Histogenetic and disease-relevant phenotypes in thymic epithelial tumors (TETs): The potential significance for future TET classification.

Thymic epithelial tumors (TETs) encompass morphologically various subtypes. Thus, it would be meaningful to explore the expression phenotypes that delineate each TET subtype or overarching multiple subtypes. If these profiles are related to thymic physiology, they will improve our biological understanding of TETs and may contribute to the establishment of a more rational TET classification. Against this background, pathologists have attempted to identify histogenetic features in TETs for a long time. As part of this work, our group has reported several TET expression profiles that are histotype-dependent and related to the nature of thymic epithelial cells (TECs). For example, we found that beta5t, a constituent of thymoproteasome unique to cortical TECs, is expressed mainly in type B thymomas, for which the nomenclature of cortical thymoma was once considered. Another example is the discovery that most thymic carcinomas, especially thymic squamous cell carcinomas, exhibit expression profiles similar to tuft cells, a recently discovered special type of medullary TEC. This review outlines the currently reported histogenetic phenotypes of TETs, including those related to thymoma-associated myasthenia gravis, summarizes their genetic signatures, and provides a perspective for the future direction of TET classification.

Surgical treatment of intermediate to high grade thymic neuroendocrine neoplasms: case series of five patients and literature review.

Background: Thymic neuroendocrine neoplasms (Th-NENs) are extremely rare. Th-NENs are divided into four pathological subtypes: typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC), and small cell carcinoma (SCC). The latter three subtypes are highly aggressive with poor prognosis. There are limited reports on the optimal surgical strategies for Th-NENs. This study aims to report a case series of Th-NENs after surgical treatment and review the literatures. Methods: We report a case series of five patients diagnosed with Th-NENs and summarize their clinical characteristics. Literatures related to surgical treatment of Th-NENs were reviewed. Results: There were three males and two females, and mean age was 53.6 years. No myasthenia gravis or neuroendocrine symptoms were found. Three patients were diagnosed with AC and the other two were diagnosed with LCNEC. Two patients were stage II-b, one patient was stage III-a, and two patients were stage IV-b. One patient received preoperative chemotherapy, one patient received preoperative chemoradiotherapy, and three patients underwent surgery directly. Two patients underwent extended thymectomy via video-assisted thoracoscopic surgery (VATS), two patients underwent extended thymectomy via median sternotomy, and one patient underwent resection of anterior mediastinal tumor, sternal metastases, superior vena cava and partial right atrium via median sternotomy and cardiopulmonary bypass. R0 resection was achieved in 80% (4/5) of patients. There was no postoperative 90-day complication and death. One patient had no recurrence. One patient had lymph node metastases and was still alive after somatostatin analogue therapy. One patient had no recurrence of Th-NENs but died of other tumors. Two patients had distant metastases. Median overall survival (mOS) was 49 (range, 4-134) months. A total of 22 original studies related to surgical treatment of Th-NENs were retrieved. Conclusions: Th-NENs is a very rare and extremely aggressive malignancy. Early diagnosis and surgical resection are the most important methods to improve prognosis. Radical resection and lymph node dissection are recommended for accurate staging and better prognosis. Currently, there are few clinical data on Th-NENs and several important surgical issues remain unresolved. In the future, multi-center, large-sample database and clinical studies are urgently needed to explore better treatment modality.

Factors predicting recurrence in thymic epithelial neoplasms.

