Adjuvant post-operative I-131 therapy in differentiated thyroid carcinoma: are the 2015 ATA guidelines an exact science or a dark art?

Therapeutic Strategy in Low-Risk Papillary Thyroid Carcinoma - Long-Term Results of the First Single-Center Prospective Non-Randomized Trial Between 2011 and 2015

Optimal therapeutic strategy in low advanced papillary thyroid carcinoma (PTC) is still a matter of debate. The management differs depending on the country. A prospective non-randomized study was performed to evaluate whether less extensive surgery could be a safe, acceptable, and sufficient therapeutic option in PTC cT1N0M0 patients. The present paper summarizes the results of over a 5-year follow-up.

MATERIAL

Our prospective group (PG) treated between 2011 and 2015 consisted of 139 patients with cT1aN0M0 PTC who underwent lobectomy (LT) as initial surgical treatment (PGcT1aN0M0 group) and 102 cT1bN0M0 patients in whom total thyroidectomy (TT) with unilateral central neck dissection (CND) was performed (PGcT1bN0M0). PG was compared with the retrospective group (RG) of patients who underwent TT with bilateral CND between 2004 and 2006: 103 cT1aN0M0 patients (RGcT1aN0M0) and 91cT1bN0M0 (RGcT1bN0M0). The risks of reoperation, cancer relapse and postoperative complications were analyzed.

RESULTS

Only 12 cT1aN0M0 patients (7.6%) withdrew from the trial and underwent TT with bilateral CND. Over 90% of patients accepted less extensive surgery. In 4 cT1aN0M0 cases, TT with CND was performed due to lymph node metastases found intraoperatively. The initial clinical stage according to the TNM/AJCC 7^th edition was confirmed histologically in 77% of cases in PGT1aN0M0 and in 72% in PGT1bN0M0, respectively. 24 PGcT1aN0M0 patients were reoperated on. In this group, cancer lesions in the postoperative histological specimens were found in 8 cases (32%). Five-year disease-free survival (DFS) was excellent. However, no statistically significant differences were found between PG and RG groups (99.3% in PGcT1aN0M0 and 99.0%, in RGcT1aN0M0; p = 0.41 and 98%, in PGcT1bN0M0 and 94.4% in RGcT1bN0M0; p=0.19). No significant differences were observed in the incidence of early paresis of the recurrent laryngeal nerves between PG and RG. However, as predicted, LT completely eliminated the risk of postoperative hypoparathyroidism.

SUMMARY

The results of the prospective clinical trial confirm that less extensive surgery in adequately selected low-advanced PTC patients is both safe and sufficient.

Evaluation of the 2015 ATA Guidelines in Patients With Distant Metastatic Differentiated Thyroid Cancer

CONTEXT

Current American Thyroid Association (ATA) Management Guidelines for the treatment of differentiated thyroid cancer (DTC) stratify patients to decide on additional radioiodine (RAI) therapy after surgery, and to predict recurring/persisting disease. However, studies evaluating the detection of distant metastases and how these guidelines perform in patients with distant metastases are scarce.

OBJECTIVE

To evaluate the 2015 ATA Guidelines in DTC patients with respect to 1) the detection of distant metastases, and 2) the accuracy of its Risk Stratification System in patients with distant metastases.

PATIENTS AND MAIN OUTCOME MEASURES

We retrospectively included 83 DTC patients who were diagnosed with distant metastases around the time of initial therapy, and a control population of 472 patients (312 low-risk, 160 intermediate-risk) who did not have a routine indication for RAI therapy. We used the control group to assess the percentage of distant metastases that would have been missed if no RAI therapy was given.

RESULTS

Two hundred forty-six patients had no routine indication for RAI therapy of which 4 (1.6%) had distant metastases. Furthermore, among the 83 patients with distant metastases, 14 patients (17%) had excellent response, while 55 (67%) had structural disease after a median follow-up of 62 months. None of the 14 patients that achieved an excellent response had a recurrence.

CONCLUSIONS

In patients without a routine indication for RAI therapy according to the 2015 ATA Guidelines, distant metastases would initially have been missed in 1.6% of the patients. Furthermore, in patients with distant metastases upon diagnosis, the 2015 ATA Guidelines are an excellent predictor of both persistent disease and recurrence.

A Survey of American Thyroid Association Members Regarding the 2015 Adult Thyroid Nodule and Differentiated Thyroid Cancer Clinical Practice Guidelines

