Open Access

Clinical utility of TERT promoter mutations and ALK rearrangement in thyroid cancer patients with a high prevalence of the BRAF V600E mutation

  • Ja Seong Bae1,
  • Yourha Kim2, 3,
  • Sora Jeon2, 3,
  • Se Hee Kim2,
  • Tae Jung Kim2,
  • Sohee Lee1,
  • Min-Hee Kim4,
  • Dong Jun Lim4,
  • Youn Soo Lee1 and
  • Chan Kwon Jung2Email author
Diagnostic Pathology201611:21

https://doi.org/10.1186/s13000-016-0458-6

Received: 5 September 2015

Accepted: 14 January 2016

Published: 9 February 2016

Abstract

Background

Mutations in the TERT promoter, ALK rearrangement, and the BRAF V600E mutation are associated with aggressive clinicopathologic features in thyroid cancers. However, little is known about the impact of TERT promoter mutations and ALK rearrangement in thyroid cancer patients with a high prevalence of BRAF mutations.

Methods

We performed Sanger sequencing to detect BRAF V600E and TERT promoter mutations and both immunohistochemistry and fluorescence in situ hybridization to identify ALK rearrangement on 243 thyroid cancers.

Results

TERT promoter mutations were not present in 192 well-differentiated thyroid carcinomas (WDTC) without distant metastasis or in 9 medullary carcinomas. However, the mutations did occur in 40 % (12/30) of WDTC with distant metastasis, 29 % (2/7) of poorly differentiated carcinomas and 60 % (3/5) of anaplastic carcinomas. ALK rearrangement was not present in all thyroid cancers. The BRAF V600E mutation was more frequently found in WDTC without distant metastasis than in WDTC with distant metastasis (p = 0.007). In the cohort of WDTC with distant metastasis, patients with wild-type BRAF and TERT promoter had a significantly higher response rate after radioiodine therapy (p = 0.024), whereas the BRAF V600E mutation was significantly correlated with progressive disease (p = 0.025).

Conclusions

The TERT promoter mutation is an independent predictor for distant metastasis of WDTC, but ALK testing is not useful for clinical decision-making in Korean patients with a high prevalence of the BRAF V600E mutation. Radioiodine therapy for distant metastasis of WDTC is most effective in patients without BRAF V600E and TERT promoter mutations.

Keywords

Thyroid cancerBRAF V600ETelomerase reverse transcriptaseAnaplastic lymphoma kinaseIodine-131

Background

Thyroid cancer is the most common type of endocrine tumor, with an incidence that has significantly increased in the last few decades [1, 2]. Although well-differentiated thyroid carcinoma (WDTC) is one of the most curable of all cancers, approximately 10–20 % of patients with WDTC suffer from disease recurrence after surgery, and some eventually die from the disease [35]. Various risk stratification methods have been used for the proper management of patients with WDTC; however, none are completely accurate [6].

Molecular biomarkers have been used as an adjunct diagnostic marker of thyroid cancer and a predictor of patient prognosis [7, 8]. The BRAF V600E mutation is the most common mutation in thyroid cancer, particularly in papillary thyroid carcinoma (PTC), and plays an important role in tumorigenesis and progression [914]. In Korea, PTC comprises 97.3 % of all thyroid cancers according to new data from the 2014 annual report of cancer statistics in Korea (http://www.cancer.go.kr/). The BRAF V600E mutation is highly prevalent in Korean PTC patients [11]. Currently, there is controversy regarding whether the BRAF V600E mutation is associated with poor prognosis and aggressive clinicopathologic features in Korean PTC patients; therefore, additional prognostic biomarkers to predict a more aggressive disease are needed [9, 1518].

Somatic mutations of the promoter region of the TERT gene have been reported in various cancers, including thyroid cancers, but are not found in normal cells [1923]. The frequent cytosine-to-thymine transition of the TERT promoter region occurs at the following positions of chr5: 1 295 228 (C228T) and 1 295 250 (C250T), which correspond to nucleotide changes -124 bp (c.-124C > T) and -146 bp (c.-146C > T) upstream from the ATG start site, respectively (Fig. 1) [1923]. These TERT promoter mutations stimulate TERT transcriptional activity in cancer cells [1923]. In thyroid cancers, TERT promoter mutations were predominantly found in more aggressive disease, such as tall cell variant PTC, widely invasive follicular thyroid carcinoma (FTC), poorly differentiated carcinoma, and anaplastic carcinoma [13, 18, 21, 24, 25].
Fig. 1

Structure of the wild-type TERT gene and representative sequencing electropherograms of the genomic DNA of the TERT promoter. The g.1295228 C > T (C228T) and g.1295250 C > T (C250T) mutations within the TERT promoter gene result in a cytosine-to thymine transition at 124 bp (c.-124C > T) and 146 bp (c.-146C > T) upstream of the ATG start codon, respectively. g.1295228 C > A (C228A) is a cytosine-to adenine transition at the 1 295 228 position of chr5

ALK gene rearrangements have recently been identified in thyroid cancer [2630]. EML4, STRN, TFG, and GTF2IRD1 have been reported as ALK fusion partners [27, 28, 3032]. The prevalence of ALK-rearranged PTCs has been reported to be up to 2.2 %, although the number of study cases is limited [26]. A previous study reported that ALK rearrangements were more frequently found in aggressive thyroid cancer, while another study found mutations only in unselected consecutive PTC cases and not in aggressive disease, such as PTCs with distant metastasis, poorly differentiated carcinomas and anaplastic carcinomas [26, 28].

We aimed to investigate the prevalence of TERT promoter and ALK mutations in thyroid cancer patients with a high prevalence of the BRAF V600E mutation and their potential contribution for the risk stratification of these patients.

