American Thyroid Association Guidelines and National Trends in Management of Papillary Thyroid Carcinoma: JAMA

The American Thyroid Association (ATA) defines low risk PTC as tumors 4 cm or less in largest diameter, confined to the thyroid, and without clinical lymph node involvement.8 The ATA has released guidelines recommending progressive de-escalation of management of low-risk PTCs.

Alex J. Gordon and team analyzed clinical characteristics and treatment of low-risk PTC using the National Cancer Database (NCDB), the largest cancer database available. This historical cohort study used the National Cancer Database. All papillary thyroid carcinomas diagnosed from 2004 to 2019 in the National Cancer Database were selected. Patients with tumors of greater than 4 cm, metastases, or clinical evidence of nodal disease were excluded. Data were analyzed from August 1, 2021, to September 1, 2022.

The primary aim was to tabulate changes in the rates of thyroid lobectomy (TL), total thyroidectomy (TT), and TT plus radioactive iodine (RAI) therapy after the 2009 and 2015 ATA guidelines. The secondary aim was to determine in which settings (eg, academic vs community) the practice patterns changed the most.

A total of 1,94,254 patients who underwent treatment during the study period were identified. Among patients who underwent surgery, rates of TL decreased from 15.1% to 13.7% after the 2009 guidelines but subsequently increased to 22.9% after the 2015 changes.

Among patients undergoing TT, rates of adjuvant RAI decreased from 48.7% to 37.1% after 2009 and to 19.3% after the 2015 guidelines.

Trends were similar for subgroups based on sex and race and ethnicity. However, academic institutions saw larger increases in TL rates (14.9% to 25.7%) than community hospitals (16.3% to 19.5%).

Additionally, greater increases in TL rates were observed for tumors 1 to 2 cm (6.8% to 18.9%) and 2 to 4 cm (6.6% to 16.0%) than tumors less than 1 cm (22.8% to 29.2%).

In this large, nationally representative cohort study, authors found de-escalation in the treatment of low-risk PTC up to 4 cm. The use of radioactive iodine therapy following TT decreased significantly. Moreover, they observed a small decrease in the rate of TL after the 2009 guidelines, followed by a large increase in the rate of TL after the updated 2015 guidelines.

The incidence of PTC has increased over the past several decades. Due to its indolent behavior and relatively favorable prognosis, the ATA has modified its guidelines and encourages treatment de-escalation for tumors that are classified as low-risk. The current study identified de-escalations in the treatment of low-risk PTC following the implementation of the 2009 and more conservative 2015 ATA guidelines, consistent with previous reports using other databases. Furthermore, this study demonstrated that the rates of change in these practice patterns were different before and after publishing these guidelines. Interestingly, the overall rate of TL decreased from 15.1% to 13.7% after the 2009 guidelines were published. At the same time, authors noted that the annual rate of change in this proportion was decreasing prior to the guidelines and became roughly constant after these guidelines. Accordingly, the overall decrease in the rate of TL likely reflects a pre-existing trend, and this increase in the annual rate of change between time periods suggests that the guidelines ultimately did correspond with practitioners' willingness to consider TL as opposed to TT.

Throughout the study period, tumors of 1 cm or smaller saw more minor changes than larger tumors, likely attributable to the more conservative management of these tumors before either of the guideline changes. Additionally, academic medical centers saw larger changes in practice patterns than community hospitals or integrated facilities. This is consistent with findings of increased surgical guideline adherence among high volume surgeons in urologic oncology and gynecologic oncology.

Overall, these findings suggest that ATA guidelines broadly correspond with the care of low-risk PTC; however, these guidelines are just one of several substantial changes in the management of thyroid carcinomas that have taken place during the study period. Improvements in ultrasonography and fine needle aspiration, the addition of molecular testing, and the reclassification of various pathologic entities as noninvasive follicular thyroid neoplasm with papillary like nuclear features are among the many factors that have altered the management of thyroid carcinomas.

These newer diagnostic and therapeutic options, in conjunction with improved understanding of the risk of adverse outcomes in these tumors, have allowed for the de-escalation of treatment proposed by the ATA guidelines. The study data suggest that the most substantial opportunity to increase adherence to guidelines might lie in more educational efforts geared toward community practitioners and physicians outside academic centers who treat low-risk thyroid cancers. Decreasing the burden of treatment for these patients could result in substantial cost savings and reduction of complications such as hypoparathyroidism and recurrent laryngeal nerve injury

The incidence of PTC has increased over the past several decades. The 2009 and 2015 ATA guidelines encourage de-escalation of treatment for low-risk PTC up to 4 cm. This analysis found that the guideline changes corresponded with de-escalation of care, both in increasing TL rates and decreasing use of adjuvant RAI in patients undergoing TT. However, the magnitude of these changes varied greatly by tumor size, practice setting, and geographic region. As physician practices could lag behind new recommendations, further de-escalation of care may take place.

Source: Alex J. Gordon, Jared C. Dublin, Evan Patel, JAMA Otolaryngology–Head & Neck Surgery

doi:10.1001/jamaoto.2022.3360