LAUSR

Medullary thyroid cancer (MTC) accounts for only approximately 5% of all thyroid cancers but confers a proportionately worse prognosis. In part because medullary thyroid cancer is such a rare malignancy, it has been a challenging disease to study within single institutions, even from high-volume hospitals that have expertise with MTC. The article in this issue of JAMA Surgery by Kuo et al1 is a populationbased study of patients with medullary thyroid cancer, attempting to define risk factors associated with disease recurrence within the confines of a large statewide cancer registry. The American Thyroid Association (ATA) published its first set of guidelines for MTC in 2015.2 The recommendation for initial operation for patients with newly diagnosed MTC includes a total thyroidectomy and bilateral central lymph node dissection. In contrast, lateral neck dissection is prompted by clinical or radiographic findings suggestive of metastases. In this population-based study of 609 patients with MTC treated from 1999 to 2012, the initial surgical treatment was only a thyroid lobectomy in 7.6% of patients. A little more than one-third of patients underwent subtotal/total thyroidectomy alone (36.3%). Despite the ATA guidelines, only 35.5% underwent subtotal or total thyroidectomy with concomitant central neck dissection as the initial treatment for MTC. Subtotal/total thyroidectomy with central and lateral neck dissection was performed in 25.5%. Similar to prior reported series, the recurrence rate was high. Of the 609 patients, the rate of reoperation was 16.3%. On multivariate analysis, the presence of nodal metastases increased the risk of reoperation (hazard ratio, 3.43; 95% CI, 2.00-5.90), while central and lateral neck dissection performed at the initial operation was protective (hazard ratio, 0.53; 95% CI, 0.30-0.93). Interestingly, reoperation was not associated with increased mortality on multivariate analysis. There are several important lessons from this population study of patients with MTC. First, despite the recommendation for total thyroidectomy and bilateral central neck dissection in patients with clinically diagnosed MTC, a fair proportion of affected patients are not getting these operations. Second, neck dissection performed at the initial operation may be protective. Third, while many patients with MTC develop recurrent disease, reoperations are not associated with increased mortality. Thus, even patients with recurrent and metastatic MTC can be treated with repeated reoperations and still live full and active lives. It is therefore critically important to minimize complications along their sometimes decades-long disease course.