Thymic Malignancies Research Articles

Robotic-assisted versus video-assisted thoracoscopic surgery for thymic epithelial tumours, from the European Society of Thoracic Surgeons Database.

Minimally invasive thymectomy is an accepted approach for early-stage thymic epithelial neoplasia, reducing pain and length of stay compared with open surgery. In this study, we compare robotic and video-assisted thymectomy to assess pathological resection status, overall and disease-free survival. Data were retrieved from the European Society of Thoracic Surgeons prospectively maintained thymic database. Eighty-two international centres were invited to participate in the ESTS registry. Thirty-seven centres agreed to take part. We included all patients who had undergone complete thymectomy for malignancy through a minimally invasive approach and excluded patients in whom complete data were not available. Between October 2001 and May 2021, a total of 899 patients with thymic malignancy underwent minimal access surgical resection and were included in the study. A propensity matched analysis was conducted with interrogation of 732 patients. Median age was 55 years, and 408 (56%) patients were female. Propensity matched was performed with 1:1 matching for surgical approach (video assisted = 366, robot assisted = 366). Robot-assisted surgery conferred significantly lower odds of incomplete resection (R1; 0.203 95% CI 0.13-0.317; P < 0.001). However, there was no difference in terms of overall and disease-free survival between the 2 techniques. In this analysis, after adjusting for thymoma stage, the odds of incomplete surgical resection were higher in patients undergoing video-assisted surgery than robotic. However, there was no difference in overall or disease-free survival. With data maturation and increased follow-up, this would need repeat analysis and perhaps may provide more credence to the concept of a prospective randomized study to compare outcomes in thymic epithelial neoplasia by surgical approach with a standardized pathological work-up.

Re-evaluation and operative indications after induction therapy for thymic epithelial tumors.

Thymic epithelial tumors (TETs), encompassing thymoma and thymic carcinoma, represent a rare and heterogeneous group of thoracic malignancies with varying prognoses and treatment strategies. Surgical resection is the cornerstone of therapy for localized stages, but the management of locally advanced or unresectable TETs often involves induction therapy, including chemotherapy and/or radiation therapy, as a neoadjuvant approach aimed at downstaging the tumor to facilitate subsequent resection. This review synthesizes current knowledge on the re-evaluation process and operative indications following induction therapy for TETs, highlighting the pivotal role of accurate assessment in guiding surgical decisions and optimizing patient outcomes. Induction therapy's efficacy is contingent upon precise re-evaluation methods to accurately gauge treatment response and assess resectability post-therapy. This review discusses the various modalities employed in re-evaluation, including computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography-CT (PET-CT), and the significance of tumor markers, underlining their strengths and limitations. The adoption of modified RECIST criteria for TETs by the International Thymic Malignancy Interest Group (ITMIG) underscores the necessity for standardized assessment guidelines to ensure consistency and reliability across studies and clinical practices. Furthermore, we explore the implications of induction therapy on surgical decision-making, emphasizing the criteria for determining the suitability of patients for surgical intervention post-therapy. The review addresses the challenges and future perspectives associated with the re-evaluation process, including the potential for advanced imaging techniques and the integration of molecular and genetic markers to enhance the precision of treatment response assessment. In conclusion, the re-evaluation of TETs post-induction therapy is a complex but critical component of the multidisciplinary management approach for these patients. Standardizing re-evaluation methodologies and incorporating novel diagnostic tools could significantly improve the prognostication and treatment stratification, ultimately enhancing the therapeutic outcomes for patients with advanced TETs.

Identification of cytokines in benign and malignant thymus tumors: based on Mendelian randomization and proteomics.

