Low-risk Papillary Thyroid Cancer Research Articles

Thyroid-stimulating hormone suppression in low-risk papillary thyroid cancer: a large-scale retrospective analysis of real-world data

Over 500,000 new cases are diagnosed with papillary thyroid cancer (PTC) globally per year, of whom the vast majority are in the low-risk stratification. Although thyroid-stimulating hormone (TSH) suppression is traditionally recommended for all postoperative PTCs in current guidelines, its necessity remains highly controversial in low-risk patients. Since relevant recommendations in current guidelines are still empirical, we aim to provide a direct, large-scale, real-world evidence. This large-scale real-world retrospective study included 11,140 low-risk PTC patients from two Chinese large-volume centers (Fudan University Shanghai Cancer Center [FUSCC] and Cancer Hospital of Chinese Academy of Medical Sciences [CH-CAMS]) treated from January 1, 2000 to June 30, 2022. The mean TSH level was calculated based on postoperative serum TSH values during follow-up. The primary outcome was the association between postoperative TSH level and structural recurrence assessed by Kaplan-Meier, log-rank, multivariate Cox regression analyses and equivalence testing by Two One-Sided Tests (TOST) procedure. Propensity score matching (PSM) was used to adjust for confounders among groups. A total of 11,140 patients with low-risk PTC were included with a median follow-up of 70 months. Based on the mean TSH level, we classified these patients into ≤0.5 (n=1,504, 13.5%), (0.5-1] (n=4,336, 38.9%), (1-2] (n=4,285, 38.5%), (2-3] (n=704, 6.3%) and >3 (n=311, 2.8%) mU/L groups. After PSM adjusting for age, sex, T and N stage, 8991 patients were included in further analysis, for whom the log-rank analyses showed no significant differences between any two groups (all P>0.05) in recurrence-free survival (RFS), locoregional recurrence-free survival (LRRFS) and distant metastasis-free survival (DMFS), and suppressed TSH was not associated with tumor recurrence in the multivariate Cox analysis (TSH > 2 group vs TSH ≤ 2 group: HR=1.30, 95% CI=0.85-2.01, P=0.23). Furthermore, the TOST equivalence tests showed that tumor recurrence status of any two TSH groups were statistically comparable (all Bonferroni-corrected P values<0.005). Subgroup multivariate analyses showed that TSH level did not impact tumor recurrence regardless of age, tumor size, lymph node metastasis, multifocality, surgical extent, biochemical evidence. Our results suggested that postoperative TSH level was not associated with tumor recurrence in patients with low-risk PTC, for whom deliberate TSH suppression may be exempted to avoid potential secondary complications. Maintaining a TSH level within the normal range may be safe for these patients. The study was supported by the National Natural Science Foundation of China (82072951 to Y.W.; 82373008 to X.S.), Shanghai Hospital Development Center (SHDC2020CR6003-001 to Y.W., SHDC2024CRI087 to Y.-J.W.), the Science and Technology Commission of Shanghai Municipality (22Y21900100/23DZ2305600 to Y.W.; 23ZR1412000 to X.S.), the Shanghai Anticancer Association Foundation (SACA-AX202213 to Yu Wang), Shanghai Municipal Health Commission and Shanghai Medicine and Health Development Foundation (WJWRC202302 to X.S.).

The Prognostic Impact of Radioiodine Therapy in Patients with Papillary Thyroid Cancer.

Radioiodine (RAI) therapy after surgery, is an important component for the treatment of patients with papillary thyroid cancer (PTC), the most common thyroid cancer. In this study we sought to evaluate the cancer-specific survival (CSS) impact of RAI in specific thyroid cancer subgroups. The Surveillance, Epidemiology, and End Results (SEER) database were used to identify patients with PTC who underwent surgery between 2000 and 2019. Patients not treated with RAI were compared to those treated with RAI using propensity score matching (PSM) on the basis of identical inclusion criteria. A total of 106 333 patients were identified from the SEER database. RAI therapy was associated with improved CSS in the matched cohort (HR: 0.83; 95% CI: 0.72-0.96, p=0.01) but not in the unmatched data set (HR: 1.46; 95% CI: 1.30-1.64, p<0.001) among all PTC patients regardless of disease stage. Detailed analyses, however, showed that only patients with high-risk disease (pT3N1, pT4N1) experienced the greatest benefit in CSS. In the lower disease stages, no significant differences were recognized in the group of PTC patients with or without RAI therapy. One exception: in the group of PTC patients in stage pT1bN0, a significant difference was seen towards RAI. This is, however, most likely due to the large number of patients investigated. In summary, RAI therapy should not be used in low-risk PTC patients and might be used to some extent in intermediate-risk PTC patients. The histological suptype of the tumor needs to be considered in this context.

