Laura Y. Wang

Invasion rather than nuclear features correlates with outcome in encapsulated follicular tumors: further evidence for the reclassification of the encapsulated papillary thyroid carcinoma follicular variant.

The prognosis of the encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) and its relationship to encapsulated follicular carcinoma (EFC) and follicular adenoma (FA) is subject to controversy. All EFVPTCs, EFCs, and FAs identified at a single institution between 1981 and 2003 were analyzed microscopically. A cohort of FAs from a different hospital was also examined. EFVPTCs were subdivided into noninvasive EFVPTC (NIEFVPTC) and invasive EFVPTC (IEFVPTC) displaying capsular/vascular invasion. There were 83 EFVPTCs (57 noninvasive, 26 invasive), 14 EFCs, and 52 FAs. Similar to FA, over a median follow-up of 9.5 years, none of the NIEFVPTCs manifested lymph node metastasis (LNM) or recurred. Furthermore, with a median follow-up of 10.5 years, none of 39 NIEFVPTCs without radioactive iodine therapy recurred. Four (15%) of 26 IEFVPTCs and none of 14 EFCs harbored distant metastasis (P = .29). There was no difference in LNM rate and degree of vascular or capsular invasion between IEFVPTC and EFC (P > .1). All 4 IEFVPTCs with adverse behavior presented with distant metastasis and no LNM. Sixteen percent of IEFVPTCs had poor outcome, whereas there was none in the NIEFVPTCs (P = .007). In conclusion, NIEFVPTC seems to behave similarly to FA, whereas IEFVPTC can metastasize and spread like EFC. Thus, invasion rather than nuclear features drives outcome in encapsulated follicular tumors. Non-IEFVPTC could be treated in a conservative manner sparing patients unnecessary total thyroidectomy and radioactive iodine therapy. The position of the EFVPTC in the classification of thyroid neoplasia should be reconsidered.

The impact of nodal status on outcome in older patients with papillary thyroid cancer

BACKGROUND The impact of clinically or radiologically detected nodal metastases on survival in patients with papillary thyroid cancer (PTC) is controversial but seems more important and relevant in older patients. The objective of this study was to determine the impact of clinically or radiologically detected nodal metastases on outcome in patients 45 years of age or older. METHODS Retrospective analysis of 834 patients 45 years or older who underwent operation for PTC between 1986 and 2005. RESULTS With a median follow up of 77 months, the 5 year disease-specific survival (DSS) and recurrence-free survival (RFS) were 99% and 94%, respectively. Patients with clinically N+ nodes with pathologic confirmation were stratified into pN0/Nx, pN1a, and pN1b, respectively. Five-year DSS was 100%, 100%, and 91% for pN0/Nx, pN1a, and pN1b disease; P < .001. Patients with pN1b disease had poorer distant RFS compared with pN0/Nx and pN1a patients (84%, 99%, and 99%; P < .001). The presence of pN1b disease was an independent predictor of worse DSS and distant RFS on multivariate analysis, conferring a 10-fold increased risk of distant metastases and death. All cause-specific deaths were due to distant metastases. CONCLUSION Older patients with PTC and N1b disease at presentation have poorer DSS compared with patients with pN0/Nx or N1a disease. The cause of death in these patients is due to distant metastases rather than locoregional recurrence.

An International Multi-Institutional Validation of Age 55 Years as a Cutoff for Risk Stratification in the AJCC/UICC Staging System for Well-Differentiated Thyroid Cancer

