Lobectomy for treatment of differentiated thyroid cancer: can patients avoid postoperative thyroid hormone supplementation and be compliant with the American Thyroid Association guidelines?

Background: The American Thyroid Association recommended thyroid lobectomy as an alternative for low-risk differentiated thyroid cancer. One hypothetical benefit includes avoiding lifelong thyroid hormone supplementation; however, guidelines recommend maintaining the thyroid-stimulating hormone <2 mIU/L postoperatively in low-risk patients. Our hypothesis is that most patients will require hormone supplementation to maintain thyroid-stimulating hormone <2 mIU/L, minimizing this advantage of lobectomy. The goal of this study is to determine how often patients have thyroid-stimulating hormone <2 mIU/L after lobectomy without thyroid hormone supplementation.

Methods: A retrospective review of 555 consecutive patients who underwent thyroid lobectomy was performed. Thyroid hormone supplementation was documented, along with thyroid-stimulating hormone levels preoperatively, 7 to 10 days, and 2 to 12 months postoperatively.

Results: In the study, 478/555 (86%) patients did not take thyroid hormone before thyroidectomy; 394/478 (82%) had thyroid-stimulating hormone levels available at 7 to 10 days postoperatively, and of these, 218 (55%) had thyroid-stimulating hormone >2 mIU/L. From 2 to 12 months postoperatively, of the 225 patients who continued to remain off thyroid hormone supplementation, 132 (59%) experienced a thyroid-stimulating hormone increase to >2 mIU/L; therefore, 350/478 (73%) patients after thyroid lobectomy had thyroid-stimulating hormone levels >2 mIU/L within a year.

Conclusion: It is important to counsel patients that to be compliant with the American Thyroid Association guidelines for differentiated thyroid cancer, the majority of patients undergoing thyroid lobectomy may require thyroid hormone supplementation to maintain a thyroid-stimulating hormone level <2 m IU/L.