Malignancy In Thymic Epithelial Tumors Research Articles

Predicting the Risk of Thymic Tumors Using Texture Analysis of Contrast-Enhanced Chest Computed Tomography.

This study aimed to explore the value of contrast-enhanced computed tomography texture features for predicting the risk of malignant thymic epithelial tumor. Data of 97 patients with pathologically confirmed thymic epithelial tumors treated at in our hospital from March 2015 to October 2021 were retrospectively analyzed. Based on the World Health Organization classification of thymic epithelial tumors, patients were divided into a high-risk group (types B2, B3, and C; n = 45) and a low-risk group (types A, AB, and B1; n = 52). Texture analysis was performed using a first-order, gray-level histogram method. Six features were evaluated: mean, variance, skewness, kurtosis, energy, and entropy. The association between contrast-enhanced computed tomography texture features and the risk of malignancy in thymic epithelial tumors was analyzed. The predictive thresholds of predictive texture features were determined by receiver operating characteristics analysis. The mean, skewness, and entropy were significantly greater in the high-risk group than in the low-risk group ( P < 0.05); however, variance, kurtosis, and energy were comparable in the two groups ( P > 0.05). The area under curve of mean, skewness, and entropy was 0.670, 0.760, and 0.880, respectively. The optimal cutoff value of entropy for predicting risk of malignancy was 7.74, with sensitivity, specificity, and accuracy of 80.0%, 80.0%, and 75%, respectively. Contrast-enhanced computed tomography texture features, especially entropy, may be a useful tool to predict the risk of malignancy in thymic epithelial tumors.

Value of 18F-FDG PET/computed tomography in predicting the simplified WHO grade of malignancy in thymic epithelial tumors.

To investigate the value of 18F-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) in predicting the simplified WHO grade of malignancy in thymic epithelial tumors. We retrospectively reviewed 81 patients with pathologically proven thymic epithelial tumors who underwent F-FDG PET/CT before surgical resection. Maximum standardized uptake value (SUVmax) and SUVmax/tumor size were measured on the primary lesion. A receiver operating characteristics (ROC) curve were performed for assessing the ability of F-FDG PET/CT as a predictor of the simplified WHO classification. There were 43 male patients (53.1%) and 38 female patients (46.9%), and the mean age was 55.6 ± 11.9 years. The mean tumor size was 53.2 ± 21.4 mm. There were 24 low-risk thymomas (29.6%) (A, AB, and B1), 29 high-risk thymomas (35.8%) (B2 and B3), and 28 thymic carcinomas (34.6%). The SUVmax and SUVmax/tumor size were found to be predictive factors that were useful to distinguish thymomas and thymic carcinomas, and area under the ROC curve were 0.820 and 0.691, respectively (P < 0.05), and the cutoff value for discriminating thymomas and thymic carcinomas was 5.34. In conclusion, a significant relationship was observed between SUVmax, SUVmax/tumor size and histological WHO classification of thymic epithelial tumors. F-FDG PET/CT may be useful for predicting the grade of malignancy in thymic epithelial.

Can 18F-FDG PET predict the grade of malignancy in thymic epithelial tumors? An evaluation of only resected tumors.

ObjectiveAlthough 18-fluorine fluorodeoxyglucose positron emission tomography (18F-FDG PET) is thought to be useful for predicting the histological grade of thymic epithelial tumors (TETs), it remains controversial. To date, just a few of many previous studies have included only resected cases. Therefore, we investigated 18F-FDG PET findings only in patients with resected TETs.Patients and methodsA total of 112 patients with TETs consisting of 92 thymomas and 20 thymic carcinomas (TCs), resected at two institutes (Shizuoka Cancer Center [Shizuoka] and National Cancer Center Hospital [Tokyo]) between October 2002 and December 2015, were evaluated. Spearman rank correlation coefficient was used to assess the association between the maximum standardized uptake value (SUVmax) in the tumor and both the histological subtype and tumor stage. The cutoff value of SUVmax for differentiating thymoma from TC was calculated.ResultsThe SUVmax was strongly related to both the World Health Organization (WHO) histological subtype and tumor stage based on the eighth edition of the tumor-node-metastasis (TNM) classification (Spearman rank correlation coefficient =0.485 and 0.432; p = 0.000 and 0.000, respectively). There was a significant difference between thymoma and TC. The optimal SUVmax cutoff value for differentiating thymoma from TC was 4.58 (sensitivity: 80% and specificity: 78.3%). In contrast, there was no significant difference between low-risk (type A, AB, and B1) and high-risk (type B2 and B3) thymoma, or between type B3 thymoma and the other subtypes.ConclusionOur results suggest that 18F-FDG PET is useful for differentiating thymoma from TC, but not for predicting the histologic grade of thymoma.

