Thyroid nodules and differentiated thyroid cancer: update on the Brazilian consensus

Abstract

Thyroid nodules are frequent findings, especially when sensitive imaging methods are used. Although thyroid cancer is relatively rare, its incidence is increasing, particularly in terms of small tumors, which have an uncertain clinical relevance. Most patients with differentiated thyroid cancer exhibit satisfactory clinical outcomes when treatment is appropriate, and their mortality rate is similar to that of the overall population. However, relapse occurs in a considerable fraction of these patients, and some patients stop responding to conventional treatment and eventually die from their disease. Therefore, the challenge is how to identify the individuals who require more aggressive disease management while sparing the majority of patients from unnecessary treatments and procedures. We have updated the Brazilian Consensus that was published in 2007, emphasizing the diagnostic and therapeutic advances that the participants, representing several Brazilian university centers, consider most relevant in clinical practice. The formulation of the present guidelines was based on the participants' experience and a review of the relevant literature. Arq Bras Endocrinol Metab. 2013;57(4):240-64 Keywords Thyroid nodules; thyroid cancer; Brazilian consensus; update RESUMO Nódulos tireoidianos são muito frequentes, sobretudo quando se empregam métodos sensí-veis de imagem. Embora o câncer seja proporcionalmente raro, sua incidência vem aumentando, especialmente de tumores pequenos, cuja evolução clínica é incerta. A maioria dos pacientes com carcinoma diferenciado de tireoide evolui bem quando adequadamente tratada, com índices de mortalidade similares à população geral. Por outro lado, um percentual não desprezível apresenta recidivas e alguns eventualmente não respondem às terapias convencionais, evoluindo para óbito. Assim, o desafio é distinguir os pacientes merecedores de condutas mais agressivas e, ao mesmo tempo e não menos importante, poupar a maioria de tratamentos e procedimentos desnecessários. Atualizamos o Consenso Brasileiro publicado em 2007, ressaltando os avanços diagnósticos e terapêuticos que os participantes, de diferentes Centros Universitários do Brasil, consideram mais relevantes para prática clínica. A elaboração dessas diretrizes foi baseada na experiência dos participantes e revisão da literatura pertinente. Arq Bras Endocrinol Metab. 2013;57(4):240-64 Descritores

Persistent and recurrent disease in patients with papillary thyroid carcinoma with clinically apparent (cN1), but not extensive, lymph node involvement and without other factors for poor prognosis

“…The present study was conducted to answer this question. The criterion used for the definition of LN status (preoperative US and intraoperative inspection by the surgeon) agrees with current guidelines since there is no clear indication for elective LN dissection in patients with tumors ≤ 4 cm and without apparent extrathyroid invasion (1)(2)(3)(4)(5)(6)(7)23). …”

“…Although the impact on the prognosis is questionable, the presence of clinically apparent LNM [cN1, defined as LNM identified by preoperative physical examination or ultrasonography (US), or intraoperative inspection by the surgeon] excludes the patient from the group of low recurrence risk (1)(2)(3)(4)(5)(6) and frequently indicates a more aggressive initial approach (1)(2)(3)(4)(5)(6)(7)(8).…”

Thyroglobulin levels before radioactive iodine therapy and dynamic risk stratification after 1 year in patients with differentiated thyroid cancer

“…The prevalence of DTC has risen in recent years, largely due to the increase in diagnosis of microcarcinomas (tumors up to 1 cm across at widest point) and representing the fourth most prevalent malignant neoplasm in Brazilian women (5,(18)(19)(20). Studies suggest that the majority of DTC does not clinically progress, explaining the continued low death rates despite increased incidence (21,22).…”

“…Consequently, it is essential to perform initial staging of the disease (5). Several systems have been developed to assess prognosis, risk of recurrence and death, to help inform decisions on post-operative therapy and the frequency and intensity of follow-up, as well as to standardize language and facilitate communication of the multi-disciplinary team involved in the follow-up of these patients (3)(4)(5). However, these classification systems are, in general, only static representations of the patient after surgery and are not modifiable during follow-up, proving useful only to guide initial therapeutic measures.…”

“…Based on global consensus on management of DTC, initial treatment includes thyroidectomy with or without lymph node chain resection, in association with administration of I 131 radioactive iodine therapy (RIT) in patients with significant risk of death or recurrence (3)(4)(5). After initial therapy, the daily administration of suppression doses of levothyroxine has an important adjuvant role in high-risk patients since suppression of thyroid stimulating hormone (TSH) inhibits tumor growth and progression, thereby reducing the risk of disease recurrence and associated death (6)(7)(8)(9).…”