Risk factors for nonsynchronous second primary malignancy and related death in patients with differentiated thyroid carcinoma

Comparative analysis through propensity score matching in thyroid cancer: unveiling the impact of multiple malignancies

Background

The incidence of thyroid cancer is on the rise worldwide, with childhood exposure to radiation being the sole acknowledged catalyst for its emergence. Nonetheless, numerous other factors that may pose risks are awaiting thorough examination and validation. This retrospective study aims to explore the malignancies linked to thyroid cancer and contrast the survival rates of those afflicted with a solitary tumor versus those with multiple primary neoplasms (MPN).

Methods

This retrospective study examined data from King Hussein Cancer Center (KHCC), Jordan. Among 563 patients diagnosed with thyroid cancer, 30 patients had thyroid malignancy as part of MPN. For a 1:3 propensity score-matched analysis, 90 patients with only a primary thyroid malignancy were also enrolled.

Results

Hematologic and breast malignancies were among the most frequent observed cancers alongside thyroid neoplasm. Patients who had MPN were diagnosed at older age, had higher body mass index and presented with higher thyroglobulin antibody levels (p < 0.05 for each). Additionally, MPN patient displayed a stronger family history for cancers (p= 0.002). A median follow-up duration of 135 months unveiled that MPN patients faced a worse 5-year survival compared to their counterparts with a singular neoplasm (87% vs 100% respectively; p < 0.01). However, no distinction emerged in the 5-year event-free survival between these two groups.

Conclusion

MPN correlates with a significantly altered survival outcome of thyroid cancer patients. The diagnosis of thyroid carcinoma at an older age, accompanied by elevated initial thyroglobulin antibody levels and a notable familial predisposition, may raise concerns about the potential occurrence of synchronous or metachronous tumors.

Use of multikinase inhibitors/lenvatinib in patients with synchronous/metachronous cancers coinciding with radioactive-resistant differentiated thyroid cancer

This review focuses on patients with differentiated thyroid carcinoma (DTC) associated with multiple primary malignant neoplasm (MPMN) treated by multikinase inhibitors (MKIs) as systemic treatment for advanced disease. Despite the increasing frequency of MPMNs (many at an advanced stage) and the usefulness of MKIs for multiple metastatic cancers, published data on the management of MPMN and MKI therapies in this scenario are scarce. There are infrequent descriptions of patients with advanced MPMN treated with MKIs, but only a few have described advanced DTC. The management of MPMNs, including DTC and its particular circumstances, is reviewed, focusing on the evidence for MKI therapies. Some considerations for MPMN patients with advanced DTC are discussed, with the intention of helping physicians make decisions in these challenging situations and improving treatment and patient outcomes.

Non-thyroidal second primary malignancy in papillary thyroid cancer patients

INTRODUCTION

The occurrence of non-thyroidal second primary malignancy (NTSPM) in patients with papillary thyroid cancer (PTC) is well documented, but epidemiological data are conflicting.

OBJECTIVE

The aim of this study was to evaluate the incidence of NTSPM in a large series of patients with PTC and to assess its potential risk factors.

METHODS

Single-center cohort study with retrospective data collection conducted on consecutive PTC patients diagnosed from 1988 to 2018 with a minimum follow-up time of 2 years. NTSPM was defined as any primary malignancy with histological confirmation occurring in an anatomical site other than the thyroid. According to the timing of occurrence, NTSPM were subdivided into anachronous, synchronous or metachronous (diagnosed >6 months before, within 6 months and >6 months after PTC diagnosis, respectively).

RESULTS

We included 773 individuals (83.3% females), median age at PTC diagnosis was 47.0 (IQR: 37.0-58.0) years and median follow-up time was 9.9 (6.2-16.3) years. Incidence of NTSPM was 15.5% (n = 120) and its standard incidence ratio (SIR) was higher when compared to the general population (SIR: 2.70). Family history of malignancy and younger age at diagnosis were associated respectively with 206 and 4% increased risk of developing metachronous neoplasia (HR: 2.06 (95% CI: 1.10-3.86) and 1.04 (95% CI: 1.02-1.05), respectively).