A Qualitative Thematic Analysis Exploring Chinese Young Adults' Experiences in Decision Making on the Management of Low-Risk Papillary Thyroid Cancer.

Background: Thyroid cancer is the most common endocrine neoplasm in China. Questions regarding the extent of patient involvement in shared decision-making (SDM) processes persist; this is particularly pertinent to patients considering treatment options for low-risk papillary thyroid cancer (PTC). In this study, we aimed to explore Chinese young adults' experiences of SDM relating to the choice of treatment for low-risk PTC. Methods: The study used a qualitative descriptive design and semistructured interviews. Interviews were conducted with 24 patients (ages ranging from 18 to 38 years; 4 men and 20 women) diagnosed with low-risk (PTC) between March 2023 and May 2024. Twenty-two of 24 patients' tumor size measured 1 cm or smaller; the largest tumor size measured 1.47 cm. Reflexive thematic analysis was used to identify key themes from the transcribed interviews. Results: The analysis revealed that the SDM experiences of young patients with low-risk PTC involve four themes: challenges in information sharing; reasons for information seeking; factors influencing decision making; and self-positioning in treatment decision making. Three self-positions relating to treatment decision making were identified. These included dependent positioning, which reflects a "paternalistic" decision-making pattern; collaborative positioning, reflecting a "sharing" of decision making; and autonomous positioning, reflecting an increased sense of personal responsibility for both managing their health and engagement in decision making. Limited treatment options being offered, overuse of medical terminology, and communication gaps between clinicians and patients were the main challenges described during the information-sharing process. Information that needs persisting after physician-patient consultations resulted in active information-seeking behavior. The key variables identified in this study that potentially affected the decision-making process were future personal considerations, language used to discuss cancer, and negative emotions. Conclusions: These results highlight the necessity of adopting flexible strategies when supporting collaborative treatment decision making in the context of the doctor-patient interaction for low-risk PTC. Based on these findings, clinicians can take measures to enhance the quality of SDM by inquiring about patients' role preferences, providing details of the full range of treatment options, and encouraging patients to share their preferences and concerns relating to possible treatment options.

RAI therapy in low-risk papillary thyroid cancer: recurrence reduction and long-term outcomes in the Turkish population

PurposePapillary thyroid cancer (PTC) is the most common thyroid malignancy, characterized by its slow progression and favorable prognosis. This study re-evaluates the efficacy of radioactive iodine (RAI) therapy versus no RAI in low-risk PTC patients following total thyroidectomy.MethodsA retrospective analysis was conducted on 588 patients treated between 2010 and 2016 at a major tertiary center in Turkey. Patients were divided into two cohorts: those receiving total thyroidectomy (TT) with high-dose RAI (100 mCi) and those receiving TT alone. A matched cohort of 138 patients per group was analyzed to minimize bias.ResultsFollow-up data indicated that at 24 months, the RAI group demonstrated a higher percentage of excellent treatment responses (86%) compared to the non-RAI group (74%). Long-term follow-up showed that 99.3% of the RAI group achieved no evidence of disease (NED), versus 90.6% in the non-RAI group. Recurrence rates were significantly lower in the RAI group (1%) compared to the non-RAI group (5.8% with a > 2.0 ng/ml cut-off for biological events).ConclusionIn summary, the findings from this study underscore the efficacy of RAI therapy in reducing recurrence rates and enhancing long-term disease control in low-risk papillary thyroid cancer patients. While total thyroidectomy alone is effective, the addition of RAI therapy provides a marked improvement in treatment responses and reduces the risk of disease recurrence. This indicates that personalized treatment plans incorporating RAI may offer significant advantages in managing low-risk PTC.

