Patterns of care of gestational trophoblastic disease in Ontario: a population-based study

Objectives — Gestational trophoblastic disease (GTD) is a rare condition that affects reproductive-age women with excellent clinical outcomes if treated appropriately. The study aims to describe patterns of care of GTD in Ontario, Canada between 2005-2022.

Methods — Using province-wide administrative databases, individuals with molar pregnancies and gestational trophoblastic neoplasia (GTN) were identified between 2005-2022. Patient characteristics included age, socioeconomic status, comorbidities, type of treatment, type of provider and type of chemotherapy. Descriptive statistics were used to analyze baseline characteristics. Characteristics of low-risk GTN were compared to those of high-risk GTN to determine differences. Overall survival is reported with Kaplan–Meier curves.

Results — Between 2005-2022, there were 2,334,219 hospital births recorded in Ontario, among which 1,660 molar pregnancies were identified (0.7 per 1,000 births). Suction evacuation was the most common management (91.0%), while 9.0% underwent hysterectomy. Patients treated with hysterectomy were significantly older (mean 36 vs. 31 years, p<0.01). Procedures were performed by general gynecologists (83.0%) and gynecologic oncologists (16.0%, p<0.01). Among 385 patients treated with GTN-chemotherapy, 87.3% had low-risk and 12.7% high-risk GTN. High-risk patients were older (mean 37 vs. 33 years, p=0.01) and more likely to have undergone hysterectomy (24.5% vs. 10.1%, p<0.01). Low-risk and high-risk GTN were mostly treated with a single line of chemotherapy (77.7%). Gynecologic oncologists provided most first-line chemotherapy (77.4%) compared to medical oncologists (19.5%). At least 1 subsequent hospital birth was noted in 28.0% of GTN patients and 17.4% had 2 or more. Eight deaths occurred (2.1%), primarily within the first 2 years of diagnosis, yielding a 5-year overall survival of 97.9%.

Conclusions — While survival for GTN in Ontario appears excellent for a cohort including mostly low-risk GTN, under-ascertainment may mask variability in treatment and outcomes. Our findings support mandatory reporting, centralized referral, and a provincial registry to reliably define care and drive improvements.