International Thymic Malignancy Interest Group Research Articles

ITMIG 2017—Interview with Dr. Ugo Pastorino: open surgery or minimally invasive surgery for patients with early stage thymoma?

© Mediastinum. All rights reserved. med.amegroups.com Mediastinum 2018;2:6 Page 1 of 2 On Sep 23, the 8th International Thymic Malignancy Interest Group Annual Meeting (ITMIG 2017) held Torino, Italy, successfully ended after a dense 3-day agenda blending a superb scientific and educational program, with over 150 participants in the field from more than 20 countries or regions.

ITMIG 2017—Dr. Andreas Rimner: expertise, equipment, and experience are critical prerequisites in intraoperative radiotherapy

On Sep 23, the 8th International Thymic Malignancy Interest Group Annual Meeting (ITMIG 2017) held in Torino, Italy, successfully ended after a dense 3-day agenda blending a superb scientific and educational program, with over 150 participants in the field from more than 20 countries or regions.

ITMIG 2017—Dr. Giuseppe Giaccone: focus on data and keep up-to-date

On Sept 23, the 8th International Thymic Malignancy Interest Group Annual Meeting (ITMIG 2017) held in Torino, Italy, successfully ended after a dense 3-day agenda blending a superb scientific and educational program, with over 150 participants in the field from more than 20 countries or regions. During the meeting, we were honored to conduct an interview with Dr. Giuseppe Giaccone from Lombardi Comprehensive Cancer Center, Georgetown University, USA.

Evaluation of the new TNM-staging system for thymic malignancies: impact on indication and survival

BackgroundThe objective of this study is the evaluation of the Masaoka-Koga and the International Association for the Study of Lung Cancer (IASLC)/International Thymic Malignancy Interest Group (ITMIG) proposal for the new TNM-staging system on clinical implementation and prognosis of thymic malignancies.MethodsA retrospective study of 76 patients who underwent surgery between January 2005 and December 2015 for thymoma. Kaplan–Meier survival analysis was used to determine overall and recurrence-free survival rates.ResultsIndication for surgery was primary mediastinal tumor (n = 55), pleural manifestation (n = 17), or mediastinal recurrence (n = 4) after surgery for thymoma. Early Masaoka-Koga stages I (n = 9) and II (n = 14) shifted to the new stage I (n = 23). Advanced stages III (Masaoka-Koga: n = 20; ITMIG/IASLC: n = 17) and IV (Masaoka-Koga: n = 33; ITMIG/IASLC: n = 35) remained nearly similar and were associated with higher levels of WHO stages. Within each staging system, the survival curves differed significantly with the best 5-year survival in early stages I and II (91%). Survival for stage IV (70 to 77%) was significantly better compared to stage III (49 to 54%). Early stages had a significant longer recurrence-free survival (86 to 90%) than advanced stages III and IV (55 to 56%).ConclusionsThe proportion of patients with IASLC/ITMIG stage I increased remarkably, whereas the distribution in advanced stages III and IV was nearly similar. The new TNM-staging system presents a clinically useful and applicable system, which can be used for indication, stage-adapted therapy, and prediction of prognosis for overall and recurrence-free survival.

Paraneoplastic Syndromes and Thymic Malignancies: An Examination of the International Thymic Malignancy Interest Group Retrospective Database

Thymic epithelial tumors (TETs) are associated with paraneoplastic/autoimmune (PN/AI) syndromes. Myasthenia gravis is the most common PN/AI syndrome associated with TETs. The International Thymic Malignancy Interest Group retrospective database was examined to determine (1) baseline and treatment characteristics associated with PN/AI syndromes and (2) the prognostic role of PN/AI syndromes for patients with TETs. The competing risks model was used to estimate cumulative incidence of recurrence (CIR) and the Kaplan-Meier method was used to calculate overall survival (OS). A Cox proportional hazards model was used for multivariate analysis. A total of 6670 patients with known PN/AI syndrome status from 1951 to 2012 were identified. PN/AI syndromes were associated with younger age, female sex, thymoma histologic type, earlier stage, and an increased rate of total thymectomy and complete resection status. There was a statistically significant lower CIR in the group with a PN/AI syndrome than in the group without a PN/AI syndrome (10-year CIR 17.3% versus 21.2%, respectively [p= 0.0003]). The OS was improved in the group with a PN/AI syndrome compared to the group without a PN/AI syndrome (median OS 21.6 years versus 17.0 years, respectively [hazard ratio= 0.63, 95% confidence interval: 0.54-0.74, p < 0.0001]). However, in the multivariate model for recurrence-free survival and OS, PN/AI syndrome was not an independent prognostic factor. Previously, there have been mixed data regarding the prognostic role of PN/AI syndromes for patients with TETs. Here, using the largest data set in the world for TETs, PN/AI syndromes were associated with favorable features (i.e., earlier stage and complete resection status) but were not an independent prognostic factor for patients with TETs.