7478 Effects of RAI on Papillary Thyroid Carcinoma with Positive Lymph Nodes

Abstract Disclosure: K.N. Rachmasari: None. A. Osman: None. D. Toro Tobon: None. S.B. Lund: None. D.J. Merlino: None. A.R. Hsu: None. M.M. Ryder: None. Background: In low-risk papillary thyroid cancer (PTC), radioactive iodine (RAI) remnant ablation has shown no impact on disease recurrence rates, which are overall low. The role of adjuvant RAI in intermediate risk disease (i.e. T3, N1) remains unproven with no randomized clinical trials to objectively assess efficacy. Thus, in our institution, its use is highly heterogenous. We retrospectively investigated the effects of adjuvant RAI on recurrence and recurrence free survival (RFS) in patients with PTC and positive cervical lymph nodes (CLN). Methods: We performed a retrospective review of patients who underwent surgery at Mayo Clinic Rochester, MN for PTC between January 2007 and December 2016. Adult patients with Tx-T3 disease according to the 8th edition of American Joint Committee on Cancer (AJCC) were identified. Patients with positive CLN (N1) and a minimum follow up of 36 months were included. Demographics, clinicopathologic characteristics, use of RAI therapy and recurrence were analyzed. Results: A total of 367 patients with PTC, Tx-3, N1, M0 were identified, of which 187 received adjuvant RAI and 180 did not. Most patients were female (63.8%), with a median age of 44 years (IQR 34-54), and a median follow up of 77 months (IQR 58.5-101.5). There were no differences in age, type of surgery, histology, multifocality, and follow up period between the RAI and no RAI subgroups. Adjuvant Thyrogen-stimulated or thyroid hormone withdrawal-based RAI was recommended at the discretion of the treating provider and/or per patient preference. Diagnostic I-123 whole body scans were performed in all patients and mostly demonstrated remnant uptake. The median dose of I-131 was 75 mCi (range 50-100). Recurrence was defined by new occurrence of disease after at least a year of absence of clinical, biochemical, and imaging evidence of disease since initial surgery. Within the entire cohort, 35 (9.5%) developed recurrence with a median time of 41 months (28-59.5). Overall, recurrence rate and RFS were not significantly different between both subgroups (p = 0.2). A subanalysis was performed in patients with clinically detectable nodal disease (n = 161), defined by abnormal cervical lymph node on preoperative neck ultrasound with or without positive fine needle aspiration biopsy. Overall recurrence rates were 17 (10.6%) in this group. There were no differences in recurrence rates and RFS in those that received RAI versus those that did not (p = 0.8). Conclusions: In patients with intermediate risk PTC defined by nodal disease and/or T3 disease, recurrences were not different between patients that did or did not receive adjuvant I-131 therapy postoperatively. A randomized, noninferiority study of adjuvant I-131 compared to no I-131 postoperatively for N1 disease is needed to determine the benefit of near total thyroidectomy and adjuvant I-131 for this cohort. Presentation: 6/3/2024

Assessing Decision Regret for Active Surveillance versus Surgery in Patients with Low-Risk Papillary Thyroid Cancer

Assessing Decision Regret for Active Surveillance versus Surgery in Patients with Low-Risk Papillary Thyroid Cancer

Racial-Ethnic Comparison of Treatment for Papillary Thyroid Cancer in the Military Health System.

We aimed to compare Asian or Pacific Islander, Black, Hispanic, and non-Hispanic White patients in treatment for papillary thyroid cancer (PTC) in the equal access Military Health System to better understand racial-ethnic cancer health disparities observed in the United States. We used the MilCanEpi database to identify a cohort of men and women aged 18 or older who were diagnosed with PTC between 1998 and 2014. Low- or high-risk status was assigned using tumor size and lymph node involvement. Treatment with surgery (e.g., thyroidectomy) overall and treatment by risk status [active surveillance (low-risk) or adjuvant radioactive iodine (RAI) (high-risk)] was compared between racial-ethnic groups using multivariable logistic regression and expressed as adjusted odds ratios (AOR) with 95% confidence intervals (CIs). The study included 598 Asian, 553 Black, 340 Hispanic, and 2958 non-Hispanic White patients with PTC. Asian (AOR = 1.21, 95% CI 0.98, 1.49), Black (AOR = 1.07, 95% CI 0.87, 1.32), and Hispanic (AOR = 0.92, 95% CI 0.71, 1.19) patients were as likely as White patients to receive surgery. By risk status, there were no significant racial-ethnic differences in receipt of active surveillance or thyroidectomy for low-risk PTC or in thyroidectomy or total thyroidectomy with adjuvant RAI for high-risk PTC. In the Military Health System, where patients have equal access to care, there were no overall racial-ethnic differences in surgical treatment for PTC. As American Thyroid Association guidelines evolve to include more conservative treatment, further research is warranted to understand potential disparities in active surveillance and surgical management in U.S. healthcare settings.