CONCLUSION

In our series, the occurrence of NTSPM was not uncommon and its incidence was higher compared to the general population. First-degree family history of malignancy was a strong risk factor for multiple primary malignancies.

Co-Occurrence of Differentiated Thyroid Cancer and Second Primary Malignancy: Correlation with Expression Profiles of Mismatch Repair Protein and Cell Cycle Regulators

Simple Summary

Although the incidence of thyroid cancer is increasing, improvements in treatment have resulted in more patients being confirmed to have a second primary cancer. However, studies on potential biomarkers for predicting the risk of second primary malignancy are extremely limited. Therefore, our objective was to establish molecular biomarkers for the risk prediction of second primary malignancy using routinely collected formalin-fixed paraffin-embedded tissue specimens. Our results suggest that the deficient mismatch repair phenotype, the expression of pRb, and the lack of CDK4 or CDK6 are significantly associated with co-occurrence of nonthyroid malignancy. The predictive value of these immunohistochemical profiles for the co-occurrence of nonthyroid malignancy was also assessed. The combined evaluation of a four-biomarker signature model may provide the most important predictive innovation. Our study proposes the first tissue-based screening tool for risk stratification and further active surveillance in patients with thyroid cancer.

Abstract

Some patients with thyroid cancer develop a second primary cancer. Defining the characteristics of patients with double primary cancers (DPCs) is crucial and needs to be followed. In this study, we examine molecular profiles in DPC. We enrolled 71 patients who received thyroid cancer surgery, 26 with single thyroid cancer (STC), and 45 with DPC. A retrograde cohort was used to develop immunohistochemical expressions of mismatch repair (MMR) proteins and cell-cycle-related markers from tissue microarrays to produce an equation for predicting the occurrence of DPC. The multivariate logistic model of 67 randomly selected patients (24 with STC and 43 with DPC) identified that the expression of deficient MMR (dMMR) (odds ratio (OR), 10.34; 95% confidence interval (CI), 2.17–49.21) and pRb (OR, 62.71; 95% CI, 4.83–814.22) were significantly associated with a higher risk of DPC. In contrast, the expression of CDK4 (OR, 0.19; 95% CI, 0.04–0.99) and CDK6 (OR, 0.03; 95% CI, 0.002–0.44) was significantly associated with a lower risk of DPC. Collectively, dMMR, pRb, CDK4, and CDK6 have a sensitivity of 88.9% (95% CI, 75.1–95.8) and a specificity of 69.2% (95% CI, 48.1–84.9) for occurrence of DPC in all 71 patients. This is the first report to demonstrate the molecular differentiation of STC and DPC. Overall, the integral molecular profile performed excellent discrimination and denoted an exponential function to predict the probability of DPC.

Analysis of overall survival in differentiated thyroid cancer patients with double primary malignancy

Differentiated thyroid cancer (DTC) survivors are at increased risk of developing double primary malignancy (DPM). The aim of this study was to investigate clinicopathological characteristics and survival in DTC patients diagnosed with DPM. A total of 975 patients with DTC diagnosed between 2013 and 2017, treated, and followed at a medical center in Taiwan were retrospectively reviewed. Data from enrolled patients were analyzed for differences in prognosis dependent on the presence of DPM, and which clinicopathological variables affected their prognosis. Among 975 thyroid cancer patients, 94 (9.6%) were diagnosed with DPMs and 16 (1.6%) patients died of any cause. DPM patients had a greater proportion of males, had a higher mean age, more commonly presented with a thyroid mass incidentally by imaging and cervical lymph node metastases, showed a more advanced thyroid cancer stage, and had a higher proportion of lymph node metastases. Overall survival (OS) was significantly lower in patients diagnosed with DPM. Male gender (hazard ratio [HR] = 4.597), two or more DPMs (HR = 8.071), and shorter time interval between two cancers occurrences (HR = 7.101) were significantly risk factors for DPM-related death. In conclusion, the risk of developing DPM in DTC patients was elevated in older, male patients with an advanced tumor-node-metastasis stage. DPM adversely affected the OS of thyroid cancer patients. Male gender, two or more DPMs, and shorter time interval between occurrences were significant risk factors for OS in DPM patients.

