eleRecombinant human thyrotropin to help confirm lack of evidence of radiation-induced differentiated thyroid cancer in young women seeking pregnancy

Abstract

BACKGROUND: Women with a history of differentiated thyroid
carcinoma who are contemplating pregnancy may wish reassurance
regarding apparent remission. However, the thyroid
hormone withdrawal needed to obtain serum thyroglobulin
testing (Tg) results in weeks-long biochemical and clinical hypothyroidism,
which could increase miscarriage and fetal death
rates if pregnancy occurred during withdrawal of thyroxine or
soon thereafter. Recombinant human thyrotropin (rhTSH) elevates thyrotropin exogenously, allowing uninterrupted thyroid
hormone therapy and avoids hypothyroidism.

MATERIAL AND METHODS: Thirty female radiation-induced
papillary thyroid carcinoma survivors who had undergone
total- or near-total thyroidectomy and who were now seeking
pregnancy (mean age 23.9 ± 1.8 years), and who were considered
cancer-free by local standards, underwent rhTSH-aided Tg
testing to help confirm remission. At the time of rhTSH testing,
mean follow-up after primary surgical treatment was 11.1 ±
3.9 years, and all patients had negative neck ultrasonography,
undetectable unstimulated serum Tg (< 0.2 ng/mL) and no
interfering anti-Tg antibodies. However, based on T3, N1 or M1
status, 28/30 (93.3%) patients had high recurrence risk.

RESULTS: rhTSH produced no serum Tg increase in 27/30
women (90.0%). Serum Tg increases to 0.4-0.9 ng/ml were
observed in 3 women, but careful neck ultrasonography found
no lymphadenopathy. Reassured about their remission, 14/30
women (46%) have become pregnant and delivered healthy
children in the 3 years since rhTSH-aided testing.

CONCLUSIONS: rhTSH-aided Tg testing is useful in confirming
absence of tumor in female patients with a history of radiation-induced
thyroid cancer who are seeking pregnancy, but who also
have a high risk of thyroid cancer recurrence