Evolution in the management of thyroid surgery over a period of 15 years in a Belgian center

BackgroundGuidelines for thyroid surgery have evolved to reflect advances in medical knowledge and decrease the overdiagnosis of low-risk thyroid cancer. Our goal was to analyze the change made in operative thyroid management and the impact on thyroid cancer diagnosis.BackgroundGuidelines for thyroid surgery have evolved to reflect advances in medical knowledge and decrease overdiagnosis of low risk thyroid cancer. Our goal was to study the evolution, over a long period, of pre- and postoperative management and the influence on histological cancer diagnosis and, more particularly, microcancer.MethodsIn this retrospective cohort study, we included 891 consecutive patients who underwent thyroid surgery between 2007 and 2020.ResultsRespectively 305, 290 and 266 patients underwent surgery over the 3 periods of 2007–2010, 2011–2015 and 2016–2020. In all three periods, women represented approximately 70% of the population, and the mean age was 54 years old (range: 67). Most surgeries (90%) involved total thyroidectomies. Over the study period, the proportion of preoperative fine needle aspiration (FNA) increased from 13 to 55%, p < 0,01. Cancer was found in a total of 116 patients: 35 (11%) patients between 2007 and 2010, 50 (17%) between 2011 and 2015 and 32 (12%) between 2016 and 2020 (p = 0.08). For all 3 periods, papillary thyroid cancer (PTC) was the most prevalent, at approximately 80%. The proportion of thyroid cancer > T1a increased significantly from 37% (2011–2015 period) to 81% (2016–2020 period), p = 0.001. Patients treated with radioiodine remained relatively stable (approximately 60%) but were more frequently treated with a low dose of radioiodine (p < 0.01) and recombinant human TSH (p < 0.01). Operative thyroid weight decreased over time in all but the low-risk T1a PTC cases.ConclusionsOver a period of 15 years and according to the evolution of recommendations, the care of patients who underwent thyroid surgery changed with the increased use of preoperative FNA. This change came with a decrease in low-risk T1a PTC.

Decision Regret Following the Choice of Surgery or Active Surveillance for Small, Low-Risk Papillary Thyroid Cancer: A Prospective Cohort Study.

Background: It is important to understand cancer survivors' perceptions about their treatment decisions and quality of life. Methods: We performed a prospective observational cohort study of Canadian patients with small (<2 cm) low-risk papillary thyroid cancer (PTC) who were offered the choice of active surveillance (AS) or surgery (Clinicaltrials.gov NCT03271892). Participants completed a questionnaire one year after their treatment decision. The primary intention-to-treat analysis compared the mean decision regret scale total score between patients who chose AS or surgery. A secondary analysis examined one-year decision regret score according to treatment status. Secondary outcomes included quality of life, mood, fear of disease progression, and body image perception. We adjusted for age, sex, and follow-up duration in linear regression analyses. Results: The overall questionnaire response rate was 95.5% (191/200). The initial treatment choices of respondents were AS 79.1% (151/191) and surgery 20.9% (40/191). The mean age was 53 years (standard deviation [SD] 15 years) and 77% (147/191) were females. In the AS group, 7.3% (11/151) of patients crossed over to definitive treatment (two for disease progression) before the time of questionnaire completion. The mean level of decision regret did not differ significantly between patients who chose AS (mean 22.4, SD 13.9) or surgery (mean 20.9, SD 12.2) in crude (p = 0.730) or adjusted (p = 0.29) analyses. However, the adjusted level of decision regret was significantly higher in patients who initially chose AS and crossed over to surgery (beta coefficient 10.1 [confidence interval; CI 1.3-18.9], p = 0.02), compared with those remaining under AS. In secondary adjusted analyses, respondents who chose surgery reported that symptoms related to their cancer or its treatment interfered with life to a greater extent than those who chose AS (p = 0.02), but there were no significant group differences in the levels of depression, anxiety, fear of disease progression, or overall body image perception. Conclusions: In this study of patients with small, low-risk PTC, the mean level of decision regret pertaining to the initial disease management choice was relatively low after one year and it did not differ significantly for respondents who chose AS or surgery.

Abstract 4820: Comparison of Black and White patients in treatment for papillary thyroid cancer in an equal access health system