How to handle borderline/precursor thyroid tumors in management of patients with thyroid nodules

Thyroid carcinomas originating from follicular cells have the prognosis of heterogeneous diseases, but pathologists classify them all as malignant disease. Epidemiologists have issued a stern warning regarding over-diagnosis and overtreatment of patients with indolent thyroid tumors that cause no harm to the patients. Review of the literature revealed that there were several proposals of borderline/precursor tumors to some indolent thyroid carcinomas. Thyroid tumor of uncertain malignant potential (UMP) was first proposed by Williams for encapsulated follicular pattern thyroid tumors to solve problems due to observer variation. Rosai et al. proposed to rename papillary microcarcinoma (PMC) to papillary micro-tumor as the overwhelming majority of them are of no clinical significance. Liu et al. proposed well-differentiated tumor with uncertain behavior (WDT-UB) which covered WDT of UMP (WDT-UMP) and non-invasive encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC). The EFVPTC without invasion was renamed as non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) by an international panel of pathologists. A new prognostic classification of thyroid tumors was proposed by Kakudo et al., in which extremely low risk tumors were grouped in a borderline tumors category. The borderline/precursor thyroid tumors included encapsulated tumors [capsular invasion only follicular carcinoma, encapsulated papillary carcinoma without invasion, WDT-UMP and follicular tumor of UMP (FT-UMP)] and non-encapsulated tumors (PMC). The UMP and NIFTP were incorporated in the 4th edition WHO classification of thyroid tumors as a new tumor entity in chapter 2-2A: other encapsulated follicular patterned thyroid tumors. Their behavior codes were decided to be 1 (borderline or uncertain behavior), and not 0 (benign), 2 (in situ carcinoma) or 3 (malignant). These borderline/precursor thyroid tumors are indolent tumors biologically and should be treated more conservatively than as previously recommended for thyroid follicular cell carcinomas [total thyroidectomy (TTX) followed by radio-active iodine (RAI) treatment] by western clinical guidelines.

Is prophylactic central neck dissection necessary for cN0 differentiated thyroid cancer patients at initial treatment? A meta-analysis of the literature

Central lymph node metastases are common in patients with differentiated thyroid cancer (DTC). The management of preoperatively nodenegative (cN0) DTC is still under debate. The aim of this study was to analyse the difference in recurrence and surgical complications between thyroidectomy (TT) alone and TT combined with prophylactic central neck dissection (pCND) as initial treatments to DTC patients with cN0 and evaluate the clinic significance of pCND for these patients. PubMed, Ovid, Cochrane Library, and Web of Science databases were systematically searched using multiple search terms. Twenty-three articles with 6,823 patients were identified. The quality of evidence was assessed by Jadad quality scores and the Newcastle-Ottawa Quality assessment scale. The results showed that compared with patients who underwent TT alone, patients who underwent TT plus pCND had a significant higher rate of transient recurrent laryngeal nerve injury (p = 0.023), transient hypocalcaemia (p < 0.01) and permanent hypocalcaemia (p<0.01). There was a trend towards lower central neck recurrence rate in TT plus pCND (p < 0.01). Combined TT and pCND as initial treatment for DTC patients with cN0 may reduce the risk of recurrence, but increases the incidence of some complications. Methodologically high-quality comparative studies are needed for further evaluation.

Second Primary Cancer in Patients with Differentiated Thyroid Cancer: Does Radioiodine Play a Role?

