Key Points
Question
How have the 2009 and 2015 American Thyroid Association guidelines corresponded with the management of low-risk papillary thyroid carcinomas?
Findings
In this cohort study of 194 254 patients, the rate of thyroid lobectomy increased significantly from 15.1% to 22.9%, while the rate of adjuvant radioactive iodine therapy decreased significantly from 48.7% to 19.3%. These changes were more significant in magnitude among academic centers than in community hospitals.
Meaning
The changes to the 2009 and 2015 American Thyroid Association guidelines corresponded with significant changes in the treatment of low-risk papillary carcinomas; however, these changes were not uniform across practice settings.
Abstract
Importance
Over time, the American Thyroid Association (ATA) guidelines have increasingly promoted more limited treatments for well-differentiated thyroid cancers.
Objective
To determine whether the 2009 and 2015 ATA guidelines were associated with changes in the management of low-risk papillary thyroid carcinomas on a national scale.
Design, Setting, and Participants
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.
Main Outcomes and Measures
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.
Results
A total of 194 254 patients (155 796 [80.2%] female patients; median [range] age at diagnosis, 51 [18-90] years) 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%).
Conclusions and Relevance
In this cohort study among patients with papillary thyroid carcinomas up to 4 cm, ATA guideline changes corresponded with increased TL and reduced adjuvant RAI. These changes were primarily seen in academic institutions, suggesting an opportunity to expand guideline-based care in the community setting.
This cohort study determines how the 2009 and 2015 American Thyroid Association guidelines may have corresponded with trends in the management of patients with low-risk papillary thyroid carcinoma.
Introduction
In the US, the incidence of thyroid cancer has increased by 3% annually over the past several decades. This is attributable to increased diagnosis of papillary thyroid carcinoma (PTC), the most common subtype.1,2,3 Historically, total or near-total thyroidectomy (TT) and adjuvant radioactive iodine (RAI) therapy were recommended for most well-differentiated thyroid malignancies. However, recent studies have demonstrated equivalence in survival outcomes with thyroid lobectomy (TL) compared with TT.4,5,6 Other studies, such as that by Schvartz et al,7 have reported that adjuvant RAI does not improve overall or disease-free survival following TT for low-risk well-differentiated thyroid carcinomas.
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. In the 2009 ATA guidelines, the use of RAI was not recommended for cancers 1 cm or smaller, and lobectomy alone, or at most TT, was stated to be sufficient. For the treatment of low-risk cancers between 1 and 4 cm, 2009 ATA guidelines endorsed TT with the option to include RAI depending on patient-specific factors.9 The 2015 ATA guidelines went further and recommended that TL could be sufficient for low-risk tumors up to 4 cm.10
Evidence on outcomes of ATA de-escalation recommendations is limited. Previous studies that have used the Surveillance, Epidemiology, and End Results Program database to analyze changes in treatment for PTC of all sizes have observed no significant changes after the implementation of 2009 ATA guidelines and increased proportions of TT (2000, 78.2%; 2014, 85.7%) and decreases in TL (2000, 16.6%; 2014, 11.4%).1 More recent studies using the same source incorporated 2015 ATA guidelines and reported slight increases in rates of TL (2008, 20.5%; 2016, 26.9%) and corresponding decreases in TT (2008, 18.9%; 2016, 7.1%) for tumors 1 cm or smaller.8 For tumors 1 to 2 cm, slight increases in TL (2008, 5.7%; 2016, 11.4%) and TT without adjuvant RAI (2008, 59.7%; 2016, 66.7%) were reported.
We set out to analyze clinical characteristics and treatment of low-risk PTC using the National Cancer Database (NCDB), the largest cancer database available. This study’s primary aim was to determine how the 2009 and comparatively stricter 2015 ATA guidelines have corresponded with the management of patients with low-risk PTC. Our secondary aim was to investigate if these changes have been adopted equally throughout the US and in different practice settings to identify further opportunities to encourage guideline-based management.
