Pregnancy Does not Affect the Prognoses of Differentiated Thyroid Cancer Patients With Lung Metastases

Abstract Context Pregnancy-related hormones may stimulate thyroid cancer growth, but whether pregnancy affects the prognoses of patients with lung metastases from differentiated thyroid cancer (DTC-LM) after surgery and radioiodine therapy is unclear. Objective To assess the impact of pregnancy on DTC-LM through the comparison of prognoses between female patients with DTC-LM who did and did not become pregnant after surgery and radioiodine therapy. Methods We retrospectively analyzed the records of 124 female patients aged 16 to 35 years who underwent surgery and radioiodine therapy for DTC-LM. These patients were divided into pregnancy group (n = 37) and nonpregnancy group (n = 87) according to whether they became pregnant after surgery and radioiodine therapy, regardless of whether they had a pregnant history before treatment. Results The 5- and 10-year progression-free survival rates were 94.52% and 63.22% in pregnancy group versus 89.82% and 58.13% in nonpregnancy group. The 5- and 10-year cumulative overall survival rates of pregnancy group were 97.30% and 85.77% versus 93.50% and 81.95% in nonpregnancy group (all P > 0.05). The median time of follow-up in the pregnancy and nonpregnancy groups was 82 months (25-136 months) and 68 months (13-133 months), respectively. Non–radioiodine-avid LM and primary tumors needing repeated resection were independent predictors of poor progression-free survival for patients in pregnancy group. Conclusion Pregnancy does not affect the prognoses of patients with DTC-LM after surgery and radioiodine therapy. Non–radioiodine-avid LM and repeated primary tumor surgeries are independent risk factors for poor prognoses of pregnant patients.