BACKGROUND

Well-differentiated thyroid cancer (WDTC) is the most common endocrine neoplasia, and its incidence is rising. Studies have reported an increased risk of second primary cancer (SPC) in WDTC survivors, but its relationship with radioiodine treatment (RAIT) and other risk factors remains controversial. This study evaluated whether RAIT is an independent risk factor for SPC in WDTC patients.

METHODS

This was a retrospective single-center study. A total of 2031 patients with WDTC diagnosed between 1998 and 2009, treated and followed at the authors' tertiary cancer center, were included.

RESULTS

The median age of patients was 48 years (range 5-90 years); 83% were women and 77% underwent RAIT. The median follow-up was 8.8 years (range 5.0-17.0 years). A total of 130 SPC were diagnosed: 108/1570 (6.9%) received RAIT (RAIT+) and 22/461 (4.8%) did not (RAIT-). The most common SPC was breast cancer (31%), followed by genitourinary and gastrointestinal cancer (18% each). The 10-year cumulative incidence of SPC was 8.2% in RAIT+ and 4.5% in RAIT-. The absolute risk increase in the RAIT+ group versus the RAIT- group at 10 years of follow-up was 0.039 [confidence interval (CI) 0.011-0.067] per patient-year. The number needed to harm (NNH) was 25.6 [CI 15.0-87.2], indicating that on average during a 10-year follow-up period, there is one additional case of SPC for every 26 patients receiving RAIT. When controlling for age, sex, and familial and personal histories of cancer, there was an 84% increase in the risk of SPC in the RAIT+ group compared to the RAIT- group (p = 0.026; relative risk = 1.84 [CI 1.02-3.31]). There was an association between SPC incidence and total cumulative activity administered, which was statistically significant >200 mCi. The incidence of SPC was higher in both the WDCT and the RAIT+ cohorts compared to the general population (standardized incidence ratios = 1.32 and 1.40, respectively).

CONCLUSION

These results indicate that in spite of the low incidence of SPC in WDTC patients, the risk is increased after RAIT, particularly for activities >200 mCi. Thus, considering the excellent survival of patients with WDTC, clinicians need to weigh the risks and benefits of RAIT, especially in patients with low-risk thyroid cancer.

Trends of Second Primary Malignancy in Patients with Thyroid Cancer: A Population-Based Cohort Study in Israel

BACKGROUND

Thyroid cancer (TC) is the most common endocrine malignancy. TC patients have a good prognosis and a low disease-related mortality rate. Since such patients are often young, they may be at a higher risk for a second primary malignancy (SPM). This study sought to determine the incidence, risk, and types of SPM between 1980 and 2011, and to assess SPM trends over time among Israeli TC patients.

METHODS

Data were derived from the Israel National Cancer Registry. Primary TC patients diagnosed during 1980-2009 were followed up for SPM incidence until December 31, 2011. Standardized incidence ratios (SIRs) of observed to expected SPM (based on the general population rates) were calculated using Poisson regression. Analyses were stratified by time period of initial TC diagnosis (1980-1995 and 1996-2009).

RESULTS

A total of 11,538 TC patients were identified. After exclusion of 107 duplicate cases, records of 1032 patients with SPM were analyzed (an SPM incidence of 8.9%). SIRs for all-site SPMs were 1.23 [confidence interval 1.08-1.35] for males and 1.19 [confidence interval 1.10-1.27] for females. SIRs for tumors of the urinary system and prostate were significantly elevated in males, as were SIRs for tumors of the brain, urinary system, breast, and lung in females. Variables associated with increased risk of developing SPMs included a younger age at TC diagnosis, a shorter latency period, being born in Asia/Africa for both sexes, and being born in Israel for females. Compared with the general population, a subanalysis by TC diagnosis during 1980-1995 and 1996-2009 disclosed a higher SPM incidence for the latter time period in males and for both time periods, with a slightly higher SIR for the latter time period in females.

