JAMA: After five years of follow-up, a majority of asymptomatic, benign
thyroid nodules exhibited no significant change in size, or actually
decreased in size, and diagnoses of thyroid cancer were rare, according
to a study in the March 3 issue of JAMA.
Detection of asymptomatic thyroid nodules has increased, largely from
improved detection of small incidentally discovered nodules. Consensus
is lacking regarding the optimal follow-up of cytologically (analysis of
aspirated cells) proven benign lesions and sonographically (an imaging
technique using ultrasonic waves) nonsuspicious nodules. Current
guidelines recommend serial ultrasound examinations and repeat cytology
exam if significant growth in the nodule is observed. However, little is
known about the actual frequency and magnitude of nodule growth, and
there is no reliable method for identifying patients likely to
experience growth. The assumption that growing nodules increase a
patient’s risk of malignancy has been untested, according to background
information in the article.
Sebastiano Filetti, M.D., of the Universita di Roma Sapienza, Rome,
and colleagues studied the frequency, magnitude, and factors associated
with changes in thyroid nodule size. The study involved 992 patients
with 1 to 4 asymptomatic, sonographically or cytologically benign
thyroid nodules. Patients were recruited from 8 hospital-based
thyroid-disease referral centers in Italy between 2006 and 2008. Data
collected during the first 5 years of follow-up, through January 2013,
were analyzed.
Nodule growth occurred in 153 patients (15.4 percent). One hundred
seventy-four of the 1,567 original nodules (11.1 percent) increased in
size. Nodule growth was associated with presence of multiple nodules. In
184 individuals (18.5 percent), nodules shrank. Thyroid cancer was
diagnosed in 5 original nodules (0.3 percent), only 2 of which had
grown. New nodules developed in 93 patients (9.3 percent), with
detection of one cancer.
“One of the goals of surveillance is the prompt detection and
treatment of thyroid cancers that arise during follow-up or have been
missed on the initial assessment. In the population we studied, these
events were rare,” the authors write.
“Only 2 of the 5 diagnoses of cancer in an established nodule were
preceded by significant growth of the cancerous nodule. These data
suggest that the American Thyroid Association’s recommendation for
indication for repeat cytology should be revised. Clinical and
sonographic findings should probably play larger roles in the
decision-making process.”
(doi:10.1001/jama.2015.0956; Available pre-embargo to the media at http://media.jamanetwork.com)