Improved Adherence to ATA Medullary Thyroid Cancer Treatment Guidelines

The 2009 American Thyroid Association (ATA) guidelines for medullary thyroid cancer (MTC) were created to unify national practice patterns. Our aims were to (1) evaluate national adherence to ATA guidelines before and after 2009, (2) identify factors that are associated with concordance with guidelines, and (3) evaluate whether there is an association between survival and concordant treatment.

Patients with MTC were identified from the 2009 to 2015 National Cancer Database. Adherence to ATA recommendations regarding extent of surgery (R61-R66) was analyzed. Logistic regression was used to determine predictors of discordance and propensity score matching was used to compare concordant treatment rates between time periods. Kaplan-Meier survival analysis was used to determine association between survival and concordant treatment.

There were 3421 patients with MTC, and of these 3087 had M0 disease and 334 had M1 disease. We found that 72% of M0 cases adhered to R61-66, and 68% of M0 cases without advanced local disease were adherent to R61-63. Following propensity score matching, the adherence rate was 67% before 2009 and 74% after. Patient factors associated with discordant treatment were female gender, older age, treatment at a nonacademic facility, and living within 50 miles of the treatment facility. Adherence to guidelines was associated with improved overall survival (OS) (p < 0.01).

Treatment of MTC was discordant from guidelines in 26% of cases from 2009 to 2015 compared with 33% prior to 2009 in a propensity matched analysis, and was most often in cases with localized, noninvasive disease. Improved adherence to guidelines may improve overall survival.