CONCLUSIONS

The overall risk of SPM in Israeli TC patients was significantly greater for both sexes compared with the general population, thus identifying TC patients as a high-risk group and calling for caretakers to apply specific follow-up guidelines.

Nonoperative management of low-risk differentiated thyroid carcinoma

Purpose of review

The global incidence of small papillary thyroid carcinoma (PTC) is increasing remarkably, mostly due to the increased use of imaging studies worldwide. The issue of how to manage low-risk small PTC has become urgent. In this review, we focus on how to treat low-risk papillary thyroid microcarcinomas (PMCs; i.e., PTCs measuring ≤10 mm).

Recent findings

Studies of large numbers of patients with low-risk PMC clarified that most of the PMCs did not grow or grew very slowly and were harmless. Active observations of these patients discriminated rare progressive cases from the majority. Surgery performed after the detection of progression signs was not too late, and surgery immediately after the detection and diagnosis of low-risk PMC may be overtreatment for most patients. Interestingly, low-risk PMCs in elderly patients were most unlikely to progress, in sharp contrast to clinical PTC. The reason for this phenomenon remains unknown.

Summary

Active observation without immediate surgery can be a leading alternative to the classical surgical treatment in the majority of the patients with low-risk PMC. It is not too late to perform surgery after the detection of progression signs for these patients.

Video abstract

http://links.lww.com/COON/A10

Head and neck mucoepidermoid carcinoma: a curious association with second primary malignancy

OBJECTIVE

We noticed that a significant proportion of our patients with head and neck mucoepidermoid carcinoma (HNMEC) had second primary malignancies. To our knowledge, such an association has never been described. The aim of our study is to elucidate the association between second primary malignancies and HNMEC.

STUDY DESIGN

Case series with chart review.

SETTING

Tertiary referral center.

SUBJECTS AND METHODS

We included all patients with histologically proven HNMEC managed in the Department of Surgery, Queen Mary Hospital, from January 2003 through December 2013. Medical records were retrospectively reviewed and analyzed.

RESULTS

Fifty-seven patients with HNMEC were identified. Fourteen (24.6%) had second primary malignancies. The commonest second primary malignancy was nasopharyngeal carcinoma, followed by carcinoma of the thyroid. Second primary malignancies developed before HNMEC in 7 patients, with a mean interval of 196 months. Five patients had second primary malignancies after development of HNMEC, with a mean interval of 65 months. Two patients had synchronous second primary malignancies. Clinical patterns of patients with HNMEC with and without second primary malignancies were compared. Major salivary glands were more frequently affected among patients with second primary malignancies, while minor salivary glands were more frequently affected among those without secondary primary malignancies (P = .032). Development of second primary malignancy was not found to affect the survival.

CONCLUSION

About one-fourth of patients with HNMEC had a second primary malignancy. Major salivary glands were more frequently affected among patients with second primary malignancies. Development of second primary malignancy did not affect survival.

Introducing the reporting system for thyroid fine-needle aspiration cytology according to the new guidelines of the Japan Thyroid Association

The Japan Thyroid Association (JTA) recently published new guidelines for clinical management of thyroid nodules. This paper introduces their diagnostic system for reporting thyroid fine-needle aspiration cytology. There are two points where the new reporting system that differs from existing internationally-accepted ones. The first is the subclassification of the so-called indeterminate category, which is divided into 'follicular neoplasm' and 'others'. The second is the subclassification of follicular neoplasm into 'favor benign', 'borderline' and 'favor malignant'. It is characterized by self-explanatory terminologies as to histological type and probability of malignancy to establish further risk stratification as well as to facilitate communication between clinicians and cytopathologists. The different treatment strategies adopted for thyroid nodules is deeply influenced by the particular diagnostic system used for thyroid cytology. In Western countries all patients with follicular neoplasms are advised to have immediate diagnostic surgery while patients in Japan often undergo further risk stratification without immediate surgery. The JTA diagnostic system of reporting thyroid cytology is designed for further risk stratification of patients with indeterminate cytology. If a surgeon applies diagnostic lobectomy to all patients with follicular neoplasm unselectively, this subclassification of follicular neoplasm has no practical meaning and is unnecessary. Cytological risk stratification of follicular neoplasms is optional and cytopathologists can choose either a simple 6-tier system without stratification of follicular neoplasm or a complicated 8-tier system depending on their experience in thyroid cytology and clinical management.