Methods
In this cohort study, the data were obtained from the NCDB, a hospital-based database jointly sponsored by the American College of Surgeons and the American Cancer Society that collects data from more than 1500 Commission on Cancer–accredited facilities and represents more than 70% of newly diagnosed cancer cases in the US.11 The NCDB was selected due to its large, nationally representative sample size, particularly in the context of head and neck cancers.12 Because the NCDB is a deidentified database, this study was determined to be exempt from review per the standing policy of the NYU Langone Health Institutional Review Board. The data used in the study are derived from a de-identified NCDB file, thus informed consent was waived. The American College of Surgeons and the Commission on Cancer have not verified and are not responsible for the analytic or statistical methodology used or the conclusions drawn from these data by the investigators.
We queried the NCDB for all PTCs diagnosed between 2004 and 2019 (Figure 1). Patients were identified with histology codes: 8050, 8260, 8350, 8340 through 8344 from the International Classification of Diseases for Oncology, Third Edition, First Revision (ICD-O-3.1), referring to papillary carcinoma. Tumors of the thyroid gland were identified using the ICD-O-3.1 topography code C73.
Figure 1. Patient Selection Diagram Showing Exclusion Criteria and Number Excluded Due to Each Criterion.
NCDB indicates National Cancer Database.
Patient demographics, clinical and pathologic characteristics, and treatments were extracted for all patients. Patients with T0 tumors, T3 and T4 tumors, tumors of unknown size, or tumors greater than 4 cm were excluded (Figure 1). In addition, patients with clinically or pathologically positive lymph nodes and those with incomplete treatment data were excluded.
The primary objective was to assess the association of the 2009 and 2015 ATA recommendations with the treatment of low-risk PTC. All included patients were treated by surgery, and treatments were grouped as TL or TT. Patients who underwent TT were further grouped by whether they received adjuvant RAI. Because the 2009 and 2015 guidelines were published in November 2009 and January 2016, respectively, patients were grouped by date of diagnosis: between 2004 and 2009, between 2010 and 2015, and between 2016 and 2019. Proportions undergoing each treatment were calculated for each period. Proportions were compared between time periods using χ2 tests. Additionally, the annual rates of change in the proportion of each treatment were calculated within each period using linear regression. To compare rates of change between consecutive time periods, we then created statistical interaction terms between year of diagnosis (as a continuous variable) and guideline era (preguideline vs postguideline change). The statistical significance of the interaction terms was then used to assess whether the rates of change in practice patterns differed significantly between consecutive periods. Subgroup analyses were then performed, stratifying patients by tumor size (1 cm or smaller, 1-2 cm, and 2-4 cm), practice setting, and US Census Bureau geographic region. Exploratory analyses did not reveal differences in practice patterns based on patient self-reported race and ethnicity or gender. The practice setting was categorized as academic, community, or integrated network cancer programs per the NCDB. As tumors 1 cm or smaller represent the least controversial group for de-escalation of treatment, proportions of each treatment within this group were compared by practice setting. Finally, the practice patterns of academic and community centers were compared across each geographic region. All analyses were conducted using R-statistical software, version 3.6.3 (R Project for Statistical Computing). Statistical significance was assessed at a 2-sided P < .05. This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline. Data were analyzed from August 1, 2021, to September 1, 2022.
Results
We identified 194 254 patients with PTC (155 796 [80.2%] female patients; median [range] age at diagnosis, 51 [18-90] years) in the NCDB from the years 2004 to 2019. Patient demographics are described in the Table. The majority were female patients, White individuals (149 976, 77.2%), and patients with no major comorbidities (160 463, 82.6%). Approximately half of all tumors were 1 cm or smaller (98 000, 50.4%), followed by 1 to 2 cm in size (60 760, 31.3%), and 2 to 4 cm in size (35 494, 18.3%). A total of 43 611 patients (22.5%) were diagnosed from 2004 to 2009, 97 766 (50.3%) from 2010 to 2015, and 52 877 (27.2%) from 2016 to 2019. More than half of patients underwent TT without RAI (104 968, 54.0%), followed by TT with RAI (57 211, 29.5%), and TL alone (32 075, 16.5%).