Abstract Introduction: In the U.S., Black patients with papillary thyroid cancer (PTC) are less likely to receive treatment than non-Hispanic White patients. Access to care and insurance status may be related to these disparities. We aimed to compare Black and White patients in receipt of cancer care for PTC in the equal access Military Health System. Materials and Methods: We used the MilCanEpi database to identify a cohort of men and women aged 18 or older who were diagnosed with PTC between January 1, 1998 and December 31, 2014. Patients were assessed for treatment by surgery (e.g., lobectomy, thyroidectomy), adjuvant radioactive iodine (RAI), or active surveillance. Treatment appropriate for risk status (low-risk or high-risk) was compared between non-Hispanic White and Black patients using multivariable logistic regression and expressed as adjusted odds ratios (aOR) with 95% confidence intervals (CIs). Results: Among 3,511 patients with PTC, 65.0% White and 65.5% Black received surgical treatment (aOR 0.97, 95% CI 0.80-1.18 for Black vs. White). For patients with low-risk PTC, overall receipt of either surgery or active surveillance (aOR 0.86, 95% CI 0.67-1.10 for Black vs. White) was similar between races. For patients with high-risk PTC, overall receipt of surgery (aOR 1.19, 95% CI 0.71-2.01) or adjuvant RAI (aOR 1.44, 95% CI 0.60-3.44) was similar for Black compared to White patients. Conclusions: In an equal access health system, there were no overall racial differences in receipt of surgical treatment for PTC. Further, in analysis by risk status, there were no significant racial differences in receipt of active surveillance for low-risk PTC nor receipt of adjuvant RAI for high-risk PTC. This suggests the role of access to care in reducing racial disparities in treatment for PTC observed in the general U.S. population. Funding and Acknowledgement: The authors thank the Joint Pathology Center (JPC) for providing the DoD cancer registry data and the Defense Health Agency (DHA) for providing the MHS data repository (MDR) data. This project was supported by the Murtha Cancer Center Research Program (MCCRP) of the Department of Surgery, Uniformed Services University of the Health Sciences (USUHS) under the auspices of the Henry M. Jackson Foundation for the Advancement of Military Medicine (HJF, Inc.), grant numbers HHU0001-16-2-0014 and HU0001-18-2-0032 awarded to C.S. Disclaimer: The contents of this abstract are the sole responsibility of the authors and do not necessarily reflect the views, assertions, opinions, or policies of the Uniformed Services University of the Health Sciences, the Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., the Department of Defense, or the Departments of the Army, Navy, or Air Force. Mention of trade names, commercial products, or organizations does not imply endorsement by the U.S. government. Citation Format: Yvonne L. Eaglehouse, Sarah Darmon, Craig D. Shriver, Kangmin Zhu. Comparison of Black and White patients in treatment for papillary thyroid cancer in an equal access health system [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4820.

Radiofrequency Ablation of Low-Risk Papillary Thyroid Cancer Is Often Successful but Depends on the Definition

Radiofrequency Ablation of Low-Risk Papillary Thyroid Cancer Is Often Successful but Depends on the Definition

Efficacy and Safety of Thermal Ablation for Solitary Low-Risk T2N0M0 Papillary Thyroid Carcinoma.

To evaluate the efficacy and safety of thermal ablation in treating solitary low-risk T2N0M0 papillary thyroid cancer (PTC) and compare the outcomes of microwave ablation (MWA) and radiofrequency ablation (RFA). This retrospective, single center study involved 34 patients (age: 40.0 ± 13.9 years; 28 female) who had low-risk T2N0M0 PTC with a maximum diameter >2 cm and ≤4 cm and underwent MWA (n = 15) or RFA (n = 19) from November 2016 to April 2023. The primary outcomes were the cumulative rate of disease progression and delayed surgery rates. In contrast, the secondary outcomes included changes in tumor size, cumulative rate of complete tumor disappearance, and complication rates. The median follow-up period was 18.0 months (interquartile range [IQR]: 9.0-40.0 months). At 12 months, the median volume reduction rate of the ablation zone was 74.2% (IQR: 53.7%-86.0%). Disease progression was noted in two patients within 1 year, including one patient with local tumor progression post-RFA and one with a new tumor post-MWA, resulting in a constant cumulative disease progression rate of 8.8% (95% confidence interval [CI]: 0%-19.8%) throughout the remaining follow-up period. Both patients were subsequently treated with additional ablation and did not require surgery. The cumulative rates of complete tumor disappearance at 1, 3, and 5 years were 4.0% (95% CI: 0%-11.4%), 26.8% (95% CI: 2.7%-44.9%), and 51.2% (95% CI: 0%-79.1%), respectively. No significant differences were observed in the disease progression (P = 0.829) or complete tumor disappearance (P = 0.633) rates between the MWA and RFA groups. Complications occurred in 14.7% (5/34) of patients presenting with transient hoarseness. RFA had a higher but not statistically significant complication rate than MWA did (21.1% [4/19] vs. 6.7% [1/15]; P = 0.355). Both MWA and RFA demonstrated promising short-term outcomes in terms of efficacy and safety in treating solitary low-risk T2N0M0 PTC, with no significant differences.

Ultrasound Imaging in Active Surveillance of Small, Low-Risk Papillary Thyroid Cancer.