Second primary malignancies following thyroid cancer: a population-based study in Taiwan

OBJECTIVE

Most studies on second primary malignancies (SPMs) after primary thyroid cancer were conducted in USA or Europe. The discrepancy between SPMs in these studies could be attributed to geographical and ethnic heterogeneity. Thus, there is a clear need for another large-scale epidemiological study, particularly in Asian countries, to define the incidence and risk of SPMs in thyroid cancer survivors.

DESIGN

A population-based study was conducted using the nation-wide database from Taiwan Cancer Registry between 1979 and 2006.

METHODS

We quantified standardized incidence ratios (SIRs) and cumulative incidence of SPMs among 19,068 individuals (4205 males and 14,863 females) with primary thyroid cancer.

RESULTS

A total of 644 cases (3.38%) developed at least a SPM during 134,678 person-years of follow-up. The risk for subsequent SPMs was significantly greater than that of the general population (SIR=1.33, 95% CI 1.23-1.44). There was a greater risk of developing major salivary glands, nasopharyngeal, lung, thymus, breast (females), bladder, and brain cancers, and leukemia and lymphoma. We observed that the risk was highest within the first 5 years of diagnosis of thyroid cancer (SIR=5.29, 1.68, and 0.68 for ≤ 5, 5-10, and >10 respectively) and in the younger patients (SIR=1.81 vs 1.61 for <50 and ≥ 50 respectively). The median overall survival for primary thyroid cancer patients was 23.28 years, but it was only 4.73 years for those who developed SPMs.

CONCLUSION

Thyroid cancer is associated with a 33% risk increment of SPMs, which had a negative impact on survival. There are sites of SPMs in the Asian population that are distinctive from those in the Western population, suggesting that other genetic predisposition or environmental factors may play a role.

Secondary malignancy in patients with sporadic neuroendocrine neoplasia

The incidence of neuroendocrine neoplasias (NENs), especially of the gastro-entero-pancreatic (GEP), system relatively increased over the past decades, as a result of advanced diagnostic tools, a better clinical awareness, and distinguished pathological diagnostic recognition. Previous reports hypothesized an increased risk for secondary malignancies in patients with NEN especially in GEP-NENs. The present study was designed to investigate the coincidence of NENs and secondary malignancies in a large patient collective. A retrospective analysis was performed on 161 patients (85 female and 76 male) with NEN of various origins. Clinical data of these patients, different classification systems (TNM/WHO), proliferations-based grading, and clinical follow-up were collected and analyzed. Out of 143 patients with a sporadic NEN, 15 (10.49 %) patients were identified with secondary malignant tumors. Median age at the time of the primary operation for NEN was 65 years, whereas the median age of initial diagnosis of associated tumors was 59 years. Mean follow-up time was 61 months. The risk of developing a secondary malignancy was most elevated for patients with an NEN of the lung, the stomach, and the ileum (60, 50 and 20 %, respectively). The spectrum of secondary malignancies included various types of cancer. Kaplan-Meier survival analysis shows a difference suggesting that patients with a secondary malignancy demonstrate a worse survival compared to patients without a secondary tumor; no significance was detected (p = 0.349). Our data suggest that secondary malignancies in patients with NEN's especially in GEP-NENs are found more frequently than in general population. Therefore, patients with NEN need a continuous and detailed follow-up. The reason for the increased incidence of secondary malignancies in patients with NENs remains to be elucidated.