Value of 18F-FDG PET-CT in predicting the WHO grade of malignancy in thymic epithelial tumors

Objective To investigate the value of18F-FDG PET-CT in predicting the simplified WHO grade of malignancy in thymic epithelial tumors. Methods The 18F-FDG PET-CT imaging of forty-five patients with pathologically proven thymic epithelial tumors was analyzed retrospectively. The patients were subdivided into a low-risk group and a high-risk group based on the simplified WHO histological classification. Spearman rank correlation analysis was used to determine the relation between parameters of PET-CT and simplified WHO histological classification. An univariate logistic regression analysis and ROC curve were performed for assessing the ability of 18F-FDG PET-CT as a predictor of the simplified WHO classification. Results There were ten patients classified into low-risk group, and thirty-five patients classified into high-risk group. Both SUVmax and SUVmax / T showed significant relationship with patients subgroup (Spearman correlation coefficients were 0.577 and 0.621, respectively, P<0.000 1). The SUVmax and SUVmax /T were found to be predictive factors that were useful to distinguish high-risk tumor from low-risk tumor(area under the ROC curve were 0.888 and 0.917, respectively, P<0.000 1). Conclusions A significant relationship is observed between 18F-FDG PET-CT findings and histological WHO classification of thymic epithelial tumors. PET-CT may be useful for predicting the grad of malignancy in thymic epithelial tumors. Key words: Thymic epithelial tumors; Histological classification; Fluorodeoxyglucose F18; Positron-emission tomography

Expression of thymidylate synthase, orotate phosphoribosyltransferase and dihydropyrimidine dehydrogenase in thymic epithelial tumors

BackgroundIt remains unclear whether thymidylate synthase (TS), orotate phosphoribosyltransferase (OPRT) and dihydropyrimidine dehydrogenase (DPD) expressions are associated with the pathogenesis of thymic epithelial tumors. Therefore, we investigated the expression of TS, OPRT and DPD in thymic epithelial tumors. Patients and methodsFifty-six patients with thymic epithelial tumors were included in this study. Tumors sections were stained by immunohistochemistry for TS, OPRT, DPD, microvessel density (MVD) determined by CD34, and p53. We also conducted in vitro study of TS, OPRT and DPD expression using thymic carcinoma, thymic tumor and thymic fibroblast cell lines. ResultsTS, OPRT and DPD were expressed in 61%, 48% and 41%, respectively. High grade malignancy is significantly associated with higher expression of TS, OPRT and DPD in thymic epithelial tumors. These biomarkers were closely associated with p53 and MVD, and the overexpression of TS and DPD was a prognostic marker for predicting poor outcome in univariate analysis. Our in vitro study showed that marked overexpression of TS and OPRT was observed in thymic carcinoma cells, but not in thymic tumor cells, or thymic fibroblast cells. ConclusionsThe expression of TS, OPRT and DPD was closely related to the grade of malignancy in thymic epithelial tumors. A positive expression of TS, DPD and OPRT might be an important factor in predicting the effectiveness of 5-FU based chemotherapy in this disease.

