TERT promoter mutations are emerging prognostic biomarkers in multiple cancers and are found in highly aggressive thyroid cancer. Our aim is to investigate the prognostic value of these mutations for the outcome of thyroid cancer-related mortality in a large cohort of thyroid cancer patients. This was a retrospective study of 409 patients (393 with differentiated thyroid cancer) with a median age of 44 years (range 16–81 years) and median follow-up of 13 years (interquartile range 11–16 years). Analyses of associations between mutational status and various clinicopathological variables were performed. TERT promoter mutations were identified in 32 (9.8%) papillary, 11 (16.7%) follicular and seven (43.8%) poorly differentiated/anaplastic thyroid cancer patients. The presence of TERT promoter mutations was associated with factors such as increased age (P < 0.001), extrathyroidal invasion (P = 0.01), increased stage at diagnosis (P < 0.001) and dedifferentiated histological type (P = 0.001). A TERT promoter mutation was independently associated with poorer overall survival in patients with differentiated thyroid cancer (10-year survival rate, 66.2% vs 98.3% for wild type; adjusted HR, 7.18; 95% CI: 2.77–18.59) and in patients with papillary cancer (74.2% vs 99.3%; 14.20; 3.03–66.68). Concomitant TERT and BRAF mutations worsened the survival rate of patients with papillary cancer (82.6% vs 99.4% for exclusively BRAF mutation alone; 5.62; 1.85–17.09). In conclusion, the presence of TERT promoter mutations is independently associated with increased mortality in patients with differentiated thyroid cancer. The results suggest that inclusion of TERT promoter mutation analysis with conventional clinicopathological evaluation can lead to better prognostication and management for individual patients.
Tae Hyuk Kim, Young-Eun Kim, Soomin Ahn, Ji-Youn Kim, Chang-Seok Ki, Young Lyun Oh, Kyunga Kim, Jae Won Yun, Woong-Yang Park, Jun-Ho Choe, Jung-Han Kim, Jee Soo Kim, Sun Wook Kim, and Jae Hoon Chung
Soomin Ahn, Tae Hyuk Kim, Sun Wook Kim, Chang Seok Ki, Hye Won Jang, Jee Soo Kim, Jung Han Kim, Jun-Ho Choe, Jung Hee Shin, Soo Yeon Hahn, Young Lyun Oh, and Jae Hoon Chung
PD-L1 expression is being considered a potential biomarker for response of anti-PD-1 or anti-PD-L1 agents in various tumors. The reported frequency of PD-L1 positivity varies in thyroid carcinomas, and multiple factors may contribute to the variability in PD-L1 positivity. We evaluated the PD-L1 expression in various thyroid cancers on a large scale. A total of 407 primary thyroid cancers with a median 13.7-year of follow-up were included. We evaluated the frequency of PD-L1 expression using a rabbit monoclonal antibody (clone SP142). In addition, we analyzed the relationships between PD-L1 expression and clinicopathologic factors, including TERT promoter, BRAF status and disease progression. Tumoral PD-L1 was expressed in 6.1% of papillary thyroid carcinomas, 7.6% of follicular thyroid carcinomas and 22.2% of anaplastic thyroid carcinomas. The distribution of PD-L1 positivity was different according to cancer histology types (P < 0.001). All PD-L1-positive cases of follicular thyroid carcinoma and anaplastic thyroid carcinoma showed strong intensity. The proportions of positivity in PD-L1 positive anaplastic thyroid carcinomas were more than 80%. PD-L1 in immune cells was positive in 28.5% of papillary thyroid carcinoma, 9.1% of follicular thyroid carcinomas and 11.1% of anaplastic thyroid carcinomas. There was no significant association between clinicopathologic variables, disease progression, oncogenic mutation and PD-L1 expression. PD-L1 was highly expressed in a subset of patients with advanced thyroid cancer, such as follicular and anaplastic thyroid carcinoma. Identification of PD-L1 expression may have direct therapeutic relevance to patients with refractory thyroid cancer.
