THE SIGNIFICANCE OF PROLIFERATING CELL NUCLEAR ANTIGEN IN HUMAN TROPHOBLASTIC DISEASE - AN IMMUNOHISTOCHEMICAL STUDY

The expression of proliferating cell nuclear antigen (PCNA) in human t rophoblastic disease was assessed immunohistochemically in tissue from 29 spontaneous abortions, 33 partial moles, 40 complete moles and 23 choriocarcinomas using the monoclonal antibody PC10. PCNA immunoreacti vity occurred predominantly in the cytotrophoblasts in each of the fou r types of tissues. Quantitative analysis showed that the choriocarcin oma group gave a statistically significant higher PCNA index than the other three. There was no significant difference between the groups of spontaneous abortion, partial or complete mole. Sixteen of the 73 pat ients with partial and complete moles developed persistent gestational trophoblastic disease and there was no significant difference between the patients requiring chemotherapy and those who did not. We conclud e that choriocarcinoma has a significantly higher PCNA proliferative i ndex whilst hydatidiform moles cannot be distinguished from abortions by such analysis. The PCNA index does not appear to be useful in predi cting the progression of molar pregnancies to persistent trophoblastic diseases.