Expression of Excision Repair Cross-Complementation Group 1, Breast Cancer Susceptibility 1, and β III-Tubulin in Thymic Epithelial Tumors

We investigated the clinical significance of excision repair cross-complementation group 1 (ERCC1), breast cancer susceptibility 1 (BRCA1), and class III β-tubulin (TUBB3) expression in thymic epithelial tumors. Fifty-six patients with thymic epithelial tumors were included in this study. Tumors sections were stained by immunohistochemistry for ERCC1, BRCA1, TUBB3, microvessel density, and p53. ERCC1, BRCA1, and TUBB3 were expressed in 48%, 50%, and 27%, respectively. The expression of ERCC1, BRCA1, and TUBB3 was significantly correlated with the grade of malignancy in thymic epithelial tumors. These biomarkers were closely associated with p53 and microvessel density and were a prognostic marker for predicting poor outcome. We also found that overexpression of ERCC1 and TUBB3 was associated with resistance to platinum- and taxane-based chemotherapy. An expression of ERCC1, BRCA1, and TUBB3 was correlated strongly with each other and was significantly associated with a poor outcome in thymic epithelial tumors. High-ERCC1 and TUBB3 expressions might be associated with resistance to platinum- and taxane-based chemotherapy, respectively.

MUC1 expression in thymic epithelial tumors: MUC1 may be useful marker as differential diagnosis between type B3 thymoma and thymic carcinoma

MUC1 is a transmembrane mucin that has been related to tumor progression and outcome in various malignancies. However, the clinical significance in thymic epithelial tumors remains unknown. We investigated the clinical significance of MUC1 expression in thymic epithelial tumors. Fifty-five patients with thymic epithelial tumors were included in this study. Tumors sections were stained by immunohistochemistry for MUC1, vascular endothelial growth factor (VEGF), microvessel density (MVD) determined by CD34, and p53. MUC1 were expressed in 29%. The expression of MUC1 was significantly correlated with the grade of malignancy in thymic epithelial tumors. MUC1 was closely associated with VEGF, p53 and MVD, and the overexpression of MUC1 was a prognostic marker for predicting poor outcome in univariate analysis. A positive rate of MUC1 expression was 94% (16/17) in thymic carcinomas and 0% (0/5) in type B3 thymomas, demonstrating a significant difference (p < 0.0001). The expression of MUC1 was closely related to the grade of malignancy in thymic epithelial tumors. A positive expression of MUC1 was significantly associated with poor outcome in this disease. MUC1 may be useful marker for differentiating thymic carcinoma from type B3 thymoma.

CD98 expression is associated with the grade of malignancy in thymic epithelial tumors

CD98 has been associated with tumor growth and is highly expressed in human neoplasms. The aim of this study was to evaluate the clinicopathological significance of CD98 expression in thymic epithelial tumors. Forty-nine patients with thymic epithelial tumors were included in this study. Tumor sections were stained by immunohistochemistry for CD98; vascular endothelial growth factor (VEGF); micro-vessels (CD31 and CD34); cell cycle control marker (p53); and apoptosis marker (Bcl-2). CD98 expression for low-risk thymomas, high-risk thymomas, and thymic carcinomas were 1 (4%) of 27, 9 (82%) of 11, and 11 (100%) of 11, respectively. There was positive correlation between CD98 and VEGF (p<0.001), microvessel density (CD31 and CD34) (p<0.001) and p53 (p<0.001). However, Bcl-2 showed no positive correlation with CD98 expression. The expression of CD98 were also significantly associated with the grade of malignancy in thymic epithelial tumors. Multivariate analysis revealed that overexpression of CD98 was a significant independent factor predicting a poor outcome in thymic epithelial tumors. CD98 expression was associated with the grade of malignancy in thymic epithelial tumors. Moreover, CD98 expression was closely correlated with angiogenesis and cell cycle control, and was useful for predicting poor outcome.

