[Analysis of prophylactic chemotherapy outcome and clinical characteristics in patients of high-risk hydatidiform mole].

Objective: To analyze prophylactic chemotherapy outcome and clinical characteristics in patients of high-risk hydatidiform mole.

Methods: Twenty-three patients who were diagnosed as high-risk hydatidiform mole and undergone prophylactic chemotherapy in our hospital were retrospectively analyzed. After prophylactic chemotherapy, 11 patients didn't develop to gestational trophoblastic neoplasia (GTN), while the other 12 patients developed to GTN and needed a regimen change to combination chemotherapy. The clinical characteristics of these patients and outcome of prophylactic chemotherapy were compared between two groups.

Results: There was no significant difference between the two groups on patients' age, weeks of delayed menses, enlarged uterine size excessive for gestational age, and incidence of theca-lutein cysts of ovaries. However, the median levels of pre-evacuation serum β-hCG in two groups were 469 144 U/L and 768 044 U/L respectively, and median days needed for β-hCG declining to normal (≤ 2 U/L) at the first time were 71 and 120 days respectively, which were both significantly different between two groups. Analyzed with receiver operating characteristics (ROC), the level of serum β-hCG could be a predictor for prognosis. Choosing 750,000 U/L as the cut-off value, we could expect the serum β-hCG to have a specificity of 91% and a sensitivity of 58% to predict whether prophylactic chemotherapy will be successful.

Conclusions: For those patients who have to receive prophylactic chemotherapy because of risk factors and unavailable hCG assessments for follow-up, it's better to use double-agent or combination chemotherapy if the level of serum β-hCG reached 750 000 U/L so as to reduce therapy duration and prevent relevant chemoresistance.