Guidelines For Management Of Thyroid Cancer Research Articles

Changing trends in thyroid cancer incidence in Canada: A histologic examination, 1992 to 2016.

Age-standardized incidence rates (ASIRs) of thyroid cancer (TC) have increased in many parts of the world, primarily because of increased papillary TC detection. While rapid increases in TC incidence have also been reported in Canada, an analysis of incidence and survival by histologic subtype has been lacking. Moreover, recent data points in Canada suggest that the era of rapid annual increases may have ended. Data are from the Canadian Cancer Registry, the Canadian Vital Statistics-Death Database and an analytic file linking the two. Annual percent changes (APCs) in incidence and mortality rates are estimated using Joinpoint regression. Net survival (NS) is derived using the Pohar Perme estimator. Among females, TC ASIRs decreased by 3.0% annually from 2012 to 2016, following years of rapid growth. Among males, a long period of rapid increase ended in 2012 with no subsequent decline. For both sexes the overall incidence trend was driven by changes over time in papillary TC and incidence trends in non-papillary TC varied significantly. From 1992 to 2016, TC mortality rates were stable among females and increased slightly among males (APC = 1.2). Five-year NS was higher among papillary cases (99%) than among non-papillary cases (80%) and among females (99%) than among males (94%). Overall, five-year NS increased by 2.1 percentage points from the period from 1992 to 1996 to the period from 2010 to 2014. The results of this study confirm the central role of papillary TC cases in TC incidence and survival trends in Canada. Given recent changes in trend and TC management guidelines, projected increases in TC rates after 2016 could be re-examined.

Papillary Thyroid Cancers with Focal Tall Cell Change are as Aggressive as Tall Cell Variants and Should Not be Considered as Low-Risk Disease.

The tall cell variant of papillary thyroid carcinoma (PTC) is as an aggressive histological variant. The proportion of tall cells needed to influence prognosis is debated. Patients with PTC and tall cells, defined as having a height-to-width ratio of ≥ 3:1, seen at a high-volume center between 2001 and 2015, were reviewed. Specimens were classified as (1) focal tall cell change, containing < 30% of tall cells; (2) tall cell variant, ≥ 30% of tall cells; and (3) control cases selected from infiltrative classical PTCs without adverse cytologic features. Univariate, sensitivity, and multivariate analyses were performed with persistent/recurrent disease as the primary outcome. We identified 96 PTCs with focal tall cell change, 35 with the tall cell variant and 104 control cases. Factors associated with poor clinical prognosis were significantly greater in those with focal tall cell change and tall cell variants. Regarding primary outcome, hazard ratios were 2.3 (95% confidence interval [CI] 1.0-5.7) for focal tall cell change, and 3.4 (95% CI 1.2-8.7) for tall cell variants compared with controls. Five-year disease-free survival was higher for the control group (92.7%, CI 87.4-98.0) compared with focal tall cell change (76.3%, CI 66.1-86.5) and the tall cell variant (62.2%, CI 43.2-81.2). When stratified in groups consisting of tall cell proportions (< 10%, 10-19%, 20-29% and ≥ 30%), identification of ≥ 10% tall cell change was associated with worse outcome (p = 0.002). PTCs with ≥ 10% tall cell change have worse prognosis than those without tall cells. Our data indicate that thyroid cancer management guidelines should consider PTCs with focal tall cell change outside of the low-risk classification.

Risk Stratification in Differentiated Thyroid Cancer: From Detection to Final Follow-Up.

Modern management of differentiated thyroid cancer requires individualized care plans that tailor the intensity of therapy and follow-up to the estimated risks of recurrence and disease-specific mortality. This summary is based on the authors' knowledge and extensive clinical experience, supplemented by review of published review articles, thyroid cancer management guidelines, published staging systems, and original articles identified through a PubMed search, which included terms such as risk stratification, staging, clinical outcomes, and differentiated thyroid cancer. In the past, risk stratification in differentiated thyroid cancer usually referred to a static estimate of disease-specific mortality that was based on a small set of clinicopathological features available within a few weeks of completing initial therapy (thyroidectomy, with or without radioactive iodine). Today, risk stratification is a dynamic, active process used to predict the appropriateness for minimalistic initial therapy, disease-specific mortality, risk of recurrence, and the most likely response to initial therapy. Rather than being a static prediction available only after initial therapy, modern risk stratification is a dynamic, iterative process that begins as soon as a suspicious nodule is detected and continues through final follow-up. Dynamic risk assessment should be used to guide all aspects of thyroid cancer management, beginning before a definitive diagnosis is made and continuing through the final follow-up visit.