The aim of this study was to identify potential causal cytokines in thymic malignancies and benign tumors from the FinnGen database using Mendelian randomization (MR). In this study, data from genome-wide association studies (GWAS) of 91 cytokines were used as exposure factors, and those of thymic malignant tumors and thymic benign tumors were the outcome variables. Two methods were used to determine the causal relationship between exposure factors and outcome variables: inverse variance weighting (IVW) and MR-Egger regression. Sensitivity analysis was performed using three methods, namely, the heterogeneity test, the pleiotropy test, and the leave-one-out test. There was a causal relationship between the expression of fibroblast growth factor 5, which is a risk factor for thymic malignant tumors, and thymic malignant tumors. C-C motif chemokine 19 expression, T-cell surface glycoprotein CD5 levels, and interleukin-12 subunit beta levels were causally related to thymic malignant tumors and were protective. Adenosine deaminase levels, interleukin-10 receptor subunit beta expression, tumor necrosis factor (TNF)-related apoptosis-inducing ligand levels, and TNF-related activation-induced cytokine levels showed a causal relationship with thymic benign tumors, which are its risk factors. Caspase 8 levels, C-C motif chemokine 28 levels, interleukin-12 subunit beta levels, latency-associated peptide transforming growth factor beta 1 levels, and programmed cell death 1 ligand 1 expression showed a causal relationship with thymic benign tumors, which are protective factors. Sensitivity analysis showed no heterogeneity. Cytokines showed a causal relationship with benign and malignant thymic tumors. Interleukin-12 subunit beta is a common cytokine that affects malignant and benign thymic tumors.

Thymic Imaging Pitfalls and Strategies for Optimized Diagnosis.

Thymic imaging is challenging because the imaging appearance of a variety of benign and malignant thymic conditions are similar. CT is the most commonly used modality for mediastinal imaging, while MRI and fluorine 18 fluorodeoxyglucose (FDG) PET/CT are helpful when they are tailored to the correct indication. Each of these imaging modalities has limitations and technical pitfalls that may lead to an incorrect diagnosis and mismanagement. CT may not be sufficient for the characterization of cystic thymic processes and differentiation between thymic hyperplasia and thymic tumors. MRI can be used to overcome these limitations but is subject to other potential pitfalls such as an equivocal decrease in signal intensity at chemical shift imaging, size limitations, unusual signal intensity for cysts, subtraction artifacts, pseudonodularity on T2-weighted MR images, early imaging misinterpretation, flow and spatial resolution issues hampering assessment of local invasion, and the overlap of apparent diffusion coefficients between malignant and benign thymic entities. FDG PET/CT is not routinely indicated due to some overlap in FDG uptake between thymomas and benign thymic processes. However, it is useful for staging and follow-up of aggressive tumors (eg, thymic carcinoma), particularly for detection of occult metastatic disease. Pitfalls in imaging after treatment of thymic malignancies relate to technical challenges such as postthymectomy sternotomy streak metal artifacts, differentiation of postsurgical thymic bed changes from tumor recurrence, or human error with typical "blind spots" for identification of metastatic disease. Understanding these pitfalls enables appropriate selection of imaging modalities, improves diagnostic accuracy, and guides patient treatment. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

State of the art in radiation therapy for thymic malignancies: extended abstract

State of the art in radiation therapy for thymic malignancies: extended abstract

Superior Vena Cava Syndrome in Men with Thymic Atypical Carcinoid (Neuroendocrine Tumor Grade 2)

Introduction: Cases of neuroendocrine tumors (NET) can occur in various organs, generally in the form of gastroenteropancreatic (GEP-NET) and pulmonary tract (PNET). The incidence of thymic neuroendocrine tumors (TNET) is rare, accounting for less than 5% of thymic and mediastinal malignancies, and 0.4% of all neuroendocrine tumors. Case presentation: A 57-year-old man came to RSUP Dr. Mohammad Hoesin Palembang with complaints of coughing, bluish and curved blood vessels in the chest, and shortness of breath during activities that have been getting worse for six months. CT scan showed a tumor measuring 18.6 x 11.7 x 11 cm in the anterior mediastinum and pressing on the superior vena cava and abdominal aorta. TTNA and core biopsy with CT guidance showed NET Grade 2, mitoses 6/2 mm2, positive tumor cells with immunohistochemistry for synaptophysin, chromogranin, CD 56, AE1/AE3, and Ki67 9%. The patient received paclitaxel and carboplatin chemotherapy for 6 cycles. Conclusion: The prognosis for atypical carcinoid patients is 20-80% for a 5-year survival rate. Appropriate patient management is needed to improve the outcome of patients with primary thymic atypical carcinoid (NET, grade 2).

