Management of differentiated thyroid cancer diagnosed during pregnancy

Abstract

Objective: To assess the outcome of thyroid cancer diagnosed during pregnancy. Design: Retrospective analysis of patients diagnosed between 1949 and 1997 with thyroid cancer presenting during pregnancy. Results: Nine women with a median age of 28 years were identified. A thyroid nodule was discovered by the clinician during routine antenatal examination in four cases, the remainder had noted a lump in the neck. In all patients, the nodule was reported to almost double in size during the pregnancy. One patient underwent subtotal thyroidectomy during the second trimester; eight were operated on within 3 to 10 months from delivery. Total thyroidectomy was performed in five and subtotal thyroidectomy in four. All tumours were well differentiated and ranged in size from 1 to 6 cm. Outcome: The median follow-up was 14 years (5-31 years). One patient relapsed locally requiring further surgery. One patient developed bone metastases dying 7 years after presentation; her planned treatment had been delayed because of an intervening pregnancy. Eight of the original cohort of patients are currently disease free. Conclusions: Differentiated thyroid cancer presenting in pregnancy generally has an excellent prognosis. When the disease is discovered early in pregnancy, surgery should be considered in the second trimester but radioiodine scans and treatment can be safely delayed until after delivery. In all cases, treatment should not be delayed for more than a year.

Recommendations of the Latin American Thyroid Society on diagnosis and management of differentiated thyroid cancer

“…Pregnant women who are diagnosed with thyroid cancer share similar physical findings, pathological tumor features and outcome as those who were not pregnant (73). Treatment in this group of patients is also similar to that in non-pregnant women.…”

Optimal timing of surgery in well-differentiated thyroid carcinoma detected during pregnancy

“…One survey found that 4.4% of thyroid cancers in young women were diagnosed during pregnancy [8], and it has been suggested that up to 10% of thyroid cancers that occur in women during their reproductive years are diagnosed during pregnancy or during the first year after delivery [13]. In contrast, our survey of patients over a 13-year period found 1,240 Korean women between 15 and 45 years old who were diagnosed with thyroid cancer, among which 20 cancers were detected during pregnancy, yielding an incidence of 1.6%.…”

“…According to the first opinion, since human chorionic gonadotropin released during pregnancy accelerates the growth of thyroid carcinomas [5,6], surgery should be performed during the second trimester rather than postponed until after delivery [7,8]. According to the second opinion, since the prognosis of thyroid cancer detected during pregnancy is similar to the prognosis in nonpregnant woman, surgery should be delayed until after delivery, thus preventing maternal complications and fetal death associated with surgery during pregnancy [9,10].…”

Cancer Treatment in Pregnancy

“…Surgery, in the form of thyroidectomy , can safely be performed during the mid-trimester with no increase in adverse maternal or neonatal outcomes [ 110 ]. Alternatively, if a differentiated cancer is noted later in gestation or the patient declines therapy during her pregnancy, surgery can be postponed until after delivery without impacting the long-term prognosis.…”