Extent of Surgery and the Prognosis of Unilateral Papillary Thyroid Microcarcinoma.

Hengqiang Zhao,Le Cui

doi:10.3389/fendo.2021.655608

Hengqiang Zhao, Le Cui

Open Access

https://doi.org/10.3389/fendo.2021.655608

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Abstract

It remains controversial whether patients with papillary thyroid microcarcinoma (PTMC) benefit from total thyroidectomy (TT) or thyroid lobectomy (TL). We aimed to investigate the impact of extent of surgery on the prognosis of patients with unilateral PTMC. Patients were obtained from the Surveillance, Epidemiology, and End Results database from 2004 to 2015. Cancer-specific survival (CSS) and overall survival (OS) were evaluated by Cox regression and Kaplan–Meier curves with propensity score matching. Of 31167 PTMC patients enrolled, 22.2% and 77.8% of which underwent TL and TT, respectively. Patients with TT were more likely to be younger, females, present tumors of multifocality, extrathyroidal extension, cervical lymph node metastasis (CLNM), distant metastasis, and receive radioactive iodine (RAI) compared with those receiving TL. The multivariate Cox regression model showed that TT was not associated with an improved CSS and OS compared with TL with hazard ratio (HR) and 95% confidence interval (CI) of 0.53 (0.25-1.12) and 0.86 (0.72-1.04), respectively. In addition, the Kaplan–Meier curves further confirmed the similar survival between TL and TT after propensity score matching. The subgroup analysis showed that TT was associated with better CSS for patients < 55 years, those with tumors of gross extrathyroidal extension, CLNM (N1b), and cases not receiving RAI with HR 95% CI of 0.13 (0.02-0.81), 0.12 (0.02-0.66), 0.11 (0.02-0.64) and 0.36 (0.13-0.90), respectively. TT predicted a trend of better OS for patients with N1b and distant metastasis after adjustment. In addition, TT was associated with better CSS than TL for patients with risk factors like N1b combined with gross extrathyroidal extension, and/or multifocality after matching. In conclusion, TL may be enough for low-risk PTMC patients. TT may improve the prognosis of unilateral PTMC patients with 2 or more risk clinicopathologic factors like CLNM, multifocality, extrathyroidal extension and a younger age compared with TL.

Highlights

Papillary thyroid microcarcinoma (PTMC) is defined as a papillary thyroid carcinoma (PTC) ≤ 1.0 cm in diameter, which has been increasingly detected in recent decades across the world with the popularity of ultrasound and fineneedle aspiration cytology [1, 2]
We investigated the extent of surgery and the prognosis of patient with unilateral PTMC
TT was not associated with improved Cancer-specific survival (CSS) and overall survival (OS) compared with Thyroid lobectomy (TL) in the total population after Propensity score matching (PSM)

Summary

Introduction

Papillary thyroid microcarcinoma (PTMC) is defined as a papillary thyroid carcinoma (PTC) ≤ 1.0 cm in diameter, which has been increasingly detected in recent decades across the world with the popularity of ultrasound and fineneedle aspiration cytology [1, 2]. Active surveillance has been recommended as an alternative approach for low-risk PTMC according to the American Thyroid Association (ATA) guidelines [4]. Thyroid lobectomy (TL) alone was sufficient for unifocal and intrathyroidal PTMC in the absence of clinically detectable cervical nodal metastasis [4]. The rate of pathological cervical lymph node metastasis (CLNM) was 48.0% for PTC [6], and 42.4% for PTMC when prophylactic central lymph node dissection was performed [7], which does pose a risk for local recurrence [8]. Postoperative local lymph node recurrence was associated with reoperations and the excess morbidity from reoperations [9]

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