The acceleration in papillary thyroid cancer incidence rates is similar among racial and ethnic groups in the United States

BACKGROUND

Reports of similar age-specific incidence rates and a female-to-male gender disparity by racial/ethnic groups suggests that further consideration of race-specific patterns may confer insight into the possible causes of thyroid cancer or explanations for the increase in incidence.

METHODS

We used the National Cancer Institute's (NCIs) surveillance, epidemiology, and end results (SEER) program and Joinpoint Regression for cases diagnosed during 1992-2009 to investigate trends and rates of acceleration for papillary thyroid cancer by gender and race/ethnicity.

RESULTS

We determined the annual percent change (APC) and found a yearly increase of 7.0 % for papillary thyroid cancer for the most recent APC trend, with an APC of 6.3 and 7.1 % for white males and females, respectively; an APC of 4.3 and 8.4 % for black males and females, respectively; an APC of 4.2 and 6.7 % for Hispanic males and females, respectively; and an APC of 3.4 and 6.4 % in Asian/PI males and females, respectively. The APC projections show the rates of papillary thyroid cancer rising in males, but the patterns are more dramatic in females, with rates of papillary thyroid cancer in females surpassing rates of common cancers and becoming the third most common cancer in women of all ages by 2019.

CONCLUSIONS

Although the lowest rates of thyroid cancer are observed in blacks, the greatest rate of acceleration is occurring in black females. Our data also show that the rate of papillary thyroid cancer will continue to surpass rates of ovarian cancer, and in white women: it is projected to be more incident than colorectal cancer as well; and in Hispanic and Asian/Pacific Islander women, rates of papillary thyroid cancer are projected to be higher than lung, colorectal, and ovarian cancers in the near future.

Long-term survival in young women: hazards and competing risks after thyroid cancer

Background. Differentiated thyroid cancers (DTCs) are one of the most common and survivable cancers diagnosed in women. We examine factors associated with long-term survival and competing risks of death in women diagnosed with DTC under the age of 40 (<40) and aged 40 and older (40+). Methods. SEER data was used to identify DTCs diagnosed in women from 1975 to 2009. We examined overall (OS), disease-specific (DSS), other cancer (OCS), and non-cancer-related (NCS) survival using multivariate Cox proportional hazards modeling. Results. Observed survival was 97.2% for <40 (n = 14,540) and 82.5% for 40+ (n = 20,513). Distant stage (HR = 1.96, 95% CI 1.23–3.07), non-Hispanic Black (HR = 2.04, 95% CI 1.45–2.87), being unmarried (HR = 1.26, 95% 1.03–1.54), and subsequent primary cancers (HR = 4.63, 95% CI 3.76–5.71) were significant for OS in women <40. Age was an effect modifier for all survival outcomes. Racial disparities in NCS were most pronounced for young non-Hispanic black women (HR = 3.36, 95% CI 2.17–5.22). Women in both age groups were more likely to die from other causes. Conclusions. Age at diagnosis remains one of the strongest prognostic factors for thyroid cancer survival. More directed efforts to ensure effective care for comorbid conditions are needed to reduce mortality from other causes.

The role of prophylactic central neck dissection in differentiated thyroid carcinoma: issues and controversies

Prophylactic central neck dissection (pCND) in differentiated thyroid carcinoma (DTC) is one of the most controversial surgical subjects in recent times. To date, there is little evidence to support the practice of pCND in patients with DTC undergoing total thyroidectomy. Although the recently revised American Thyroid Association (ATA) guideline has clarified many inconsistencies regarding pCND and has recommended pCND in “high-risk” patients, many issues and controversies surrounding the subject of pCND in DTC remain. The recent literature has revealed an insignificant trend toward lower recurrence rate in patients with DTC who undergo total thyroidectomy and pCND than those who undergo total thyroidectomy alone. However, this was subjected to biases, and there are concerns whether pCND should be performed by all surgeons who manage DTC because of increased surgical morbodity. Performing a unilateral pCND may be better than a bilateral pCND given its lower surgical morbidity. Further studies in this controversial subject are much needed.