In many countries, the incidence of thyroid cancer, especially small papillary carcinoma, increased without increase in thyroid cancer mortality during the recent 3 decades. Thus, how to treat small papillary carcinoma became a big clinical issue. In 1993, active surveillance (AS) for low-risk papillary thyroid microcarcinomas (PTMCs) was initiated by Akira Miyauchi at Kuma Hospital under the hypothesis that most low-risk PTMCs do not grow and it is not too late to treat PTMCs after seeing progression signs such as size enlargement and novel appearance of nodal metastases.
At 10 years of AS only 8.0% of patients showed enlargement of ≥3 mm, while only 3.8% showed nodal metastasis. None of the patients, including those who underwent rescue surgery after the detection of progression, showed life-threatening recurrence or died of thyroid carcinoma. Adverse events such as vocal cord paralysis and hypoparathyroidism were significantly more frequent in patients who underwent immediate surgery than in those who had AS. In addition, the total medical cost of immediate surgery with postoperative management for 10 years was 4.1 times the total cost of AS for 10 years.
Patients’ point of view or emotional issue on AS is also important. Our questionnaire survey on the patients on AS at Kuma Hospital revealed that 37% of patients had some cancer worry, which decrease over time and that 83% of patients replied that choosing AS was the best decision for them personally.
Therefore, currently at Kuma Hospital, we recommend AS as the first-line management for the patients with low-risk PTMCs. AS of low-risk PTMCs was approved in JAES guidelines in 2010, in its revised version in 2018 and ATA guidelines in 2015.