Clinical outcome of micrometastasis in the lung in stage IA persistent gestational trophoblastic disease

Computed tomography (CT) of the thorax can be used in the staging of persistent gestational trophoblastic disease (PGTD). However, the prognostic significance of micrometastasis in the lung detected by CT of the thorax has not been well documented. The aim of the study is to define the effect of micrometastasis on the clinical course of the disease.

Thirty-five patients who had nonmetastatic GTD underwent CT thorax examination before treatment in the Department of Obstetrics and Gynaecology, University of Hong Kong. All patients had workups which showed no evidence of metastasis and were diagnosed as FIGO stage IA. They all received methotrexate (MTX) infusion therapy.

Three groups of patients were identified based on the thorax CT findings. Sixteen patients (45.7%) showed no evidence of micrometastasis on CT thorax. Two of them (12.5%) had poor response to MTX with unsatisfactory fall in serum hCG levels requiring change of chemotherapy to actinomycin D. Nine patients had suspicious micrometastasis and one (11.1%) of them needed change of MTX. Ten patients had micrometastasis and one (10%) of them needed change of MTX. There was only one recurrence and it was in the suspicious micrometastasis group (11.1%). There was no statistically significant difference in the rate of poor drug response or recurrence among the three groups of patients.

Micrometastases in the lung do not affect the clinical outcome of patients with FIGO stage IA disease. CT thorax is not essential in the staging of GTD.