OBJECTIVES: Thymic epithelial neoplasms (TENs) represent a heterogeneous group of rare thoracic malignancies. We analysed the clinicopathological features, survival outcomes, risk factors, and patterns of recurrence in patients undergoing resection. METHODS: Records were reviewed for adult patients with TEN who underwent resection from 2006 to 2019. Survival rates were assessed using the Kaplan-Meier method. Univariable and multivariable analyses were performed using the log-rank test and Cox proportional hazards model. RESULTS: A total of 100 patients were analysed (51 females, median age 58 years). Thymoma was the most common histology (n = 92), followed by thymic carcinoma (n = 5) and thymic neuroendocrine tumour (n = 3). Stage II (Masaoka) tumours were most common (n = 51), followed by stage I (n = 27). World Health Organization B2/B3 was the most prominent histological subtype (n = 34). Complete resection (R0) was achieved in 91 patients: 86/92 thymoma, 4/5 thymic carcinoma and 1/3 neuroendocrine tumour. The most common treatment modality was surgery alone in 72 patients, followed by surgery and radiation therapy in 24, and adjuvant chemoradiotherapy in 3 patients. Only one patient with thymic carcinoma received neoadjuvant chemotherapy. The 10-year overall and disease-free survival rates were 86.6% and 83.9%, respectively. Recurrence was most common in neuroendocrine tumours (3/3). Risk factors for recurrence identified on multivariable analyses were: R1/2 resection (hazard ratio 9.30; 95% confidence interval 1.82-36.1), TEN subtype (hazard ratio 8.08; 95% confidence interval 1.24-34.6), and presence of lymphovascular invasion (hazard ratio 9.56; 95% confidence interval 2.56-25.8). CONCLUSIONS: Complete resection remains critical in patients with TEN. Incomplete resection, high-risk histology, and lymphovascular invasion highlight the need for effective adjuvant modalities. Given the rarity of these diseases, emphasis must be placed on collaborative research conducted on TEN.

Robot-Assisted Thoracic Surgery Thymectomy.

Robotic thymectomy has been adopted recently and has been shown to be safe and feasible in treating thymic tumors and myasthenia gravis. The surgical indications of robotic technology are expanding, with advantages including an excellent surgical view and sophisticated manipulation. Herein, we describe technical aspects, considerations, and outcomes of robotic thymectomy.

[Chinese guideline for clinical diagnosis and treatment of thymic epithelial tumors (2021 Edition)].

Thymic tumor is a relatively rare type of thoracic cancer, which is pathologically-classified as thymic epithelial tumors by World Health Organization (WHO), including thymoma and thymic carcinoma. The incidence of thymic epithelial tumors in China is about 4.09 per million, which is slightly higher than that in European and American countries. For surgically-resectable thymic epithelial tumors, complete resection with or without postoperative radiotherapy or chemotherapy is preferred. For advanced unresectable disease, conventional radiotherapy and chemotherapy is the mainstream treatment but lack of standard first-line and second-line regimens. In recent years, targeted drugs and the immune checkpoint inhibitors have gradually exhibited certain therapeutic prospect in this subset of tumor. Since there was no guideline regarding thymic epithelial tumor released in China, Multidisciplinary Committee on Oncology, Chinese Physicians Association analyze, summarize and discuss the relevant research data for the diagnosis, treatment and prognosis of thymic epithelial tumors, and formulate the "Chinese guidelines for clinical diagnosis and treatment of thymic epithelial tumors (2021 Edition)" for clinicians' reference.

Role of modern neoadjuvant chemoradiotherapy in locally advanced thymic epithelial neoplasms.

PURPOSE: To improve resectability in patients with stage III-IVA thymic epithelial neoplasms, neoadjuvant chemotherapy and radiotherapy are considered. This retrospective study aimed to investigate the efficacy and safety of neoadjuvant therapies using modern techniques in thymic epithelial neoplasms. METHODS: We included 32 patients with Masaoka stage III-IV disease treated at our institution from January 2010 to December 2017. Data regarding clinicopathologic characteristics, treatment protocols, toxicities, and survival were collected. Response was evaluated according to the Response Evaluation Criteria in Solid Tumours 1.1. Survival was assessed using the Kaplan-Meier method. Adverse events were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. RESULTS: Neoadjuvant radiotherapy alone, chemotherapy alone, sequence chemoradiotherapy, and concurrent chemoradiotherapy were administered to 10 (31.3%), 9 (28.1%), 3 (9.4%), and 10 (31.3%) patients, respectively. Twenty-nine patients (90.6%) underwent R0 resection. The median follow-up time was 38.0 months (3.3-109.5 months). After neoadjuvant therapy, 18 patients (56.3%) achieved partial response and 14 (43.8%) had stable disease. Pathologic complete response was achieved in 6 patients (18.8%), all of whom had thymic carcinoma. The 5-year overall and progression-free survival rates were 90.9% and 67.5%, respectively. For patients with thymic carcinoma, the 5-year overall and progression-free survival rates were 80.0% and 66.2%, respectively. Grade 3 toxicities were observed in only 1 patient (leukopenia). CONCLUSIONS: For patients with primary unresectable thymic neoplasms, neoadjuvant chemoradiotherapy is an efficient and safe choice, with favorable response and survival and moderate toxicities. Patients with thymic carcinoma might benefit more from neoadjuvant therapies.