CD98 expression is associated with the grade of malignancy in thymic epithelial tumors

CD98 has been associated with tumor growth and is highly expressed in human neoplasms. The aim of this study was to evaluate the clinicopathological significance of CD98 expression in thymic epithelial tumors. Forty-nine patients with thymic epithelial tumors were included in this study. Tumor sections were stained by immunohistochemistry for CD98; vascular endothelial growth factor (VEGF); micro-vessels (CD31 and CD34); cell cycle control marker (p53); and apoptosis marker (Bcl-2). CD98 expression for low-risk thymomas, high-risk thymomas, and thymic carcinomas were 1 (4%) of 27, 9 (82%) of 11, and 11 (100%) of 11, respectively. There was positive correlation between CD98 and VEGF (p<0.001), microvessel density (CD31 and CD34) (p<0.001) and p53 (p<0.001). However, Bcl-2 showed no positive correlation with CD98 expression. The expression of CD98 were also significantly associated with the grade of malignancy in thymic epithelial tumors. Multivariate analysis revealed that overexpression of CD98 was a significant independent factor predicting a poor outcome in thymic epithelial tumors. CD98 expression was associated with the grade of malignancy in thymic epithelial tumors. Moreover, CD98 expression was closely correlated with angiogenesis and cell cycle control, and was useful for predicting poor outcome.

18FDG PET for grading malignancy in thymic epithelial tumors: Significant differences in 18FDG uptake and expression of glucose transporter-1 and hexokinase II between low and high-risk tumors: Preliminary study

To evaluate (18)F-fluorodeoxyglucose (FDG) uptake to predict the malignant nature and analyze the correlation between FDG uptake and expression of glucose transporter 1 (Glut-1) and hexokinase II (HK-II) in thymic epithelial tumors. Eleven patients with a thymic epithelial tumor who underwent FDG PET/CT before therapy were reviewed. The thymic tumors were classified by the WHO histological classification and Masaoka clinical staging. Comparison of maximum standardized uptake value (SUV(max)) of the lesion was made between the low-risk (Type A, AB and B1) and high-risk {Type B2, B3 and C (thymic cancer)} groups and among clinical stages. Expression of Glut-1 and HK-II was analyzed immunohistochemically. All 11 tumors showed FDG uptake visually. SUV(max) was significantly higher in the high-risk group (n=5, 5.24 ± 2.44) than the low-risk group (n=6, 3.05 ± 0.55) (P=0.008). Staining scores of both Glut-1 and HK-II were significantly higher in the high-risk group than in the low-risk group (Glut1: P=0.034 and HK-II: P=0.036). There were no significant differences in SUV(max) (P=0.11), Glut-1 (P=0.35) and HK-II scores (P=0.29) among clinical stages. SUV(max) was significantly correlated to each of the staining scores of Glut-1 (ρ=0.68, P=0.031) and HK-II (ρ=0.72, P=0.024). These preliminary results support the previously published view that SUV(max) may be useful to predict the malignant nature of thymic epitherial tumors and suggest that the degree of FDG uptake in the thymic epitherial tumors is closely related to the amount of Glut-1 and HK-II in the tumor.

Utility of 18FDG-PET for differentiating the grade of malignancy in thymic epithelial tumors

The objective of this study was to assess the value of (18)F-FDG PET in thymic epithelial tumors according to the WHO histologic classification and to evaluate its potential for differentiating the grade of malignancy in thymic epithelial tumors. Thirty-six patients with a thymic epithelial tumor who underwent (18)F-FDG PET examination before treatment were enrolled in the present study. The T/M ratio, which is the ratio of the peak standardized uptake value (SUV) of the tumor to the mean SUV of mediastinum, was compared in subgroups of a simplified WHO histological classification; low-risk thymoma (Types A, AB and B1), high-risk thymoma (Types B2 and B3), and thymic carcinoma. Tumors included 15 low-risk thymomas, 10 high-risk thymomas and 11 thymic carcinomas. Upon visual inspection, all tumors showed (18)F-FDG accumulation and the mean T/M ratio in these three subgroups was 2.64, 4.29 and 8.90, respectively. The differences between the three subgroups were statistically significant (low-risk vs. high-risk: p=0.01, high-risk vs. thymic carcinoma: p=0.01). A significant relationship was seen between (18)F-FDG PET accumulation and histologic subtype in thymic epithelial tumors when they were classified into three groups. PET may be useful for predicting the grade of malignancy in thymic epithelial tumors.