Trophoblastic neoplasia—A Workshop Report

Abstract

Gestational trophoblastic disease (GTD) represents a unique spectrum of disease that includes hydatidiform moles (HM) [complete, partial (PM) and invasive moles (IM)], choriocarcinoma (CC), persistent trophoblastic disease (PTD) and placental site trophoblastic tumour (PSTT). Different histopathological entities, biochemical features and cytogenetic status can define these diseases. These issues were the topics of the workshop on GTD, which was conducted by Hiroaki Soma (Saitama, Japan) and Brent Dubeshter (Rochester, New York). Most of the information available concerning the epidemiology of GTD continues to be poorly understood, because until now, geographical variations in the incidence of GTD only were being reported. For example, most reports of HM in developing countries come from data based in individual hospitals. Therefore, little information is available to account for the differences in the incidence of GTD in different countries and regions. Since the setting up of the Trophoblastic Disease Committee by the Japan Society of Obstetrics and Gynecology in 1956, the Committee has gradually made progress in promoting research on this disease. Registration records for GTD patients in every district have been collected annually in Japan since 1974 and have been based upon the population statistics. In the Introduction, presented by Hiroaki Soma, recent trends reflecting the incidence of antecedent pregnancies in choriocarcinoma patients registered from 1994 to 1997 collated by the Trophoblastic Disease Committee in Japan, demonstrated dramatic changes. The percentage of antecedent pregnancy for choriocarcinoma was preceded not by hydatidiform moles (16 per cent), but by normal birth (42 per cent), because of a significant decrease in the reported number of patients with hydatidiform moles in Japan. In comparison, a large number of hydatidiform moles have occurred in South Vietnam, which was associated with the war. In contrast, although the epidemiology of gestational trophoblastic disease in Himalayan mountain people is still unknown, an incidence of gestational trophoblastic disease in Nepal, based on reports from two hospitals, ranged from 2.64 to 7.07 per 1000 pregnancies and from 3.02 to 8.4 per 1000 deliveries. To date, there has been a considerable difference in the management of gestational trophoblastic disease between