Lung metastases in low-risk gestational trophoblastic neoplasia: a retrospective cohort study.

Objective: Presence of lung metastases in low-risk gestational trophoblastic neoplasia (GTN) is generally considered not to influence prognosis. However, in a recent study in the Netherlands, GTN patients with lung metastases had a higher recurrence rate and more disease-specific deaths compared with patients without metastases. The aim of the present study was to validate these findings in a different country.

Design: Historical cohort study.

Setting: Charing Cross Hospital, United Kingdom.

Population: A total of 1040 low-risk GTN patients treated with methotrexate (MTX) between 2002 and 2016 were identified: 65 with lung metastases (group 1) and 975 without metastases (group 2).

Methods: Baseline characteristics, MTX resistance, survival and recurrence rates were recorded and compared between both groups.

Main Outcome Measures: MTX resistance, recurrence rate and survival.

Results: The occurrence of MTX resistance and median number of MTX courses to achieve remission was significantly higher in patients with lung metastases than patients without metastases (60% versus 38.9%, P = 0.001; and nine versus six courses, P < 0.001). All choriocarcinoma patients (n = 4) with lung metastases developed MTX resistance. The recurrence rate was also higher in group I (9.2% versus 2.7%; P = 0.012). Disease-specific survival was 100% in both groups.

Conclusions: The presence of lung metastases at the start of MTX therapy is associated with increased incidence of MTX resistance and recurrence in low-risk GTN without affecting overall survival, which remains 100%. However, individuals with low-risk choriocarcinoma with lung metastases are likely to become resistant to MTX and primary multi-agent chemotherapy should be considered.

Tweetable Abstract: The presence of lung metastases appears to increase the risk of recurrence in low-risk GTN, but does not affect overall cure rates and survival.