Practical Barriers to Implementation of Thyroid Cancer Guidelines in the Asia-Pacific Region

Numerous published guidelines have described the optimal management of thyroid cancer. However, these rely on the clinical availability of diagnostic and therapeutic modalities. We hypothesized that the availability of medical resources and economic circumstances vary in Asia-Pacific countries, making it difficult to implement guideline recommendations into clinical practice. We surveyed participants at the 2009 and 2013 Congresses of the Association of Southeast Asian Nations Federation of Endocrine Societies by distributing questionnaires to attendees at registration. Responses were obtained from 268 respondents in 2009 and 163 respondents in 2013. Similar to the high prevalence of low-risk thyroid cancer observed in the Surveillance, Epidemiology, and End Results database, across the Asia-Pacific countries surveyed in 2009 and 2013, 50 to 100% of the respondents from the Philippines, Malaysia, Singapore, China, Taiwan, Thailand, Hong Kong, Korea, and Sri Lanka reported that more than 50% of the patients had low-risk thyroid cancer on follow-up. Importantly, there was much variation with regards to the perceived availability of investigation and treatment modalities. We found a wide variation in clinicians' perception of availability of diagnostic and therapeutic modalities in the face of a rise in thyroid cancer incidence and thyroid cancer management guidelines that emphasized their importance. The lack of availability of management tools and treatments will prove to be a major barrier to the implementation of thyroid cancer management guidelines in Southeast Asia, and likely in other parts of the world as well.

Mixed medullary-follicular thyroid cancer treated with surgery and radioiodine ablation: An illustrative case

Introduction: Differentiated thyroid cancer is the commonest cancer affecting thyroid gland. Medullary thyroid carcinoma (MTC) constitutes only 2-8% of all thyroid cancers. Simultaneous occurrence of mixed medullary and follicular thyroid carcinoma (mixed MTCFTC) is rare. This may pose challenges in diagnosis, treatment, follow up and future prediction of prognosis. Case presentation: A 24 -year-old female presented with a neck swelling that increased in size over 2 months period. She was clinically and biochemically euthyroid. Thyroid Technetium Pertechnetate (99mTcO4) scan showed a cold nodule in the right lobe and ultrasound thyroid confirmed the presence of hypo-echoic well defined lesion. Fine needle aspiration biopsy (FNAB) revealed a medullary thyroid cancer. She underwent total thyroidectomy and lymph node dissection. The histopathology showed a solitary tumor with mixed features, predominantly medullary with areas of follicular architecture, confirmed by immunohistochemical staining as mixed MTC-FTC. Work up for MEN II and RET-proto-oncogen was negative. Postoperative isotope scan showed an increased uptake in the remnant thyroid tissue. She was treated with adjuvant radioactive iodine therapy. Her initial calcitonin level post operatively was 13.4 pg/ml (NR &lt; 5.0), CEA 36 ng/ml (NR &lt;3.8), and thyroglobulin was 0.7 ng/ml (NR &lt;1). On follow up visits, the thyroglobulin as well as calcitonin and CEA levels were all suppressed. Conclusion: Cases of mixed follicular and medullary cancer present significant diagnostic and management challenges. Although we have managed our case surgically as well as by radioactive iodine and we are satisfied that follow up with calcitonin and thyroglobulin did not show any evidence of recurrence, we propose that mixed tumors be included in thyroid cancer management guidelines.

Selective use of RAI for ablation and adjuvant therapy after total thyroidectomy for differentiated thyroid cancer: A practical approach to clinical decision making

For the past 40 years, many clinicians have recommended RAI remnant ablation for essentially all differentiated thyroid cancer patients with a primary tumor size greater than 1.5 cm or with any evidence of even microscopic disease outside the thyroid capsule. This "one size fits all" approach exposes many low risk thyroid cancer patients to the risks of ionizing radiation with little potential benefit. Current thyroid cancer management guidelines call for a far more risk adapted approach to the selection of patients for post-operative RAI treatment. We will review the current selective use of RAI ablation recommendations and provide a practical approach to implementation of a risk adapted approach to post-operative RAI administration. We will show how thoughtful integration of pre-operative, intra-operative, and post-operative clinico-pathologic factors allows the clinician to accurately identify patients most likely to benefit from RAI administration. This approach ensures that patients most likely to experience a clinical benefit are selected for RAI ablation while avoiding unnecessary exposure to ionizing radiation in the majority of low to intermediate risk thyroid cancer patients.