BACKGROUND Age is a critical factor in outcome for patients with well-differentiated thyroid cancer. Currently, age 45 years is used as a cutoff in staging, although there is increasing evidence to suggest this may be too low. The aim of this study was to assess the potential for changing the cut point for the American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) staging system from 45 years to 55 years based on a combined international patient cohort supplied by individual institutions. METHODS A total of 9484 patients were included from 10 institutions. Tumor (T), nodes (N), and metastasis (M) data and age were provided for each patient. The group was stratified by AJCC/UICC stage using age 45 years and age 55 years as cutoffs. The Kaplan-Meier method was used to calculate outcomes for disease-specific survival (DSS). Concordance probability estimates (CPE) were calculated to compare the degree of concordance for each model. RESULTS Using age 45 years as a cutoff, 10-year DSS rates for stage I-IV were 99.7%, 97.3%, 96.6%, and 76.3%, respectively. Using age 55 years as a cutoff, 10-year DSS rates for stage I-IV were 99.5%, 94.7%, 94.1%, and 67.6%, respectively. The change resulted in 12% of patients being downstaged, and the downstaged group had a 10-year DSS of 97.6%. The change resulted in an increase in CPE from 0.90 to 0.92. CONCLUSIONS A change in the cutoff age in the current AJCC/UICC staging system from 45 years to 55 years would lead to a downstaging of 12% of patients, and would improve the statistical validity of the model. Such a change would be clinically relevant for thousands of patients worldwide by preventing overstaging of patients with low-risk disease while providing a more realistic estimate of prognosis for those who remain high risk.

Survival from Differentiated Thyroid Cancer: What Has Age Got to Do with It?

BACKGROUND In most staging systems, 45 years of age is used to differentiate low risk thyroid cancer from high risk thyroid cancer. However, recent studies have questioned both the precise 45 year age point and the concept of using a binary cut off as accurate predictors of disease specific mortality. METHODS A cohort of 3664 thyroid cancer patients that received surgery and adjuvant treatment at Memorial Sloan Kettering Cancer Center (MSKCC) from the years 1985 to 2010 were analyzed to determine the significance of age at diagnosis as a categorical variable at a variety of age cutoffs (5 year intervals between 30 and 70 years of age). The unadjusted and adjusted hazard ratio for the association between disease-specific survival and age was determined using a Cox proportional hazards model adjusted for other predictive variables sex, histology, and pathological T, N, and M status. Furthermore, predictive nomograms of disease-specific mortality were created and validated on an external dataset of 4551 patients to evaluate the impact of age at diagnosis as both a categorical and continuous variable. RESULTS In the MSKCC cohort, with a median follow-up time of 54 months (range 1-332), there were 59 deaths from thyroid cancer with a 10 year disease-specific survival of 96%. Adjusted hazard ratios for all age cutoffs from age 30 to age 70 years were significant. There was no specific cutoff age which risk stratifies patients with differentiated thyroid cancer (DTC). Categorizing age into five strata (<40, 40-49, 50-59, 60-69 and >70 years) showed a 37-fold increase in hazard ratio from age <40 years to age >70 years. A predictive nomogram using age as a continuous variable with other predictive variables had a high concordance index of 96%. Validation on the external cohort had a concordance index of 73%. CONCLUSIONS Mortality from DTC increases progressively with advancing age. There is no specific cutoff age which risk stratifies patients with DTC. A predictive nomogram using age as a continuous variable may be a more appropriate tool for stratifying patients with DTC and for predicting outcome.

Outcomes for patients with papillary thyroid cancer who do not undergo prophylactic central neck dissection

The role of prophylactic central neck dissection (CND) in the management of papillary thyroid cancer (PTC) is controversial. This report describes outcomes of an observational approach in patients without clinical evidence of nodal disease in PTC.

Increasing diagnosis of subclinical thyroid cancers leads to spurious improvements in survival rates.

Survival rates are commonly used to measure success in treating cancer, but can be misleading. Modern diagnostic practices can lead to the appearance of improving cancer survival, as tumors are diagnosed earlier (lead‐time bias) or as an increasing proportion are slow‐growing (length bias), whereas the actual burden of cancer deaths is unchanged. Increasingly, more subclinical thyroid cancers are being diagnosed. The objective of the current study was to determine whether thyroid cancer survival rates have been affected by this phenomenon.

The Oral Microbiome and Oral Cancer

The role that bacteria play in the etiology and predisposition to cancer is of increasing interest, particularly since the development of high-throughput genetic-based assays. With this technology, it has become possible to comprehensively examine entire microbiomes as a functional entity. This article focuses on the understanding of bacteria and its association with oral squamous cell carcinoma.