Table. Clinicopathologic Factors of 194 254 Patients With Papillary Thyroid Carcinoma.
| Clinicopathologic factors | No. (%) | |||
|---|---|---|---|---|
| All patients | 2004-2009 | 2010-2015 | 2016-2019 | |
| Total | 194 254 | 43 611 | 97 766 | 52 877 |
| Age, median (range), y | 51 (18-90) | 50 (18-90) | 51 (18-90) | 52 (18-90) |
| Sex | ||||
| Female | 155 796 (80.2) | 35 359 (81.1) | 78 533 (80.3) | 41 904 (79.2) |
| Male | 38 458 (19.8) | 8252 (18.9) | 19 233 (19.7) | 10 973 (20.8) |
| Race and ethnicity | ||||
| African American/Black | 13 754 (7.1) | 2762 (6.3) | 7347 (7.5) | 3645 (6.9) |
| Asian | 9858 (5.1) | 1593 (3.7) | 4680 (4.8) | 3585 (6.8) |
| Hispanic/Latinx | 15 692 (8.1) | 2822 (6.5) | 7345 (7.5) | 5525 (10.4) |
| White | 149 976 (77.2) | 35 272 (80.9) | 76 000 (77.7) | 38 704 (73.2) |
| Other | 4974 (2.6) | 1162 (2.7) | 2394 (2.4) | 1418 (2.7) |
| Comorbidity | ||||
| 0 | 160 463 (82.6) | 36 832 (84.5) | 80 148 (82.0) | 43 483 (82.2) |
| 1 | 26 854 (13.8) | 5639 (12.9) | 14 392 (14.7) | 6823 (12.9) |
| 2 | 5036 (2.6) | 897 (2.1) | 2546 (2.6) | 1593 (3.0) |
| ≥3 | 1901 (0.9) | 243 (0.6) | 680 (0.7) | 978 (1.8) |
| Size, cm | ||||
| <1 | 98 000 (50.4) | 22 683 (52.0) | 51 579 (52.8) | 23 738 (44.9) |
| 1-2 | 60 760 (31.3) | 13 012 (29.8) | 29 176 (29.8) | 18 572 (35.1) |
| 2-4 | 35 494 (18.3) | 7916 (18.2) | 17 011 (17.4) | 10 567 (20.0) |
| T classification | ||||
| T1 | 113 480 (58.4) | 29 382 (67.4) | 56 519 (57.8) | 27 579 (52.2) |
| T2 | 35 918 (18.5) | 7861 (18.0) | 16 668 (17.0) | 11 389 (21.5) |
| Unknown | 44 856 (23.1) | 6368 (14.6) | 24 579 (25.1) | 13 909 (26.3) |
| N classification | ||||
| N0 | 194 254 (100.0) | 43 611 (100.0) | 97 776 (100.0) | 52 877 (100.0) |
| M classification | ||||
| M0 | 190 569 (98.1) | 42 719 (98.0) | 95 254 (97.4) | 52 596 (99.5) |
| Unknown | 3685 (1.9) | 892 (2.0) | 2512 (2.6) | 281 (0.5) |
| Treatment | ||||
| Lobectomy | 32 075 (16.5) | 6568 (15.1) | 13 380 (13.7) | 12 127 (22.9) |
| Thyroidectomy | 104 968 (54.0) | 18 992 (43.5) | 53 101 (54.3) | 32 875 (62.2) |
| Thyroidectomy + RAI | 57 211 (29.5) | 18 051 (41.4) | 31 285 (32.0) | 7875 (14.9) |
| Facility type | ||||
| Academic | 59 061 (30.4) | 11 739 (26.9) | 30 321 (31.0) | 17 001 (32.2) |
| Community | 59 867 (30.8) | 14 636 (33.6) | 29 639 (30.3) | 15 592 (29.5) |
| Integrated | 30 207 (15.6) | 6739 (15.5) | 15 495 (15.8) | 7973 (15.1) |
| Unknown | 45 119 (23.2) | 10 497 (24.1) | 22 311 (22.8) | 12 311 (23.3) |
| US census region | ||||
| Midwest | 35 231 (18.1) | 7982 (18.3) | 17 586 (18.0) | 9663 (18.3) |
| Northeast | 41 998 (21.6) | 9604 (22.0) | 21 712 (22.2) | 10 682 (20.2) |
| South | 48 416 (24.9) | 10 354 (23.7) | 24 892 (25.5) | 13 170 (24.9) |
| West | 7541 (3.9) | 1772 (4.1) | 3772 (3.9) | 1997 (3.8) |
| Unknown | 61 068 (31.4) | 13 899 (31.9) | 29 804 (30.5) | 17 365 (32.8) |
Abbreviation: RAI, radioactive iodine.