Methods

Patients

We retrospectively enrolled 243 patients who underwent thyroid surgery for thyroid cancer at Seoul St. Mary’s Hospital of The Catholic University of Korea with the approval of the Institutional Review Board. Informed consent was obtained from every patient. The thyroid cancers studied included 192 consecutive WDTCs without distant metastasis (consisting of 127 classic PTCs, 11 classic PTCs with tall cell features, 9 encapsulated follicular variant PTCs, 7 infiltrative follicular variant PTCs, 16 tall cell variant PTCs, 1 oncocytic PTC, 1 Warthin-like PTC, and 20 minimally invasive FTCs), 30 consecutive WDTCs with distant metastasis (consisting of 14 classic PTCs, 4 classic PTCs with tall cell features, 1 encapsulated follicular variant PTC, 1 macrofollicular variant PTC, 5 tall cell variant PTCs, 1 columnar cell variant PTC, 1 diffuse sclerosing variant PTC, 2 minimally invasive FTCs, and 1 widely invasive FTC), 7 poorly differentiated carcinomas, 5 anaplastic carcinomas, and 9 medullary carcinomas. PTC was defined as a classic type with tall cell features if it consisted of less than 50 % tall cells and as a tall cell variant if it consisted of 50 % or more tall cells [33].

Mutational analyses for BRAF and TERT promoter mutations

Genomic DNA was isolated from manually dissected 10-μm thick paraffin-embedded tissue sections using the RecoverAll™ Total Nucleic Acid Isolation Kit (Life Technologies, Carlsbad, CA, USA). Sanger sequencing was performed to detect the presence of BRAF V600E and TERT promoter mutations. Exon 15 of the BRAF gene was PCR-amplified as previously reported using the following forward primer (5′-TCATAATGCTTGCTCTGATAGGA-3′) and reverse primer (5′-GGCCAAAAATTTAATCAGTGGA-3′), resulting in a 224 bp PCR product [11, 33, 34]. A 193 bp fragment of the TERT promoter was amplified by PCR as previously reported using the following forward primer (5′-CACCCGTCCTGCCCCTTCACCTT-3′) and reverse primer (5′-GGCTTCCCACGTGCGCAGCAGGA-3′) [35]. All TERT promoter mutations were confirmed using another previously reported primer set that included the following forward primer (5′-AGTGGATTCGCGGGCACAGA-3′) and reverse primer (5′-CAGCGCTGCCTGAAACTC-3′) and resulted in a 235 bp PCR product [21].

Immunohistochemistry for ALK overexpression

Immunohistochemistry was performed on paraffin-embedded whole tissue sections of surgical specimens using the ALK antibody (clone p80, Novocastra Laboratories Ltd., Newcastle upon Tyne, UK) and the Polink-2 HRP plus anti-rabbit DAB detection kit (GBI Labs, Mukilteo, WA, USA). As a positive control, we used paraffin-embedded tissue sections from two lung adenocarcinomas with previously confirmed ALK rearrangement by fluorescence in situ hybridization (FISH).

FISH for ALK rearrangement

We performed FISH to detect ALK rearrangement using a ZytoLight SPEC ALK Dual Color Break Apart Probe and Kit (ZytoVision GmbH, Bremerhaven, Germany) according to the manufacturer’s protocol [29]. The positive criterion for ALK rearrangement was defined as > 15 % of split signal separation and/or isolated red signal in at least 100 tumor cells as previously described [26, 29].

Evaluation of response to radioiodine therapy

All 30 WDTC patients with distant metastasis underwent radioactive iodine (RAI) therapy. The response to RAI ablation was evaluated with a whole body iodine -131 scan, evaluation of serum thyroglobulin levels, and a computerized tomography scan. Clinical outcomes to RAI therapy were classified as complete remission (CR), partial response (PR), stable disease (SD), and progressive disease (PD) according to previously described criteria [36].

Statistical analysis

The Pearson’s chi-square test or Fisher’s exact test was used to assess the relationship between two nominal variables. The Student’s t-test and Mann–Whitney test were used to compare two different groups of continuous parametric or nonparametric data, respectively. For the multivariate analysis, parameters that were significant at p < 0.25 in the univariate analysis were included in a multiple logistic regression test. Two-sided tests with p < 0.05 were considered to be statistically significant. Statistical analysis was performed with SPSS ver. 21.0 software (SPSS Inc., Chicago, IL, USA) and SAS ver. 9.3 software (SAS Institute Inc., Cary, NC, USA).

Meta-analysis of the proportion of TERT promoter mutations

We searched the literature for TERT promoter mutations in thyroid cancer using PubMed and Google up to November 2015, and selected eligible articles. We then conducted a meta-analysis of the proportion of TERT promoter mutations according to the histologic types of thyroid cancers. Cochran Q test and I2 values were employed to assess statistical heterogeneity among studies. If significant heterogeneity was observed (p < 0.10 or I2 > 50 %), the random effect model was used for meta-analysis. Otherwise, we used a fixed-effect model for the meta-analysis. Meta-analyses were performed using done using MedCalc version 13.0.2 software (MedCalc, Ostend, Belgium).