MS 06.01 Proposal of Change for Future Staging System for Thymic Tumor

Although Masaoka clinic-pathological staging system has been accepted as the global standard staging system for thymic epithelial tumors, several problems of this staging system have been pointed out because clinical practices in diagnosis, medical treatment and surgical procedure has enormously advanced during more than 30 years. Furthermore, there has not been a TNM classification system approved by UICC to describe a tumor’s clinical status adequately. To overcome these situations, International Thymic Malignancy Interest Group (ITMIG) established global database and proposed a novel staging system based on TNM definition in collaboration with IASLC staging committee in 2016. This is a great progress in clinical medicine in the field of thymic epithelial tumor, but as a matter of fact, stage grouping according to this novel TNM classification is mostly defined by tumor invasion to adjacent organs similarly to Masaoka staging system. Japanese Association for Research of the Thymus (JART) established by Akira Masaoka and colleagues contributed to the ITMIG project of global database, and several studies using JART database were performed and reported from Japanese researchers. Novel findings in the JART database study are reviewed and new insights in further modification in TNM staging system are addressed in the present article. The significance of involved organs as a prognostic factor has been a great interest, because some structures are easily resected while others are difficult to be completely resected. Actually, some previous studies showed prognostic significance of involvement of the great vessels. Based on the ITMIG database, involvement of the pericardium alone is defined as T2 in the UICC TNM classification while involvement of SVC and brachiocephalic vein is defined as T3 and involvement of the aorta, aortic branches and intrapericardial vessels is defined as T4. One of the JART database study focusing on the involved organs in Masaoka stage III tumors showed that invasion to the chest wall is an independent prognostic factor by multivariate analysis while involvement of the great vessels is not. The hazard ratio of involvement of the chest wall is 4.07. Invasion to the chest wall is defined as T3, but when invasion to the sternum is extended, resection of the chest wall including sternum is sometimes a difficult procedure, and complete resection is hard to be achieved. Lymphatic channels are distributed in the chest wall, of which involvement by the tumor can result in nodal metastasis. Thus, invasion to the chest wall might be considered as an important factor to determine the tumor spread, and therefore, as one factor in T definition. Involvement of SVC and brachiocephalic vein is defined as T3, but is heterogenous variable because some tumors invade to the outer surface of the vessel but others enter the lumen of the vessel, which can result in pulmonary metastasis. The extent in involvement of the great vessels could be a significant factor in T definition. Tumor size could reflect the time from initiation of the tumor and the larger tumor is more likely to be in an advanced status. Actually, tumor size is a critical factor in T definition in lung cancers. In thymic epithelial tumors, however, T definition does not reflect the tumor size. Using JART database, oncological significance of the tumor size was examined in thymoma and thymic carcinoma, separately. In thymoma, the rate of R0 resection in the tumors less than 5.0 cm, 5.1 to 10 cm, and more than 10.1 cm was 94.4%, 91.3%, and 84.0%, respectively. Recurrence rate after R0 resection in the tumors less than 5.0 cm, 5.1 to 10 cm, and more than 10.1 cm was 3.0%, 8.9% and 27.2%, respectively. In thymic carcinoma, the rate of R0 resection in the tumors less than 5.0 cm, 5.1 to 10 cm, and more than 10.1 cm was 80.2%, 63.2%, and 62.5%, respectively. Recurrence rate after R0 resection in the tumors less than 5.0 cm, 5.1 to 10 cm, and more than 10.1 cm was 28.2%, 53.7% and 62.5%, respectively. Thus, there was apparent difference in oncological behavior between tumors less than 5.0 cm and those more than 5.1 cm both in thymoma and thymic carcinoma. These observations suggest that tumors size also should be included in T definition in thymic epithelial tumors. Finally, the category of Masaoka stage IVA disease includes pleural dissemination, but the situation of pleural dissemination varies greatly from a single lesion to numerous lesions. Furthermore, some disseminations are resectable while others are not. JART study revealed that the number of disseminated lesions on the pleura In conclusion, T definition remains to be further evaluated in reference to tumor size, chest wall invasion and extent of involvement of the great vessels. M definition also remains to be further discussed in terms of extent of the pleural dissemination. Thymic carcinoma, TNM classification, Thymoma