Survival Outcome After Surgery in Patients With Thymoma Distant Recurrence

ObjectiveThe aim of this study is to describe characteristics and survival outcome of patients who underwent surgical treatment for distant thymoma relapse according to the definition of the International Thymic Malignancy Interest Group. MethodsData of patients affected by thymoma recurrence from four different institutions were collected and retrospectively reviewed. Patients with locoregional metastases who underwent nonsurgical therapies and with incomplete data on follow-up were excluded. According to the International Thymic Malignancy Interest Group distant recurrence definition, patients with recurrence due to hematogenic localization were included. Clinical and pathologic characteristics were described using descriptive statistics, whereas survival outcome was calculated using Kaplan-Meier curves and Cox regression analysis. ResultsThe analysis was conducted on 40 patients. A single localization was present in 13 patients, the relapse was intrathoracic in 28 cases (70%), and lung involvement was found in 26 cases. The liver was operated in seven cases, whereas other kinds of abdominal involvement were detected in eight cases. Adjuvant treatment was administered in 22 cases (55%).Five- and 10-year overall survival (OS) were 67% and 30%, respectively. Univariable analysis identified as significant favorable factor a low-grade histology (A, B1, B2): five-year OS at 92.3% versus 53.3% in high-grade (B3–C) (p = 0.035). Site of recurrence and number of localization did not influence the prognosis, but in patients with adjuvant therapy administration, there was a survival advantage also if not statistically significant: five-year OS 84.8% versus 54.5% in patients without adjuvant therapy (p = 0.101).Multivariable analysis confirmed as independent prognostic factor low-grade histology: hazard ratio = 0.176, 95% confidence interval 0.042–0.744, p = 0.018. ConclusionsOur study revealed a good survival outcome in patients who underwent surgery for distant thymoma recurrence, independently from the number and site of the relapse localization. Patients with A, B1, or B2 histology presented a significantly better survival than patients with B3-C.

Perioperative outcomes and survival of modified subxiphoid video-assisted thoracoscopic surgery thymectomy for T2-3 thymic malignancies: A retrospective comparison study

ObjectiveOur previous study demonstrated that modified subxiphoid video-assisted thoracic surgery thymectomy with an auxiliary sternal retractor is feasible for locally invasive thymic malignancies. This study aimed to compare perioperative and oncological outcomes of modified subxiphoid video-assisted thoracoscopic surgery thymectomy versus median sternotomy thymectomy for locally advanced thymic malignancies. MethodsIn total, 221 patients with T2-3 thymic malignancies who underwent modified subxiphoid video-assisted thoracoscopic surgery thymectomy or median sternotomy thymectomy between 2015 and 2020 were enrolled in our prospectively maintained database. A 1:1 propensity score–matching analysis was performed to balance the bias. Surgical difficulty was evaluated with a modified resection index. Perioperative and oncological results were compared between the modified subxiphoid video-assisted thoracoscopic surgery thymectomy group and the median sternotomy thymectomy group. ResultsThere were 72 patients in each group in the final analysis. Our results showed that the modified subxiphoid video-assisted thoracoscopic surgery thymectomy group had a shorter operative duration (98 vs 129 minutes, P < .001), less blood loss (40 vs 100 mL, P < .001), shorter drainage duration (3 vs 5 days, P < .001), shorter length of hospital stay (5 vs 6 days, P < .001), and fewer postoperative complications (5.6% vs 23.6%; P = .005). No significant difference was detected in complete resection (98.6% vs 98.6%, P = 1.000) between the 2 groups. Conversion occurred in 5 of 106 patients (4.7%). Survival analyses indicated similar recurrence-free survival (hazard ratio, 0.94; 95% CI, 0.40-2.20; P = .883) and overall survival (hazard ratio, 0.52; 95% CI, 0.05-5.02; P = .590) between the 2 groups. ConclusionsModified subxiphoid video-assisted thoracoscopic surgery thymectomy was safe and effective for T2-3 thymic malignancies and could be an alternative for selected patients with locally advanced thymic diseases. Further prospective studies are needed to evaluate the long-term survival of those undergoing modified subxiphoid approach thoracoscopic thymectomy.