Results

Prevalence of TERT promoter mutations, the BRAF V600E mutation, and ALK rearrangement in thyroid cancers

TERT promoter mutations were found in 12 (40 %) of 30 WDTCs with distant metastasis, 2 (29 %) of 7 poorly differentiated carcinomas, and 3 (60 %) of 5 anaplastic carcinomas. However, no such mutations were present in the 192 WDTCs without distant metastasis or the 9 medullar carcinomas (Table 1). Among TERT promoter mutations, the most common type was C228T (76 %), followed by C250T (18 %) and C250A (6 %) (Table 1) (Fig. 1). Among 12 WDTCs with TERT promoter mutations, the most frequent histologic subtype was the tall cell variant of PTC (Table 1).
Table 1

TERT promoter mutations, BRAF V600E mutation and ALK rearrangement in 243 Korean patients with thyroid cancer

 

Patient

TERT promoter mutation

BRAF V600E

ALK rearrangement

C228T

C250A

C250T

Overall

WDTC without distant metastasis

192

0

0

0

0

142 (74 %)

0

 PTC, classic

127

0

0

0

0

110 (87 %)

0

 PTC, classic with TCF

11

0

0

0

0

10 (91 %)

0

 PTC, EFV

9

0

0

0

0

1 (11 %)

0

 PTC, IFV

7

0

0

0

0

5 (71 %)

0

 PTC, tall cell

16

0

0

0

0

15 (94 %)

0

 PTC, oncocytic

1

0

0

0

0

1 (100 %)

0

 PTC, Warthin-like

1

0

0

0

0

0

0

 FTC, minimally invasive

20

0

0

0

0

0

0

WDTC with distant metastasis

30

10 (33 %)

0

2 (7 %)

12 (40 %)

15 (50 %)

0

 PTC, classic

14

3 (21 %)

0

0

3 (21 %)

7 (50 %)

0

 PTC, classic with TCF

4

2 (50 %)

0

1 (25 %)

3 (75 %)

4 (100 %)

0

 PTC, EFV

1

0

0

0

0

0

0

 PTC, macrofollicular

1

0

0

0

0

0

0

 PTC, tall cell

5

4 (80 %)

0

0

4 (80 %)

3 (60 %)

0

 PTC, columnar cell

1

0

0

1 (100 %)

1 (100 %)

1 (100 %)

0

 PTC, diffuse sclerosing

1

0

0

0

0

0

0

 FTC, minimally invasive

2

1 (50 %)

0

0

0

0

0

 FTC, widely invasive

1

0

0

0

1(100 %)

0

0

Poorly differentiated carcinoma

7

1 (14 %)

1 (14 %)

0

2 (29 %)

1 (14 %)

0

Anaplastic carcinoma

5

2 (40 %)

0

1 (20 %)

3 (60 %)

4 (80 %)

0

Medullary carcinoma

9

0

0

0

0

0

0

WDTC well-differentiated thyroid carcinoma, PTC papillary thyroid carcinoma, TCF tall cell features, EFV encapsulated follicular variant, IFV infiltrative follicular variant, FTC follicular thyroid carcinoma

The BRAF V600E mutation was found in 142 (83 %) of 172 PTCs without distant metastasis, 15 (56 %) of 27 PTCs with distant metastasis, 1 (14 %) of 7 poorly differentiated carcinomas and 4 (80 %) of 5 anaplastic carcinomas (Table 1). However, the BRAF V600E mutation was not found in 23 FTCs and 9 medullary carcinomas.

None of the 243 thyroid cancers had positive ALK immunohistochemistry or ALK break apart FISH (Table 1).

Relationship between TERT promoter mutations and clinicopathologic features of WDTCs

In 222 patients with WDTC, the presence of TERT promoter mutations was associated with older age (p = 0.017), larger tumor size (p = 0.043), aggressive histologic subtypes (p < 0.001), advanced pathologic T stage (p = 0.014), extrathyroidal extension (p = 0.035), lymph node metastasis (p = 0.011), lateral lymph node metastasis (p < 0.001), distant metastasis (p < 0.001), and advanced AJCC stage (p < 0.001) (Table 2). There was no association between TERT promoter mutations and the BRAF V600E mutation (Table 2).
Table 2

Association between TERT promoter mutations and clinicopathologic features in 222 patients with well-differentiated thyroid carcinoma

 

TERT promoter mutations

 

Absent (n = 210)

Present (n = 12)

p-value

Age (mean years)

45.5 ± 13.3

55.0 ± 11.8

0.017

Gender

   

 Female

164 (94.8 %)

9 (5.2 %)

0.801

 Male

46 (93.9 %)

3 (6.1 %)

Tumor size (mean mm)

14.8 ± 12.5

31.9 ± 22.9

0.043

Histologic types

   

 Aggressive varianta)

18 (75.0 %)

6 (25.0 %)

<0.001

 Less-aggressive variant

192 (97.0 %)

6 (3.0 %)

Pathologic T stage

   

 pT 1–2

97 (99.0 %)

1 (1.0 %)

0.014

 pT 3–4

113 (91.1 %)

11 (8.9 %)

Extrathyroidal extension

   

 Absent

105 (98.1 %)

2 (1.9 %)

0.035

 Present

105 (91.3 %)

10 (8.7 %)

Pathologic N stage

   

 pN0

105 (99.1 %)

1 (0.9 %)

0.011

 pN1

105 (91.3 %)

10 (8.7 %)

Lateral lymph node metastasis

   

 Absent

166 (98.8 %)

2 (1.2 %)

<0.001

 Present

43 (82.7 %)

9 (17.3 %)

Distant metastasis

   

 Absent

192 (100 %)

0

<0.001

 Present

18 (60.0 %)

12 (40 %)

AJCC stage

   

 I-II

120 (100 %)

0

<0.001

 III-IV

90 (88.2 %)

12 (11.8 %)

BRAF V600E mutation

   

 Absent

62 (95.4 %)

3 (4.6 %)

0.738

 Present

148 (94.3 %)

9 (5.7 %)

a)Aggressive variant includes 21 tall cell, 1 columnar cell, and 1 diffuse sclerosing variant of papillary carcinoma and 1 widely invasive follicular carcinoma

Relationship between clinicopathologic and molecular features and distant metastases of WDTCs

The mean follow-up period of the patients with WDTC was 36.1 months. In 14 patients, distant metastases were found within 6 months of first diagnosis. Distant metastases occurred in the lung (n = 24), bone (n = 3), lung and bone (n = 2), and brain (n = 1). Distant metastasis was associated with larger tumor size (p = 0.001), aggressive histologic subtype (p = 0.003), advanced pT stage (p < 0.001), extrathyroidal extension (p = 0.001), lymph node metastasis (p < 0.001), lateral lymph node metastasis (p < 0.001) and the TERT promoter mutation (p < 0.001). However, the BRAF V600E mutation was inversely associated with distant metastasis (p = 0.007).

