The classification of thymoma has always been controversial topil in recent years. It hasn’t been unified because of the morphological diversity of thymoma, the heterogeneity of tumour cells and the lack of simple and effective observation index. With the development of diagnostic technique and oncobiology research, several classification methods have been drawn off, including its World Health Organization(WHO) lassification. We reviewed the main classification and discussed the problems of each classification method and their clinical guiding significamce, summarized the development tendency, methods assist the classification and clinical research of thymoma.
Abstract： Objective To investigate the expression and correlation of phosphatase and tensin homologue deleted on chromosome ten(PTEN)， epidermal growth factor receptor(EGFR) and Ki-67 in human thymic tumors, and their possible role in tumor genesis， infiltration and metastasis. Methods The expression of PTEN， EGFR and Ki-67 were detected by using SP immunohistochemical technique in 45 cases of thymic tumors and 5 cases of normal thymic tissues. Results In 5 cases of normal thymic tissues, the expression of PTEN was bly positive, whereas EGFR and Ki -67 were weakly positive or negative. In 45 cases of thymic tumors, the positive ratio of PTEN were significantly reduced from benign thymoma， invasive thymoma to thymic carcinoma (χ2=7.808, P=0.020), but the positive ratio of EGFR and Ki-67 were gradually increased(χ2=8.032, 0.018，7.006；P=0.030). The positive ratio of PTEN， EGFR and Ki-67 protein were significantly related to Levine classification, Masaoka staging and lymph node metastasis (Plt;0.05). PTEN positive cases were negatively correlated with EGFR and Ki-67(r=－0.632，－0.653；Plt;0.01), EGFR positive cases were positively correlated with Ki-67 in thymic tumors(r=0.807,Plt;0.01). Conclusions Reduced or absent PTEN and increased EGFR and Ki-67 expression might play an important role in the genesis， invasiveness and metastasis of thymic tumors. The expression of PTEN is bly associated with the expression of abnormal EGFR and Ki-67. Detection of the three protein expressions simultaneously might be more helpful in making an early diagnosis of the tumors jndgement of theirs malignant degree，invasiveness and metastasis capacity, as well as the prognosis.
Objective To investigate and evaluate the clinical features, diagnostic methods, surgical management and postoperative adjuvant therapy of thymic carcinoma so as to improve the treatment outcome. Methods Forty-three patients of thymic carcinoma , surgically intervened and pathologically confirmed in Peking Union Medical College Hospital through June 1961 to June 2004, were retrospectively analysed. Complete resection of the tumor was performed in 15 patients, partial or incomplete expiration in 23 , exploratory thoracotomy and biopsy in 5. Results All tumors were found inencapsulated and invading the surroundings,including pericardium, superior vena cava, left or right innominate vein, rnediastinal pleura, phrenic nerve and lung. In this series there was no perioperative death. Eight patients died within the first year postoperatively, 4 died within the second year postoperatively, 2 and 1 patients died in the 5th and 8th year postoperatively respectively. Through half to 18 years follow-up, according to the life table method, the 1,3,5 and 8 year survival rate were 68.29%, 56. 67%, 41.56% and 27. 71% respectively. Conclusions Thymic carcinoma is different from malignant thymoma in clinical manifestations, radiological features, pathological characteristics and prognosis, hence it is very important for thoracic surgeons to pay more attention to those differentiation. Chest CT is an effective method for diagnosis of thymic carcinoma. It is emphasized on that aggressive radical resection of the tumor with involved tissue or organs, even removal of superior vena cava and subsequent reconstruction of vessel, will effectively extend long-term survival. Postoperative radiotherapy and combination adjuvant chemotherapy, especially based on cisplatin, play a significant role in improvement of prognosis.
Objective To evaluate the influence of resection status, pathological type, pathological stage and postoperative adjuvant therapy on prognosis of surgically treated thymic carcinoma. Methods In this retrospective study, 56 patients with surgically treated thymic carcinoma in the Department of Thoracic Surgery, Peking Union Medical College Hospital from January 2005 to December 2015 were enrolled. There were 30 males and 26 females aged 52.1±11.5 years ranging from 22 to 81 years. The survival curve was performed by Kaplan-Meier method. The prognostic factors affecting overall survival (OS) and disease-free survival (DFS) were analyzed by one-way analysis of variance (ANOVA). Results R0 resection was performed in 37 patients (67.9%), and other resections in 19 (32.1%); 13 patients suffered thymic carcinoma with Masaoka stage Ⅰ-Ⅱ, 26 Ⅲ, and 17 Ⅳ. Low-grade thymic carcinoma was found in 42 patients, and high-grade in 14. Postoperative radiotherapy, chemotherapy and chemoradiotherapy were performed on 17, 12 and 18 patients respectively and 9 patients were untreated. Forty-one patients was followed up for 1 to 10 years, and the follow-up rate was 73%. The 1-, 3- and 5-year OS rates were 93%, 74% and 61%, respectively. Resection status and pathological stage affected OS. Postoperative radiotherapy after R0 resection affected DFS, but did not affect OS. Conclusion Most patients with thymic carcinoma after surgery can survive for a long period, and R0 resection is the most important prognostic factor of thymic carcinoma. Postoperative radiotherapy after R0 resection in patients with Masaoka stage Ⅱ-Ⅲ is recommended.
ObjectiveTo evaluate the influence of clinical, pathological and treatment factors on the prognosis of thymic carcinoma patient accepted surgical treatment.MethodsRetrospective analysis was performed on 38 patients with thymic carcinoma undergoing surgical treatment between January 2008 and December 2017. The association between the prognostic factors including age, sex, thymectomy, radical resection, pathological type, TNM stage, Masaoka-Koga stage, tumor size, and survival was assessed using the Kaplan-Meier method.ResultsThe 5-year overall survival rate of our cohort was 51.9%. Kaplan-Meier univariate survival analysis showed that radical resection (P=0.003), TNM stage (P=0.038), Masaoka-Koga stage (P=0.033), and tumor size (P=0.030) were related to the prognosis of patients with thymic carcinoma. Radical resection was also validated as an independent prognostic factor in multivariate Cox analysis (P=0.009, hazard ratio 2.31, 95%CI 1.23-4.33).ConclusionRadical surgical treatment could improve the prognosis of patients with resectable thymic carcinoma.
Objective To examined gene mutations in thymic carcinoma (TC) patients and to explore prognostic correlates and potential targets for therapy. MethodsWe retrospectively included TC patients in Sichuan Cancer Hospital between January 2015 and Febuary 2021.Whole-exome sequencing was performed on tumor tissues from TC patients and their control peripheral blood samples, and the raw data were subjected to bioinformatics analysis and statistical analysis. Results We finally included 24 TC patients with 16 males and 8 females at a median age of 55 (42-74) years. The highest frequency of single nucleotide mutations in this cohort were in the TTN gene (42%), HSPG2 (29%), and OBSCN (29%). Higher frequency of copy number variations occurred in ZNF276 gene (54%, loss), BEND3 (50%, loss), DHODH (50%, loss), and VAC14 (50%, loss). Microsatellite instability (MSI) phenotype was found in 25% of the patients, and the mean tumor mutation burden (TMB) was 9.86. Conclusion This study is the first comprehensive analysis of the mutation profile of thymic carcinoma in China to date. The mutation frequencies of TTN, OBSCN, and ZNF276 genes were high. The biomarker analysis suggests that patients may benefit from immunotherapy and have a long effective survival.