Objective The aim of this study was to evaluate the efficacy and toxicity profile of the cyclophosphamide, hydroxyurea, actinomycin D, methotrexate, and vincristine (CHAMOC) regimen in the treatment of high-risk gestational trophoblastic neoplasia (GTN).

Methods We conducted a retrospective study of all patients with GTN treated with the CHAMOC regimen between 1985 and 2012 in a tertiary referral center in Hong Kong. Medical records were reviewed, and data were analyzed. Response rate and toxicity profile were assessed.

Results The CHAMOC regimen was given to 79 patients from 1985 to 2012, with a total of 388 cycles administered. Among the 79 patients, CHAMOC was given to 68 as the primary treatment of high-risk GTN, whereas it was used as the salvage chemotherapy in 11 patients for failure with other chemotherapy regimens or recurrent disease. Complete remission was achieved in 58 patients (85.3%) in the primary treatment group and 8 patients (72.7%) in the salvage treatment group. Grade 3 and grade 4 neutropenia were observed in 13.0% and 3.4% of the chemotherapy cycles, respectively. Grade 3 or 4 thrombocytopenia was rare (1.3% of all treatment cycles). No secondary malignancy was observed in our patients with a mean duration of follow-up of 9.7 to 13 years, except 1 patient with advanced colon cancer diagnosed shortly after chemotherapy, which was unlikely to represent a secondary malignancy from the chemotherapy.

Conclusions The CHAMOC regimen should be considered as an alternative to other chemotherapy regimens in the primary treatment of high-risk gestational trophoblastic disease, with comparable efficacy, similar short-term side-effects profile, and potentially fewer long-term complications.