Kyungmin Lee, Sang-Hyun Lee, Wooil Kim, Jangwook Lee, Jong-Gil Park, Jang-Seong Kim, Jung Tae Kim, Yea Eun Kang, Minho Shong, Hyo Jin Lee, Jin-Man Kim, Won Gu Kim, Bon Seok Koo, Koon Soon Kim, and Jeong-Ki Min
Anaplastic thyroid cancer (ATC) is a rapidly growing, highly metastatic cancer with limited therapeutic alternatives, thus targeted therapies need to be developed. This study aimed to examine desmoglein 2 (Dsg2) expression in ATC and its biological role and potential as a therapeutic target in ATC. Consequently, Dsg2 was downregulated or aberrantly expressed in ATC tissues. ATC patients with low Dsg2 expression levels also presented with distant metastasis. Dsg2 depletion significantly increased cell migration and invasion, with a relatively limited effect on ATC cell proliferation in vitro and increased distant metastasis in vivo. Dsg2 knockdown induced cell motility through the hepatocyte growth factor receptor (HGFR, c-Met)/Src/Rac1 signaling axis, with no alterations in the expression of EMT-related molecules. Further, specific targeting of c-Met significantly inhibited the motility of shDsg2-depleted ATC cells. Decreased membrane Dsg2 expression increased the metastatic potential of ATC cells. These results indicate that Dsg2 plays an important role in ATC cell migration and invasiveness. Therapies targeting c-Met might be effective among ATC patients with low membrane Dsg2 expression levels, indicating that the analysis of Dsg2 expression potentially provides novel insights into treatment strategies for ATC.
Seog Yun Park, Yuh-S Jung, Chang Hwan Ryu, Chang Yoon Lee, You Jin Lee, Eun Kyung Lee, Seok-Ki Kim, Tae Sung Kim, Tae Hyun Kim, Jeyun Jang, Daeyoon Park, Seung Myung Dong, Jae-Goo Kang, Jin Soo Lee, and Junsun Ryu
We undertook this study to estimate an accurate incidence and spread patterns of occult papillary thyroid carcinoma (PTC) in patients with a preoperative diagnosis of solitary PTC by using whole-specimen mapping of all specimens after a total thyroidectomy. Enrolled prospectively in this whole-thyroid mapping study are 82 consecutive patients who underwent a total thyroidectomy under a preoperative diagnosis of solitary PTC. All thyroidectomy specimens were serially sectioned in 2 mm thickness and whole-thyroid mapping was carried out for additional foci of occult PTC. The frequencies of occult lesions detected in the whole and contralateral lobe were determined, and clinicopathologic factors associated with multifocality were assessed. Whole-thyroid mapping revealed 66 occult PTC lesions missed by preoperative ultrasound in 37 (45.1%) of the 82 patients. The great majority (92.5%) of the occult PTC was smaller than 3 mm in size and 25 patients (30.5%) had contralateral lesions. We found that the male sex was an independent predictor of multifocality (odds ratio (OR), 3.00; 95% CI, 1.11–8.14), adjusting for preoperative findings. Analysis with pathologic parameters showed that the male sex (OR, 5.03; 95% CI, 1.68–15.08) and extrathyroidal extensions (OR, 3.03; 95% CI, 1.03–8.95) were associated with multifocal PTC. However, none of the clinicopathologic factors evaluated predicted contralateral PTC. Our study demonstrates the diagnostic limitations of ultrasound for the detection of multifocal PTC and the need to consider the possibility of occult lesions in the management of solitary PTC, especially in male patients.
Gahee Park, Tae Hyuk Kim, Hae-Ock Lee, Jung Ah Lim, Jae-Kyung Won, Hye Sook Min, Kyu Eun Lee, Do Joon Park, Young Joo Park, and Woong-Yang Park
The anaplastic lymphoma kinase (ALK) gene is frequently rearranged in various types of cancer and is highly responsive to targeted therapeutics. We developed a system to detect rearrangement of ALK in a large group of Korean thyroid cancer patients. We screened 474 malignant or benign thyroid tumor cases to identify ALK fusions. Expression and translocation of the ALK gene were analyzed by immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and digital multiplexed gene expression (DMGE) analysis in formalin-fixed paraffin-embedded tissues. Four cases of rearrangement of ALK were detected by IHC, and these cases were validated with FISH on 189 samples. On the other hand, DMGE analysis using Nanostring detected three out of four IHC-positive cases. Two rearrangements of ALK were striatin (STRN)–ALK fusions, which were identified by 5′ RACE analysis. Rearrangements of ALK were found exclusively in v-raf murine sarcoma viral oncogene homolog B (BRAF) WT papillary carcinomas. Given the wide availability and accuracy of IHC for detecting ectopic expression of ALK in the thyroid, we suggest that IHC-based screening can be a practical method for identifying patients with ALK rearrangements in differentiated thyroid cancer.