Trends in TL
Among patients who underwent surgery, the rate of TL initially decreased from 15.1% to 13.7% after the 2009 guideline changes. However, this trend reversed subsequently, and TL rates increased to 22.9% after the 2015 changes. Prior to the 2009 guidelines, the annual change in the rate of TL was −1.1% per year (95% CI, −1.3%/y to −0.8%/y). Subsequently, between the 2009 and 2015 guidelines, this decrease in the rate of TL was not observed (0.4%/y; 95% CI, 0.0%/y-0.8%/y). Finally, after the 2015 guidelines, an annual increase of 3.0% was observed (95% CI, 2.9%/y-3.2%/y).
Trends in Adjuvant RAI Therapy
Among patients that underwent TT, the rates of adjuvant RAI administration decreased steadily from 48.7% to 37.1% after the 2009 guideline changes and then to 19.3% after the 2015 changes. Before the 2009 guidelines, the rate of adjuvant RAI administration was consistent with an annual change of −0.2%/y (95% CI, −1.1%/y to 0.7%/y). Between the 2 guidelines, the rate of change of RAI administration was −2.3%/y (95% CI, −2.5%/y to −2.0%/y), and after the 2015 guidelines, the rate of change was −7.2%/y (95% CI, −9.7%/y to −4.8%/y).
Stratification by Tumor Size
For tumors 1 cm or smaller, the rate of TL decreased from 22.8% between 2004 and 2009 to 20.0% between 2010 and 2015 and subsequently increased to 29.2% between 2016 and 2019 (Figure 2). Among patients who underwent TT, there was a large decrease in the use of adjuvant radioiodine therapy from 32.8% between 2004 and 2009, to 19.2% between 2010 and 2015, and 8.5% between 2016 and 2019 (Figure 3).
Figure 2. Proportions of Patients Undergoing Thyroid Lobectomy From 2004 to 2019.
Figure 3. Rates of Radioiodine Administration Among Patients Undergoing Total Thyroidectomy From 2004 to 2019.
RAI indicates radioactive iodine therapy.
For tumors 1 to 2 cm, the TL rate did not change from the 2004 to 2009 range to the 2010 to 2015 range (6.8% to 6.5%). The TL rate then increased to 18.9% from 2016 to 2019 (Figure 2). The rate of adjuvant RAI administration steadily decreased from 61.4% between 2004 and 2009, to 50.1% between 2010 and 2015, and 23.7% between 2016 and 2019 (Figure 3).
Similarly, for tumors 2 to 4 cm, the rate of TL remained roughly constant from 6.6% between 2004 and 2009 to 7.0% between 2010 and 2015, but the rate more than doubled to 16.0% between 2016 and 2019 (Figure 2). The rate of adjuvant RAI administration decreased from 65.8% between 2004 and 2009, to 61.3% between 2010 and 2015, and 32.4% between 2016 and 2019 (Figure 3).
Stratification by Practice Setting
Academic medical centers experienced the largest changes in treatment patterns. The 2004 to 2009 rate of TL was 14.9% and decreased to 13.9% from 2010 to 2015, followed by an increase to 25.7% from 2016 to 2019 (Figure 2). Among patients who underwent TT, rates of RAI administration decreased from 45.7% between 2004 and 2009, to 32.8% between 2010 and 2015, and 16.1% between 2016 and 2019 (Figure 3).
Community hospitals, on the other hand, saw smaller changes. The rate of TL decreased from 16.3% between 2004 and 2009 to 14.7% between 2010 and 2015, followed by an increase to 19.5% between 2016 and 2019 (Figure 2). Rates of RAI administration decreased from 47.7% between 2004 and 2009, to 39.0% between 2010 and 2015, and to 22.5% between 2016 and 2019 (Figure 3).
Integrated network cancer centers experienced similar changes. The 2004 to 2009 rate of TL was 15.9% and decreased to 13.2% between 2010 and 2015, followed by an increase to 20.5% between 2016 and 2019 (Figure 2). Rates of RAI administration decreased from 50.6% between 2004 and 2009, to 40.2% between 2010 and 2015, and to 20.3% between 2016 and 2019 (Figure 3).
