Identifying a risk profile for thyroid cancer

Predictive Value of BRAFV600E Mutation for Lymph Node Metastasis in Papillary Thyroid Cancer: A Meta-analysis

BRAF^V600E mutation has been thought to be a valuable molecular marker that may predict a worse prognosis for papillary thyroid cancer (PTC). But whether BRAF^V600E mutation is associated with lymph node metastasis (LNM) remains controversial. Different surgical strategies may bring a bias in demonsstrating the association between them. In order to delineate a risk stratification to guide a tailored initial approach to tumors that express BRAF^V600E mutation, we performed this meta-analysis by using the articles in which total or near-total thyroidectomy plus bilateral central lymph node dissection was routinely performed to avoid the bias from the surgical strategy. We searched the Medline, Embase and CNKI database for eligible studies from January 2003 to May 2018. Meta-analysis was performed using the STATA 12.0 software. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated under fixed-effects or randomeffects models. Fifteen clinical studies were included with a total of 4909 PTC patients. Our meta-analysis results reported that BRAFV600E mutation was associated with LNM (OR=1.34; 95% CI: 1.09-1.65; P=0.005), as well as central LNM (OR=1.59; 95% CI: 1.35-1.88; P<0.00001). Moreover, in patients with papillary thyroid microcarcinoma, we also confirmed the predictive value of BRAF^V600E mutation for LNM (OR=3.49; 95% CI: 2.02-6.02; P<0.00001). This meta-analysis demonstrates that BRAF^V600E mutation is closely related to LNM in PTC patients. The results suggest that BRAF^V600E mutation can be considered as a risk factor for LNM in PTC. Moreover, combining BRAF^V600E mutation with other risk factors to determine the initial surgical treatment may bring benefits for PTC patients.

Trends of Thyroid Cancer in Israel: 1980-2012

OBJECTIVES

Thyroid cancer incidence is increasing worldwide, while mortality from thyroid cancer is stable or decreasing. Consequently, survival rates are rising. We describe time trends in the incidence, mortality, and 5-year survival of thyroid cancer in Israel in 1980-2012, in light of the global trends.

METHODS

Israel National Cancer Registry database provided information regarding thyroid cancer incidence and vital status, which enabled computation of survival rates. The Central Bureau of Statistics database provided information on thyroid cancer mortality. Incidence and mortality rates were age-adjusted and presented by population group (Jews/Arabs) and gender. Relative 5-year survival rates which account for the general population survival in the corresponding time period were presented by population group and gender. Joinpoint analyses were used to assess incidence trends over time.

RESULTS

In 1980-2012 significant increases in the incidence of thyroid cancer were observed, with an annual percent change (APC) range of 3.98-6.93, driven almost entirely by papillary carcinoma (APCs 5.75-8.86), while rates of other types of thyroid cancer remained stable or decreased. Furthermore, higher rates of early detection were noted. In 1980-2012, a modest reduction in thyroid cancer mortality was observed in Jewish women (APC -1.07) with no substantial change in Jewish men. The 5-year relative survival after thyroid cancer diagnosis has increased to ≥90% in both population groups and both genders.

CONCLUSIONS

The Israeli secular trends of thyroid cancer incidence (increasing), mortality (mostly stable), and survival (modestly increasing) closely follow reported global trends.

BRAF mutation in papillary thyroid cancer: A cost-utility analysis of preoperative testing

BACKGROUND

Papillary thyroid carcinoma (PTC) with BRAF mutation carries a poorer prognosis. Prophylactic central neck dissection (CND) reduces locoregional recurrences, and we hypothesize that initial total thyroidectomy (TT) with CND in patients with BRAF-mutated PTC is cost effective.

METHODS

This cost-utility analysis is based on a hypothetical cohort of 40-year-old women with small PTC [2 cm, confined to the thyroid, node(-)]. We compared preoperative BRAF testing and TT+CND if BRAF-mutated or TT alone if BRAF-wild type, versus no testing with TT. This analysis took into account treatment costs and opportunity losses. Key variables were subjected to sensitivity analysis.

RESULTS

Both approaches produced comparable outcomes, with costs of not testing being lower (-$801.51/patient). Preoperative BRAF testing carried an excess expense of $33.96 per quality-adjusted life-year per patient. Sensitivity analyses revealed that when BRAF positivity in the testing population decreases to 30%, or if the overall noncervical recurrence in the population increases above 11.9%, preoperative BRAF testing becomes the more cost-effective strategy.

CONCLUSION

Outcomes with or without preoperative BRAF testing are comparable, with no testing being the slightly more cost-effective strategy. Although preoperative BRAF testing helps to identify patients with higher recurrence rates, implementing a more aggressive initial operation does not seem to offer a cost advantage.

