# Evolving Practices in Low-Risk Papillary Thyroid Cancer: Impact of the 2015 ATA Guidelines

## TL;DR

This study shows that following 2015 guidelines, less invasive thyroid surgery became more common and led to fewer complications for low-risk thyroid cancer patients.

## Contribution

The study provides real-world evidence of changing surgical practices and outcomes following the 2015 ATA guidelines for low-risk papillary thyroid cancer.

## Key findings

- Thyroid lobectomy increased from 0% in 2014 to nearly 60% in 2023 for low-risk papillary thyroid cancer.
- Total thyroidectomy was associated with higher complication rates, including hypoparathyroidism, compared to thyroid lobectomy.
- Adoption of conservative surgery reduced postoperative complications at the population level.

## Abstract

This study examined how surgical management of low-risk papillary thyroid carcinoma (PTC) changed after the 2015 American Thyroid Association guidelines recommended more conservative approaches. Researchers retrospectively analyzed 1644 patients treated between 2014 and 2023. Over time, thyroid lobectomy (TL) increasingly replaced total thyroidectomy (TT), rising from 0% in 2014 to nearly 60% in 2023, especially for microcarcinomas and tumors up to 2 cm. TT remained common for lesions larger than 2 cm. The need for completion thyroidectomy after TL dropped sharply. Compared with TL, TT showed higher rates of overall complications, including transient and permanent hypoparathyroidism, and required longer operative time and hospitalization. As TL became more widely adopted, postoperative hypoparathyroidism decreased. Overall, the findings indicate a gradual but clear shift toward less extensive surgery for low-risk PTC, supporting the safety and clinical benefits of the guideline-recommended conservative approach.

Background/Objectives: The extent of initial surgical resection for low-risk papillary thyroid carcinoma (PTC) remains debated. Traditionally, total thyroidectomy (TT) has been the standard approach, although the 2015 American Thyroid Association (ATA) guidelines endorsed a more conservative strategy. The real-world adoption of these recommendations, however, is unclear. This study evaluated changes in the surgical management of low-risk PTC in a high-volume center following the implementation of the ATA guidelines and analyzed the impact on postoperative outcomes. Methods: We conducted a retrospective study of 1644 patients who underwent surgery for localized low-risk PTC < 4 cm between 2014 and 2023. Temporal trends in the initial surgical procedure (TT vs. thyroid lobectomy [TL]) were analyzed overall and by tumor size and patient demographics. The need for completion thyroidectomy after TL and postoperative outcomes were also assessed. Results: The use of TL increased from 0% in 2014 to 59.4% in 2023 (p < 0.001). For microcarcinomas, TL rose from 17.5% in 2016 to 78% in 2023, with similar but less pronounced trends for 1–2 cm tumors. TT remained predominant for nodules > 2 cm. The completion thyroidectomy rate declined from 32% in 2016 to 4% in 2022. Patients undergoing TT experienced higher rates of postoperative complications (12.4% vs. 3.0%), particularly transient hypoparathyroidism (8.9% vs. 0%), and permanent hypoparathyroidism (1.8% vs. 0%), as well as longer operative time and hospital stay (all p < 0.001). The incidence of hypoparathyroidism decreased over time as TL use increased. Conclusions: Adoption of the 2015 ATA guidelines has progressively increased the use of TL in the management of low-risk PTC. This shift in surgical practice is associated with a reduction in the overall postoperative complication burden at the population level, largely driven by decreased hypoparathyroidism. Although guideline uptake has been gradual, current trends suggest increasing acceptance of less aggressive surgical strategies in routine clinical practice.