Comparison of 5-day MTX and 5-day ETP treatment results and early predictors of drug resistance to 5-day MTX in patients with post-molar low-risk gestational trophoblastic neoplasia.

OBJECTIVE: To determine the primary remission rates and predictors of drug resistance in patients with post-molar low-risk gestational trophoblastic neoplasia (GTN) who were treated with a 5-day intramuscular methotrexate (5-day IM MTX) or a 5-day drip infusion etoposide (5-day DIV ETP) regimen. METHODS: Between 1980 and 2014, 166 consecutive patients with low-risk post-molar GTN were initially treated with a 5-day IM MTX or a 5-day DIV ETP regimen. The primary remission rates, changes in chemotherapy due to drug resistance or toxicity, and relapse rates were compared. Furthermore, we analyzed the factors that influenced the development of resistance to MTX. RESULTS: Primary remission rates were significantly higher among the ETP-treated patients than among the MTX-treated patients. Among the 42 patients who required a change in chemotherapy, 23 patients (22.6%) and 4 patients (6.3%) were diagnosed as being resistant to MTX and EPT, respectively. Maternal age and the presence of metastasis did not significantly influence the development of MTX resistance, although higher FIGO scores and pre-treatment human chorionic gonadotropin (hCG) levels of >5×10(4)mIU/mL were significantly more common among patients who developed MTX resistance. Moreover, a <30% decrease in hCG after the first cycles of MTX chemotherapy was significantly associated with the development of MTX resistance. CONCLUSIONS: All patients with low-risk GTN eventually achieved complete remission, although several patients developed drug resistance to the first-line chemotherapy. A <30% decrease in hCG during the first chemotherapy cycle may be an early indicator of drug resistance after commencing a 5-day MTX regimen.

Normal human chorionic gonadotropin regression curves in uneventful postmolar patients.

OBJECTIVE: To review current follow-up measures of human chorionic gonadotropin (hCG) in uneventful postmolar patients, and to evaluate criteria for initiating chemotherapy. STUDY DESIGN: Between 1993 and 2011 hCG data from 395 patients with uneventful complete moles (CMs) (195 patients) and partial moles (PMs) (205 patients) were obtained at 4 hospitals in Japan. All patients had been followed regularly at various intervals based on the preceding hCG titers and normal hCG regression curve. RESULTS: All patients achieved hCG normalization spontaneously (range, 3.1-29.7 weeks). Approximately half of the patients with CM and PM had attained an undetectable hCG level at 9.3 and 8.3 weeks after evacuation of mole, respectively. The reconstructed normal hCG regression curve consisted of hCG levels of 1,000 mIU/mL at 5 weeks, 100 mIU/mL at 8 weeks and nondetectable hCG levels at 24 weeks. Plotting preceding hCG titers on this hCG regression curve, the intervals of visits to measure hCG were changing, and the real number of visits was significantly fewer than that of recommended weekly measurement of hCG (p<0.0001). CONCLUSION: The use of the present hCG regression curve after evacuation of a molar pregnancy can aid in estimation of the risk of developing gestational trophoblastic neoplasia, especially in women who have suboptimal compliance and follow-up.