Active surveillance is cheaper than immediate surgery in low-risk papillary thyroid microcarcinoma

Daniela Barros, postgraduate student of the Surgical Clinic Program at Ribeirão Preto Medical School, University of São Paulo (FMRP-USP), Ribeirão Preto, SP, Brazil.

The management of low-risk papillary thyroid microcarcinoma (PTMC) is controversial. The traditional approach, like immediate surgery with total thyroidectomy (TT), has been considered excessive given the reduced rates of recurrence and mortality associated with the disease and the potential for surgical complications. According to guidelines by the American Thyroid Association (HAUGEN et al., 2015), patients with unifocal and intrathyroidal PTMC without clinically detectable cervical lymph node metastasis may be treated with partial thyroidectomy (PT) alone to reduce short-term and long-term postoperative morbidity. Additionally, many cases of PTMC may not require surgery, and active surveillance (AS) has been demonstrated to be a safe management strategy in these cases (SUGITANI, I, 2023.; MIYAUCHI, A., et al., 2023).

Cost analyses of AS for PTMC have methodological limitations and exhibit variability based on clinical protocols, follow-up duration, and the country where the analysis is conducted (HASER, G.C., et al., 2016). Therefore, costs should be considered individually for each specific region. To date, no studies have been conducted comparing the costs of managing low-risk PTMC in Latin America.

In this context, researchers guided by Fernanda Nascimento Faro, from Unidade de Doenças da Tireoide, Divisão de Endocrinologia, Departamento de Medicina, and Serviço de Medicina Nuclear, Irmandade da Santa Casa de Misericórdia de São Paulo (São Paulo, Brasil), compared the long-term medical costs of AS, PT, and TT in patients with low-risk PTMC receiving care covered by the Brazilian Public Health System (SUS) (FARO, F.N., et al., 2024). The research results were presented in the article Active surveillance versus immediate surgery in the management of low-risk papillary thyroid microcarcinoma: comparison of long-term costs in Brazil, published in the journal Archives of Endocrinology and Metabolism (vol. 68, 2024).

From a review of previous cohorts undergoing AS and analysis of their own data, the authors created a model of AS, PT, and TT flow care for low-risk PTMC over 10, 20, and 30 years, following national (ROSARIO, P.W., et al., 2019; WARD, L.S., et al., 2022) and international guidelines (HAUGEN, B.R., et al., 2015; SUGITANI, I., et al., 2021) and the clinical practices in their service.

Based on data from 2,803 patients with low-risk PTMC on AS, they calculated that 13.3% required surgery during follow-up and that TT was the surgery of choice in these cases. The mean time to conversion from AS to surgery after diagnosis was 21.3 months. Based on a review of the literature (KOIMTZIS, G.D., et al., 2021), they considered a 4% rate of permanent hypoparathyroidism in patients undergoing TT and a 43% rate of hypothyroidism in those undergoing PT (LEE, S.J., et al., 2021).

Imagem: stefamerpik (Freepik).

The most economical alternative was AS. The costs of TT per patient were higher than those of AS by 182.8% over 10 years (866.89 versus 306.49 US dollars [USD], respectively), by 152.9% over 20 years (1,023.66 versus 404.73 USD, respectively), and by 134.7% over 30 years (1,180.42 versus 502.96 USD, respectively). The costs of PT per patient were higher than those of AS by 16.0% over 10 years (355.66 versus 306.49 USD, respectively), by 16.9% over 20 years (473.41 versus 404.73 USD, respectively), and by 17.5% over 30 years (591.17 versus 502.96 USD, respectively). The authors concluded that the AS approach was less costly than immediate surgery throughout 30 years of follow-up. Hence, the implementation of AS in Brazil should not be hindered by cost considerations (FARO, F.N., et al., 2024).

This is the first study comparing long-term medical costs associated with AS, PT, and TT for low-risk PTMC in Latin America. The results indicate that the total costs of AS were lower than those for TT or PT at diagnosis and continued to be lower throughout 30 years of follow-up. These results are aligned with findings from similar studies in the literature. A systematic review analyzing the cost-effectiveness of AS compared with immediate surgery found that most studies favored AS (BAEK, H.S., et al., 2021). Oda and cols. (ODA, H., et al., 2017) reported that the total costs of immediate surgery with postoperative care for 10 years were 4.1 times higher than those associated with AS at the Kuma Hospital in Japan.

A position statement from the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism on treatment strategies for low-risk PTMC emphasizes that the follow-up of patients treated with lobectomy should be based mainly on results from neck ultrasound, that tumor recurrence occurs in about 5% of all patients, and that the emergence of new nodules is not infrequent (WARD, L.S., et al., 2022). Based on these facts, Faro and cols. considered that the clinical follow-up after PT should be the same as that suggested for AS (FARO, F.N., et al., 2024).

To analyze the “simple cost” of AS while taking into consideration that anxiety is a major cause of conversion from AS to surgery, the authors performed a subanalysis excluding conversion surgery and found that the difference between the “simple cost” of AS and immediate surgery became even more expressive. This finding was corroborated by Oda and cols. (ODA, H., et al., 2017). In this case, the cost difference between AS and PT reduces over time, but PT remains more expensive than AS after 30 years.

A limitation of the present trial, by Faro and cols, is that they did not perform a meta-analysis to calculate the percentage of patients converting from AS to surgery during follow-up. Second, they did not evaluate the impact of patients’ age at diagnosis on costs. Third, their study underestimated costs, as they derived the costs from the Table of Procedures, Medications, and Orthoses, Prostheses, and Special Materials (SIGTAP) (DATASUS); this SUS instrument, created and updated by the government, publishes reference values paid to professionals and health care institutions. However, there is a gap between the SIGTAP values, and the actual amounts paid, which is why the surgical procedures costs were underestimated, and the PT cost at presentation was so close to the AS cost (FARO, F.N., et al., 2024).

In conclusion, cost analyses have several methodological limitations, and costs may differ due to clinical heterogeneity and protocols, follow- up duration, medical costs specific to each country, public versus private systems, and criteria used in the analysis (e.g., age and quality of life). The present comparison of costs of AS versus immediate surgery (PT and TT) in managing low-risk PTMC showed that AS is the least costly strategy throughout 30 years of follow-up care. Thus, the economic impact on public health care should not be a barrier to implementing AS for patients with low-risk PTMC in Brazil (FARO, F.N., et al., 2024).

References

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To read the article, access

FARO, F.N., et al. Active surveillance versus immediate surgery in the management of low-risk papillary thyroid microcarcinoma: comparison of long-term costs in Brazil. Arch. Endocrinol. Metab [online]. 2024, vol. 68, e230349 [viewed 2 Aug 2024].   https://doi.org/10.20945/2359-4292-2023-0349. Available from: https://www.scielo.br/j/aem/a/QpPCsp4h39Vr7CDT9h7V38d/

External links

Archives of Endocrinology and Metabolism – AEM: https://www.scielo.br/aem

Fernanda Nascimento Faro – ORCID: https://orcid.org/0000-0002-3240-075X