In the multivariate analysis, the odds ratio (OR) for distant metastasis of WDTC in patients harboring tumors with TERT promoter mutations and lateral lymph node metastases was 155.298 (95 % confidence interval (CI) 3.362–999.990) and 11.159 (95 % CI 1.902–65.461), respectively (Table 3). The OR for distant metastases of WDTC in patients harboring tumors with the BRAF V600E mutation was 0.083 (95 % CI 0.021–0.327) (Table 3).
Table 3

Multivariate analysis of factors affecting distant metastasis

 

Odds Ratio

95 % CI

p-value

Age

1.046

0.999–1.095

0.054

Gender

0.688

0.197–2.401

0.557

Tumor size

1.04

0.999–1.095

0.083

Histologic type

0.816

0.182–3.66

0.790

Pathologic T stage

0.142

0.005–4.016

0.252

Extrathyroidal extension

19.535

0.618–617.017

0.091

Pathologic N stage

0.922

0.141–6.053

0.933

Lateral lymph node metastasis

11.159

1.902–65.461

0.008

TERT promoter mutation

155.298

3.362–999.990

0.009

BRAF V600E mutation

0.083

0.021–0.327

<0.001

Impact of molecular genotypes on response of metastatic WDTCs to RAI therapy

Of the 30 WDTCs with distant metastasis, 9 (30 %) had coexisting BRAF V600E and TERT promoter mutations and 12 (40 %), including follicular and diffuse sclerosing variants of PTC, had no mutations (Fig. 2a).
Fig. 2

Molecular genotypes and radioactive iodine therapy. a Molecular genotypes of 30 well-differentiated thyroid carcinomas with distant metastases based on TERT promoter mutations and BRAF V600E. b Structural response of distant metastatic disease to radioactive iodine therapy classified by molecular genotypes in 30 well-differentiated thyroid carcinoma patients with distant metastasis. PTC, papillary thyroid carcinoma; TCF, tall cell features; FTC, follicular thyroid carcinoma; TERT, TERT promoter mutations; BRAF, BRAF V600E; (+), mutation positive; (-), mutation negative

The structural response of distant metastatic disease to RAI was evaluated at least 6 months after RAI therapy. Of the 30 WDTC patients with distant metastasis, six (20 %) patients had PR and six (20 %) had SD after RAI ablation whereas none achieved CR and 18 (60 %) had PD. There was a significant correlation between tumors with the BRAF V600E mutation alone and the progression of distant metastatic disease after RAI therapy (p = 0.025), but TERT promoter mutations alone were not associated with PD (Fig. 2b). PR or SD after RAI therapy was significantly more likely in patients with wild-type BRAF and TERT promoter genes (p = 0.024) (Fig. 2b). However, other combinations of genetic mutations were not correlated with RAI response.

Meta-analysis of TERT promoter mutation prevalence in thyroid cancer

Our study and 13 articles were included for the meta-analysis of TERT promoter mutation prevalence in various thyroid cancers [17, 18, 21, 24, 25, 32, 3743]. Significant heterogeneity was found in classic PTC, FTC, Hürthle cell carcinoma, and anaplastic carcinoma among the studies (Figs. 3 and 4). The mean frequencies of TERT promoter mutations in PTC, conventional FTC, Hürthle cell carcinoma, poorly differentiated carcinoma and anaplastic carcinoma were 11.3 % (95 % CI 9.3–13.5), 21.3 % (95 % CI 14.2–29.4), 6.7 % (95 % CI 0.2–21.4), 39.6 % (95 % CI 31.3–48.2), and 38.5 % (95 % CI 32.6–44.7), respectively (Figs. 3 and 4). When PTCs were stratified by histologic subtype, mean frequencies of TERT promoter mutations in classic, follicular, and tall cell variants were 8.8 % (95 % CI 6.8–11.1), 6.6 % (95 % CI 4.5–9.3), 27.5 % (95 % CI 21.0–34.7), respectively (Fig. 3). TERT promoter mutations were not found in a total of 132 medullary carcinoma patients including our case series [17, 21, 24, 25, 41].
Fig. 3

Forest plots of the meta-analysis for the prevalence of TERT promoter mutations in all papillary thyroid carcinomas (PTC), classic PTC (b), follicular variant of PTC (c), and tall cell variant of PTC (d). *Only TERT C228T was examined. TCGA, The Cancer Genome Atlas

Fig. 4

Forest plots of the meta-analysis for the prevalence of TERT promoter mutations in follicular thyroid carcinomas (a), Hürthle cell carcinoma (b), poorly differentiated carcinoma (c), and anaplastic carcinoma (d)

Discussion

We found that TERT promoter mutations are prevalent in aggressive thyroid cancers and are associated with distant metastasis of WDTCs in Korean patients with a high prevalence of the BRAF V600E mutation. When we examined TERT promoter mutations in a consecutive series of 192 WDTC patients who had no distant metastasis during the follow-up period, none carried the mutation. However, TERT promoter mutations were found in 40 % of WDTC patients with distant metastasis. In all 222 WDTC patients, the overall prevalence of TERT promoter mutations was 5.4 %. These results are lower than those reported in other countries. The prevalence of TERT promoter mutations reported in the literature ranged from 7.3 to 25.5 % in PTC and from 4.3 to 36.4 % in FTC [17, 18, 21, 24, 25, 32, 3743].

