficiency. Associations were evaluated against clinical data, such as years, menopausal category and presenting symptoms, and histopathological data, such as tumour type, grade and stage. Results: Mismatch repair deficiency was detected in 28.7% of patients. The commonest pattern of concomitant loss of two proteins, mainly in tumours of endometrioid histology. Tumours that were deficient were statistically significantly associated with higher tumour grade and increased depth of myometrial invasion. However, no significant association was found with patient age, menopausal status or tumour stage. The results indicate a discrete subset of tumours with specific biological behaviour. Conclusions: A considerable proportion of endometrial carcinomas harbour mismatch repair deficiency. Routine immunohistochemical assessment may be an inexpensive screening tool to identify that subset of patients who would benefit from further molecular testing, genetic counselling and targeted therapeutic approaches including immunotherapy.