Stratification by Practice Setting Among Tumors Less Than 1 Centimeter
Among tumors of less than 1 cm, academic centers saw a decrease in TL from the 2004 to 2009 range to the 2010 to 2015 range (21.1% to 19.2%) and an increase from the 2010 to 2015 range to the 2016 to 2019 range (19.2% to 31.5%). Similarly, community hospitals saw a decrease in TL from between 2004 and 2009 to between 2010 and 2015 (24.1% to 21.6%) and an increase from between 2010 and 2015 to between 2016 and 2019 (21.6% to 26.2%). Lastly, integrated centers saw a decrease in TL from between 2004 and 2009 to between 2010 and 2015 (24.1% to 20.1%) and an increase from between 2010 and 2015 to between 2016 and 2019 (20.1% to 27.9%).
Decreases in RAI use among tumors of less than 1 cm were more uniform across different practice settings. Academic centers saw decreases from between 2004 and 2009 to between 2010 and 2015 (29.3% to 16.1%) and from between 2010 and 2015 to between 2016 and 2019 (16.1% to 6.6%). Similarly, community hospitals saw decreases in RAI from the 2004 to 2009 range to the 2010 to 2015 range (33.3% to 21.4%) and from the 2010 to 2015 range to the 2016 to 2019 range (21.4% to 10.6%). Lastly, integrated centers saw decreases from the 2004 to 2009 range to the 2010 to 2015 range (33.7% to 20.5%) and from the 2010 to 2015 range to the 2016 to 2019 range (20.5% to 7.8%).
Stratification by Geographic Region
States in the Western US saw a slight increase in the rate of TL following the 2009 ATA guideline changes (11.3% to 13.3%), while small decreases were seen in the Midwest (16.2% to 13.6%), Northeast (17.9% to 16.5%), and South (13.8% to 12.6%). The rate of TL increased in all regions after the 2015 guidelines (Northeast, 26.4%; West, 23.6%; Midwest, 20.8%; South, 18.7%) (Figure 2).
All regions saw large decreases in the rate of RAI administration over the study period. The West saw the largest changes (54.1% to 36.9% to 15.9%), followed by the Midwest (54.7% to 44.0% to 23.0%), Northeast (42.5% to 31.6% to 18.0%), and South (44.5% to 35.3% to 18.3%) (Figure 3).
Comparison of Academic and Community Centers by Geography
Among academic medical centers, changes in TL rates were relatively uniform across each geographic region. Again, the Western US saw the largest overall change from before the 2009 guidelines to after the 2015 guidelines (11.2% to 38.9%), but large increases in TL were also observed for the Midwest (12.5% to 23.0%), Northeast (18.0% to 27.7%), and South (11.6% to 21.6%). Similarly, among community hospitals, the West had the largest overall increase in TL (11.1% to 20.5%). Smaller increases were observed for the Midwest (16.7% to 17.9%), Northeast (18.5% to 22.7%), and South (15.9% to 17.4%).
Use of adjuvant RAI decreased across all regions from before the 2009 guidelines to after the 2015 guidelines, both for academic and community centers. However, there was considerable variation in magnitude. Among academic centers, the Midwest experienced the largest decrease (44.5% to 13.1%), followed by the South (42.7% to 12.5%), West (34.8% to 8.2%), and Northeast (33.2% to 11.1%). For community centers, the largest decrease was observed in the West (51.4% to 13.5%), followed by the Midwest (47.7% to 22.9%), South (35.1% to 17.3%), and Northeast (34.1% to 16.9%).
Discussion
In this large, nationally representative cohort study, we 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, we 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.2,3 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. However, evidence-based literature on the association of ATA guideline revisions with changing practice patterns is limited. 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.1,8 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, we 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.13,14 Other studies in otolaryngology have reported no difference in guideline adherence between otolaryngologists in academic and community practice; however, both studies relied on self-reporting of guideline adherence.15,16 Reasons for the greater changes in practice patterns observed among academic institutions may include better access to current literature, more frequent attendance at national meetings, and quality improvement efforts aimed to promote evidence-based care. Regardless of the cause of this discrepancy, the study data suggest that there might be an opportunity to further de-escalate the management of low-risk PTC in the community setting, particularly in considering TL instead of TT.
Interestingly, the differences we observed between academic and community centers varied considerably by region, particularly with regards to TL. While academic centers in all US Census regions experienced significant increases in the rate of TL over the study period, this was not the case for community centers in all regions. Furthermore, in each region, increases in the rate of TL among academic centers were larger than those of community centers in the same region. Ultimately, these results suggest that adoption of the ATA guidelines among community hospitals has lagged behind that of academic centers, even when controlling for geography.