Evolution of thyroid cancer mortality in adults in Brazil

OBJECTIVE: To assess the trend of thyroid cancer mortality in Brazil between 1980 and 2010. MATERIALS AND METHODS: An ecological study of time series. Mortality rates for thyroid cancer adjusted by age according to gender were calculated between 1980 and 2010. Data were analyzed by three distinct strategies: polynomial regression, joinpoint analysis, and moving averages. RESULTS: Over 70% of deaths occur in the elderly, regardless of sex. Among young adults, the mortality rate is low, with no difference between men and women. Among mature adults and elderly, mortality is increasing, and significantly, for women. There is a trend of decreasing mortality in all female adults and overall population, and in males and 40-59 years and overall population, both excluding the elderly, with statistical significance. CONCLUSION: Knowledge about trends allows setting priorities and allocating resources toward positive changes in this scenario in the Brazilian population.

Genes of detoxification are important modulators of hereditary medullary thyroid carcinoma risk

CONTEXT

Different inherited profiles of genes involved in cellular mechanisms of activation and detoxification of carcinogenic products can provide specific protection or determine the risk for cancer. Low-penetrance polymorphic genes related to the biotransformation of environmental toxins have been associated with susceptibility to and the phenotype of, human tumours.

OBJECTIVE

To investigate the role of germline inheritance of polymorphisms in CYP1A2*F, CYP1A1 m1, GSTP1, NAT2 and TP53 genes in hereditary medullary thyroid carcinoma (HMTC) patients.

DESIGN

This study was developed in University of Campinas (Unicamp).

PATIENTS

We studied 132 patients with HMTC, 88 first-degree relatives of HMTC patients and 575 control individuals.

MEASUREMENTS

All patients with MTC and their relatives were sequenced for the RET gene and five genes were genotyped using TaqMan(®) system.

RESULTS

We observed that the inheritance of CYP1A2*F (OR = 2·10; 95% CI = 1·11-3·97; P = 0·022), GSTP1 (OR = 4·41; 95% CI = 2·47-7·88; P < 0·001) and NAT2 (OR = 2·54; 95% CI = 1·16-5·58; P = 0·020) variants increased the risk for HMTC. In addition, multiple regression analysis showed that the inheritance of GSTP1 polymorphisms was associated with the diagnosis in older patients (B = 8·0229; 95% IC = ± 5·5735; P = 0·0054). Concerning the group of HTMC relatives, CYP1A2*F (OR = 2:40; 95% CI = 1·19-4·86; P = 0·015), CYP1A1 m1 (OR = 2·79; 95% CI = 1:04-7·51; P = 0·042), GSTP1 (OR = 2·86; 95% IC = 1·53-5·32; P < 0·001) and NAT2 (OR = 2·25; 95% IC = 1·20-4·22; P = 0·012) were associated with HMTC risk.

CONCLUSIONS

We have demonstrated that the inheritance of specific genes determining the individual response to environmental toxins may contribute to the risk and phenotypic variability that exists in patients with HMTC. Moreover, we identified a group at risk in relatives of HMTC patients.

Clinical Significance of BRAF Mutation in Thyroid Papillary Cancer

Objective

To correlate the presence of BRAF V600E mutation with clinicopathological parameters.

Study Design

Case-control study.

Setting

BRAF mutation represents the most common oncogenic event in sporadic papillary thyroid cancer (PTC). There are, however, significant discrepancies regarding the overall frequency and its relationship with clinicopathological parameters of poor outcome. We analyzed BRAF mutation in a cohort of patients affected by PTCs to identify its association with clinical variables.

Subjects and Methods

We analyzed retrospectively a series of 304 patients, treated for PTC from 1999 to 2011 at Bologna University Hospital. We searched BRAF mutation by reverse transcription polymerase chain reaction (PCR) followed by PCR and direct sequencing.

Results

BRAF mutation was found in 77.4% of classical PTCs, 31.9% of the follicular variant, and 72.2% of high tall cell PTCs, being significantly associated, at univariate analysis, with recurrence, stage, multicentricity, histologic subtype, extrathyroidal extension, nodule dimension, body mass index, and American Thyroid Association (ATA) risk stratification. Furthermore, higher T, but not N or M, stage was associated with BRAF mutation. In the multivariate analysis, the BRAF mutation was significantly associated only with the ATA risk stratification, in turn showing a significant negative association with recurrence-free survival time with Cox multivariate analysis.

Conclusion

Our results indicate that BRAF mutation identifies a subset of PTC with increased risk of recurrence. The presence of BRAF mutation might be a valuable diagnostic and prognostic marker of the disease. To confirm the diagnostic usefulness of this marker, further studies should be carried out.

