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. Historically, total
or near-total thyroidectomy (TT) and adjuvant radioactive iodine (RAI) therapy
were recommended for most well differentiated thyroid malignancies.
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