Medullary Thyroid Cancer: Are Practice Patterns in the United States Discordant from American Thyroid Association Guidelines?

Background: Surgery is the mainstay of treatment for medullary thyroid cancer (MTC), with long-term patient outcomes associated with adequacy of resection. This study benchmarked national practice patterns against 2009 American Thyroid Association (ATA) guidelines for MTC regarding use of thyroidectomy, lymphadenectomy, radioactive iodine (RAI), and external-beam radiotherapy (EBRT).

Methods: This is a cross-sectional, retrospective cohort study of MTC patients in the Surveillance, Epidemiology, and End Results Program database, 1973 to 2006. ATA recommendations 61 to 66 (extent of surgery), 85 (RAI), and 93 (EBRT) were analyzed. Outcome of interest was practice accordance with these recommendations. Predictors of accordance were determined and Kaplan-Meier survival analyses were performed.

Results: A total of 2033 patients with MTC were identified. Fifty-nine percent were women; 78% were white. Forty-one percent of patients did not receive appropriate surgical therapy (recommendations 61 to 63). Most patients with distant metastatic disease had less aggressive surgery and more EBRT (P < 0.001) (recommendations 64 to 66). Four percent of patients received inappropriate RAI (recommendation 85). Two hundred nine patients had gross incomplete resections, with 33% receiving postoperative EBRT (recommendation 93). Statistically significant predictors of receiving surgery discordant with ATA recommendations in multivariate analysis were patient age >65, female sex, earlier year of diagnosis (1988 to 1997), geographic region, intrathyroidal tumor extent, and tumor size of </=1 cm. Patients receiving surgery discordant with recommendations had shorter survival than those receiving surgery according to recommendations (P < 0.05).

Conclusions: Variation in practice patterns exist in the United States with regard to extent of surgery and lymphadenectomy for MTC. Dissemination of standardized guidelines is important to ensure optimal treatment with less variation in quality of care.