Small papillary thyroid carcinomas grow
very slowly
(July 2003)
The background of the study. Papillary
thyroid carcinomas that are ≤1 cm (0.4 in.) in diameter are
called microcarcinomas. They are usually detected by chance, and
the diagnosis is confirmed by fine-needle aspiration biopsy. In
this study, the growth rate of microcarcinomas was studied in patients
who declined surgery at the time of initial diagnosis.
How the study was done. The study
subjects were 732 patients with thyroid nodules ≤1 cm in diameter
detected by ultrasonography and found on fine-needle aspiration
biopsy to have the cytologic changes of papillary carcinoma. The
patients were offered two options—immediate surgery, or observation
with periodic ultrasonography and repeat biopsy.
The results of the study. Among
the 732 patients, 570 chose immediate surgery and 162 chose to be
followed. The mean tumor diameter was 7 mm. During an average follow-up
period of 46 months (range, 18 to 113), the microcarcinoma did not
change (as defined by an increase or decrease of <2 mm in maximal
diameter) in approximately 65 percent of the patients, it increased
by ≥2 cm in 25 percent, and it decreased by ≥2 cm in
10 percent.
Among the 162 patients not operated on initially, 56 had surgery
19 to 56 months later. The tumor had increased in size in 23 percent,
had decreased in 13 percent, and had not changed in 64 percent.
On histologic study, all the tumors proved to be papillary carcinomas.
During an average postoperative follow-up period of 49 months,
16 of the 626 patients (3 percent) who were operated on had a recurrence.
No patient died from papillary carcinoma.
The conclusions of the study. Most
papillary thyroid microcarcinomas do not enlarge during the first
five years after diagnosis.
The original article. Ito Y, Uruno
T, Nakano K, Takamura Y, Miya A, Kobayashi K, Yokozawa T, Matsuzuka
F, Kuma S, Kuma K, Miyauchi A. An observation trial without surgical
treatment in patients with papillary microcarcinoma of the thyroid.
Thyroid 2003;13:381-7.
|
