The Effect Of Prophylactic Chemotherapy On Treatment Outcome Of Postmolar Gestational Trophoblastic Neoplasia

Objective:To evaluate if prophylactic chemotherapy(P-Chem)increased the drug resistance of postmolar gestational trophoblastic neoplasia(GTN)and if an alternative agent different from P-Chem should be suggested as first-line chemotherapy for low-risk GTN.Methods:Postmolar GTN received P-Chem were classified as P-Chem group,while postmolar GTN without P-Chem were matched according to age and high risk/low risk GTN,and then were randomly selected as control group according to the ratio of 1:3(P-Chem:control).The clinical parameters of these patients were collected and compared.Results:Totally 455 low-risk and 32 high-risk postmolar GTN patients were treated at ourhospital between 2008.01.01 and 2017.12.31.P-Chem group included 24 low-risk and3 high-risk GTN,while control group included 72 low-risk and 9 high-risk GTN.Among low-risk GTN patients,interval from HM to GTN was significantly longer in the P-Chem group than control(69 vs 44 days,P=0.001),while the serum h CG level before first-line chemotherapy was significantly lower in the P-Chem group than control(415.8 vs 4503.5 IU/L,P=0.000).In a result,there was no significantly different for WHO risk score(2 vs 2,P=0.208)between both groups.More over,chemotherapy cycles to achieve h CG normalization(4 vs 3,P=0.157)and first-line resistant rate(40% vs 42%,P=0.904)were similar between control and P-Chem group.Among high-risk GTN patients,WHO risk score,chemotherapy cycles to achieve h CG normalization and resistant rate were also similar between P-Chem and control.Chemotherapy response was further compared between low-risk GTN treated with same agent as P-Chem(group A)and GTN treated with alternative agent(group B).Total chemotherapy cycles and resistant rate were similar between group A and group B.But group A needed more chemotherapy cycles to achieve h CG normalization than group B,no matter in all 24 P-Chem GTN(4.4 vs 2.8,P=0.024)or in 22 GTN received methotrexate as P-Chem(3 vs 2,P=0.004).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 increasing chemotherapy response in low-risk postmolar GTN.