In our study, TERT promoter mutations were associated with older age, larger tumors, higher stage and distant metastases in WDTCs. These findings are consistent with those of previous reports indicating that TERT promoter mutations are associated with aggressive clinical behavior [21, 24]. In the stratified meta-analysis by histologic subtype of PTC, we found that the prevalence of TERT promoter mutations was correlated with the degree of tumor aggressiveness. The tall cell variant of PTC exhibits more aggressive behavior than classic PTC [27, 33], while clinical features of the follicular variant of PTC are between classic PTC and FTC [44]. The TERT promoter mutations were most frequently found in tall cell variant (27.5 %, 95 % CI 21.0–34.7), followed by classic PTC (8.8 %, 95 % CI 6.8–11.1) and follicular variant (6.6 %, 95 % CI 4.5–9.3). These results are consistent with findings of present study.

Many studies have shown the role of BRAF V600E in advanced clinical stage and distant metastasis of PTC [7, 45]. In contrast, we found that the BRAF V600E status was inversely correlated with the rate of distant metastasis in WDTCs. This contradiction may be related to case selection bias. Of 30 metastatic tumors enrolled in our study, 20 % included follicular and diffuse sclerosing variants of PTC and FTCs, which were all negative for the BRAF V600E mutation. It is well-known that the incidence of BRAF V600E is very low in the follicular and diffuse sclerosing variants of PTC, and no FTCs have the BRAF V600E mutation [11, 34, 46].

In our study, the BRAF V600E mutation was significantly associated with low response rate of metastatic WDTCs to RAI therapy. These results are consistent with previous studies that have demonstrated high frequency of BRAFV600E mutation in RAI-refractory metastatic thyroid cancers [1, 47]. However, there was no significant effect of TERT promoter mutations on distant metastasis of WDTCs. The most likely mechanism of resistance to RAI therapy is the impaired iodide-handling machinery in metastatic thyroid cancer [1]. Many studies have reported that BRAFV600E mutation reduces the expression of thyroid iodine-handling genes (sodium iodide symporter, thyroid-stimulating hormone receptor, thyroglobulin, and thyroperoxidase) in thyroid cancer [1, 47, 48]. However, mechanism underlying the RAI therapy resistance associated with TERT promoter mutations remains uncertain. Xing et al reported that coexisting BRAF V600E and TERT C228T mutations defined the most aggressive subgroup of PTC when analyzed in terms of clinicopathologic features, tumor recurrence and disease-free survival rate [18]. We did not observe this trend in our study (data not shown).

Two TERT C228T and C250T mutations create consensus binding motifs for the E-twenty-six (ETS)/ternary complex transcription factor (TCF) and increase the transcriptional activity of the TERT promoter [19, 23]. TERT promoter mutations in thyroid cancer and glioma were associated with increased mRNA expression and telomerase activity [17, 49]. BRAF V600E and TERT promoter mutations can activate the mitogen-activated protein kinase (MAPK) signaling pathway in thyroid cancer [21]. In previous studies, TERT promoter mutations were more frequently found in BRAF V600E mutation-positive PTCs, suggesting an incremental and synergistic effect of the coexisting two mutations in tumorigenesis [18, 21]. In our study, the TERT promoter mutation status was not associated with the incidence of the BRAF V600E mutation. These discrepancies may be associated with ethnic differences given that there is a higher prevalence of the BRAF V600E mutation and lower occurrence of TERT promoter mutations in Korean patients than in Western patients. Therefore, our study results cannot be generalized to other populations.

We found no TERT promoter mutations in medullary carcinoma. This finding is consistent with previous reports [21, 24]. Moreover, TERT promoter mutations were not found in benign thyroid nodules, whereas they were more prevalent in poorly differentiated or anaplastic carcinomas than in WDTCs [21, 24]. Therefore, it is suggested that TERT promoter mutations are involved only in the tumorigenesis of follicular-cell derived thyroid cancers, particularly in aggressive subtypes, and may occur as a late molecular-genetic event that induces dedifferentiation of WDTCs [21].

ALK gene rearrangements are mutually exclusive with all other known thyroid cancer driver mutations and have been reported in up to 2.2 % of PTCs, 4 % of poorly differentiated carcinomas, and 4 % of anaplastic carcinomas [26, 28, 32]. In our study, ALK rearrangement was not identified in any thyroid cancers.

The main limitations of our study were the relatively small sample size of metastatic cancers and the short follow-up period. Although the analyses for disease recurrence and survival of patients were not available, we could evaluate the therapeutic response to RAI based on the distant metastatic disease genotypes. We report for the first time the clinical impact of TERT promoter mutations on thyroid cancers that occur in a BRAF V600E prevalent area.

Conclusions

Our study demonstrated that Korean patients have a higher BRAF V600E prevalence and lower prevalence of the TERT promoter mutation and ALK rearrangement in thyroid cancers than do Western patients. TERT promoter mutation is associated with aggressive clinicopathologic features and is a strong predictor of distant metastasis of WDTC. In Korea, the BRAF V600E-negative WDTCs more frequently develop distant metastasis than BRAF V600E-positive tumors. When WDTC patients develop distant metastases, RAI therapy is most effective in patients without BRAF V600E and TERT promoter mutations. Further prospective evaluation that includes a larger sample size is needed.

Abbreviations

CI: 

confidence interval

CR: 

complete remission

FISH: 

fluorescence in situ hybridization

FTC: 

follicular thyroid carcinoma

MAPK: 

mitogen-activated protein kinase

PD: 

progressive disease

PR: 

partial response

PTC: 

papillary thyroid carcinoma

RAI: 

radioactive iodine

SD: 

stable disease

WDTC: 

well-differentiated thyroid carcinoma

Declarations

Acknowledgement

This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and future planning (2013R1A2A2A01068570).