Chinese guideline for clinical diagnosis and treatment of thymic epithelial tumors (2021 Edition) / 中华肿瘤杂志

Thymic tumor is a relatively rare type of thoracic cancer, which is pathologically-classified as thymic epithelial tumors by World Health Organization (WHO), including thymoma and thymic carcinoma. The incidence of thymic epithelial tumors in China is about 4.09 per million, which is slightly higher than that in European and American countries. For surgically-resectable thymic epithelial tumors, complete resection with or without postoperative radiotherapy or chemotherapy is preferred. For advanced unresectable disease, conventional radiotherapy and chemotherapy is the mainstream treatment but lack of standard first-line and second-line regimens. In recent years, targeted drugs and the immune checkpoint inhibitors have gradually exhibited certain therapeutic prospect in this subset of tumor. Since there was no guideline regarding thymic epithelial tumor released in China, Multidisciplinary Committee on Oncology, Chinese Physicians Association analyze, summarize and discuss the relevant research data for the diagnosis, treatment and prognosis of thymic epithelial tumors, and formulate the "Chinese guidelines for clinical diagnosis and treatment of thymic epithelial tumors (2021 Edition)" for clinicians' reference.

Interdisciplinarity: An essential requirement for translation of radiomics research into clinical practice -a systematic review focused on thoracic oncology. / Interdisciplinaridad: un requerimiento esencial para la traslación de investigación en radiómica a la práctica clínica.

BACKGROUND: Recently, evidence has accumulated that demonstrates the potential for future applications of radiomics in many clinical settings, including thoracic oncology. Methodological reasons for the immaturity of image mining (radiomics and artificial intelligence-based) studies have been identified. However, data on the influence of the composition of the research team on the quality of investigations in radiomics are lacking. AIM: This review aims to evaluate the interdisciplinarity within studies on radiomics in thoracic oncology in order to assess its influence on the quality of research (QUADAS-2 score) in the image mining field. METHODS: We considered for inclusion radiomics investigations with objectives relating to clinical practice in thoracic oncology. Subsequently, we interviewed the corresponding authors. The field of expertise and/or educational degree was then used to assess interdisciplinarity. Subsequently, all studies were evaluated applying the QUADAS-2 score and assigned to a research phase from 0 to IV. RESULTS: Overall, 27 studies were included. The study quality according to the QUADAS-2 score was low (score ≤5) in 8, moderate (=6) in 12, and high (≥7) in 7 papers. An interdisciplinary team (at least 3 different expertise categories) was involved in half of the papers without any type of validation and in all papers with independent validation. Clinicians were not involved in phase 0 studies while they contributed to all papers classified as phase I and to 4/5 papers classified as phase II with independent validation. CONCLUSIONS: The composition of the research team influences the quality of investigations in radiomics. Also, growth in interdisciplinarity appears to reflect research development from the early phase to a more mature, clinically oriented stage of investigation.

Micronodular thymoma with lymphoid stroma: report of two cases and review of literature.

Micronodular thymoma with lymphoid stroma (MNT) is a rare subtype of organoid thymic epithelial tumor that occurs in middle-aged and elderly people. Histologically, MNT is characterized by multiple epithelial nodules that are scattered or fused and abundant lymphocyte stroma with prominent germinal centers. It has a benign course and a good prognosis, and its diagnosis mainly depends on histopathologic and immunohistochemical markers. This article reports two cases of MNT to explore its clinicopathologic features, diagnosis and differential diagnosis to improve understanding of this subtype. In addition, we review previously reported cases of MNT.

