The Journal of the Arkansas Medical Society Med Journal Dec 2019 | Page 16

SCIENTIFIC ARTICLE
Thyroid Cancer in Arkansas: Facts & Figures
Sarah N. O’Connor, BS 1 ; Abby Holt, MPH 2 ; L. Joseph Su, PhD, MPH 1,3 ; Kristyn Vang, MPH 2
1
Department of Epidemiology, UAMS, 2 Arkansas Central Cancer Registry, Arkansas Department of Health, 3 Winthrop P. Rockefeller Cancer Institute, UAMS
Abstract
It is estimated that in 2018, thyroid
cancer will be the 12th most common
malignancy in the U.S. Among females,
the thyroid gland is projected to be fifth
in the ranking of top-ten leading cancer
sites. Contrarily, among males, the thyroid
gland will not rank among the ten leading
cancer sites. While age-adjusted incidence
rates of thyroid cancer have been steadily
increasing over recent decades, especially
among females, age-adjusted mortality
rates have remained stable for both sexes.
This report describes thyroid cancer inci-
dence and mortality trends in Arkansas
from 2001 to 2015.
estimates two out of 20 thyroid nodules are malig-
nant or cancerous (ACS, 2018).
Types of Thyroid Cancer
noses for both papillary and follicular thyroid can-
cers are favorable as both types are often treated
successfully and are infrequently fatal (ACS, 2018).
Medullary carcinomas are considered to be
The four main types of thyroid cancer include: undifferentiated and account for an estimated 4%
papillary, follicular, medullary, and anaplastic (NCI, of thyroid cancers (ACS, 2018). Both medullary
2018). Papillary and follicular types are frequently and anaplastic types of thyroid cancer are undif-
referred to as differentiated thyroid cancers. The ferentiated because of the atypical appearance of
most common type of thyroid cancer is papillary, the malignant cells when compared with normal
with an estimated eight out of 10 cases diagnosed thyroid cells (ACS, 2018). They are often more
as papillary (ACS, 2018). Papillary cancers are slow difficult to detect, diagnose, and treat compared
Thyroid
in Arkansas:
& lobe
Figures
growing Cancer
and commonly
develop Facts
in one
of the to differentiated types of thyroid cancer. Medul-
thyroid gland (ACS, 2018). Additionally, papillary lary thyroid cancer develops from cells of the
thyroid
that in
produce
hormone
thyroid cancer
before
the age and
of 13.7
incidence
rate occurs
in AR most
was often
5.1 per
100,000
per gland
100,000
2001 calcitonin,
and 2015, a respectively
45, is more common in females than in males, and which helps to regulate the amount of calcium in
the blood
There
two 2001
subtypes
(Figure
1). The to combined
year age-adjusted
rate (ACS,
in AR 2018).
during
the are
years
through
often spreads
the lymph nodes
in the neck (NCI, incidence
of medullary thyroid cancer. Familial medullary
2018 & ACS, 2018).
2015 was 8.6 per 100,000 (ACCR, 2018). The ACS thyroid
estimates
that is 380
new cases
of thyroid
cancer
cancer
hereditary
and often
develops
The second most common type of thyroid during childhood or adolescence (ACS, 2018). Ap-
Keywords: Thyroid cancer; Arkansas will
cancer
is follicular. in An AR estimated
one out 2018).
of 10 The proximately
be diagnosed
in 2018 (ACS,
statistically
significant
percent
two
out of 10 average
medullary annual
carcinomas
thyroid cancers are follicular (ACS, 2018). Follicular result from inheriting an abnormal gene (ACS,
Introduction
change
in the
incidence
of thyroid
cancer was 7.0% (p<0.05) and 4.5% (p<0.05) in the US
cancers (AAPC)
occur more
frequently
in countries
where
2018). The second subtype of medullary thyroid
hyroid cancer is a disease in dietary iodine intake is low (ACS, 2018). The prog- cancer is considered sporadic (ACS, 2018).
and AR, respectively (Figure 1).
which cancerous cells form in the
tissues of the thyroid (National
Cancer Institute [NCI], 2018). The thyroid is
a gland located at the base of the throat adjacent to
the trachea (NCI, 2018). Butterfly-shaped, the gland
has two lobes: one left and one right connected by
a thin piece of tissue called the isthmus (American
Cancer Society [ACS], 2016). The thyroid gland is
an integral component of the endocrine system and
is predominantly responsible for utilizing the min-
eral iodine to produce and release hormones to be
dispersed throughout the body (American Thyroid
Association [ATA], 2016). A healthy thyroid gland is
about one inch wide. In some situations, changes in
the gland’s shape and size can be palpated or even
visualized by patients or by their physician. A change
in the gland’s shape or size could be indicative of an
abnormal growth of cells, also known as a nodule
(ACS, 2018). While most thyroid nodules are benign
or noncancerous, the American Cancer Society (ACS)
Figure 1: Age-Standardized Thyroid Cancer Incidence Trends with 95%
Figure 1: Age-Standardized Thyroid Cancer Incidence Trends with 95 Percent
Confidence Intervals,
Arkansas
and United
States,
2001-2015
Confidence
Intervals, Arkansas
and United
States,
2001 - 2015
Arkansas; AAPC = 7.2*
T
16
14
12
10
8
6
4
2
0
7.7
4.9
8.3
4.6
8.8
5.5
9.5
6.1
10.3 10.9
11.8
United States; AAPC = 4.6*
12.8
13.5 13.7
14
14.4 14.7 14.5 14.4
12.5
6.3
7.7
7.8
8.3
9
13.6
9.7 10.1 10.1 9.1
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
Year
*The AAPC is significantly different from zero (p < 0.05). Note: Abbreviation: AAPC - Annual Average Percent Change.
*The AAPC is significantly different from zero (p < 0.05). Note: Abbreviation: AAPC - Annual Average Percent Change. AAPCs were calculated using
AAPCs were
calculated
using Incidence
weighted rates
least per
squares
method.
Incidence
rates per to 100,000
age-adjusted
the States
weighted
least squares
method.
100,000
population;
age-adjusted
the 2000 population;
U.S. Standard
Population. to
United
Department
Health and
Human Services,
Disease Control
and Prevention
and Services,
National Cancer
National
Program
2000 U.S. of Standard
Population.
United Centers
States for
Department
of Health
and Human
Centers Institute.
for Disease
Control
and of Cancer
Registries and Surveillance, Epidemiology, and End Results SEER*Stat Database: NPCR and SEER Incidence – U.S. Cancer Statistics 2001–2015
Prevention and National Cancer Institute. National Program of Cancer Registries and Surveillance, Epidemiology, and End
Public Use Research Database, based on November 2017 submission. Cases were identified based on “Site and Morphology Site Recode ICD-O-
Results
SEER*Stat
Database:
and SEER Incidence – U.S. Cancer
Statistics
3/WHO
2008
= Thyroid”.
Accessed NPCR
at www.cdc.gov/cancer/npcr/public-use.
Retrieved
on 2001–2015
10/03/2018. Public Use Research Database,
based on November 2017 submission. Cases were identified based on “Site and Morphology Site Recode ICD-O-3/WHO
According
to 2018
estimates, thyroid cancer
is the on fifth
most common cancer among
2008 = Thyroid”.
Accessed
at www.cdc.gov/cancer/npcr/public-use.
Retrieved
10/03/2018.
males
136 • THE JOURNAL OF THE ARKANSAS MEDICAL females
SOCIETY (NCI, 2018). Contrarily, it is not among the ten leading cancer sites among
VOLUME
116 (NCI,
2018). For reasons currently unknown, thyroid cancer occurs approximately 2.6 times more often