VANCOUVER — Physicians may be winning the battle against pediatric papillary thyroid carcinoma—while losing the war, Ian D. Hay, M.B., said at the annual meeting of the American Thyroid Association.
He studied 189 consecutive patients who underwent initial surgical management of papillary thyroid carcinoma prior to age 21 (median age, 16 years). They were then followed far into adulthood, for a median of 28 years and a maximum of 60 years.
The good news is mortality due to recurrent thyroid cancer was a mere 3% through 50 years of follow-up, with the first such death not occurring until 26 years after initial therapy. The bad news: a much higher than expected late all-cause mortality, mostly due to non-thyroid cancers, said Dr. Hay, professor of medicine at the Mayo Clinic, Rochester, Minn.
All-cause mortality wasn't excessive through the first 20 years of follow-up but began rising thereafter. During years 30–50 of follow-up, when actuarial data predicted 9.3 deaths, there were actually 22 deaths. Sixteen of the 22 were due to cancer, with 13 of the 16 deaths involving 9 separate types of non-thyroid cancer.
All but 2 of the 13 patients who died of non-thyroid cancer had a history of therapeutic radiation as part of the treatment for their thyroid cancer. Since 1950, postoperative radioiodine remnant ablation has been administered to 28% of thyroid cancer patients at the Mayo Clinic, he said.