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Authors’ Affiliations

(1)
Department of Surgery, College of Medicine, The Catholic University of Korea
(2)
Department of Hospital Pathology, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea
(3)
Department of Biomedicine & Health Sciences, College of Medicine, The Catholic University of Korea
(4)
Department of Internal Medicine, College of Medicine, The Catholic University of Korea

References

  1. Xing M. Molecular pathogenesis and mechanisms of thyroid cancer. Nat Rev Cancer. 2013;13(3):184–99. doi:10.1038/nrc3431.PubMed CentralView ArticlePubMedGoogle Scholar
  2. Jemal A, Bray F, Center MM, Ferlay J, Ward E, Forman D. Global cancer statistics. CA Cancer J Clin. 2011;61(2):69–90. doi:10.3322/caac.20107.View ArticlePubMedGoogle Scholar
  3. Toniato A, Boschin I, Casara D, Mazzarotto R, Rubello D, Pelizzo M. Papillary thyroid carcinoma: factors influencing recurrence and survival. Ann Surg Oncol. 2008;15(5):1518–22. doi:10.1245/s10434-008-9859-4.View ArticlePubMedGoogle Scholar
  4. Mazzaferri EL, Jhiang SM. Long-term impact of initial surgical and medical therapy on papillary and follicular thyroid cancer. Am J Med. 1994;97(5):418–28.View ArticlePubMedGoogle Scholar
  5. Tuttle RM, Ball DW, Byrd D, Dilawari RA, Doherty GM, Duh QY, et al. Thyroid carcinoma. J Natl Compr Canc Netw. 2010;8(11):1228–74.PubMedGoogle Scholar
  6. Melck AL, Yip L, Carty SE. The utility of BRAF testing in the management of papillary thyroid cancer. Oncologist. 2010;15(12):1285–93. doi:10.1634/theoncologist.2010-0156.PubMed CentralView ArticlePubMedGoogle Scholar
  7. Kim TH, Park YJ, Lim JA, Ahn HY, Lee EK, Lee YJ, et al. The association of the BRAF(V600E) mutation with prognostic factors and poor clinical outcome in papillary thyroid cancer: a meta-analysis. Cancer. 2012;118(7):1764–73. doi:10.1002/cncr.26500.View ArticlePubMedGoogle Scholar
  8. Xing M, Haugen BR, Schlumberger M. Progress in molecular-based management of differentiated thyroid cancer. Lancet. 2013;381(9871):1058–69. doi:10.1016/S0140-6736(13)60109-9.PubMed CentralView ArticlePubMedGoogle Scholar
  9. Kim TY, Kim WB, Song JY, Rhee YS, Gong G, Cho YM, et al. The BRAF mutation is not associated with poor prognostic factors in Korean patients with conventional papillary thyroid microcarcinoma. Clin Endocrinol (Oxf). 2005;63(5):588–93. doi:10.1111/j.1365-2265.2005.02389.x.View ArticleGoogle Scholar
  10. Fukushima T, Suzuki S, Mashiko M, Ohtake T, Endo Y, Takebayashi Y, et al. BRAF mutations in papillary carcinomas of the thyroid. Oncogene. 2003;22(41):6455–7. doi:10.1038/sj.onc.1206739.View ArticlePubMedGoogle Scholar
  11. Cho U, Oh WJ, Bae JS, Lee S, Lee YS, Park GS, et al. Clinicopathological features of rare BRAF mutations in Korean thyroid cancer patients. J Korean Med Sci. 2014;29(8):1054–60. doi:10.3346/jkms.2014.29.8.1054.PubMed CentralView ArticlePubMedGoogle Scholar
  12. Xing M. BRAF mutation in thyroid cancer. Endocr Relat Cancer. 2005;12(2):245–62. doi:10.1677/erc.1.0978.View ArticlePubMedGoogle Scholar
  13. Xing M, Westra WH, Tufano RP, Cohen Y, Rosenbaum E, Rhoden KJ, et al. BRAF mutation predicts a poorer clinical prognosis for papillary thyroid cancer. J Clin Endocrinol Metab. 2005;90(12):6373–9. doi:10.1210/jc.2005-0987.View ArticlePubMedGoogle Scholar
  14. Davies H, Bignell GR, Cox C, Stephens P, Edkins S, Clegg S, et al. Mutations of the BRAF gene in human cancer. Nature. 2002;417(6892):949–54. doi:10.1038/nature00766.View ArticlePubMedGoogle Scholar
  15. Nam JK, Jung CK, Song BJ, Lim DJ, Chae BJ, Lee NS, et al. Is the BRAF(V600E) mutation useful as a predictor of preoperative risk in papillary thyroid cancer? Am J Surg. 2012;203(4):436–41. doi:10.1016/j.amjsurg.2011.02.013.View ArticlePubMedGoogle Scholar
  16. Ito Y, Yoshida H, Maruo R, Morita S, Takano T, Hirokawa M, et al. BRAF mutation in papillary thyroid carcinoma in a Japanese population: its lack of correlation with high-risk clinicopathological features and disease-free survival of patients. Endocr J. 2009;56(1):89–97.View ArticlePubMedGoogle Scholar
  17. Vinagre J, Almeida A, Populo H, Batista R, Lyra J, Pinto V, et al. Frequency of TERT promoter mutations in human cancers. Nat Commun. 2013;4:2185. doi:10.1038/ncomms3185.View ArticlePubMedGoogle Scholar