Research progresses of imaging examinations on staging and typing of thymic epithelial tumors / 中国医学影像技术

Thymic epithelial tumors (TETs) are the most common tumors in the anterior mediastinum, and the staging system and histological classification are complex. CT is the most important imaging examination for TETs. MRI has a certain value in the diagnosis of TETs. PET/CT in classification of TETs is progressing rapidly, but the results are controversial. The research progresses of imaging examinations on staging and typing of TETs were reviewed in this article.

Computed tomography of solitary fibrous tumor of the pleura abutting the mediastinum: A diagnostic challenge.

BACKGROUND: Solitary fibrous tumor of the pleura (SFTP) arising from the mediastinal pleura may be confused with primary mediastinal tumors. We studied the computerized tomographic (CT) findings of patients with SFTP that could suggest a diagnosis of SFTP. MATERIALS AND METHODS: At our hospital from January 1995 to June 2012, 39 patients with histologically confirmed SFTP were surgically treated; seven of them abutting the mediastinal pleura. The study group included seven patients aged between 53 and 81 years. Baseline CT scans were retrospectively reviewed to identify radiological findings suggestive of SFTP including: (1) smooth and sharply delineated contours; (2) obtuse, acute, or tapering angles between the lesion and the mediastinum depending on the size; (3) homogeneous soft-tissue attenuation; (4) "geographic pattern" due to the contemporary presence of large vessels, necrosis, and calcifications; (5) displacement of the lung parenchyma; (6) presence of a cleavage plane; and (7) absence of lymphadenopathy or pleural methastasis. RESULTS: All tumors formed acute angles with the pleura. Six out of the seven presented smoothly tapering margins, three had a "geographic pattern" of attenuation and displaced the anterior junction line; one showed an outside junction line development. Four cases had a clear pleural origin. CONCLUSIONS: The possibility of SFTP should be taken into account when a mass abuts the mediastinum projecting inside the thoracic cavity in the presence of an intense and "geographical pattern" of enhancement without lymphoadenopathy or pleural metastasis. These findings assume greater significance in the presence of discrepancy between the size of the lesion and the clinical presentation.

Thymic tumor:a systematic review of non-surgical treatment / 中华放射肿瘤学杂志

Thymoma of non-surgical treatment or combined modality therapy must be considered in advanced or unresectable cases, which includes radiotherapy, chemotherapy, targeted therapy and immunotherapy. The first choice of resectable advanced thymoma is surgery followed by adjuvant radiotherapy or chemotherapy. For unresectable advanced thymoma, inducted therapy followed by surgery and adjuvant therapy is a rational pattern. But the best treatment mode is still unclear. We review the effect and prognosis about non-surgical treatment of thymoma recent years, to offer advice about making the best decision in the treatment of thymoma.

PD-L1, PD-1, CD4, and CD8 expression in neoplastic and nonneoplastic thymus.

The checkpoint protein programmed cell death ligand-1 protein (PD-L1) binds to its receptor (PD-1) activating the PD-L1/PD-1 pathway, an important therapeutic target. There is limited information regarding PD-L1 and PD-1 expression in thymic lesions. Sections from nonneoplastic thymi (n = 20), thymomas World Health Organization types A, AB, B1, B2, and B3 (n = 38) and thymic squamous cell carcinoma (n = 8) were stained for PD-L1 (clone SP142; Spring BioScience), PD-1 (MRQ22; Cell Marque), CD4 (clone SPO32; Cell Marque), and CD8 (JCB117; Ventana). Immunoreactivity for each antibody was classified as focal or diffuse and scored as follows: 0, negative; 1%-5%, 1+; 6%-20%, 2+; and >20%, 3+. The proportions of cases expressing PD-L1, PD-1, CD4, and C8 at score ≥1+ were compared by diagnosis, using χ2 statistics. PD-L1 was expressed in 90% of nonneoplastic thymi, 92% of thymomas, and 50% of carcinomas, with significantly higher scores (P < .01) in B2 and B3 thymomas and carcinomas than in AB and B1 thymomas; PD-L1 was diffuse in most B2 and B3 thymomas and focal in carcinomas. PD-1 was focally expressed, and mostly with scores 1+, in 55% of nonneoplastic thymi, 63% of thymomas, and 37.5% of carcinomas. CD4+ and CD8+ cells were diffusely distributed with scores 3+ in all lesions other than B3 thymomas and carcinomas. The latter showed CD4+ cells mostly at the interface between neoplastic cells and stroma. PD-L1 and PD-1 are not expressed in similar locations and cellular proportions in thymic lesions, raising a question as to whether the PD-L1/PD-1 pathway is an actionable therapeutic target in these lesions.

