The influence of lung metastasis on prognosis of previously untreated gestational trophoblastic neoplasia patients

Abstract

Objective: To investigate the impact of lung metastases on the prognosis of patients with gestational trophoblastic neoplasia (GTN). Methods: Patients with International Federation of Gynaecology and Obstetrics (FIGO) stage Ⅰ-Ⅲ GTN receiving primary chemotherapy in Peking Union Medical College Hospital between July 2014 and December 2018 were retrospectively analyzed and divided into group 1 with lung metastasis and group 2 without lung metastasis. The baseline characteristics and treatment outcomes of the two groups were compared. The optimal cut-off values of the diameter of largest lung nodule associated with recurrence were identified by receiver operating characteristic (ROC) curves. Logistic regression analyses were performed to identify risk factors for prognosis. Survival analysis was performed by Kaplan-Meier method and Log rank test. Results: Of the 381 GTN patients enrolled (216 with lung metastases and 165 without lung metastases), the pretreatment β human chorionic gonadotrophin [median: 12 572 IU/L (1 832-51 594 IU/L) vs. 5 614 IU/L (559-26 140 IU/L), P=0.001] and FIGO score [median: 3 (1-6) vs. 2 (1-4), P=0.038] were significantly higher in patients with lung metastases than those without lung metastases. In patients with FIGO score≥5, the emergence of resistance (26.76% vs. 10.26%, P=0.036) and median number of chemotherapy courses to achieve complete remission [6 (6-8) vs. 5 (4-6), P<0.001] were significantly higher than patients with lung metastases. In patients with FIGO score 0-4, no significant difference was found in the treatment outcomes between the two groups(P=0.833). Among all patients with lung metastases, the ROC curve showed a sensitivity and specificity of 62.5% and 78.8%, respectively, for predicting recurrence when the length of the largest lung nodule was 1.6 cm, with an area under the curve (AUC) of 0.711 (95% CI: 0.550, 0.871, P=0.044). Multivariate logistic regression analysis suggested a significantly higher recurrence rate when the largest lung nodule was ≥1.6 cm (OR=7.394, 95% CI: 1.003, 54.520, P=0.049). The 1-year disease-free survival rate was significantly lower in patients with the largest lung nodule ≥1.6 cm than in patients with the nodule <1.6 cm (98.2% vs. 82.4%, P=0.001). Conclusions: Lung metastasis is associated with increased first-line chemotherapy resistance in patients with FIGO scores≥5. The diameter of the largest lung metastatic nodule ≥1.6 cm is an effective factor for predicting recurrence.