  18. Xing M, Liu R, Liu X, Murugan AK, Zhu G, Zeiger MA, et al. BRAF V600E and TERT promoter mutations cooperatively identify the most aggressive papillary thyroid cancer with highest recurrence. J Clin Oncol. 2014;32(25):2718–26. doi:10.1200/JCO.2014.55.5094.PubMed CentralView ArticlePubMedGoogle Scholar
  19. Horn S, Figl A, Rachakonda PS, Fischer C, Sucker A, Gast A, et al. TERT promoter mutations in familial and sporadic melanoma. Science. 2013;339(6122):959–61. doi:10.1126/science.1230062.View ArticlePubMedGoogle Scholar
  20. Liu X, Wu G, Shan Y, Hartmann C, von Deimling A, Xing M. Highly prevalent TERT promoter mutations in bladder cancer and glioblastoma. Cell Cycle. 2013;12(10):1637–8. doi:10.4161/cc.24662.PubMed CentralView ArticlePubMedGoogle Scholar
  21. Liu X, Bishop J, Shan Y, Pai S, Liu D, Murugan AK, et al. Highly prevalent TERT promoter mutations in aggressive thyroid cancers. Endocr Relat Cancer. 2013;20(4):603–10. doi:10.1530/erc-13-0210.PubMed CentralView ArticlePubMedGoogle Scholar
  22. Killela PJ, Reitman ZJ, Jiao Y, Bettegowda C, Agrawal N, Diaz Jr LA, et al. TERT promoter mutations occur frequently in gliomas and a subset of tumors derived from cells with low rates of self-renewal. Proc Natl Acad Sci U S A. 2013;110(15):6021–6. doi:10.1073/pnas.1303607110.PubMed CentralView ArticlePubMedGoogle Scholar
  23. Huang FW, Hodis E, Xu MJ, Kryukov GV, Chin L, Garraway LA. Highly recurrent TERT promoter mutations in human melanoma. Science. 2013;339(6122):957–9. doi:10.1126/science.1229259.PubMed CentralView ArticlePubMedGoogle Scholar
  24. Melo M, da Rocha AG, Vinagre J, Batista R, Peixoto J, Tavares C, et al. TERT promoter mutations are a major indicator of poor outcome in differentiated thyroid carcinomas. J Clin Endocrinol Metab. 2014;99(5):E754–65. doi:10.1210/jc.2013-3734.PubMed CentralView ArticlePubMedGoogle Scholar
  25. Liu T, Wang N, Cao J, Sofiadis A, Dinets A, Zedenius J, et al. The age- and shorter telomere-dependent TERT promoter mutation in follicular thyroid cell-derived carcinomas. Oncogene. 2014;33(42):4978–84. doi:10.1038/onc.2013.446.View ArticlePubMedGoogle Scholar
  26. Chou A, Fraser S, Toon CW, Clarkson A, Sioson L, Farzin M, et al. A detailed clinicopathologic study of ALK-translocated papillary thyroid carcinoma. Am J Surg Pathol. 2015;39(5):652–9. doi:10.1097/pas.0000000000000368.PubMed CentralView ArticlePubMedGoogle Scholar
  27. Demeure MJ, Aziz M, Rosenberg R, Gurley SD, Bussey KJ, Carpten JD. Whole-genome sequencing of an aggressive BRAF wild-type papillary thyroid cancer identified EML4-ALK translocation as a therapeutic target. World J Surg. 2014;38(6):1296–305. doi:10.1007/s00268-014-2485-3.View ArticlePubMedGoogle Scholar
  28. Kelly LM, Barila G, Liu P, Evdokimova VN, Trivedi S, Panebianco F, et al. Identification of the transforming STRN-ALK fusion as a potential therapeutic target in the aggressive forms of thyroid cancer. Proc Natl Acad Sci U S A. 2014;111(11):4233–8. doi:10.1073/pnas.1321937111.PubMed CentralView ArticlePubMedGoogle Scholar
  29. Park G, Kim TH, Lee HO, Lim JA, Won JK, Min HS, et al. Standard immunohistochemistry efficiently screens for anaplastic lymphoma kinase rearrangements in differentiated thyroid cancer. Endocr Relat Cancer. 2015;22(1):55–63. doi:10.1530/erc-14-0467.View ArticlePubMedGoogle Scholar
  30. Perot G, Soubeyran I, Ribeiro A, Bonhomme B, Savagner F, Boutet-Bouzamondo N, et al. Identification of a recurrent STRN/ALK fusion in thyroid carcinomas. PLoS One. 2014;9(1):e87170. doi:10.1371/journal.pone.0087170.PubMed CentralView ArticlePubMedGoogle Scholar
  31. McFadden DG, Dias-Santagata D, Sadow PM, Lynch KD, Lubitz C, Donovan SE, et al. Identification of oncogenic mutations and gene fusions in the follicular variant of papillary thyroid carcinoma. J Clin Endocrinol Metab. 2014;99(11):E2457–62. doi:10.1210/jc.2014-2611.PubMed CentralView ArticlePubMedGoogle Scholar
  32. Network TCGAR. Integrated genomic characterization of papillary thyroid carcinoma. Cell. 2014;159(3):676–90. doi:10.1016/j.cell.2014.09.050.View ArticleGoogle Scholar
  33. Oh WJ, Lee YS, Cho U, Bae JS, Lee S, Kim MH, et al. Classic papillary thyroid carcinoma with tall cell features and tall cell variant have similar clinicopathologic features. Korean J Pathol. 2014;48(3):201–8. doi:10.4132/KoreanJPathol.2014.48.3.201.PubMed CentralView ArticlePubMedGoogle Scholar
  34. Jung CK, Im SY, Kang YJ, Lee H, Jung ES, Kang CS, et al. Mutational patterns and novel mutations of the BRAF gene in a large cohort of Korean patients with papillary thyroid carcinoma. Thyroid. 2012;22(8):791–7. doi:10.1089/thy.2011.0123.View ArticlePubMedGoogle Scholar