Positron Emission Tomography in Thymic Tumors: Analysis Using a Prospective Research Database

Positron emission tomography may have a role in the pretreatment workup of patients with thymic malignancies. This study was undertaken to determine the utility of the maximum standardized uptake value (SUVmax) in predicting histologic type and tumor stage in a large cohort of thymic epithelial tumors. The large, multiinstitutional, prospective database of The International Thymic Malignancy Interest Group (ITMIG) was queried for the use of positron emission tomography in the pretreatment workup of patients with thymic tumors. Data analyzed included demographics, SUVmax, histologic tumor type, and tumor stage. The distribution of SUVmax according to histologic type and Masaoka-Koga pathologic stage was determined, and the ability of SUVmax to predict these two variables was calculated using analysis of receiver operating characteristic curves. Since 2012, data from 926 patients with thymic malignancies were entered into the ITMIG prospective database, of which 154 had a reported value for SUVmax. The area under the receiver operating characteristic curve for SUVmax in predicting histologic type and pathologic stage was 0.79 (95% confidence interval, 0.70 to 0.88; p < 0.001) and 0.81 (95% confidence interval, 0.73 to 0.88; p < 0.001), respectively. In addition, there was a significant relationship between SUVmax and histologic type (p < 0.001) as well as Masaoka-Koga pathologic stage (p < 0.001). Positron emission tomography has utility in predicting clinicopathologic features of thymic malignancies. These results may have clinical application in the pretreatment workup of patients with these rare tumors.

MR Imaging of Mediastinal Masses.

The mediastinum contains vital vascular and nonvascular structures and organs, and a wide variety of abnormalities may arise from this region of the thorax. Although mediastinal masses may be initially detected on chest radiography, cross-sectional imaging plays an important role in the identification and evaluation of mediastinal lesions, enabling the formulation of focused differential diagnoses and ultimately guiding management. Computed tomography (CT) is considered the imaging modality of choice for evaluating most mediastinal masses; however, the role of magnetic resonance (MR) imaging continues to expand, as it is superior to CT in differentiating between cystic and solid masses, identifying cystic and solid components within complex lesions, and distinguishing thymic hyperplasia and normal thymus from thymic epithelial neoplasms and other neoplasms. In addition, it facilitates the staging and restaging of patients with thymic epithelial neoplasms and other tumors that cannot undergo contrast-enhanced CT imaging due to severe contrast allergy and/or impaired renal function. As division of the mediastinum into specific compartments is beneficial for diagnostic and treatment planning purposes and facilitates communication between clinicians in a multidisciplinary setting, a new classification model based on cross-sectional imaging has been developed by the International Thymic Malignancy Interest Group (ITMIG) and accepted as a new standard. In this article, we describe the role of MR imaging in the evaluation of mediastinal masses in conjunction with the new mediastinal compartment classification system introduced by ITMIG.