Clinical implementation of robot assisted trans-subxiphoid (extended) thymectomy / 中国胸心血管外科临床杂志

@#Objective    To present the preliminary clinical experience of robot assisted trans-subxiphoid (extended) thymectomy in patients with thymic neoplasms or myasthenia gravis. Methods    A total of 62 patients (34 males and 28 females at an average age of 38±11 years) suffering from thymic neoplasms or myasthenia gravis who underwent robotic (extended) thymectomy via subxiphoid approach were included in our department between August 2016 and August 2017. All of the operation were completed through 4 ports. In details, the observation hole was created just below the xiphoid process, two ports for arm 1 and arm 2 were created below bilateral subcostal arch at the midclavicular line, and trocar for arm 3 was placed in the 5th or 6th intercostal space at the anterior axillary line, respectively. Patients with thymic neoplasms received thymectomy. Patients with myasthenia gravis received extended thymectomy. Results    All the patients experienced uneventful operations. The mean operative time was 116.0±34.0 min. The mean intraoperative blood loss was 5.6±4.3 ml. The mean postoperative hospital stay was 4.0±2.2 days. There was no intra-operational massive hemorrhage, mortality, conversion or postoperative complication during the postoperative and follow-up period. Conclusion    Robotic trans-subxiphoid thymectomy is safe and feasible, which is a promising technique for extensive application.

Thymic malignancies: Moving forward with new systemic treatments.

Thymic neoplasms are rare malignant tumours, for which the mainstay of treatment is surgical resection. Platinum-based chemotherapy remains the principal treatment in metastatic tumours, with no standard second-line option. Many genes implicated in tumour onset, growth and metastases have been demonstrated to be therapeutic targets in thymic malignancies. Other current efforts to improve outcomes are based on a better understanding of the stromal compartment and tumour microenvironment, facilitating novel therapeutic approaches such as angiogenesis inhibition and immunotherapy. This review seeks to explore the present cutting edge for systemic treatment of advanced thymic neoplasms, examining novel agents under clinical investigation such as cytotoxic therapies, targeted therapies and immunotherapy. Based on the literature review we have selected potential treatment schemes, which could be used in daily clinical practice as second-line treatment.

Treatment results and prognostic indicators in thymic epithelial tumors: a clinicopathological analysis of 45 patients.

BACKGROUND: Thymomas are rare epithelial tumors arising from thymus gland. This study aims at investigating the clinical presentation, prognostic factors and treatment outcome of forty five patients with thymoma and thymic carcinoma. METHODS: Forty-five patients being histologically diagnosed with thymoma or thymic carcinoma that were treated and followed-up at a tertiary academic hospital during January 1987 and December 2008 were selected for the present study. Twelve patients were solely treated with surgery, 14 with surgery followed by adjuvant radiotherapy, 12 with sequential combined treatment of surgery, radiotherapy and/or chemotherapy and 7 with non-surgical approach including radiotherapy and/or chemotherapy.  Tumors were classified based on the new World Health Organization (WHO) histological classification. RESULTS: There were 18 women and 27 men with a median age of 43 years. Twelve patients (26.7%) had stage I, 7 (17.8%) had stage II, 23 (51%) had stage III and 2 (4.5%) had stage IV disease. Tumors types were categorized as type A (n=4), type AB (n=10), type B1 (n=9), type B2 (n=10), type B3 (n=5) and type C (n=7). In univariate analysis for overall survival, disease stage (P=0.001), tumor size (P=0.017) and the extent of surgical resection (P<0.001) were prognostic factors. Regarding the multivariate analysis, only the extent of the surgical resection (P<0.001) was the independent prognostic factor and non-surgical treatment had a negative influence on the survival. The 5-year and 10-year overall survival rates were 70.8% and 62.9%, respectively. CONCLUSION: Complete surgical resection is the most important prognostic factor in patients with thymic epithelial tumors.