The recent surge in the incidence of small papillary thyroid cancers (PTCs) has been linked to the widespread use of ultrasonography, thereby prompting concerns regarding overdiagnosis. Active surveillance (AS) has emerged as a less invasive alternative management strategy for low-risk PTCs, especially for PTCs measuring ≤1 cm in maximal diameter. Recent studies report low disease progression rates of low-risk PTCs ≤1 cm under AS. Ongoing research is currently exploring the feasibility of AS for larger PTCs (<20 mm). AS protocols include meticulous ultrasound assessment, emphasis on standardized techniques, and a multidisciplinary approach; they involve monitoring the nodules for size, growth, potential extrathyroidal extension, proximity to the trachea and recurrent laryngeal nerve, and potential cervical nodal metastases. The criteria for progression, often defined as an increase in the maximum diameter of the PTC, warrant a review of precision and ongoing examinations. Challenges exist regarding the reliability of volume measurements for defining PTC disease progression. Although ultrasonography plays a pivotal role, challenges in assessing progression and minor extrathyroidal extension underscore the importance of a multidisciplinary approach in disease management. This comprehensive overview highlights the evolving landscape of AS for PTCs, emphasizing the need for standardized protocols, meticulous assessments, and ongoing research to inform decision-making.

Minimally Invasive Open Bilateral Total Thyroidectomy Using Unilateral Neck Incision in Thyroid Cancer: Preliminary Surgical and Quality of Life Outcomes.

Thyroid cancer incidence has increased in recent decades, and thyroid surgery is continuously evolving in response to demands for postoperative comfort and cosmesis. This study aimed to introduce a new surgical method for minimally invasive open bilateral total thyroidectomy (MI-BTT) using a unilateral 2.5-3.0 cm neck incision. Furthermore, we reported the surgical outcomes and postoperative quality of life (QoL) using a validated Korean translated Dermatology Life Quality Index (DLQI) questionnaire. We retrospectively evaluated 41 Asian patients who underwent MI-BTT for low-risk papillary thyroid cancer by a single surgeon from March 2019 to December 2021. A total of 4 male and 37 female patients were included. The mean age and body mass index were 46.2±10.1 years and 23.3±3.3 kg/m², respectively. The average tumor size was 1.1±0.6 cm, and 36 patients (87.8%) had bilateral cancer. Twenty-three (56.1%) patients had occult central lymph node (CLN) metastasis in the final pathologic report, with the mean number of dissected CLNs being 7.2±6.5. Gross capsular extension was found in 6 patients (14.6%). Moreover, 28 patients (68.3%) received additional treatment after surgery with low or high doses of radioactive iodine. The average serum-stimulated thyroglobulin value identified during treatment was 1.57±2.30 ng/mL. The mean operation time was 78.0±13.9 minutes, and postoperative complications included transient hypocalcemia (36.6%), transient hoarseness (24.4%), and seroma (2.4%). The mean total DLQI score was 2.73±0.78, indicating a small effect on QoL. MI-BTT is a novel, safe, and feasible technique to improve patient satisfaction for surgical scars and QoL.

Radiofrequency ablation for papillary thyroid cancer located in isthmus: comparison with that originated in thyroid lobe

Purpose To analyze the outcomes of radiofrequency ablation (RFA) for isthmus papillary thyroid cancer (PTC) versus PTC originating from the lobes. Methods Patients with solitary low-risk PTC treated with RFA between July 2014 and December 2019 were retrospectively reviewed. This study was approved by our institutional review board. Of the 562 patients, 104 and 458 had PTCs located in the thyroid isthmus and thyroid lobes, respectively. Local tumor progression (LTP), LTP-free survival (LTPFS), changes in tumor volume, and complications were compared between the two groups using propensity-score matching (PSM). Results The isthmic and lobar groups showed no significant differences in LTP (2.9% vs. 3.8%), new PTC (2.9% vs. 2.9%), persistent lesions (0.0% vs. 0.2%), or LTPFS after PSM. Before PSM, the two groups showed significant differences in the volume reduction ratio (VRR) of the ablated tumors at 1, 3, 24, 30, and 48 months after RFA, but no differences between the two groups were observed in tumor volume, VRR, or disappearance rate after PSM (p > .05). One patient in the isthmic group presented with coughing, while another complained of hoarseness. Complications did not differ significantly between the two groups (p > .05). Conclusions The outcomes of RFA for patients with low-risk PTC in the thyroid isthmus and thyroid lobes were similar. Therefore, RFA may serve as an alternative treatment option for patients with low-risk isthmic PTC.