Multidisciplinary Tumor Board Decision Making for Postoperative Radiotherapy in Thymic Epithelial Tumors: Insights from the RYTHMIC Prospective Cohort

IntroductionThymic epithelial tumors (TETs) are rare intrathoracic malignancies for which surgery represents the mainstay of the treatment. Current practice for postoperative radiotherapy (PORT) is highly variable, and there is a lack of prospective, high level evidence. Réseau Tumeurs Thymiques et Cancer (RYTHMIC) is the nationwide network for TETs in France. Established in 2012, it prospectively collects data on all TET patients, for whom management is discussed at a national multidisciplinary tumor board (MTB). We assessed whether PORT decisions at the MTB were in accordance with RYTHMIC guidelines and ultimately implemented in patients. MethodsAll consecutive patients for whom PORT was discussed at the MTB from 2012 to 2015 were identified from the RYTHMIC prospective database, and a complete review of their medical records was performed. ResultsA total of 274 patients, including 243 with thymoma (89%) and 31 with thymic carcinoma (11%), were analyzed. The decision of the MTB was in accordance with guidelines in 221 patients (92%) of the 241 with stage I or III TET. An MTB decision to deliver PORT was made for 117 patients (43%). PORT was ultimately initiated in 101 patients. The most frequent reason for not delivering PORT was excessive (>3 months) delay after surgery. Dose-volume constraints defined by the International Thymic Malignancy Interest Group were followed in all but four patients. ConclusionOur data provide a unique insight into the decision-making process for PORT in TETs, highlighting the need for systematic discussion at an expert MTB, while stressing the value of current available guidelines.

Assessment of the ITMIG Statement on the WHO Histological Classification and of the Eighth TNM Staging of Thymic Epithelial Tumors of a Series of 188 Thymic Epithelial Tumors

IntroductionThymic epithelial tumors (TETs) are rare intrathoracic malignancies that are categorized histologically according to the WHO classification, which was recently updated in 2015 on the basis of a consensus statement of the International Thymic Malignancy Interest Group (ITMIG); at the same time, the standard Masaoka-Koga staging system is scheduled to be replaced by the eighth edition of the TNM staging classification by the American Joint Committee on Cancer/Union for International Cancer Control consortium. Our objectives were to analyze the feasibility of assessing ITMIG consensus major and minor morphological and immunohistochemical criteria and the eighth edition of the TNM staging classification in a routine practice setting. MethodsThis is a single-center study conducted at the Louis-Pradel Hospital of Lyon University, one of the largest centers for TETs in France. Overall, a large surgical series of 188 TETs diagnosed in 181 patients between 2000 and 2014 at our center were analyzed. ResultsThere were 89 men (49%) and 92 women (51%); 57 patients (31%) presented with myasthenia gravis at time of diagnosis. According to the WHO classification, there were nine type A thymomas (5%), 67 type AB thymomas (36%), 19 type B1 thymomas (10%), 46 type B2 thymomas (24%), 27 type B3 thymomas (14%), and 20 thymic carcinomas (11%). ITMIG consensus major criteria were identified in 100% of type A, AB, B1, and B2 thymomas. After restaging according to the eighth edition of the TNM staging classification, there were 127 stage I (84%), three stage II (2%), 17 stage IIIa (11%), no stage IIIb, two stage IVa (1%), and three stage IVb (2%) thymomas. Significant correlation between histological type and stage at diagnosis was maintained after restaging according the TNM classification. ConclusionComprehensive analysis of our well-characterized surgical series of 188 TETs indicates the feasibility and the diagnostic value of the ITMIG consensus statement on WHO histological classification and highlights the major switch in staging when the eighth edition of the TNM staging classification is applied.

Lymph node metastases in thymic malignancies: a Chinese Alliance for Research in Thymomas retrospective database analysis.

