Background: Gestational trophoblastic tumor is one of the diseases arising from the trophoblastic epithelium of the placenta that causes many mothers to face serious risks and complications every year; Since the gestational trophoblastic tumors have different potentials for local invasion and distant metastasis, rapid diagnosis of the tumor, followed by appropriate treatment and prevention of its severe complications, is highly important.

Methods: In this cohort study, 272 women with pathologic diagnosis of trophoblastic tumors that referred to the gynecological oncology clinic of Imam Khomeini Hospital, were selected and then they were evaluated for clinical symptoms, disease stage, and treatment results in terms of complete response to chemotherapy and the number of required chemotherapy cycles for treatment. Data were analyzed using SPSS software

Results: The most common symptoms were vaginal bleeding with 64.3% and pelvic pain with 18.4%, respectively. 62% had hydatidiform mole and abortion was observed in 22% of cases. In total, resistance to chemotherapy was observed in 24% of cases. Regarding the response to single-drug treatment in stages 1 and 2, which were low risk, the effectiveness of treatment was 66.7% in methotrexate and 83.6% in actinomycin. Resistance to single-drug chemotherapy in the methotrexate and actinomycin D groups was 16% and 33.3%, respectively. In the EMACO combination drug regimen, the therapeutic efficacy was 93.8% and in the EMAEP was 100%, and the resistance to chemotherapy in the EMACO combination drug treatment was 6.2% and in the EMAEP was very low.

Conclusion: Resistance to chemotherapy medications was observed in about a quarter of cases. Advances in targeted molecular therapy and new medications could be effective in improving therapeutic performance, especially in drug-resistant patients

Keywords: Gestational trophoblastic tumor, Clinical symptoms, Malignancy, Drug resistance