Timoma epitelial como causa de dolor torácico durante una exacerbación atípica de asma: reporte de un caso / Epithelial thymoma as a cause of thoracic pain during an atypical exacerbation of bronchial asthma: a case report

Introducción: la evaluación de un paciente con exacerbación de asma bronquial incluye la búsqueda de enfermedades que pueden simular, complicar o perpetuar esa situación. El dolor retrosternal es un síntoma atípico en pacientes con exacerbación asmática y entre las causas que lo pueden originar están las masas mediastínicas como el timoma. Un tercio de los pacientes con timomas pueden tener síntomas asociados a enfermedades autoinmunes y síndromes paraneoplásicos; sin embargo, aunque el asma bronquial tiene un componente inmunológico importante en su fisiopatología, la asociación del timoma con el asma está poco documentada. Objetivo: ofrecer una enseñanza clínica a través de la presentación de un caso con asociación inusual de timoma y asma bronquial. Presentación del caso: se presenta el caso de una paciente de 50 años que acudió a servicios de urgencias con exacerbación asmática y dolor torácico retrosternal. En tomografía computarizada de alta resolución se observó una masa en mediastino anterosuperior que tras realizar exéresis quirúrgica y estudios inmunohistoquímicos fue diagnosticada como un timoma epitelial tipo IIB. Conclusiones: la presencia de síntomas inusuales en una paciente con exacerbación asmática condujo al diagnóstico de un timoma epitelial, aun cuando no se ha demostrado la asociación entre estas dos enfermedades.

Background: the evaluation of a patient with bronchial asthma exacerbation includes the search for diseases which can simulate, complicate or perpetuate that situation. The retrosternal pain is an atypical symptom in patients with asthmatic exacerbation and among the causes that can originate this symptom are mediastinal masses like thymoma. A third part of patients with thymomas might have symptoms associated with autoimmune diseases and paraneoplastic syndromes; however, although asthma has an important immunologic component in its pathophysiology, association of thymoma with asthma is poorly documented. Objective: to offer a clinical lesson through a presentation of a case with unusual association of thymoma and asthma. Case presentation: a 50 year-old female patient with asthmatic exacerbation and retrosternal thoracic pain came to emergency services. A mass in anterosuperior mediastinum was observed in computed tomographic high-resolution scan and after performing surgical exeresis and immune histochemistry studies an epithelial timoma type IIB was diagnosed. Conclusions: the presence of unusual symptoms in a patient with asthma exacerbation led to an epithelial thymoma, even when there has not been shown association between these two diseases.

Role of combined 18F-FDG-PET/CT for predicting the WHO malignancy grade of thymic epithelial tumors: a multicenter analysis.

INTRODUCTION: To investigate the performance of combined (18)F-FDG-PET/CT as a predictor of the WHO-classification based malignancy grade in thymic epithelial tumors. METHODS: From 05/06 to 02/12, the data of 47 patients with thymic epithelial tumors assessed by (18)F-FDG-PET/CT before being surgically treated were collected in 3 centers and retrospectively reviewed for the purposes of this study. The SUVmax and the SUVmax/T index (the ratio tumor-SUVmax to tumor-size) have been matched with specific subgroups of the WHO-classification: low-risk thymomas (types A-AB-B1), high-risk thymomas (types B2-B3) and thymic carcinomas (type C). RESULTS: There were 22 men and 25 women (age range: 31-84 yrs). Mean tumor size was 44.7 ± 19.0 mm. The WHO-classification was: type-A #2, type-AB #11, type-B1 #9, type-B2 #9, type-B3 #9 and type-C #7. The SUVmax and the SUVmax/T were found to be predictive factors useful to distinguish thymomas from thymic carcinomas (SUVmax: area under ROC-curve: 0.955, p = 0.0045; SUVmax/T-size: area under ROC-curve: 0.927, p = 0.0022). Moreover, both parameters were found to be correlated with the WHO malignancy grade (low-risk thymomas; high-risk thymomas; thymic carcinoma), Spearman correlation coefficients being 0.56 (p < 0.0001) and 0.76 (p < 0.0001), respectively for the SUVmax and for the SUVmax/T index. In addition, the SUVmax is also significantly correlated with Masaoka stage (Spearman correlation coefficient: 0.30, p = 0.0436) CONCLUSIONS: A significant relationship was observed between (18)F-FDG-PET/CT findings and histologic WHO-classification for this cohort of thymic epithelial tumors. Thus, on the basis of these evidences, we infer that (18)F-FDG-PET/CT may be useful to predict histology and the WHO classes of risk.