FRI525 Gender Differences In Fears Related To Low Risk Papillary Thyroid Cancer And Its Treatment

Abstract Disclosure: A.M. Sawka: None. S. Ghai: None. L. Rotstein: None. J.C. Irish: None. J.D. Pasternak: None. P.J. Gullane: None. E. Monteiro: None. J. Su: None. W. Xu: None. J.M. Jones: None. A. Gafni: None. N.N. Baxter: None. D.P. Goldstein: None. Background: It is important to understand the fears of individuals newly diagnosed with papillary thyroid cancer (PTC) to optimize patient counselling and supportive care. Our aim was to explore for potential gender differences in fears experienced by individuals with PTC prior to treatment. Methods: In this prospective study conducted in Toronto, Canada, we enrolled patients with untreated small low risk PTC (&amp;lt; 2 cm in maximal diameter), and offered them the choice of thyroidectomy or active surveillance (Clinicaltrials.gov: NCT03271892). All participants had a surgical consultation prior to assessment. Participants completed Fear of Progression (Short Form) and Fear of Surgery (referring to thyroidectomy) questionnaires, prior to making a decision on PTC management. We also evaluated potential fears that were specific to thyroidectomy (e.g. voice change, thyroid hormone treatment, hypocalcemia, and scar appearance). Total fear scores were calculated for the respective questionnaires. We compared data collected in women and men and explored for factors associated with respective fears using multivariable linear regression analyses. Results: We included 153 women of mean age 50.7 years (standard deviation, SD 15.0) and 47 men of mean age 56.3 years (SD 13.8). There were no significant differences in primary tumor size, marital status, education, parental status, or employment status of women and men. On a scale of 5 to 60 (where 60 is the worst), the mean total fear of disease progression questionnaire score was 26.2 (SD 9.7) in women and 23.0 (SD 9.2) in men (p=0.031). On a scale of 0 to 80 (80 being the worst), the mean total surgical fear questionnaire score was 34.1 (SD 20.3) in women and 22.0 (17.9) in men (p&amp;lt;0.001). Women were also more fearful than men about potential postoperative change in voice (p=0.001), hypocalcemia (p=0.003), and scar appearance (p&amp;lt;0.001). In respective multivariable linear regression analyses, age group (p&amp;lt;0.001) was independently inversely associated with fear of disease progression, whereas being a woman was independently associated with surgical fear (p=0.002). Conclusions: Demographic factors appear to be associated with fears of low-risk PTC patients who are considering primary disease management. Younger patients may have a greater fear of disease progression while women may have a greater fear of the morbidity from thyroidectomy. These factors may be important to consider in patient counselling. Presentation: Friday, June 16, 2023

SAT515 Searching For Markers To Identify Angioinvasion In Papillary Thyroid Cancer

Abstract Disclosure: A. Buczyńska: None. M. Kościuszko: None. I. Sidorkiewicz: None. A. Wiatr: None. K. Siewko: None. A. Adamska: None. A. Krętowski: None. A. Popławska-Kita: None. The incidence of Papillary Thyroid Cancer (PTC) has increased significantly over last decades. Despite the great progress in PTC clinical management, the association of angioinvasion with tumor aggressiveness in PTC remains as significant clinical problem, suggesting worse patients prognosis. Therefore cancer metastasis occurs through cell detachment and angioinvasion, epithelial–mesenchymal transition (EMT) and cell migration, changes in cell morphology are initiated through Rho-GTPase-dependent actin cytoskeleton polymerization. 8-hydroxydeoxyguanosine (8-OHdG) is generated accordingly to increased oxidative stress, however has been characterized by paradoxical anti-oxidative, anti-inflammatory and anti-mutagenic effects following Rho-GTPase inhibition, which were noted in various cancer models. Since oxidative stress has been recognized as one of the main risk factors for thyroid cancer development and progression, the total oxidative and antioxidant capacities may also be potentially involved in the process of angioinvasion. Regardless, the identification of angioinvasion in PTC remains controversial mainly due to loose criteria in judging vascular invasion. Thus, searching for laboratory biomarkers of angioinvasion is of paramount importance.In this study, the potential screening utility of oxidative stress-related markers, such as total oxidative capacity (TOC), total antioxidant capacity (TAC) and 8-OHdG was assessed to identify angioinvasion in PTC patients.For the purpose od this study, 50 patients diagnosed with angioinvasive PTC (study group) and 50 patients with very low risk PTC (control group) were enrolled. The TOC, TAC and 8-OHdG concentrations were evaluated using enzyme-linked immunosorbent assay (ELISA). Following the received results, the TAC and 8-OHdG concentrations were decresed among study group comparing to control group (p&amp;lt;0.001; p&amp;lt;0.02, respectively). However, there were no differences in TOC among studied groups (p&amp;gt;0.05). The AUC values for TAC=0.76 and AUC for 8-OHdG= 0.70 (all, p&amp;lt;0.05) suggest their screening utility. The results indicate that angioinvasion process is associated with decreased antioxidant defense in PTC patients which may insight new medical targets in the future. Presentation Date: Saturday, June 17, 2023

Men and Women Have Different Fears When Choosing a Treatment for Low-Risk Papillary Thyroid Cancer

Men and Women Have Different Fears When Choosing a Treatment for Low-Risk Papillary Thyroid Cancer

Dynamic Risk Stratification Integrated with ATA Risk System for Predicting Long-Term Outcome in Papillary Thyroid Cancer.

