Most people diagnosed with papillary thyroid carcinoma (PTC)—the most common form of thyroid cancer—have a low risk of dying from their disease or experiencing a recurrence. This position statement, developed by the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism (SBEM), presents current evidence-based recommendations that favor less aggressive approaches for carefully selected low-risk patients, including active surveillance (monitoring without immediate surgery), thyroid lobectomy (removing only part of the thyroid) instead of total thyroidectomy, and restricted use of radioactive iodine therapy. The statement details the precise criteria that define low-risk disease, explains changes to the cancer staging system, and provides practical guidance on follow-up strategies that keep patients safe while avoiding unnecessary treatment.
The past decade has witnessed a fundamental shift in how doctors approach papillary thyroid carcinoma (PTC). Instead of a one-size-fits-all treatment plan, physicians now use an individualized approach based on a careful assessment of each patient's specific risk. This change was driven by three developments: increasingly sensitive diagnostic methods, a better understanding of the molecular biology of thyroid cancer, and well-conducted prospective studies that tracked patient outcomes over time.
These advances have led to the development of risk assessment tools that help doctors predict, early in the course of the disease, which patients are likely to have meaningful outcomes—such as death from the disease or structural disease persistence/recurrence (the cancer coming back).
The result is that the majority of patients with PTC are now classified as having a low risk of mortality (death) and a low risk of disease persistence or recurrence. For these patients, current treatment recommendations favor less invasive and less intensive therapies. This position statement from the Brazilian Society of Endocrinology and Metabolism translates the latest scientific evidence into practical guidance for doctors managing patients with low-risk PTC.
The first thing patients often worry about after a cancer diagnosis is whether they could die from the disease. To address this concern, doctors use a staging system to predict cancer-specific mortality (the risk of dying from the cancer itself).
The most widely used system worldwide is the American Joint Committee on Cancer (AJCC) staging system, commonly known as TNM—which stands for Tumor (size and extent of the primary tumor), Node (whether the cancer has spread to lymph nodes), and Metastasis (whether the cancer has spread to distant organs). The TNM system divides patients by age group and has been shown to perform well compared with other staging classifications.
The recent AJCC 8th edition introduced several important changes that improve the accuracy of predicting disease-specific mortality:
Additionally, older patients with lymph node disease (N1) are no longer automatically upstaged to stage III or IV disease. Patients with N1 disease who are younger than 55 years are now classified as having stage I disease, while those 55 years or older are classified as stage II.
Multiple publications have demonstrated that, compared with the AJCC 7th edition, the 8th edition downstages a substantial number of low-risk patients and provides better separation between stage groups. The practical impact of this is significant: more than 90% of patients are now categorized into stages I and II, and their risk of cancer-related death is below 1%.
Because patients with differentiated thyroid cancer (the most common type) have such low mortality rates, doctors realized that assessing the risk of disease persistence or recurrence (the cancer coming back or remaining after treatment) is more useful for guiding treatment decisions than mortality risk alone.
The American Thyroid Association (ATA) developed a widely used risk-stratification system that classifies patients into three categories based on the risk of disease recurrence:
This risk assessment is based on histopathological features of the tumor (what the tumor looks like under the microscope) and will likely include molecular features in the near future. Doctors also consider operative findings that may not appear in the pathology report, such as vocal cord paralysis, the extent of gross extrathyroidal invasion (visible invasion beyond the thyroid during surgery), and how completely the tumor was removed.
Low-risk disease accounts for about 57% of all patients with PTC. This means that more than half of all papillary thyroid cancer patients fall into a category where less aggressive treatment can be safely considered.
According to the ATA guidelines, the category of low-risk disease includes the following specific situations:
Molecular characterization of the tumor (testing for genetic mutations) has not yet been routinely adopted. The impact of BRAF or TERT mutations on risk assessment is still a matter of debate among experts. However, patients classified as having AJCC/TNM stage I or II disease—based on age, tumor size with no extrathyroidal invasion, and lymph node status (fewer than 5 involved nodes, all smaller than 0.2 cm)—are considered to be at low risk for structural disease recurrence and disease-specific death.
One of the most significant changes in thyroid cancer management is the concept of active surveillance (AS)—a strategy of carefully monitoring a low-risk tumor without immediately performing surgery. This approach was initially recommended for micropapillary thyroid carcinoma (microPTC, tumors smaller than 1 cm) and gained international recognition in 2010, when a pioneer group in Japan published the first data showing that patients with microPTC could be followed safely without intervention, provided the tumor could be clearly visualized on ultrasound.
Guidelines, including the ATA recommendations, endorse AS as the initial approach in selected patients with microPTC. The ATA also recommends AS for low-risk, completely intrathyroidal tumors measuring up to 1.5 to 2 cm.