Is There a Role of Postoperative Radiation Therapy in Completely Resected Stage I/II Thymic Epithelial Tumor?

PURPOSE: Retrospective analyses of patients with stage I-II thymic epithelial tumors (TET) who were treated with either surgery alone (S) or surgery plus postoperative radiation therapy (SRT) were conducted to evaluate the role of adjuvant radiation therapy (RT). MATERIALS AND METHODS: A total of 110 stage I-II TET patients following complete resection were included in this study. Postoperative radiation therapy was recommended for those with aggressive histologic type and/or invasive features according to the surgeons' judgment during the operation. A median dose of 54.0 Gy (range, 44 to 60 Gy) focused on the primary tumor bed was administered to 57 patients (51.8%). RESULTS: In all patients, the rates of overall survival, disease-specific survival, and disease-free survival at 10 years were 91.7%, 97.1%, and 95.8%, respectively. No significant differences in disease-specific survival (100% in the S group and 93.5% in the SRT group at 10 years, p=0.12) and disease-free survival (98.1% in the S group and 94.5% in the SRT group at 10 years, p=0.41) were observed between the treatment groups, although a significantly larger number of World Health Organization (WHO)-type B2-C (p<0.001) and Masaoka stage II (p=0.03) tumors were observed in the SRT group than in the S group. No local recurrence was observed in the SRT group. No grade 2 or greater RT-related toxicities were observed in the SRT group. CONCLUSION: Excellent outcomes were achieved in patients with stage I-II TET who underwent complete resection. Considering excellent local control and low morbidity, adjuvant RT may be considered in high risk patients with WHO-type B2-C histology and Masaoka stage II.

Is There a Role of Postoperative Radiation Therapy in Completely Resected Stage I/II Thymic Epithelial Tumor? / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Retrospective analyses of patients with stage I-II thymic epithelial tumors (TET) who were treated with either surgery alone (S) or surgery plus postoperative radiation therapy (SRT) were conducted to evaluate the role of adjuvant radiation therapy (RT). MATERIALS AND METHODS: A total of 110 stage I-II TET patients following complete resection were included in this study. Postoperative radiation therapy was recommended for those with aggressive histologic type and/or invasive features according to the surgeons' judgment during the operation. A median dose of 54.0 Gy (range, 44 to 60 Gy) focused on the primary tumor bed was administered to 57 patients (51.8%). RESULTS: In all patients, the rates of overall survival, disease-specific survival, and disease-free survival at 10 years were 91.7%, 97.1%, and 95.8%, respectively. No significant differences in disease-specific survival (100% in the S group and 93.5% in the SRT group at 10 years, p=0.12) and disease-free survival (98.1% in the S group and 94.5% in the SRT group at 10 years, p=0.41) were observed between the treatment groups, although a significantly larger number of World Health Organization (WHO)-type B2-C (p<0.001) and Masaoka stage II (p=0.03) tumors were observed in the SRT group than in the S group. No local recurrence was observed in the SRT group. No grade 2 or greater RT-related toxicities were observed in the SRT group. CONCLUSION: Excellent outcomes were achieved in patients with stage I-II TET who underwent complete resection. Considering excellent local control and low morbidity, adjuvant RT may be considered in high risk patients with WHO-type B2-C histology and Masaoka stage II.