  35. Liu T, Brown TC, Juhlin CC, Andreasson A, Wang N, Backdahl M, et al. The activating TERT promoter mutation C228T is recurrent in subsets of adrenal tumors. Endocr Relat Cancer. 2014;21(3):427–34. doi:10.1530/erc-14-0016.PubMed CentralView ArticlePubMedGoogle Scholar
  36. Sabra MM, Dominguez JM, Grewal RK, Larson SM, Ghossein RA, Tuttle RM, et al. Clinical outcomes and molecular profile of differentiated thyroid cancers with radioiodine-avid distant metastases. J Clin Endocrinol Metab. 2013;98(5):E829–36. doi:10.1210/jc.2012-3933.PubMed CentralView ArticlePubMedGoogle Scholar
  37. Landa I, Ganly I, Chan TA, Mitsutake N, Matsuse M, Ibrahimpasic T, et al. Frequent somatic TERT promoter mutations in thyroid cancer: higher prevalence in advanced forms of the disease. J Clin Endocrinol Metab. 2013;98(9):E1562–6. doi:10.1210/jc.2013-2383.PubMed CentralView ArticlePubMedGoogle Scholar
  38. Liu X, Qu S, Liu R, Sheng C, Shi X, Zhu G, et al. TERT promoter mutations and their association with BRAF V600E mutation and aggressive clinicopathological characteristics of thyroid cancer. J Clin Endocrinol Metab. 2014;99(6):E1130–6. doi:10.1210/jc.2013-4048.PubMed CentralView ArticlePubMedGoogle Scholar
  39. Dettmer MS, Schmitt A, Steinert H, Capper D, Moch H, Komminoth P, et al. Tall cell papillary thyroid carcinoma: new diagnostic criteria and mutations in BRAF and TERT. Endocr Relat Cancer. 2015;22(3):419–29. doi:10.1530/erc-15-0057.View ArticlePubMedGoogle Scholar
  40. Gandolfi G, Ragazzi M, Frasoldati A, Piana S, Ciarrocchi A, Sancisi V. TERT promoter mutations are associated with distant metastases in papillary thyroid carcinoma. Eur J Endocrinol. 2015;172(4):403–13. doi:10.1530/eje-14-0837.View ArticlePubMedGoogle Scholar
  41. Muzza M, Colombo C, Rossi S, Tosi D, Cirello V, Perrino M, et al. Telomerase in differentiated thyroid cancer: promoter mutations, expression and localization. Mol Cell Endocrinol. 2015;399:288–95. doi:10.1016/j.mce.2014.10.019.View ArticlePubMedGoogle Scholar
  42. Qasem E, Murugan AK, Al-Hindi H, Xing M, Almohanna M, Alswailem M, et al. TERT promoter mutations in thyroid cancer: a report from a Middle Eastern population. Endocr Relat Cancer. 2015;22(6):901–8. doi:10.1530/erc-15-0396.View ArticlePubMedGoogle Scholar
  43. Shi X, Liu R, Qu S, Zhu G, Bishop J, Liu X, et al. Association of TERT promoter mutation 1,295,228 C > T with BRAF V600E mutation, older patient age, and distant metastasis in anaplastic thyroid cancer. J Clin Endocrinol Metab. 2015;100(4):E632–7. doi:10.1210/jc.2014-3606.View ArticlePubMedGoogle Scholar
  44. Yu XM, Schneider DF, Leverson G, Chen H, Sippel RS. Follicular variant of papillary thyroid carcinoma is a unique clinical entity: a population-based study of 10,740 cases. Thyroid. 2013;23(10):1263–8. doi:10.1089/thy.2012.0453.PubMed CentralView ArticlePubMedGoogle Scholar
  45. Hong AR, Lim JA, Kim TH, Choi HS, Yoo WS, Min HS, et al. The frequency and clinical implications of the BRAF(V600E) mutation in papillary thyroid cancer patients in Korea over the past two decades. Endocrinol Metab (Seoul). 2014;29(4):505–13. doi:10.3803/EnM.2014.29.4.505.View ArticleGoogle Scholar
  46. Pillai S, Gopalan V, Smith RA, Lam AK. Diffuse sclerosing variant of papillary thyroid carcinoma--an update of its clinicopathological features and molecular biology. Crit Rev Oncol Hematol. 2015;94(1):64–73. doi:10.1016/j.critrevonc.2014.12.001.View ArticlePubMedGoogle Scholar
  47. Zhang Z, Liu D, Murugan AK, Liu Z, Xing M. Histone deacetylation of NIS promoter underlies BRAF V600E-promoted NIS silencing in thyroid cancer. Endocr Relat Cancer. 2014;21(2):161–73. doi:10.1530/erc-13-0399.PubMed CentralView ArticlePubMedGoogle Scholar
  48. Yang K, Wang H, Liang Z, Liang J, Li F, Lin Y. BRAFV600E mutation associated with non-radioiodine-avid status in distant metastatic papillary thyroid carcinoma. Clin Nucl Med. 2014;39(8):675–9. doi:10.1097/rlu.0000000000000498.View ArticlePubMedGoogle Scholar
  49. Huang DS, Wang Z, He XJ, Diplas BH, Yang R, Killela PJ, et al. Recurrent TERT promoter mutations identified in a large-scale study of multiple tumour types are associated with increased TERT expression and telomerase activation. Eur J Cancer. 2015;51(8):969–76. doi:10.1016/j.ejca.2015.03.010.PubMed CentralView ArticlePubMedGoogle Scholar

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