Why is this approach so attractive? It prevents excessive early treatment, along with the surgical risks and lifelong consequences of thyroid removal. Studies from several different countries have confirmed the original Japanese data, showing:
Fewer studies have included tumors measuring up to 1.5 or 2.0 cm, so more data are needed for larger tumors. Notably, these nodules have an approximate 50% chance of growth over 10 years in patients younger than 40 years, particularly in those closer to age 20. However, the prognosis is not affected if AS is chosen and future surgery becomes necessary due to nodular growth—meaning surgery performed later appears to be just as effective as immediate surgery.
Before starting active surveillance, doctors evaluate three main areas: the characteristics of the nodule, the characteristics of the patient, and the characteristics of the medical team that will follow the patient. Based on this analysis, patients are classified as ideal, appropriate, or inappropriate candidates for AS.
Ideal candidates for active surveillance have:
Appropriate candidates include:
Inappropriate candidates—who should be referred directly for surgery—include:
Patients who are ideal candidates should be offered AS along with information that future surgery may be necessary if the nodule grows, if signs of lymph node or distant metastases emerge, or at the patient's discretion.
Family history of thyroid cancer. Familial nonmedullary thyroid carcinoma (thyroid cancer that runs in families) has a prevalence of around 3% to 10% and is defined as the presence of nonmedullary thyroid carcinoma in at least three first-degree relatives (parents, siblings, or children) in the absence of other known familial syndromes. Although some studies show that the risk of recurrence or mortality is comparable between familial and sporadic (non-inherited) cases, familial cases appear to have an increased risk of multifocal lesions (multiple tumors in the thyroid). Although AS may be a therapeutic option in confirmed cases of familial microPTC, surgery is a better choice and total thyroidectomy is recommended in these cases.
Pregnancy and childbearing age. Some reports have associated levels of beta human chorionic gonadotropin (hCG)—the pregnancy hormone—with an increased number and volume of thyroid nodules during pregnancy. However, the aggressiveness of these tumors is not increased. Therefore, women of childbearing age or those who are pregnant and diagnosed with microPTC may also undergo AS using the same criteria, though more long-term studies are needed in pregnant women and those planning pregnancy.
Concomitant thyroid disorders. Evidence shows an increased risk of thyroid cancer in patients with autoimmune diseases such as Graves' disease and Hashimoto's thyroiditis. However, AS is currently not contraindicated in these patients. Two aspects must be kept in mind:
Regarding benign nodules found alongside the cancer, treatment is not required when these nodules are not clinically significant (for example, toxic nodules causing overproduction of thyroid hormone, or bulky nodules causing compressive symptoms).
TSH suppression therapy during AS. Some doctors previously used levothyroxine (thyroid hormone medication) to suppress TSH and theoretically slow tumor growth. However, evidence of benefit from this approach remains inconclusive, since no randomized trials have been conducted. The current recommendation is to maintain TSH values within the normal range to prevent nodular growth while avoiding the harmful effects of excessive thyroid hormone, especially in elderly patients.
Patients undergoing AS must be reassessed at each visit, with attention to the characteristics of the nodule and the ability of both the patient and the medical staff to continue AS. Figure 1 in the original statement outlines this process.
A neck CT scan may be helpful for nodules close to or in contact with the trachea, to better visualize the contact angle between them. An obtuse angle between the tumor and the trachea is an indication for surgery, as it suggests potential airway invasion.
Indications for surgery during active surveillance include:
Based on current recommendations, clinical and ultrasound assessments should be performed every 6 months for the first 2 years and annually thereafter, if there are no clinical or ultrasound changes.
Before implementing active surveillance, a medical center must ensure that patients can be safely followed. The position statement emphasizes four key points:
When surgery is recommended, the next question is how much of the thyroid to remove. The choice between total thyroidectomy (TT) (removing the entire thyroid gland) and lobectomy (removing only the half of the thyroid containing the tumor, also called partial thyroidectomy or hemithyroidectomy) has little impact on recurrence rates or the risk of death from thyroid cancer.
Solid evidence shows that simple observation of the opposite (contralateral) lobe is safe in patients with low-risk disease after lobectomy. According to the ATA consensus, partial thyroidectomy or lobectomy is considered sufficient treatment for T1 and T2 tumors confined to the thyroid gland, considering that the extent of the thyroidectomy has no effect on survival in PTC and that recurrence after lobectomy can be successfully treated without a negative impact on overall survival.
A notable systematic review and meta-analysis that included 13,801 patients with microPTC (8,812 who underwent total thyroidectomy and 4,989 who underwent partial thyroidectomy) from 11 different cohorts concluded that partial thyroidectomy had equivalent results in terms of mortality, which is relatively low in these cases.
In the authors' opinion, either partial thyroidectomy or lobectomy is a good option for patients in Brazil, especially considering the limited number of head and neck surgeons with high surgical volume in the country.