Lymphatic involvement is believed to be relatively rare in thymic epithelial tumours. The incidence and prognostic significance of nodal metastases are still unclear. The goal of this study was to define the incidence and prognostic relevance of nodal metastasis in patients with thymic epithelial tumours, using a nationwide retrospective database of the Chinese Alliance for Research in Thymomas. Patients who underwent upfront surgical resection without preoperative therapy were enrolled for the study. The International Thymic Malignancies Interest Group proposal of a new staging system for thymic epithelial tumours was used to redefine the pathological stage. The incidence of nodal metastasis and its relationship with clinicopathological characteristics and its impact on survival were examined accordingly. A total of 1617 patients were enrolled in this study. Lymph node metastasis was identified in 35 patients (2.2%). No nodal involvement was found in type A, AB or B1 thymomas. The incidence of nodal metastasis in thymoma (B2/B3) and thymic carcinoma was 1.3% and 7.9%, respectively, and it was most commonly seen in patients with neuroendocrine thymic tumours (16.7%, P < 0.001). According to the primary tumour invasion stage, incidences of nodal metastasis were 0.2% in T1, 6.9% in T2, 8.5% in T3 and 7.4% in T4 tumours (P < 0.001). Gender, pleural or distant metastasis and resection status were also correlated with nodal metastasis (P < 0.05) in univariable analysis. Multivariable analysis revealed that patients with non-thymoma histological characteristics (P < 0.001) and tumours in non-T1 stage (P < 0.001) had significantly greater risk of developing nodal metastasis. The overall survival of patients without nodal metastasis was significantly higher than that of patients with nodal involvement (P < 0.001). Disease-free survival of patients after R0 resection without nodal metastasis was also significantly higher than those with nodal metastasis (P < 0.001). On multivariable analysis, overall survival was significantly associated with histology of the tumour (P = 0.019) and complete resection (P = 0.047), and there was a trend towards significance (P = 0.052) in the association between overall survival and nodal involvement. Lymph node metastasis in low-grade, early stage thymic tumours is a rare phenomenon. However, it is not uncommon in tumours with a higher stage or a higher histological grade, especially in neuroendocrine thymic tumours. Nodal involvement as well as tumour invasion and histological grade may denote worse prognosis. Lymph node dissection may be warranted in selected high-risk patients.

IASLC/ITMIG Staging System and Lymph Node Map for Thymic Epithelial Neoplasms.

Thymic epithelial neoplasms are rare malignancies that arise from the thymus and include thymoma, thymic carcinoma, and thymic neuroendocrine tumors. At least 15 different stage classifications have been proposed for thymic epithelial neoplasms and used to varying degrees in clinical practice, many of which have been constructed from small groups of patients. Traditionally, the Masaoka and Masaoka-Koga staging systems have been the schemes most commonly employed, and the latter has been recommended for use by the International Thymic Malignancy Interest Group (ITMIG). An official, consistent stage classification system has recently been recognized by the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC), which are responsible for defining stage classifications for neoplasms. To establish this stage classification system, the International Association for the Study of Lung Cancer (IASLC) and ITMIG amassed a large retrospective database and evaluated this group of cases to develop proposals for the eighth edition of the stage classification manuals. For this endeavor, IASLC provided funding and statistical analysis and ITMIG provided the involvement of the clinicians and researchers actively participating in the study of thymic epithelial neoplasms. To accomplish this, a Thymic Domain of the Staging and Prognostic Factors Committee (TD-SPFC) was established to formulate the rationale, methodology, and definitions of this tumor-node-metastasis (TNM) staging system, which is presented in this article. © RSNA, 2017.

ITMIG Classification of Mediastinal Compartments and Multidisciplinary Approach to Mediastinal Masses.

Division of the mediastinum into specific compartments is beneficial for a number of reasons, including generation of a focused differential diagnosis for mediastinal masses identified on imaging examinations, assistance in planning for biopsies and surgical procedures, and facilitation of communication between clinicians in a multidisciplinary setting. Several classification schemes for the mediastinum have been created and used to varying degrees in clinical practice. Most radiology classifications have been based on arbitrary landmarks outlined on the lateral chest radiograph. A new scheme based on cross-sectional imaging, principally multidetector computed tomography (CT), has been developed by the International Thymic Malignancy Interest Group (ITMIG) and accepted as a new standard. This clinical division scheme defines unique prevascular, visceral, and paravertebral compartments based on boundaries delineated by specific anatomic structures at multidetector CT. This new definition plays an important role in identification and characterization of mediastinal abnormalities, which, although uncommon and encompassing a wide variety of entities, can often be diagnosed with confidence based on location and imaging features alone. In other scenarios, a diagnosis may be suggested when radiologic features are combined with specific clinical information. In this article, the authors present the new multidetector CT-based classification of mediastinal compartments introduced by ITMIG and a structured approach to imaging evaluation of mediastinal abnormalities. ©RSNA, 2017.