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 papillarylike nuclear features are among the many factors that have altered the management of thyroid carcinomas.17,18,19,20 These newer diagnostic and therapeutic options, in conjunction with our 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.21,22,23
Limitations
There are several limitations to this study. Patients were grouped in the study by year of diagnosis; the NCDB does not include the year of treatment, which may have more accurately reflected changes in practice patterns resulting from the ATA guidelines. In addition, the NCDB does not document high-risk pathologic factors, such as extrathyroidal extension, or imaging findings. As a result, we could not account for all factors considered when managing these patients. Similarly, because the NCDB provides data on only the final course of surgical treatment, the proportion of patients who were treated by TL initially and subsequently underwent completion thyroidectomy is unknown. Lastly, the NCDB only includes data from Commission on Cancer–accredited facilities, which may introduce some selection biases. However, a study by Janz and colleagues12 reported that the NCDB has similar demographic, treatment, and survival data to the Surveillance, Epidemiology, and End Results Program database, which is nationally representative. Despite such limitations, this study’s nationally representative cohort and large sample size allowed us to provide, to our knowledge, the most comprehensive analysis of the de-escalation of treatment for low-risk PTC. The NCDB, due to its size and detailed treatment information, is quite powerful in characterizing patterns of care, which was the aim of this investigation.
Conclusions
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.
References
- 1.James BC, Timsina L, Graham R, Angelos P, Haggstrom DA. Changes in total thyroidectomy versus thyroid lobectomy for papillary thyroid cancer during the past 15 years. Surgery. 2019;166(1):41-47. doi: 10.1016/j.surg.2019.01.007 [DOI] [PubMed] [Google Scholar]
- 2.Lim H, Devesa SS, Sosa JA, Check D, Kitahara CM. Trends in thyroid cancer incidence and mortality in the United States, 1974-2013. JAMA. 2017;317(13):1338-1348. doi: 10.1001/jama.2017.2719 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Davies L, Welch HG. Current thyroid cancer trends in the United States. JAMA Otolaryngol Head Neck Surg. 2014;140(4):317-322. doi: 10.1001/jamaoto.2014.1 [DOI] [PubMed] [Google Scholar]
- 4.Adam MA, Pura J, Gu L, et al. Extent of surgery for papillary thyroid cancer is not associated with survival: an analysis of 61,775 patients. Ann Surg. 2014;260(4):601-605. doi: 10.1097/SLA.0000000000000925 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Kim MJ, Lee MC, Lee GH, et al. Extent of surgery did not affect recurrence during 7-years follow-up in papillary thyroid cancer sized 1-4 cm: preliminary results. Clin Endocrinol (Oxf). 2017;87(1):80-86. doi: 10.1111/cen.13336 [DOI] [PubMed] [Google Scholar]
- 6.Carhill AA, Litofsky DR, Ross DS, et al. Long-term outcomes following therapy in differentiated thyroid carcinoma: NTCTCS registry analysis 1987-2012. J Clin Endocrinol Metab. 2015;100(9):3270-3279. doi: 10.1210/JC.2015-1346 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Schvartz C, Bonnetain F, Dabakuyo S, et al. Impact on overall survival of radioactive iodine in low-risk differentiated thyroid cancer patients. J Clin Endocrinol Metab. 2012;97(5):1526-1535. doi: 10.1210/jc.2011-2512 [DOI] [PubMed] [Google Scholar]