In recent years, there has been a renewed interest in thyroid cancer management paradigms that use individualized risk assessments as the basis for treatment and follow-up recommendations. In this study, we assumed that the long-term follow-up of differentiated thyroid cancer patients might be better tailored by integrating the response to initial therapy with the America Thyroid Association (ATA) risk classes. This retrospective study included low- and intermediate-risk papillary thyroid cancer (PTC) patients followed up for a median time of 8 years and classified according to the response to initial therapy assessed 6-12 months after initial treatment. After a median follow-up of 8 years, in the initial excellent response subgroup of PTC patients (n = 522), the rate of recurrent disease was significantly higher in intermediate-risk patients than in low-risk PTC patients (6.9% versus 1.2%, p = 0.0005). Similarly, in the initial biochemical incomplete response subgroup (n = 82), the rate of excellent response was significantly higher in low-risk PTC patients (58.0%) than in intermediate-risk PTC patients (33.3%) (p = 0.007). Finally, in the initial structural incomplete response subgroup (n = 66), the rate of excellent response was higher in low-risk patients (80.0%) than in intermediate-risk patients (46.4%) (p = 0.08). Moreover, all patients with initial indeterminate response had an excellent response at the last follow-up visit. ATA risk classes were independently associated with long-term outcome in each subgroup of patients classified dynamically after initial therapy and the overall prognostic performance, defined via ROC curve analysis, of response to initial therapy integrated with the ATA risk system (AUC: 0.89; 95% CI: 0.86-0.92) was significantly higher compared to the ATA risk stratification (AUC 0.69; 95% CI: 0.65-0.74, p < 0.001) or the dynamic risk stratification (DRS) systems alone (AUC: 0.86 95% CI: 0.82-0.90, p = 0.007). This study of a large cohort of PTC patients showed that the initial ATA risk criteria may be useful for improving the risk-adapted management of PTC patients based on the response to initial therapy.

Development of a novel clinical support tool for active surveillance of low risk papillary thyroid cancer.

Active surveillance (AS) is an alternative to surgery in select patients with very low risk papillary thyroid cancer (PTC). Many clinicians feel ill-equipped in selecting appropriate patients. We aimed to 1) Develop an evidence-based web delivered decision support tool to assist clinicians in identifying patients appropriate for AS; and 2) Evaluate the prevalence of patients suitable for AS in a tertiary high volume thyroid cancer centre. A REDCap web based clinical support tool was developed utilising evidence-based characteristics for AS suitability available to clinicals during initial assessment. A retrospective database was interrogated for patients who underwent hemithyroidectomy between 2012 - 2021 with final histopathology demonstrating PTC. Patients with PTCs>2cm, missing data, benign disease on surgical histopathology or incidental PTC were excluded. Between 2012 - 2021, 763 patients underwent hemithyroidectomy with final histopathology confirming PTC. Of these, 316 patients were excluded (missing data, incidental PTC, concomitant hyperparathyroidism were most common reasons for exclusion) and 114/447 remaining patients had a pre-operative fine needle aspirate (FNA) of Bethesda V or VI (high likelihood of malignancy). Using the tool, 59/114 (52%) met criteria for AS. The majority of patients were female (85% vs 15% male); median age 36 years (range 19 - 78). Following initial surgery, 10/59 patients had a completion thyroidectomy, with 4/10 demonstrating malignancy in contralateral lobe and eight of those patients undergoing I131 ablation. During a median follow up of over 3 years, 49/59 (83%) did not require further surgery or intervention with no patients developing recurrence. A subgroup analysis with second radiology assessment excluded 4/59 patients as meeting criteria for AS based on presence of ETE on preoperative ultrasound. None of these 4 patients had completion thyroidectomy. Our clinical support tool identifies patients with PTC potentially suitable for AS which could be utilised during initial patient assessment. In a retrospective cohort of patients who had hemithyroidectomy for PTC with a pre-operative FNA diagnosis of Bethesda V or VI, 55/114 (48%) patients may have been suitable for AS. Prospective validation studies are required for implementation of the tool in clinical practice.