Induction chemotherapy regimens in malignant trophoblastic tumors with high risk of resistance: retrospective study

Background. High sensitivity of gestational throphoblastic disease (GTD) to chemotherapy makes this disease highly curable, but rapid destruction of tumor can lead to development of life-threatening complications. Low-dose chemotherapy before the main anticancer treatment can reduce these risks, but the effects on long-term outcomes are not sufficiently studied. We conducted a retrospective analysis of the N . N . Blokhin National Medical Research Center of Oncology experience in treating patients with high- and ultra-high risk GTD treated with low-dose induction or full-dose chemotherapy.Materials and methods. The monocenter comparative retrospective study included patients with high or ultra-high risk GTD who received initial treatment in 2000–2023. Patients with rare GTD subtypes, patients who had previously received any chemotherapy were excluded. Patients who received low-dose induction chemotherapy with etoposide + cisplatin comprised the experimental group, while those who received full-dose chemotherapy comprised the control group. After completion of low-dose chemotherapy, standard multidrug chemotherapy was administered until normalization of serum beta human chorionic gonadotropin (β-hCG), followed by consolidation chemotherapy. The primary endpoint of the study was 1-year progression-free survival.Results. The study included 70 patients with GTD, 21 (30 %) patients received low-dose induction chemotherapy. In this group, more patients had ECOG performance status ≥2, clinically significant bleeding, or central nervous system metastases. With median follow-up of 54.6 months, 1-year progression-free survival was 81 % in the low-dose induction chemotherapy group and 90 % in the control group, the differences were not statistically significant (hazard ratio 1.63; 95 % confidence interval 0.46–5.80; p = 0.447). Complete β-hCG response was noted in 16 (77 %) patients in the lowdose induction group and 43 (88 %) patients in control group (p = 0.231). Three-year overall survival rates were 95 % and 98 %, respectively.Conclusion. The results of this retrospective study show no differences in survival of patients with high-risk and ultra-highrisk GTD receiving low-dose induction chemotherapy. In treatment of patients with high risks of complications due to tumor process and/or drug therapy, low-risk induction chemoterhapy should be considered as an option