BRAF mutation in papillary thyroid cancer and its value in tailoring initial treatment: a systematic review and meta-analysis

Clinicians have long sought to characterize biological markers of neoplasia as objective indicators of tumor presence, pathogenicity, and prognosis. Armed with data that correlate biomarker activity with disease presence and progression, clinicians can develop treatment strategies that address risks of disease recurrence or persistence and progression. The B-type Raf kinase (BRAF V600E) mutation in exon 15 of the BRAF gene has been noted to be a putative prognostic marker of the most prevalent form of thyroid cancer, papillary thyroid cancer (PTC)--a tumor type with high proclivity for recurrence or persistence. There has been a remarkable interest in determining the association of BRAF mutation with PTC recurrence or persistence. Using many new studies that have been published recently, we performed a meta-analysis to investigate correlations of BRAF mutation status with PTC prognosis, focusing on the recurrence or persistence of the disease after initial treatment. The study was based on published studies included in the PubMed and Embase databases addressing the BRAF mutation and the frequency of recurrence of PTC. We selected studies with data that enabled measurement of the risk ratio for recurrent disease. We also analyzed the factors that are classically known to be associated with recurrence. These factors included lymph node metastasis, extrathyroidal extension, distant metastasis, and American Joint Committee on Cancer (AJCC) stages III/IV. We used 14 articles that included an analysis of these factors as well as PTC recurrence data, with a total of 2470 patients from 9 different countries. The overall prevalence of the BRAF mutation was 45%. The risk ratios in BRAF mutation-positive patients were 1.93 (95% confidence interval [CI], 1.61-2.32; Z = 7.01; p < 0.00001) for PTC recurrence, 1.32 (95% CI, 1.20-1.45; Z = 5.73; p < 0.00001) for lymph node metastasis, 1.71 (95% CI, 1.50-1.94; Z = 8.09; p < 0.00001) for extrathyroidal extension, 0.95 (95% CI, 0.63-1.44; Z = 0.23; p = 0.82) for distant metastasis, and 1.70 (95% CI, 1.45-1.99; Z = 6.46; p < 0.00001) for advanced stage AJCC III/IV. Thus, in this meta-analysis, the BRAF mutation in PTC was significantly associated with PTC recurrence, lymph node metastasis, extrathyroidal extension, and advanced stage AJCC III/IV. Patients with PTC harboring mutated BRAF are likely to demonstrate factors that are associated with an increased risk for recurrence of the disease, offering new prospects for optimizing and tailoring initial treatment strategies to prevent recurrence.

Evidence that polymorphisms in detoxification genes modulate the susceptibility for sporadic medullary thyroid carcinoma

AIM

Polymorphic low-penetrance genes have been consistently associated with the susceptibility to a series of human tumors, including differentiated thyroid cancer.

METHODS

To determine their role in medullary thyroid cancer (MTC), we used TaqMan SNP method to genotype 47 sporadic MTC (s-MTC) and a control group of 578 healthy individuals for CYP1A2*F, CYP1A1m1, GSTP1, NAT2 and 72TP53. A logistic regression analysis showed that NAT2C/C (OR=3.87; 95% CI=2.11-7.10; P=2.2×10(-5)) and TP53C/C genotypes (OR=3.87; 95% CI=1.78-6.10; P=2.8×10(-4)) inheritance increased the risk of s-MTC. A stepwise regression analysis indicated that TP53C/C genotype contributes with 8.07% of the s-MTC risk.

RESULTS

We were unable to identify any relationship between NAT2 and TP53 polymorphisms suggesting they are independent factors of risk to s-MTC. In addition, there was no association between the investigated genes and clinical or pathological features of aggressiveness of the tumors or the outcome of MTC patients.

CONCLUSION

In conclusion, we demonstrated that detoxification genes and apoptotic and cell cycle control genes are involved in the susceptibility of s-MTC and may modulate the susceptibility to the disease.

Absence of Peritumoral Fibrosis or Inflammatory Infiltrate May Be Related to Clinical Progression of Papillary Thyroid Microcarcinoma

Rio Grande do Norte (RN) shows the highest relative incidence of papillary carcinomas in Brazil. To analyze histological features that might be associated with this incidence, the authors compared thyroid glands from 463 autopsies performed in RN with 427 surgical and autopsy glands previously studied in Sao Paulo (SP). The authors found 41 papillary thyroid microcarcinomas (PTMs) in 35 glands (8.1%), an incidence similar to the one reported in SP (7.8%). However, PTMs were predominantly nonencapsulated nonsclerosing at microscopy (44.0%), in contrast with SP where these types of lesion represented only 4 out of 32 PTMs (12.5%; P = .0046). The authors suggest that these nonencapsulated lesions with no sign of inflammation may represent an early stage that may evolve to clinical cancers, contributing to the high incidence of clinically differentiated thyroid carcinomas observed in RN.