Surgery alone for papillary thyroid microcarcinoma is less costly and more effective than long term active surveillance

The recent sharp increase in thyroid cancer incidence is mainly due to increased detection of small papillary thyroid microcarcinoma (PTMC). Due to the indolent nature of the disease, active surveillance (AS) of low-risk PTMCs is suggested as an alternative to immediate surgery to reduce morbidity from surgery. For appropriately selected PTMC patients, AS can be a good management option and surgical intervention can be safely delayed until progression occurs. Many considerations must be taken into account at the time of initiation of AS, including radiological tumor characteristics and clinical characteristics of the patient. A specialized medical team should be assembled to monitor patients during AS with an appropriate follow-up protocol. The fact that some patients require surgery for disease progression after long-term follow-up is a major drawback of the current AS protocol. Evaluation of tumor kinetics by three-dimensional tumor volume measurement during the initial 2–3 years of AS may be helpful for discrimination of PTMCs that need early surgical intervention. In this review, we will discuss the clinical outcomes of surgical intervention and AS, considerations during AS, and unresolved questions about AS.

Background/Objectives: Given the high incidence and generally favorable prognosis of papillary thyroid microcarcinomas (PTMs), the Porto Proposal aims to refine the management of these tumors. It designates tumors lacking certain risk factors as papillary microtumors (PMTs) to avoid overtreatment and reduce patient stress. The updated Porto Proposal (uPp) suggests criteria for reclassifying incidental PTMs as PMTs. This study seeks to validate these criteria using data from a university hospital in Catalonia, Spain, and assess the clinical and pathological characteristics of PTMs. Methods: This retrospective study analyzed patients diagnosed with PTM (≤1 cm) at a university hospital from 2000 to 2024. The study examined variables, including lymph node positivity, incidental diagnosis, tumor location, histological type, treatment, multifocality, age at diagnosis, tumor size, and survival. The uPp criteria were applied to reclassify PTMs into PMTs or PMCs (true papillary microcarcinomas). Student's t-test and chi-square tests were used to evaluate the associations between these variables and the uPp classification. Results: The cohort comprised 107 patients, with 77 (72%) women and 30 men. The mean age at diagnosis was 54.5 years. Out of the total, 77 (72%) cases were reclassified as PMTs and 30 (28%) as PMCs according to the uPp criteria. PMC tumors were larger (mean size 4.5 mm vs. 3.3 mm for PMT, p = 0.014) and were significantly associated with multifocality (52.2%; p = 0.004). Most lymph node-positive cases were classified as PMCs (69.2%; p < 0.001) and were multifocal and bilateral more commonly. However, no significant differences in outcomes between PMCs and PMTs were found (p = 0.188). Follicular histology was significantly more common in PMTs (87.0%, p < 0.001) and rarely had lymph node metastases (4.6%; p = 0.047). Conclusions: The updated Porto Proposal (uPp) effectively identifies PTMs with minimal malignant potential, distinguishing between PMT and PMC. The findings support the protocol's use in reducing unnecessary treatments and psychological stress for patients. The study highlights significant clinical and pathological differences between PTM subtypes, reinforcing the protocol's applicability in daily pathological practice.

Papillary Microcarcinoma (PMC) of thyroid is a rare type of differentiated thyroid cancer (DTC), which according to the World Health Organization measures 1.0 cm or less. The gold standard of treatment of PMC is still controversy. Our aim was to contribute in resolving the debate on the therapeutic choices of the surgical and adjuvant I-131 (RAI) treatment in PMC. From 2000 to 2012, 326 patients were found to have PMC and were retrospectively reviewed for clinicopathological characteristics, treatment outcomes and prognostic factors. Mean age of cohort was 42.6 years (range: 18–76) and the mean tumor size was 0.61 cm ± 0.24; lymph node involvement was seen in 12.9 % of cases. Median follow up period was 8.05 years (1.62–11.4). Total 23 all site recurrences (7.13 %) were observed; more observed in patients without I-131 ablation (p 0.5 cm) and lymph node involvement. Failure of RAI ablation to decrease risk in N1a/b supports prophylactic central neck dissection during thyroidectomy, however more trials are warranted. Adjuvant I-131 ablation following thyroidectomy in PMC patients, particularly with poor prognostic factors improves DFS rates.

