TSH therapy helps avoid hypothyroid period after thyroid cancer surgery

Following thyroid cancer surgery, treatment with recombinant TSH (rTSH) during radioiodine remnant ablation can allow patients to continue their thyroid hormone treatments, and thus avoid a hypothyroid period, new research suggests.

“For the last 5 years, rTSH has been approved by the US Food and Drug Administration for diagnostic purposes,” Dr. Paul Ladenson, from Johns Hopkins School of Medicine in Baltimore, told Reuters Health. “What is novel about this study is that it is the first randomized, prospective controlled trial demonstrating a therapeutic application for rTSH.”Dr. Ladenson presented his teams’ findings this week at the 86th annual meeting of The Endocrine Society in New Orleans.After total thyroidectomy, a small amount of remnant tissue is typically present. To destroy this tissue, radioactive iodine is given, which typically requires withholding thyroid hormone therapy to ensure optimal uptake of the radioiodine in the remnant. By giving rTSH, also called thyrotropin alpha (Thyrogen), adequate uptake can, in theory, still occur even if thyroid hormone therapy is not withheld.To investigate, the researchers assessed the outcomes of 63 patients who underwent surgery for thyroid cancer and were randomized to receive thyroid hormone therapy and rTSH or to withhold thyroid hormone therapy while undergoing remnant ablation.At 8-month follow-up, the effectiveness of radioiodine ablation in both groups was comparable, based on three different measures. Moreover, based on radioiodine uptake testing, ablation was 100% effective in each group. “Up to 60% of patients in the hormone withdrawal group had symptoms of hypothyroidism, such as weight gain, constipation, dry skin, and impaired mentation,” Dr. Ladenson noted. By contrast, he said, “these symptoms were absent in the rTSH group.” “The question now is whether the FDA will consider the results from this trial of 63 patients sufficient to add remnant ablation to the labeling for rTSH,” Dr. Ladenson said.(Source: Reuters Health: Anthony J. Brown, MD: Oncolink: June 2004)