Are serum inhibin concentrations new markers of placental tumours in the course of chemotherapy?

BACKGROUND: The study was conducted to evaluate whether the detection of se rum molecular forms of inhibin (A and B) could be useful for the diagnosis, prognosis and follow-up of placental tumours. METHODS: A total of 17 patie nts with hydatidiform mole (n = 13), invasive mole (n = 1) or choriocarcino ma. (n = 3) were studied; serum concentrations of inhibins A and B, human c horionic gonadotrophin (HCG) and its free beta subunit (HCG beta) were meas ured before chemotherapy (after mole evacuation for eight patients) and als o during the course of chemotherapy (for 10 patients). RESULTS: After evacu ation or before chemotherapy for refractory disease, serum inhibin A and B concentrations were found to be increased in 10/17 and 4/17 patients, when HCG and HCG beta were high in all patients. In 10 patients with a follow-up during treatment, nine had a high concentration of inhibin A which correla ted with those of HCG and HCG beta. Normalization of inhibin A was faster t han that of HCG and HCG beta for three and six patients respectively. There was no correlation between changes of inhibin B and HCG beta concentration s. CONCLUSIONS: Our results suggest that inhibins A and B are not useful ma rkers and that HCG determination still remains the most useful marker for d iagnosis and follow-up of placental tumours.