Age-stratified comparison of active surveillance versus radiofrequency ablation for papillary thyroid microcarcinoma using decision analysis

The objective of this study is to highlight the fact that papillary thyroid microcarcinoma can be aggressive, requiring therapeutic management similar to that of other differentiated thyroid cancers. This 8-year retrospective study concerned 187 surgical patients managed in an ENT and Head and Neck surgery department for thyroid cancer. 65 patients were found to have papillary microcarcinoma. 41 microcarcinomas were considered to be aggressive because of the presence of several risk factors such as larger than 5 mm, multifocal microcarcinomas, capsular effraction, vascular embolus, tumour extension beyond the thyroid parenchyma and metastatic lymphadenopathy. All patients with aggressive papillary microcarcinoma were treated by total thyroidectomy and (131)I. Ipsilateral recurrent laryngeal and lateral cervical lymph node dissections were performed in ten patients, ipsilateral cervical lymph node dissection was performed in six patients and bilateral recurrent laryngeal and lateral cervical lymph node dissections were performed in three patients. No recurrence or metastasis was observed (follow-up ranging from 6 months to 8 years). The optimal management of thyroid papillary microcarcinoma is still controversial. "Aggressive" papillary thyroid microcarcinoma is not rare and may justify aggressive treatment depending on the presence or absence of prognostic risk factors.

Objective To study the correlation between the sonographic features of papillary thyroid microcarcinoma (PTMC) and high volume lymph node metastasis. Methods Medical records of 463 PTMC patients were reviewed. Cases of all patients are completed with lymph node metastasis identified by histopathology. Sonographic features such as lesion number, lesion size, echogenicity, calcification, envelope and vascularity of papillary microcarcinoma are recorded. Univariate and multivariate analysis was performed to investigating relationship between sonographic features and high volume lymph node metastasis. Results Twenty four patients have high volume central lymph node metastasis (5.2%, 24/463), in univariate analysis, sex (11.2% in male vs 3.4% in female), age (8.3% in <45 years vs 2.4% in ≥45 years) , calcification (8.3% in micro vs 0.0% in coarse, 3.2% in mixed and 0.7% in non) , extracapsular invasion (9.3% with vs 3.2% without) and size (9.2% in ≥7 mm vs 2.5% in <7 mm) showed significant difference; multiple logistic regression analysis showed that male (OR=3.205, P=0.009) , age<45 years (OR=2.923, P=0.031), microcalcification (OR=9.380, P=0.031) and tumor size≥7mm (OR=3.272, P=0.013) is independent risk factor for high volume lymph node metastasis in the central compartment of PTMC. 10 patients have high volume lateral lymph node metastasis (2.2%, 10/463), in univariate analysis, age (4.1% in <45 years vs 0.4% in ≥45 years), number of lesions (5.3% in multiple vs 0.9% in single) showed significant difference; multiple logistic regression analysis showed that age<45 years (OR=11.939, P=0.024) and multiple lesion (OR=7.247, P=0.007) is independent risk factor for high volume lymph node metastasis in the lateral compartment of PTMC. Conclusion Sonographic features of primary papillary microcarcinoma of the thyroid has correlation with high volume lymph node metastasis. Key words: Papillary thyroid microcarcinoma; Ultrasonography, Dopper, color; Lymphatic metastasis

Given the high incidence and excellent prognosis of many papillary thyroid microcarcinomas, the Porto proposal uses the designation papillary microtumor (PMT) for papillary microcarcinomas (PMCs) without risk factors to minimize overtreatment and patients' stress. To validate Porto proposal criteria, we examined a series of 190 PMC series, also studying sex hormone receptors and BRAF mutation. Our updated Porto proposal (uPp) reclassifies as PMT incidental PMCs found at thyroidectomy lacking the following criteria: (a) detected under the age of 19 years; (b) with multiple tumors measuring >1 cm adding up all diameters; and (c) with aggressive morphologic features (extrathyroidal extension, angioinvasion, tall, and/or hobnail cells). PMCs not fulfilling uPp criteria were considered "true" PMCs. A total of 102 PMCs were subclassified as PMT, 88 as PMC, with no age or sex differences between subgroups. Total thyroidectomy and iodine-131 therapy were significantly more common in PMC. After a median follow-up of 9.6 years, lymph node metastases, distant metastases, and mortality were only found in the PMC subgroup. No subgroup differences were found in calcifications or desmoplasia. Expression of estrogen receptor-α and estrogen receptor-β, progesterone receptor, and androgen receptor was higher in PMC than in nontumorous thyroid tissue. BRAF mutations were detected in 44.7% of PMC, with no differences between subgroups. In surgical specimens, the uPp is a safe pathology tool to identify those PMC with extremely low malignant potential. This terminology could reduce psychological stress associated with cancer diagnosis, avoid overtreatment, and be incorporated into daily pathologic practice.