P 04 - Toxicity and outcomes from Intensity Modulated Proton Therapy for Thymic Malignancies

P 04 - Toxicity and outcomes from Intensity Modulated Proton Therapy for Thymic Malignancies

Major vascular reconstructions in thoracic oncological surgery.

The replacement of the superior vena cava and thoracic outlet vessels for thoracic malignancies often becomes necessary for radical oncological surgery. The pulmonary artery can be directly infiltrated by the tumor or affected by metastatic hilar lymph nodes. In some cases, it must be resected and reconstructed to achieve oncological radicality and/or avoid pneumonectomy. This study reflects a single-surgeon, retrospective experience spanning 6years (2017-2023). We reviewed data from patients undergoing early anticoagulant therapy after superior vena cava or thoracic outlet vessels bypass and from patients undergoing early antiaggregation therapy following pulmonary artery reconstruction or resection. This series comprises 41 patients treated by a single surgeon. Fourteen patients underwent superior vena cava and thoracic outlet vessel procedures. Among these, eight patients received superior vena cava replacement (six for thymic malignancies and two for lung cancer), and six patients underwent jugular and subclavian artery/vein resection or replacement (all six had sarcomas). There was one death due to respiratory failure, not associated with bleeding or bypass closure. Additionally, there was one graft closure in a patient with severe coagulopathy and three instances of hemothorax (two patients had undiagnosed complex coagulopathies not evident in pre-operative routine blood tests). Following bleeding incidents, anticoagulation was initiated the next day in one case and based on hematological indications in the two coagulopathic patients. In the pulmonary artery series, 27 patients were involved: 20 underwent direct suture after tangential resection, and 7 received pericardial patch reconstruction. Only one case experienced bleeding necessitating redo-surgery. All these patients received early and chronic antiaggregation therapy after pulmonary artery reconstruction. We conclude that major thoracic oncological vascular surgery is safe and feasible with appropriate technical skills. However, achieving optimal results requires integration with correct early anticoagulant therapy or antiaggregation to maintain the patency of bypasses/grafts and prevent life-threatening risks associated with closure of the "new vessels."

Practical methods to differentiate thymic malignancies by positron-emission tomography and tumor markers.

An accurate diagnosis of thymic malignancies is important, but challenging due to the broad range of differential diagnoses. This study aims to evaluate the efficacy of PET/CT and tumor markers for diagnosing thymic malignancies. Patients admitted to our department between January 2012 and December 2021 with primary anterior mediastinal tumors were retrospectively evaluated. We evaluated the relationship between the maximum standardized uptake value (SUVmax), tumor markers, and pathological diagnosis in four groups: thymic carcinoma, thymoma, lymphoma, and others. In total, 139 patients were included in this study. The SUVmax was significantly higher in lymphoma, thymic carcinoma, and thymoma, in that order. The cytokeratin 19 fragment (CYFRA 21-1) was significantly higher in thymic carcinoma than in the other groups. An ROC curve analysis indicated that the optimal cut-off values of SUVmax for thymic carcinoma plus lymphoma and CYFRA 21-1 for thymic carcinoma were 7.97 (AUC = 0.934) and 2.95 (AUC = 0.768), respectively. Using a combination of cut-off values (SUVmax = 8, CYFRA 21-1 = 3), the accuracy rate for diagnosing thymic carcinoma was 91.4%. The SUVmax and CYFRA 21-1 levels are significant indicators for the diagnosis of thymic carcinoma. Combining these indicators resulted in a more accurate diagnosis of thymic malignancies, which could facilitate the decision-making process for determining the optimal treatment strategies.

Cytoreductive surgery combined with hyperthermic intrathoracic chemotherapy for the treatment of thymic epithelial malignancies with pleural spread or recurrence (CHOICE): a study protocol for a prospective, open, single-arm study.

