Which do you prefer?

2016/08/19

Which do you prefer, when you have a small (<1 cm) thyroid nodule with suspicious ultrasound image, American way or Japanese way? The American Thyroid Association released the following statement and recommends physicians not to perform thyroid FNA cytology on nodules (< 1 cm) unless there is evidence of extrathyroidal extension or of lymph node or distant metastases (A). While the Japan Thyroid Association recommended so-called active surveillance (watchful follow-up in lieu of surgery) as a treatment option for papillary microcarcinoma (<1 cm) as far as it is confined to the thyroid gland (Ex0, N0, M0) and biopsy proven low-risk papillary thyroid carcinoma (possible high-risk thyroid carcinomas should be ruled out), which was introduced by Kuma hospital group and National Cancer Institute group from Japan (B,C,D). Both different clinical managements were established for the purpose to reduce over-diagnosis and overtreatment of this indolent thyroid tumor. However, these two clinical approaches were very different from each other probably because of different way of thinking and cultural background. In the Japanese way, I believe, a confirmation of low-risk papillary carcinoma by FNA biopsy is important for a peace of mind to the patient. A confirmation of benign or malignancy with FNA cytology was not recommended  in the American way.   (A): The AMERICAN THYROID ASSOCIATION recognizes that the recent increase in incidence of thyroid cancer in the United States and other countries is, in large part, due to the over diagnosis of indolent papillary microcarcinomas that will never result in symptoms or death, and which only rarely will enlarge or spread beyond the thyroid gland. The issues surrounding this problem are twofold: First, medical imaging is identifying small nodules, well below the limits of clinical detection. Second, these small nodules are subjected to ultrasound-guided FNA, and about 5% reveal cancer cells. The usual next step is surgical removal, often followed by radioactive iodine and life-long thyroid hormone therapy. This approach is costly, creates risks from the treatments, and in most patients offers little or no benefit. AMERICAN THYROID ASSOCIATION Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer (Thyroid, 2016) address this issue with three important recommendations/suggestions: (1) do not perform thyroid FNA on nodules < 1 cm unless there is evidence of extrathyroidal extension or of lymph node or distant metastases; (2) restrict surgery (currently the Standard of Care) to lobectomy and avoid radioactive iodine in those with low risk features; and (3) conduct further research (preferably in the setting of an IRB-approved clinical trial) to define the role of active surveillance instead of surgery for patients with low risk tumors (as is currently done for men with indolent prostate cancer). While additional scientific and medical knowledge is required, the AMERICAN THYROID ASSOCIATION advises that, in the interim, these recommended clinical measures may reduce the recent increased incidence of thyroid cancer and prevent overtreatment of low risk cancer. (B): Oda H, Miyauchi A, Ito Y et al: Incidences of unfavorable events in the management of low-risk papillary microcarcinoma of the thyroid by active surveillance versus immediate surgery. Thyroid 2016; 26: 150-155. (C): Ito Y and Miyauchi A: A therapeutic strategy for incidentally detected papillary microcarcinoma of the thyroid. Nature Clin Pract Endocrinol Metab 2007; 3: 240-248, 2007. (D): Sugitani I, Toda K, Yamada K et al: Three distinctly different kinds of papillary thyroid microcarcinoma should be recognized: our treatment strategies and outcomes. World J Surg 2010; 34:1222-1231.

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