For rapidly increasing low-risk papillary thyroid micocarcinoma(PTMC), Japanese scholars have proposed that immediate surgery can be replaced by active surveillance, i. e. observation strategy. The new strategy has brought not only an important update to the management of PTMC, but also controversies from different perspectives. Here we would like to give a thorough review on the observation strategy for PTMC, including its development background, available clinical data, current recommendations/suggestions by guidelines/consensuses, common misunderstandings toward this topic, challenges, and prospective in the future. (Chin J Endocrinol Metab, 2017, 33: 359-362) Key words: Thyroid; Papillary microcarcinoma; Active surveillance; Observation; Risk stratification

Papillary thyroid microcarcinoma: A study of 900 cases observed in a 60-year period

BackgroundOvertreatment of papillary thyroid microcarcinoma (PTMC) has become a common concern. This study aimed to compare clinicopathological features between PTMC and papillary thyroid carcinoma (PTC) and to explore whether surgery can confer significant survival benefits in all patients with PTC or PTMC.MethodsData of 145,951 patients with PTC registered in Surveillance, Epidemiology, and End Results (SEER) database and 8,751 patients with PTC in our institution were retrospectively collected. Patients with tumors less than 10 mm in diameter were classified as PTMC cohort and the rest as PTC cohort. Clinicopathological features between PTMC and PTC were compared on the basis of SEER cohort and validated with institutional data. Survival analysis was conducted to explore the effect of surgery on the prognosis of patients. To minimize potential confounders and selection bias, we performed propensity score matching (PSM) analysis to match more comparable cohorts.ResultsCompared with PTC, PTMC exhibited the following characteristics: more common in women and whites, older age at diagnosis, lower proportion of follicular variants, intraglandular dissemination, extraglandular and capsular invasion, higher proportion of multifocality, fewer lymph node and distant metastases, and higher cancer-specific survival (CSS) and overall survival (OS) (all p-value < 0.05). Regarding treatment, patients with PTMC received a lower proportion of radiotherapy, chemotherapy, and total thyroidectomy but a higher proportion of lobectomy and/or isthmectomy. There was no significant difference in CSS for patients with PTMC at stage T1N0M0 with or without surgery (P = 0.36).ConclusionGenerally, PTMC showed higher biological indolence than PTC, which meant a higher survival rate for patients in both OS and CSS. For patients with PTMC at staged T1N0M0, active surveillance (AS) may be a potentially feasible management strategy. However, the maintenance of good medical compliance and the management of psychological burden cannot be ignored for patients included in AS.

Active surveillance for papillary thyroid microcarcinomas (PTMCs) initiated in Japan is becoming adopted worldwide as a management option. However, it remains unclear how to manage newly appearing PTMCs in the remnant thyroid after hemithyroidectomy. We investigated the outcomes of similar observational management (OM) for PTMCs appearing in the remnant thyroid after hemithyroidectomy for papillary thyroid carcinoma (PTC) and benign thyroid nodules. Eighty-three patients were newly diagnosed with PTMC in the remnant thyroid between January 1998 and March 2017. Of these, 42 patients underwent OM with >3 times ultrasound examinations. Their initial diagnoses were PTC (initially malignant group) in 37 patients and benign nodule (initially benign group) in 5 patients. We calculated the tumor volume doubling rate (TV-DR) during OM for each PTMC. The TV-DR (/year) was <-0.1, -0.1-0.1, 0.1-0.5, and >0.5 in 12, 19, 5, and 6 patients, respectively. The TV-DRs in both groups did not statistically differ, but six patients (16%) in the initially malignant group showed moderate growth (TV-DR >0.5/year). They underwent conversion surgery and none of them had further recurrence. The remaining 36 patients retained OM without disease progression. The TV-DR in the initially malignant group was not significantly associated with patients' backgrounds or their initial clinicopathological features. None of the patients in this study showed distant metastases/recurrences or died of thyroid carcinoma. Although a portion of PTMCs appearing after hemithyroidectomy for thyroid malignancy are moderately progressive, OM may be acceptable as a management option for PTMCs appearing in the remnant thyroid after hemithyroidectomy.

Introduction: Thyroid cancer is one of the most common cancers in the world, with incidence 144,7: 100.000 population. The incidence has risen up to 211% within the last 30 years, and one–third of thyroid cancer is papillary thyroid microcarcinoma. There are still controversies regarding whether immediate surgery or active surveillance is the better option for treating this condition. This review aims to evaluate the safety and efficacy of active papillary thyroid microcarcinoma surveillance. Methods: Cochrane, PubMed, EBSCOHost, and ProQuest were searched for relevant studies of active surveillance of papillary thyroid microcarcinoma. Results: Six publications were selected after a literature search and review. Conclusion: Active surveillance could be implemented as a treatment of papillary thyroid microcarcinoma in selected cases. The overall survival rate of papillary thyroid microcarcinoma is up to 99%, with cancer growth &gt;3mm at 4.4% to 8%. Lymph node metastases were 1.2% to 3.8%, and distant metastases were only found in 0.04% of cases.