- 8.Lohia S, Morris LGT, Roman BR. Association between implementation of the 2009 American Thyroid Association guidelines and de-escalation of treatment for low-risk papillary thyroid carcinoma. JAMA Otolaryngol Head Neck Surg. 2020;146(11):1081-1082. doi: 10.1001/jamaoto.2020.3024 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Cooper DS, Doherty GM, Haugen BR, et al. ; American Thyroid Association (ATA) Guidelines Taskforce on Thyroid Nodules and Differentiated Thyroid Cancer . Revised American Thyroid Association management guidelines for patients with thyroid nodules and differentiated thyroid cancer. Thyroid. 2009;19(11):1167-1214. doi: 10.1089/thy.2009.0110 [DOI] [PubMed] [Google Scholar]
- 10.Haugen BR, Alexander EK, Bible KC, et al. 2015 American Thyroid Association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer: the American Thyroid Association guidelines task force on thyroid nodules and differentiated thyroid cancer. Thyroid. 2016;26(1):1-133. doi: 10.1089/thy.2015.0020 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Bilimoria KY, Bentrem DJ, Stewart AK, Winchester DP, Ko CY. Comparison of commission on cancer-approved and -nonapproved hospitals in the United States: implications for studies that use the National Cancer Data Base. J Clin Oncol. 2009;27(25):4177-4181. doi: 10.1200/JCO.2008.21.7018 [DOI] [PubMed] [Google Scholar]
- 12.Janz TA, Graboyes EM, Nguyen SA, et al. A comparison of the NCDB and SEER database for research involving head and neck cancer. Otolaryngol Head Neck Surg. 2019;160(2):284-294. doi: 10.1177/0194599818792205 [DOI] [PubMed] [Google Scholar]
- 13.Ehdaie B, Atoria CL, Lowrance WT, et al. Adherence to surveillance guidelines after radical cystectomy: a population-based analysis. Urol Oncol. 2014;32(6):779-784. doi: 10.1016/j.urolonc.2014.01.024 [DOI] [PubMed] [Google Scholar]
- 14.Ferron G, Martinez A, Gladieff L, et al. Adherence to guidelines in gynecologic cancer surgery. Int J Gynecol Cancer. 2014;24(9):1675-1678. doi: 10.1097/IGC.0000000000000284 [DOI] [PubMed] [Google Scholar]
- 15.Aarts MC, van der Heijden GJ, Siegers C, Grolman W, Rovers MM. Awareness of, opinions about, and adherence to evidence-based guidelines in otorhinolaryngology. Arch Otolaryngol Head Neck Surg. 2012;138(2):148-152. doi: 10.1001/archoto.2011.1166 [DOI] [PubMed] [Google Scholar]
- 16.Honeybrook A, Ellison M, Puscas L, Raynor E. Otolaryngologist adherence to the AAO-HNSF Allergic Rhinitis Clinical Practice Guideline. Int Forum Allergy Rhinol. 2018;8(6):741-750. doi: 10.1002/alr.22096 [DOI] [PubMed] [Google Scholar]
- 17.Cibas ES, Ali SZ. The 2017 Bethesda System for Reporting Thyroid Cytopathology. Thyroid. 2017;27(11):1341-1346. doi: 10.1089/thy.2017.0500 [DOI] [PubMed] [Google Scholar]
- 18.Dublin JC, Papazian M, Zan E, et al. Predictive value of a genomic classifier in indeterminate thyroid nodules based on nodule size. JAMA Otolaryngol Head Neck Surg. 2022;148(1):53-60. doi: 10.1001/jamaoto.2021.3080 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Moon WJ, Jung SL, Lee JH, et al. ; Thyroid Study Group, Korean Society of Neuro- and Head and Neck Radiology . Benign and malignant thyroid nodules: US differentiation—multicenter retrospective study. Radiology. 2008;247(3):762-770. doi: 10.1148/radiol.2473070944 [DOI] [PubMed] [Google Scholar]
- 20.Hoang JK, Lee WK, Lee M, Johnson D, Farrell S. US features of thyroid malignancy: pearls and pitfalls. Radiographics. 2007;27(3):847-860. doi: 10.1148/rg.273065038 [DOI] [PubMed] [Google Scholar]
- 21.Paluskievicz CM, Chang DR, Blackburn KW, et al. Low-risk papillary thyroid cancer: treatment de-escalation and cost implications. J Surg Res. 2022;275:273-280. doi: 10.1016/j.jss.2022.01.019 [DOI] [PubMed] [Google Scholar]
- 22.Del Rio P, Rossini M, Montana CM, et al. Postoperative hypocalcemia: analysis of factors influencing early hypocalcemia development following thyroid surgery. BMC Surg. 2019;18(suppl 1):25. doi: 10.1186/s12893-019-0483-y [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Gunn A, Oyekunle T, Stang M, Kazaure H, Scheri R. Recurrent laryngeal nerve injury after thyroid surgery: an analysis of 11,370 patients. J Surg Res. 2020;255:42-49. doi: 10.1016/j.jss.2020.05.017 [DOI] [PubMed] [Google Scholar]
