The effect of prophylactic chemotherapy on treatment outcome of postmolar gestational trophoblastic neoplasia

Objective:To evaluate whether prophylactic chemotherapy (P-chem) increased the drug resistance rate of postmolar GTN and whether the first-line chemotherapy should be different from P-chem. Methods:Postmolar GTN received P-Chem was defined as P-Chem group. Postmolar GTN without P-chem was randomly selected as control group according to the ratio of 1:3 (P-chem:control) and matched by age for low risk and high risk GTN separately. Results:Totally 455 low-risk and 32 high-risk postmolar GTN patients were included. WHO risk score, chemotherapy cycles to achieve hCG normalization and resistant rate were similar between P-chem (27 cases) and control (81 cases) group. Among low-risk GTN patients, interval from hydatidiform mole to GTN was significantly longer in P-chem group than control (44 vs 69 days, P = 0.001). Total chemotherapy cycles and resistant rate were similar between low-risk GTN treated with same agent as P-chem (group A) and alternative agent (group B). But group A needed more chemotherapy cycles to achieve hCG normalization than group B. Conclusions:P-chem delayed the time to GTN diagnosis, but didn't increase risk score or lead to drug resistance of postmolar GTN. Alternative agent different from P-chem had the potential of enhancing chemotherapy response in low- risk postmolar GTN.