Background: The 2015 American Thyroid Association (ATA) clinical practice guidelines (CPGs) on management of thyroid nodules (TNs) and differentiated thyroid cancer (DTC) in adults were developed to inform clinicians, patients, researchers, and health policy makers about the best available evidence, and its limitations, relating to management of these conditions. Methods: We conducted a cross-sectional electronic survey of ATA members' perspectives of these CPGs, using a standardized survey (Clinician Guidelines Determinant Questionnaire) developed by the Guidelines International Network. A survey link was electronically mailed to members in February of 2019, with reminders sent to nonrespondents 2 and 5 weeks later. Data were descriptively summarized, after excluding missing responses. Results: The overall response rate was 19.8% (348/1761). The effective response rate was 20.2% (348/1720), after excluding a recently deceased member and individuals who had either invalid e-mail addresses or whose e-mails were returned. Of the respondents, 37.9% (132/348) were female, 60.4% (209/346) were endocrinologists, 27.5% (95/346) were surgeons, and 3.5% (12/346) were nuclear medicine specialists. The majority of respondents (71.9%; 250/348) were at a mid- or advanced-career level, and more than half were in academia (57.5%; 195/339). The majority (69.8%; 243/348) practiced in North America. The vast majority of respondents indicated that the CPGs explained the underlying evidence (92.3%; 298/323) and 92.9% (300/323) agreed or strongly agreed with the content. Most respondents stated that they regularly used the CPGs in their practice (83.0%; 268/323). Most respondents (83.0%; 268/323) also agreed or strongly agreed that the recommendations were easy to incorporate in their practice. The most popular CPG format was an electronic desktop file (78.8%; 252/320). Shorter more frequent CPGs were favored by 55.0% (176/320) of respondents, and longer traditional CPGs were favored by 39.7% (127/320). Conclusions: The clinical content and evidence explanations in the adult TN and DTC CPGs are widely accepted and applied among ATA survey respondents. Future ATA CPG updates need to be optimized to best meet users' preferences regarding format, frequency, and length.

Papillary Thyroid Micro Carcinoma: The Incidence of High-Risk Features and Its Prognostic Implications

Background: The current management of papillary thyroid micro carcinoma (PTMC) has become more conservative. However, high-risk characteristics that can only be revealed post-surgically exist. Patients and clinicians need to estimate the risks and understand the prognostic meaning of these factors. Methods: We retrospectively analyzed 246 consecutive patients with PTMC who underwent surgery at our institution between 2015 and 2017. Clinical and histopathological parameters that may indicate recurrent disease were investigated. The responses to therapy in cases with different risks of recurrence were analyzed. Results: A total of 79.26% (195/246) of patients received total thyroidectomy (TT), of whom 177 (90.77%) also received central lymph node dissection. Radioiodine ablation (RAI) was applied in 64.23% (158/246) of patients. Intermediate-high risk features were identified in 27.64% (68/246) after primary treatment. After a median follow-up of 18 months (range, 6-39 months), 121 of 158 (76.58%) patients who received TT+RAI were evaluated as an excellent response. An incomplete response (IR) was observed in 14.56% (23/158) of this group of PTMC. Multivariate analysis identified extra thyroid extension (P = 0.001) and intermediate-high risk stratification (P = 0.014) as significant and independent risk factors for an IR. Conclusions: A total of 27.64% of PTMC cases evaluated as a low risk of recurrence pre-surgery showed intermediate to high risk disease post-surgery, and this leads to a higher rate of IR.

Possible delayed diagnosis and treatment of metastatic differentiated thyroid cancer by adopting the 2015 ATA guidelines

OBJECTIVE

According to the 2015 American Thyroid Association (ATA) guidelines, thyroid ablation by iodine-131 (I-131) therapy is absolutely recommended only in patients with high-risk differentiated thyroid cancer (DTC). Often distant metastases are not recognized early and they can stay silent for long time. The aim of our study was to retrospectively analyze the prevalence of metastatic disease before and after I-131 and to evaluate the influence of the new ATA guidelines in the management of DTC.

METHODS

We retrospectively analyzed 140 patients showing distant metastases. All metastases were detected by whole-body scan after I-131 and confirmed by histology and/or other imaging modalities.

RESULTS

In 26/140 patients metastases were detected before I-131, while in 114/140 were discovered after I-131. Comparing patients with metastases detected before and after I-131, no differences were demonstrated considering age, sex, histotype, tumor size, multifocality of cancer and metastatic localization. Metastatic DTC discovered before radioiodine had higher thyroglobulin and received a higher radioiodine total activity and number of treatments. Considering patients with distant metastases, according to the 2015 ATA guidelines, 38 patients would have been categorized as high risk, 22 as low risk and 80 as intermediate risk. Among intermediate-risk patients, only in 25 cases (31%) I-131 treatment would have been appropriate according to 2015 ATA recommendations; in the remaining 56 cases (69%), I-131 would not have been recommended.

CONCLUSIONS

According to the 2015 ATA guidelines, most of metastatic patients would not have been treated after surgery, with the risk of late diagnosis and delayed treatment.

Current Advances in Thyroid Cancer Management. Are We Ready for the Epidemic Rise of Diagnoses?

A rising incidence of thyroid cancers (TCs) mainly small tumors, observed during recent years, lead to many controversies regarding treatment strategies. TCs represent a distinct molecular background and clinical outcome. Although in most cases TCs are characterized by a good prognosis, there are some aggressive forms, which do not respond to standard treatment. There are still some questions, which have to be resolved to avoid dangerous simplifications in the clinical management. In this article, we focused on the current advantages in preoperative molecular diagnostic tests and histopathological examination including noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). We discussed the controversies regarding the extent of thyroid surgery and adjuvant radioiodine therapy, as well as new treatment modalities for radioiodine-refractory differentiated thyroid cancer (RR-DTC). Considering medullary thyroid cancer (MTC), we analyzed a clinical management based on histopathology and RET (ret proto-oncogene) mutation genotype, disease follow-up with a special attention to serum calcitonin doubling time as an important prognostic marker, and targeted therapy applied in advanced MTC. In addition, we provided some data regarding anaplastic thyroid cancer (ATC), a highly lethal neoplasm, which lead to death in nearly 100% of patients due to the lack of effective treatment options.