Choosing the right surgical approach involves weighing the advantages and disadvantages. Here is a summary from the position statement:
Advantages of lobectomy compared to total thyroidectomy:
Disadvantages of lobectomy compared to total thyroidectomy:
The maintenance of thyroid tissue in partial thyroidectomy avoids the need for thyroid hormone replacement that inevitably results from total thyroidectomy. In addition to increased physical and psychiatric burden, hypothyroidism (underactive thyroid) can lead to a substantial socioeconomic impact in the form of early retirement or loss of income. However, even after lobectomy, the need for hormone replacement is not uncommon—half of patients undergoing hemithyroidectomy may develop hypothyroidism.
Completion thyroidectomy may be required in cases of persistent or recurrent disease. After lobectomy, a pathology report showing lymph node or distant metastasis, or an increased number of risk factors for recurrence (such as extrathyroidal extension, aggressive variants, positive surgical margins, extensive blood vessel invasion, or lymphovascular or neural invasion), should prompt completion thyroidectomy and radioactive iodine treatment. The optimal time for completion thyroidectomy, with fewer complications, has been suggested to be 3 months after the initial surgery.
Recent evidence suggests that lobectomy is a cost-effective strategy in middle-aged patients with low-risk PTC, while active surveillance becomes cost-effective starting at age 69. The decision regarding the extent of surgery must involve both the surgeon and the endocrinologist and should consider the patient's beliefs, socioeconomic and cultural characteristics, and access to adequate health services.
Radioactive iodine (RAI) therapy is a treatment where patients take a pill containing radioactive iodine, which is absorbed by remaining thyroid tissue or cancer cells and destroys them. However, RAI is no longer recommended for everyone. Postoperative RAI must be considered only in patients treated with total thyroidectomy and has four potential goals:
Previously, the role of remnant ablation (destroying leftover thyroid tissue) was to facilitate postoperative follow-up and initial staging. But recent evidence has changed this practice dramatically.
A landmark study—the ESTIMABL 2 trial, a large prospective study from France—showed that in patients with low-risk thyroid cancer who underwent thyroidectomy, a follow-up strategy that did not involve radioactive iodine was noninferior to an ablation strategy with radioactive iodine regarding the occurrence of functional, structural, and biologic events at 3 years. In other words, skipping RAI did not lead to worse outcomes.
Ablation can still be considered in patients with detectable thyroglobulin antibodies (TgAb) and in those with increased postoperative thyroglobulin levels in the context of a normal cervical ultrasound. Notably, multivariate analyses from several studies have shown that postoperative serum thyroglobulin level is an independent predictor of disease recurrence—meaning the Tg trend can help identify which patients might benefit from additional treatment.
The paradigm shift described in this position statement has direct, practical implications for patients diagnosed with low-risk papillary thyroid carcinoma:
This position statement has several limitations that patients should understand when discussing their options with their doctors:
Based on this position statement, here are the key takeaways for patients diagnosed with low-risk papillary thyroid carcinoma:
Active surveillance means monitoring a low-risk thyroid tumor with regular ultrasound exams instead of removing it immediately. It is an accepted option for many small tumors under 1 cm and some up to 1.5–2 cm. The tumor grows in about 10% of patients, but later surgery appears just as effective if needed.
Ideal candidates have a single, well-defined nodule confined to the thyroid, with no lymph node or distant spread and no extrathyroidal extension. They are older than 60 years, have serious health conditions that make surgery riskier, and have an experienced team providing high-quality ultrasound and reliable follow-up.
No. The article states that the prognosis is not affected if active surveillance is chosen and surgery becomes necessary later due to tumor growth. Delayed surgery appears to be just as effective as immediate surgery, so the choice to monitor first does not harm your long-term outlook.
Lobectomy carries lower surgical risks, may avoid lifelong thyroid hormone replacement, and has survival outcomes comparable to total thyroidectomy for low-risk tumors confined to the thyroid. However, about half of patients still develop hypothyroidism, and a second completion surgery may be needed in some cases.
No. In a large French study called ESTIMABL 2, patients with low-risk thyroid cancer who did not receive radioactive iodine had outcomes no worse than those who did, at 3 years. Skipping radioactive iodine is considered as safe as receiving it for appropriately selected low-risk patients.
Low-risk means the chance of the cancer coming back is less than 5%. More than 90% of patients are now classified as stage I or II under the current staging system, and the risk of dying from the cancer is below 1% for these stages.
Original article title: Treatment strategies for low-risk papillary thyroid carcinoma
Authors: Laura Sterian Ward, Rafael Selbach Scheffel, Ana O. Hoff, Carolina Ferraz, and Fernanda Vaisman
Publication: Archives of Endocrinology and Metabolism (Arch Endocrinol Metab), 2022;66(4):522-32
DOI: 10.20945/2359-3997000000512
Received: February 11, 2022 | Accepted: July 21, 2022
Keywords: Papillary thyroid carcinoma; position statement; active surveillance
This patient-friendly article is based on peer-reviewed research.
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