Prognostic impact of extent of vascular invasion in low-grade encapsulated follicular cell–derived thyroid carcinomas: a clinicopathologic study of 276 cases

Continuous controversy surrounds the predictive value of the degree of vascular invasion (VI) in low-grade encapsulated follicular cell-derived thyroid carcinomas (LGEFCs). Some guidelines advocate conservative therapy in LGEFCs with focal VI. There is therefore a need to assess the survival rates of LGEFC patients with various degrees of VI to better stratify patients for subsequent therapy. Furthermore, the prognostic effect of VI within the different histotypes of LGEFCs is not well known. A total of 276 patients with LGEFCs were subjected to a meticulous histopathologic analysis. They were classified as encapsulated papillary thyroid carcinoma, encapsulated follicular carcinoma (EFC), and encapsulated Hurthle cell carcinoma (EHCC). Of the 276 patients, 24 had extensive VI (EVI) (≥4 foci) and 28 displayed focal (<4 foci) VI. EHCC and EFC showed a much higher rate of EVI than encapsulated papillary thyroid carcinoma. Median follow-up was 6 years. All 14 tumors with adverse behavior harbored distant metastases (DMs), of which 9 had DMs at presentation. All 3 patients without EVI who had aggressive carcinomas harbored DMs at presentation. EVI was an independent predictor of poor recurrence-free survival. Excluding cases with DMs at presentation, only patients with EVI had recurrence, and all relapsed cases were EHCC. EVI is an independent predictor of recurrence-free survival in LGEFCs. EHCC with EVI has a particularly high risk of recurrence. When DMs are not found at presentation, patients with focal VI are at a very low risk of recurrence even if not treated with radioactive iodine.

Microscopic Positive Margins in Differentiated Thyroid Cancer Is Not an Independent Predictor of Local Failure

BACKGROUND In contrast to other head and neck cancers, the impact of histological thyroid specimen margin status in differentiated thyroid cancer (DTC) is not well understood. The aim of this study was to investigate the prognostic value of margin status on local recurrence in DTC. METHOD The records of 3664 consecutive patients treated surgically for DTC between 1986 and 2010 were identified from an institutional database. Patients with less than total thyroidectomy, unresectable or gross residual disease, or M1 disease at presentation and those with unknown pathological margin status were excluded from analysis. In total, 2616 patients were included in the study; 2348 patients (90%) had negative margins and 268 patients (10%) had positive margins. Microscopic positive margin status was defined as tumor present at the specimens edge on pathological analysis. Patient, tumor, and treatment characteristics were compared by Pearsons chi-squared test. Local recurrence free survival (LRFS) was calculated for each group using the Kaplan Meier method. RESULTS The median age of the cohort was 48 years (range 7-91 years) and the median follow-up was 50 months (range 1-330 months). Age, sex, and histology types were similar between groups. As expected, patients who had positive margins were more likely to have larger tumors (p<0.001), extrathyroidal extension (ETE) (p<0.001), multicentric disease (p<0.001), or nodal disease (p<0.001) and were more likely to receive adjuvant radioactive iodine therapy (p<0.001) as well as external beam radiotherapy (p<0.001). The LRFS at 5 years for patients with positive margins status was slightly poorer compared with patients with negative margins (98.9% vs. 99.5%, p=0.018). Twelve patients developed local recurrence-8/2348 (0.34%) patients with negative margins and 4/263 (1.52%) patients with positive margins. Univariate predictors of LRFS were sex (p=0.006), gross ETE (<0.001), and positive margins (p=0.018). However, when controlling for presence of gross ETE on multivariate analysis, microscopic positive margin status was not an independent predictor of LRFS (p=0.193). CONCLUSION Patients with resectable, M0 disease that undergo total thyroidectomy have an excellent five year LRFS of 99.4%. Microscopic positive margin status was not a significant predictor for local failure after adjusting for ETE or pathological tumor (pT) stage.

Cost-Effectiveness Analysis of Papillary Thyroid Cancer Surveillance

The recent overdiagnosis of subclinical, low‐risk papillary thyroid cancer (PTC) coincides with a growing national interest in cost‐effective health care practices. The aim of this study was to measure the relative cost‐effectiveness of disease surveillance of low‐risk PTC patients versus intermediate‐ and high‐risk patients in accordance with American Thyroid Association risk categories.