BackgroundIn recent years management practices in relation to low-risk papillary microcarcinoma (PMC) have been evolving with increased awareness of the potential overdiagnosis and overtreatment of PMCs, and guidelines recommendations for non-surgical management options such as active surveillance. This study aimed to develop an in-depth understanding of patients’ experiences of the communication of their PMC diagnosis, their treatment preferences and decision making.MethodsSemi-structured qualitative interviews with 25 patients diagnosed pre-operatively with PMC < 1 year since their diagnosis and treatment. Interviews were conducted between September 2015 and July 2016 and were audio-recorded and transcribed verbatim. Framework analysis method was used to analyse the data.ResultsThe diagnosis and treatment experience of PMC patients varied widely. The majority of patients were asymptomatic, and their PMC was initially detected via an imaging test requested for a reason unrelated to a thyroid disorder or symptom. Clinicians generally described PMC to patients as being a “small” or “slow-growing” cancer, and there was little evidence that clinicians had discussions about the possibility of overdiagnosis or overtreatment. Overall, surgery was the only option discussed and offered to patients. Patients preference for treatment was largely based on eliminating the possibility of the cancer spreading (thyroidectomy) or not wanting to be on thyroid replacement medication for the rest of their life (hemi-thyroidectomy). Many patients reported emotional and physical side-effects associated with their diagnosis and treatment, however patients generally indicated that active surveillance is not something they would have been interested in if it was offered to them.ConclusionsEvidence continues to emerge that many patients with PMCs may be overdiagnosed, and management guidelines are recommending more conservative management options for these patients. As a result, shared decision making around treatment options is vital so that patients are fully aware of the meaning of their diagnosis and their management options including active surveillance. Importantly, interventions to reduce unnecessary diagnoses of PMC are critically needed.

Active surveillance (AS) can be considered as an alternative to immediate surgery in low-risk papillary thyroid microcarcinoma (PTMC) without clinically apparent lymph nodes, gross extrathyroidal extension (ETE), and/or distant metastasis according to American Thyroid Association. However, in the past AS has been controversial, as evidence supporting AS in the management of PTMC was scarce. The most prominent of these controversies included, the limited accuracy and utility of ultrasound (US) in the detection of ETE, malignant lymph node involvement or the advent of novel lymph node malignancy during AS, and disease progression. We summarized publications and indicated: (1) US, performer-dependent, could not accurately diagnose gross ETE or malignant lymph node involvement in PTMC. However, the combination of computed tomography and US provided more accurate diagnostic performance, especially in terms of selection sensitivity. (2) Compared to immediate surgery patients, low-risk PTMC patients had a slightly higher rate of lymph node metastases (LNM), although the overall rate for both groups remained low. (3) Recent advances in the sensitivity and specificity of imaging and incorporation of diagnostic biomarkers have significantly improved confidence in the ability to differentiate indolent vs. aggressive PTMCs. Our paper reviewed current imagings and biomarkers with initial promise to help select AS candidates more safely and effectively. These challenges and prospects are important areas for future research to promote AS in PTMC.

Objective: To investigate the rationality of management of active surveillance for papillary thyroid microcarcinoma (PTMC) and the main indications for active surveillance for PTMC. Methods: In this study, two criteria were used to evaluate patients with PTMC: low-risk PTMC conditions defined by Kuma hospital and Chinese Association of Thyroid Oncology (CATO) consensus on PTMC management of active surveillance. The patients had received surgical treatment. Clinicopathological characteristics and prognosis of the patients in different groups were compared. Results: A total of 778 patients were enrolled in the study, 565 (72.6%) of them met Kuma screening criteria and only 112 (14.4%) met CATO screening criteria. Kuma low-risk subgroup had lower incidence of cervical lymph node metastasis than Kuma high-risk PTMC subgroup(30.6% vs 47.9%, P<0.05). There were significant differences in multifocal lesions(6.3% vs 16.4%), extrathyroidal extension (1.8% vs 7.5%) and cervical lymph node metastasis(19.6% vs 38.0%) between low-risk and high-risk CATO PTMC subgroups. Patients in the CATO low-risk PTMC subgroup had lower recurrence and longer disease-free survival (DFS) than those in the CATO high-risk PTMC subgroup. But there was no significant difference in recurrence or DFS between Kuma low-risk and high-risk Kuma PTMC subgroups.The Chi-square test of Fisher's exact probabilities test was used to compare clinicopathological characteristics of patients between different groups.Rates of disease-free survival were calculated using the Kaplan-Meier method. Conclusion: CATO screening criteria is relatively strict and may be more suitable for Chinese patients with active surveillance for PTMC.