CLINICAL THYROIDOLOGY FOR THE PUBLIC
A publication of the American Thyroid Association
Younger patients with papillary microcarcinoma are more likely to progress to significant disease
ABBREVIATIONS & DEFINITIONS
Papillary thyroid cancer: the most common type of thyroid cancer.
Papillary microcarcinoma: a papillary thyroid cancer smaller than 1 cm in diameter.
Thyroid Ultrasound: a common imaging test used to evaluate the structure of the thyroid gland. Ultrasound uses soundwaves to create a picture of the structure of the thyroid gland and accurately identify and characterize nodules within the thyroid. Ultrasound is also frequently used to guide the needle into a nodule during a thyroid nodule biopsy.
Lymph node: bean-shaped organ that plays a role in removing what the body considers harmful, such as infections and cancer cells.
Papillary thyroid cancer is the fastest rising cancer in women. Many of these cancers are microcarconomas which are less than 1 cm in size. It is unclear whether these microcarcinomas will become clinically important or even if they need to be surgically removed. In prior studies, these authors reported on Japanese patients with biopsy-proven papillary thyroid microcarcinoma who were watched instead of having surgery. Another study from Japan showed younger patients were more likely to have growth or spread of the papillary thyroid carcinoma. In this study, the authors examined whether age would be a predictor of cancer growth or spread in patients with papillary thyroid microcarcinoma.
THE FULL ARTICLE TITLE:
Ito Y et al Patient age is significantly related to the progression of papillary microcarcinoma of the thyroid under observation. Thyroid 2014; 24:27-34. Epub November 14, 2013.
SUMMARY OF THE STUDY
Patients with biopsy-proven papillary thyroid microcarcinoma were offered observation or immediate surgery. A total of 1235 patients chose observation and this group underwent ultrasound evaluation every 6 to 12 months. Cancer progression was determined by the spread of the cancer to lymph nodes, cancer growth of 3 mm or more, or cancer growth to a size of 12 mm. A total of 82% of patients had papillary thyroid microcarcinoma ≤8 mm in size. The average period of observation was 60 months.
At 5 years, 4.9% of patients had growth of the cancers of 3 mm or more and at 10 years, 8% had growth of 3 mm or more. Lymph node spread developed in 1.7% of patients at 5 years and in 3.8% at 10 years. Progression to significant disease occurred in 3.9% of patients at 5 years and 6.8% of patients at 10 years. There appears to be a continued increase in the frequency of cancer growth, the development of lymph node spread, and progression to significant disease. Patients were divided into subgroups on the basis of age: young (
WHAT ARE THE IMPLICATIONS OF THIS STUDY?
This study suggests that low-risk papillary thyroid microcarcinoma can be observed without immediate surgery and that older patients are the best candidates for observation if they do not wish to have surgery. Younger patients with papillary thyroid microcarcinoma are at increased risk of their cancer becoming clinically significant and therefore should be treated with surgery in many cases.
—Ronald B. Kuppersmith, MD, FACS
ATA THYROID BROCHURE LINKS
Thyroid cancer: http://www.thyroid.org/cancer-of-the-thyroid-gland
Thyroid Surgery: http://thyroid.org/patients/patient_brochures/surgery.html