PREDICTION OF MALIGNANT PROGRESSION OF MOLAR PREGNANCY BY P53 PROTEIN EXPRESSION IN MOLAR TISSUE

Tasrina Akter*, Ishrat Jabin, Abu Bakar Muhammad Nizamul Hoque Sikder, Shahana Begum, Roushan Akhter Jahan and Shahena Akter

ABSTRACT

Background: Gestational trophoblastic disease (GTD) is a heterogenous group of diseases characterized by abnormal proliferation of trophoblast tissue. The most common form of GTD is molar pregnancy. Some reports suggest that p53 expression in molar tissue that progressed to malignant disease was significantly higher than in hydatidiform mole (HM) that obtained spontaneous remission. Objectives: The aim of this study was to evaluate p53 protein expression in molar tissue for predicting malignant transformation of molar pregnancy. Materials and Method: This cross sectional analytical study was performed in the Department of Obstetrics and Gynecology, Chittagong Medical College Hospital. Consecutive sixty-three women with primary diagnosis of molar pregnancy was enrolled, who were subsequently had evacuation of HM. Histopathology was done and eight patients were excluded due to negative histopathology for HM and patients were followed up for 12 weeks to see the progression of the disease (spontaneous remission or GTN) by doing serum beta human chorionic gonadotrophin (βhCG). Five patients were excluded due to loss of follow up. Molar tissue blocks were collected and preserved and p53 immunohistochemistry was done. Results: Pre-evacuation levels of serum βhCG were >100000 mIU/mL and <100000 mIU/mL in 36 (72%) and 14 (28%) patients respectively. After 12 weeks 42 (84%) patients had <5 mIU/mL serum βhCG indicating spontaneous regression of the disease. 8 (16%) patients showed malignant transformation of the disease within this period. 31 patients (62%) had positive p53 expression and 19 (38%) had negative p53 expression. p53 had high sensitivity and negative predictive value (100%) but low specificity (45.2%) and positive predictive value (25.81%). The area under the Receiver Operating Characteristics curve for predicting malignant transformation was 0.938 with a proposed cut-off value of 42.5% stained cells which had sensitivity of 87.5% and specificity of 71.3%. Conclusion: Present study concludes that p53 protein expression was associated with malignant progression of molar pregnancy. Negative expression may predict spontaneous remission.

Keywords: GTD, GTN, ?hCG, p53.