Cytoreductive surgery combined with hyperthermic intrathoracic chemotherapy (S-HITHOC) may be effective in treating thymic epithelial tumors (TETs) with pleural spread or recurrence. This study will evaluate the safety and efficacy of S-HITHOC in the treatment of TETs with pleural spread or recurrence. This study is an open, single-arm, prospective trial. Approximately 37 patients diagnosed with TETs with pleural spread or recurrence at the Zhongshan Hospital of Fudan University will be recruited and treated with S-HITHOC. The co-primary outcomes of the study are the length of postoperative hospital stay, complications, and overall quality of life (QoL). The secondary outcomes include drainage duration, volume, and cumulative pain scores. This trial was approved by the Zhongshan Hospital Research Ethics Committee. The study findings will be actively disseminated through manuscript publications and conference presentations. Information sheets will be provided to each participant, and informed written consent will be obtained for each evaluation. This prospective study will evaluate the effectiveness of a surgical resection combined with the HITHOC procedure in treating TETs with pleural spread or recurrence in China and will support the standardization of the procedure. This trial was registered on Clinialtrial.gov (No. NCT05446935).

International reproducibility study of thymic epithelial tumors staging: pT stage is an issue. proposals for improvement. A RYTHMIC/ITMIG study

IntroductionPathologists are staging thymic epithelial tumors (TET) according to the 8th UICC/AJCC TNM system. Within the French RYTHMIC network, dedicated to TET, agreement on pathologic tumor stage (pT) among the pathology panelists was difficult. The aim of our study was to determine the interobserver reproducibility of pT at an international level, to explore the source of discrepancies and potential interventions to address these. MethodsAn international panel of pathologists was recruited through the International Thymic Malignancy Interest Group (ITMIG). The study focused on invasion of mediastinal pleura, pericardium, and lung. From a cohort of cases identified as challenging within the RYTHMIC network, we chose a series of test and validation cases (n = 5 and 10, respectively). ResultsReproducibility of the pT stage was also challenging at an international level as none of the 15 cases was classified as the same pT stage by all ITMIG pathologists. The agreement rose from slight (κ = 0.13) to moderate (κ = 0.48) between test and validation series. Discussion among the expert pathologists pinpointed two major reasons underlying discrepancies: 1) Thymomas growing with their “capsule” and adhering to the pleurae, pericardium, or lung were often misinterpreted as invading these structures. 2) Recognition of the mediastinal pleura was identified as challenging. ConclusionOur study underlines that the evaluation of the pT stage of TET is problematic and needs to be addressed in more detail in an upcoming TNM classification. The publication of histopathologic images of landmarks, including ancillary tests could improve reproducibility for future TNM classifications.

TNM Staging System in Thymoma: A Critical Appraisal?

Thymomas are rare tumors of the anterior mediastinum with peculiar clinical and pathological features. They have been deeply analyzed by pioneer authors, who strictly linked their name to the main pathological and staging classifications. Before the latest edition of the WHO classification of thymic epithelial tumors, the history of thymoma pathological classification inherited the name of the pathologists who systematically addressed the issue, from Levine-Rosai to Muller-Hermelink. Similarly, the thymoma staging system is intimately related to the name of two surgeons, Masaoka and Koga, who historically dealt with this disease. More recently, the traditional tumor-nodes-metastasis (TNM) system has been developed for the staging of this condition, in a rational attempt to put thymomas in conformity with the other solid tumors. The efforts of the International Thymic Malignancies Interest Group (ITMIG) and the Thymic Domain of the Staging and Prognostic Factors Committee (TD-SPFC) of the International Association for the Study of Lung Cancer (IASLC) resulted in the TNM classification of thymic tumors, which have been included in the eighth edition of the American Joint Committee on Cancer's (AJCC) Cancer Staging Manual. Herein, we report a narrative review of the evolution of the thymic epithelial tumors (TET) staging system and present a critical appraisal of the actual TNM classification compared with the historical Masaoka-Koga classification, with special focus on the proposal for the ninth edition of the TNM, expected in 2024.

A Phase 1/2 Study to Evaluate the Safety and Activity of Nivolumab in Combination With Vorolanib, a Vascular Endothelial Growth Factor Tyrosine Kinase Inhibitor, in Patients With Refractory Thoracic Tumors

