Contrastive study of two screening criteria for active surveillance in patients with low-risk papillary thyroid microcarcinoma: a retrospective analysis of 1001 patients

Abstract

Screening out patients who do not require immediate surgery is a growing trend in the field of thyroid research. In this study, we retrospectively compared the application of two surveillance selection criteria in 1001 patients who had undergone surgical treatment of papillary thyroid microcarcinoma (PTMC): low-risk PTMC characteristics defined by Kuma Hospital and CATO consensus on PTMC management of active surveillance. Treatment outcomes were compared between groups. We then analyzed the prognostic indicators of patients who could be managed by surveillance. A total of 724 patients met Kuma screening criteria and 135 met CATO screening criteria. The Kuma low-risk group had a lower incidence of multifocal lesions and CLNM than Kuma high-risk group. We also found more obvious differences in multifocal lesions, CLNM and extrathyroidal extension when evaluating the CATO low-risk criteria in the same manner. On the other hand, patients in the CATO low-risk group had a lower disease progression rate and longer disease-free survival than those in CATO high-risk group. There was no significant difference in prognosis between the Kuma low-risk group and Kuma high-risk group. Our logistic regression analysis showed that a preoperative ultrasound size of >5 mm, male sex, younger age, and malignant lesions without concurrent benign nodules could be predictors of CLNM. In conclusion, patients classified in CATO low-risk criteria had lower proportion of clinicopathological risk factors than the ones in Kuma low-risk criteria. We also found more risk factors may not be suitable for surveillance, such as tumors without concurrent benign nodules.

High-risk morphological features are less prevalent among small (<5mm) papillary thyroid microcarcinomas compared to larger (≥5mm) tumors: a study of 206 cases

“…Therefore, the biological characteristics of PTMC have gradually attracted more attention from researchers [25]. The main questions for the clinician remain (1) how to distinguish between harmless and harmful PTMCs and (2) which PTMCs can adequately and safely be managed be active surveillance as an alternative to immediate surgery [26]. The current guidelines also recognized active surveillance as the best alternative for the patients with low-risk PTMCs [10,27].…”

Puzzle over active surveillance for micropapillary thyroid carcinoma

“…While variations on the scheme exist, risk stratification schemes have been developed based on the post-treatment failure rates and its associations with the pretreatment Patient scores, fine needle aspiration (FNA), imaging features, and American Joint Committee on Cancer clinical stage, age to define the low-risk PMC (2)(3)(4)(5).…”

“…The goal of AS is to identify and monitor this low-risk group and to intervene when necessary. Despite its indolent nature, low-risk PMC can develop local progression and distant metastasis years after diagnosis (2)(3)(4)(5).…”

“…Fluctuations in nodule size may generate anxiety and uncertainty in both patients and physicians as this may indicate disease progression requiring intervention. Not uncommonly, however, it is also a mere biological variation (2)(3)(4)(5).…”

“…Authors suggest AS as the preferred management option for low-risk PMC, that it may be offered to selected patients with favorable prognosis. In some parts of the world, AS has been embraced (2)(3)(4)(5). In other countries, the majority of individuals with low-risk small thyroid cancer still receive upfront treatment with the increased chance of lesser extent surgery, and the application of minimally invasive approaches, as well as no need for lifelong thyroid replacement therapy, a consistent follow-up, low-dose or no radioactive iodine therapy (RAI) administration and risk factor assessments (1,6,7).…”