ED05.03 The Thymic Epithelial Tumor Staging System

ED05.03 The Thymic Epithelial Tumor Staging System

Lymph node dissection in thymic malignancies

Lymph node metastasis is not uncommon and an important clinical parameter in thymic malignancies. It is consistently reported that lymph node metastasis is a poor prognostic factor in thymic malignancies (1-4). Original Masaoka stage classification system and latest International Association for the Study of Lung Cancer (IASLC)/International Thymic Malignancy Interest Group (ITMIG) stage classification system for thymic malignancies classify lymph node metastasis as stage IV (5,6). Understandings, however, about the details of lymph node metastasis in thymic malignancies such as incidence, lymphatic pathway, method of lymph node dissection (LND), and the benefit of diagnosis of lymph node metastasis are extremely limited until now.

Evolution of thymic malignancy management in Japan

Although surgery for the thymus began as early as 1940 in Japan, resection of a thymic epithelial tumor continued to be challenging for clinical practitioners until the 1970’s. Thereafter, introduction of the Masaoka clinicopathological staging system, development of extended thymectomy procedure, advancements in understanding of the pathological and biological characteristics of these tumors, and establishment of the Japanese Association for Study of the Thymus (JART) led to significant progress in clinical practice for treating affected patients. Presently, surgical resection procedures for thymic epithelia tumors are safely performed for more than 2,000 patients each year in Japan, approximately 40% of which are achieved using video-assisted thoracoscopic surgery (VATS). JART and Japanese clinicians are currently involved in global collaboration research activities with the International Thymic Malignancy Interest Group (ITMIG) and International Association for the Study of Lung Cancer (IASLC).

P2.05-023 Patterns of Failure after Adjuvant Radiation Therapy Based On “Tumor Bed with Margin” for Stage III Thymic Epithelial Tumor: Topic: Clinical Outcome

This study was conducted to assess optimal radiation target volume in patients with locally advanced thymic epithelial tumor (TET) treated by surgery and postoperative radiation therapy (PORT). The records of 54 patients with Masaoka-Koga stage III TET, who received surgical resection at Samsung Medical Center, from Jan. 2000 to Dec. 2014, were retrospectively reviewed. The most common TNM stage was T3N0M0 (n=46, 85.2%) according to the new staging system proposed by the International Association for the Study of Lung Cancer and the International Thymic Malignancy Interest Group. The median PORT dose was 54 Gy in 27 fractions. Target volume was confined to the primary tumor bed only, while did not include the regional lymphatics nor pleuro-pericardial space electively. The clinical outcomes, prognostic factors and patterns of failure were analyzed. After median follow-up of 62 months, there were 19 (35.2%) patients who had disease recurrence. Pure local failure within the PORT volume was founded in only one (1.9%) patient who had gross residual mass after surgery, pleuro-pericardial seeding in 5 (9.3%), distant metastases in 10 (18.5%), and regional recurrence in adjacent mediastinum or lymph nodes in 3 (5.6%) patients with WHO type B3 or C TET. Overall survival rate at 5 and 10 years was 83.0% and 43.6%, respectively. Recurrence free survival rate at 5 and 10 years was 62.3% and 57.9%, respectively. The age <60 years old, female gender, and tumor diameter <10 cm were favorable prognostic factors for overall survival on univariate analyses. Radiation toxicity was mild in most patients and no severe toxicity was registered. PORT confined to the primary tumor bed only is suggested to be optimal in patients with Masaoka stage III (T1b-4N0) TET considering excellent in-field control and minimal out-field regional recurrences. Development of effective systemic treatment strategy to reduce the pleuro-pericardial seeding may be warranted.

Prognostic impact of tumour size in completely resected thymic epithelial tumours.