IntroductionTargeting the tumor microenvironment may enhance response to immunotherapy (immune checkpoint inhibitors) and improve outcomes for patients. This study tested the safety and efficacy of vorolanib, a novel tyrosine kinase inhibitor of vascular endothelial growth factor, platelet-derived growth factor, and c-KIT, in combination with programmed cell death protein 1 blockade using nivolumab for refractory thoracic malignancies. MethodsThis single-arm multicenter study enrolled patients with extensive-stage SCLC, thymic carcinoma, and NSCLC, either naive or had progressed on previous chemotherapy or immune checkpoint inhibitors (either primary or acquired resistance). The primary objective of phase 1 was to determine the maximum tolerated dose, and the primary end point for each dose-expansion cohort was the objective response rate. ResultsA total of 88 patients were enrolled in phase 1 (n = 11) and dose expansion (n = 77) cohorts. Transaminitis was dose-limiting and expansion proceeded with oral vorolanib 200 mg daily combined with intravenous nivolumab 240 mg every 2 weeks. The objective response rate per cohort were as follows: NSCLC naive 33% (five of 15, 95% confidence interval [CI]: 13%–60%), NSCLC primary refractory 5.9% (one of 17, 95% CI: 0%–17.6%), NSCLC acquired resistance 11.1% (two of 18, 95% CI: 0%–27.8%); SCLC 0% (zero of 18), and thymic carcinoma 11% (one of nine, 95% CI: 0%–33%). Disease control rate ranged from 11.1% in SCLC (two of 18, 0%–27.8%) to 66.7 % in thymic carcinoma (six of nine, 95% CI: 33.3%–100%). The most common adverse events were fatigue (32%), aspartate transaminase (27%) and alanine transaminase elevation (25%), and diarrhea (19%). Transaminitis was more common in patients with thymic carcinoma than other tumors. ConclusionsVorolanib plus nivolumab had a manageable safety profile and may have clinical benefits in various thoracic malignancies. The disease control rate in thymic malignancies warrants further assessment.

Postoperative Radiation Therapy for Thymic Carcinoma: An Analysis of the International Thymic Malignancy Interest Group/European Society of Thoracic Surgeons Database

IntroductionR0 resection and radiation therapy have been associated with improved overall survival (OS) in patients with thymic carcinoma (TC). Here, we analyzed which subgroups of patients derive the greatest benefit from postoperative radiation therapy (PORT). MethodsClinical, pathologic, treatment, and survival information of 462 patients with TC from the International Thymic Malignancy Interest Group/European Society of Thoracic Surgeons database were analyzed. Variables included age, sex, continent of treatment, paraneoplastic syndrome, carcinoma subtype, tumor size, pathologic Masaoka stage, resection status, and use of chemotherapy. OS was the primary end point using the Kaplan-Meier method. Time to recurrence (TTR) was the secondary end point using a competing risk analysis. A 3-month landmark analysis was performed. ResultsPORT was associated with a significant OS benefit (5-y OS 68% versus 53%, p = 0.002). In patients with R0 resection, PORT was associated with increased OS for advanced (stages III–IV, p = 0.04), but not early (stages I–II, p = 0.14) stage TC. In patients with an R1/2 resection of advanced-stage TC, PORT was associated with significantly longer OS (5-y OS 53% versus 38%; p < 0.001). Subset analyses did not reveal clear associations of PORT with TTR. On multivariable analysis, lower pathologic stage, PORT, and R0 resection status were associated with an OS benefit, whereas only higher age and lower pathologic stage had an association with longer TTR. ConclusionsIn the largest individual patient data set on patients with TC reported to date, PORT was associated with a meaningful OS benefit in patients with advanced-stage TC after an R0 or R1/2 resection.

AB001. A study of the association between thymic malignancy histology and autoimmune paraneoplastic syndromes and opportunistic infections

AB001. A study of the association between thymic malignancy histology and autoimmune paraneoplastic syndromes and opportunistic infections

AB019. Anti-angiogenesis therapy in patients of thymic malignancies with hepatic metastasis

AB019. Anti-angiogenesis therapy in patients of thymic malignancies with hepatic metastasis

AB026. Outcomes and toxicities of definitive radiation therapy for unresected thymic malignancies

AB026. Outcomes and toxicities of definitive radiation therapy for unresected thymic malignancies

EP14.02-08 The Significance and Risk Factors of Lymph Node metastasis in Thymic Malignancies: A Large Population-based Database Analysis

EP14.02-08 The Significance and Risk Factors of Lymph Node metastasis in Thymic Malignancies: A Large Population-based Database Analysis