Recent Pregnancy Is Not Associated with High-Risk Pathological Features of Well-Differentiated Thyroid Cancer

Diagnostic and Treatment Considerations for Thyroid Cancer in Women of Reproductive Age and the Perinatal Period

Thyroid cancer is one of the most common cancers diagnosed in women of reproductive age and during pregnancy. This leads to important questions about thyroid cancer prognosis and treatment, but also fertility and risk for adverse obstetric and/or fetal and neonatal outcomes. The benefits of thyroid cancer treatment should be weighed against its harms, as various options may adversely impact maternal and fetal health. In the current review, the authors focus on perinatal-specific clinical considerations related to the care of patients with thyroid cancer.

Clinical course and outcome of differentiated thyroid cancer patients with pregnancy after diagnosis of distant metastasis

PURPOSE

There is no sufficient data about the clinical course and outcome in thyroid cancer patients who become pregnant after diagnosis of distant metastasis (DM). The current study was conducted to collect information regarding the clinical and reproductive characteristics, and outcomes in thyroid cancer patients who became pregnant after being diagnosed with DM.

METHODS

Records of 125 differentiated thyroid cancer (DTC) patients with age ≤45 years at DM diagnosis who had visited Ito Hospital from January 2005 to June 2021 were retrospectively reviewed. Among those 125 patients, 28 who became pregnant after DM diagnosis were classified as pregnancy group, and the remained 97 patients were classified as comparator group.

RESULTS

In pregnancy group, the median age at malignancy diagnosis, DM diagnosis, and first pregnancy after DM diagnosis was 25 years (range, 4-41 years), 27 years (range, 11-41 years), and 32 years (range, 25-45 years), respectively. Fifty-five pregnancies and 40 live births were reported. Other pregnancy outcomes were miscarriage (n = 14) and induced abortion (n = 1). The 10-year progression-free survival (PFS) rates of pregnant and comparator group were 92.1% and 74.4%, respectively (p = 0.018). The multivariate analysis showed that multiple ¹³¹I treatment was independent negative prognostic factor for PFS (p = 0.046).

CONCLUSIONS

DTC patients with age ≤45 years at DM diagnosis had good survival even though they became pregnant. Our results add to the information required for counseling thyroid cancer patients who have concerns about their fertility in the future.

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

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.

Pregnancy outcomes after thyroid cancer

Background Thyroid cancer is one of the most common cancers in women of reproductive age. Our purpose was to evaluate the association between thyroid cancer and maternal and neonatal outcomes of pregnancy. Methods We conducted a retrospective cohort study using the Healthcare Cost and Utilization Project, Nationwide Inpatient Sample (HCUP-NIS) database from the US. A cohort consisting of women who delivered between 1999 and 2014 was created. Multivariate logistic regression, controlling for baseline maternal characteristics, was used to compare pregnancy complications and neonatal outcomes of pregnant women with thyroid cancer [International Classification of Diseases, ninth edition (ICD-9) code 193] diagnosed before or during pregnancy with those of the obstetric population without thyroid cancer. Results The study included 14,513,587 pregnant women, of which 581 women had a diagnosis of thyroid cancer (4/100,000). During the observation period, there was an upward trend in the prevalence of thyroid cancer among pregnant women, though not statistically significant (P = 0.147). Women with thyroid cancer were more likely to be Caucasian, belong to a higher income quartile, have private insurance, to be discharged from an urban teaching hospital and to have pre-gestational hypertension. Women with thyroid cancer had a greater chance of delivering vaginally, requiring transfusion of blood and developing venous thromboembolism (VTE). Neonates of mothers with thyroid cancer were not found to be at increased risk for the adverse neonatal outcomes examined, specifically, congenital malformations, intrauterine growth restriction, fetal death and preterm labor. Conclusion Pregnancies complicated by thyroid cancer have higher incidences of VTE and need for transfusions, with comparable overall newborn outcomes.

Pregnancy as a risk factor for thyroid cancer progression

PURPOSE OF REVIEW

The current review evaluates the impact of pregnancy on women with thyroid cancer in three different clinical situations: those with newly diagnosed differentiated thyroid cancer (DTC), those under active surveillance for papillary thyroid microcarcinomas (PMCs), and those with previously treated DTC.

RECENT FINDINGS

Recent pregnancy is not associated with high-risk pathological features of DTC. In women with known PMCs under active surveillance, pregnancy does not increase the risk of disease progression. Thus, deferring surgery for newly diagnosed DTC or known PMCs until after delivery is safe for both mother and the unborn child. If a woman with previously treated DTC is planning pregnancy, response-to-therapy status is an excellent guide for predicting pregnancy-associated disease progression or recurrence.

SUMMARY

Clinical studies consistently show that pregnancy is not associated with significant disease progression in newly diagnosed thyroid cancer, PMCs under active surveillance, or previously treated DTC.