The T descriptor of thymic epithelial tumours proposed by the International Association for the Study of Lung Cancer and the International Thymic Malignancy Interest Group as well as the Masaoka-Koga system is defined by the anatomical extent of primary tumours, regardless of their size. However, the prognostic significance of tumour size in thymic epithelial tumours has not been fully elucidated. We evaluated the prognostic significance of tumour size in 154 consecutive patients with thymic epithelial tumours including 124 thymomas, 21 thymic carcinomas and 9 neuroendocrine tumours, who underwent complete resection between 2001 and 2014. Among all tumours, the median tumour size was 4.9cm. The median thymoma, thymic carcinoma and neuroendocrine tumour sizes were 4.8, 5.7 and 5.8, respectively, although the differences were not significant. In survival analysis, the 5- and 10-year overall survival (OS) and recurrence-free survival (RFS) rates for all patients were 91 and 81%, and 80 and 69%, respectively. Under the stratification of tumour size, no trend was observed for OS, whereas RFS showed stepwise deterioration as tumour size increased. For 119 patients with Stage I disease, RFS showed deterioration as tumour size increased. Multivariate analysis revealed that tumour size >4.0cm was an independent prognostic factor for worsening RFS (P=0.03). Patients with tumours >4.0cm showed significantly worse outcomes in RFS compared with those with smaller tumours. This relationship was also noted in patients with Stage I disease.

Thymic Carcinoma Management Patterns among International Thymic Malignancy Interest Group (ITMIG) Physicians with Consensus from the Thymic Carcinoma Working Group

IntroductionThymic carcinomas are rare epithelial malignancies with limited data to guide management. MethodsTo identify areas of agreement and variability in current clinical practice, a 16-question electronic survey was given to members of the International Thymic Malignancy Interest Group (ITMIG). Areas of controversy were discussed with the Thymic Carcinoma Working Group and consensus was achieved, as described. ResultsA total of 100 ITMIG members responded. There was general agreement regarding the role for multimodality therapy with definitive surgical resection in physically fit patients with advanced but resectable disease. Areas of controversy included the need for histologic confirmation before surgery, the role of adjuvant therapy, the optimal first-line chemotherapy regimen, and the recommended treatment course for marginally resectable disease with invasion into the great vessels, pericardium, and lungs. ConclusionsThe results of the questionnaire provide a description of the management of thymic carcinoma by 100 ITMIG members with a specific interest or expertise in thymic malignancies. Although there was agreement in some areas, clinical practice appears to vary significantly. There is a great need for collaborative research to identify optimal evaluation and treatment strategies. Given the need for multimodality therapy in many cases, a multidisciplinary discussion of the management of patients with thymic carcinoma is critical.

Comparison of the Masaoka-Koga and The IASLC/ITMIG Proposal for The TNM Staging Systems Based on the Chinese Alliance for Research in Thymomas (ChART) Retrospective Database

背景与目的使用中国胸腺协作组（Chinese Alliance for Research in Thymomas, ChART）回顾性数据，比较Masaoka-Koga分期系统和国际肺癌协会（International Association for the Study of Lung Cancer, IASLC）/国际胸腺肿瘤协作组（International Thymic Malignancies Interest Group, ITMIG）推荐的新TNM分期对胸腺肿瘤预后的预测作用。方法我们回顾分析了1992年-2012年ChART数据库共2, 370例患者。其中1, 198例信息完整的患者被纳入研究，按照TNM及Masaoka-Koga分期系统进行分期，并进行生存分析。评估指标为R0患者的累积复发率（cumulative incidence of recurrence, CIR）以及患者总生存率（overall survival, OS）。对比分析Masaoka-Koga分期系统和新的TNM分期系统。结果根据Masaoka-Koga分期系统，不同分期CIR差异具有统计学意义，其中Ⅰ期和Ⅱ期或者Ⅱ期和Ⅲ期之间累积复发率无差异，Ⅳ期的患者具有更高的复发率，预后最差。根据新的TNM分期系统，T1a患者的累积复发率低于其他患者（P < 0.05），T1a患者总生存高于T1b患者（P=0.004），T4患者总生存率差于其它患者。N（+）患者累及复发率及总生存率差于N0患者。在M0患者与M1b患者之间总体累积复发率和总体生存率差异具有统计学意义，但在M0和M1b患者之间二者无差异。Ⅰ期-Ⅲa期与Ⅲb期-Ⅳb期患者之间总生存率具有差异，然而Ⅲb期与Ⅳb期患者之间总生存率无差异。结论与Masaoka-Koga分期相比，IASLC/ITMIG TNM分期系统不仅描述了肿瘤侵犯的范围，也提供了有关淋巴结转移和肿瘤播散的情况。使用新的TNM分期系统进行前瞻性研究有助于更好的对胸腺肿瘤分组，预测预后，并指导治疗。