Thymic tumors

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.

Artificial intelligence-powered spatial analysis of tumor-infiltrating lymphocytes as a biomarker in locally advanced unresectable thymic epithelial neoplasm: A single-center, retrospective, longitudinal cohort study

BACKGROUND

Thymic epithelial tumors (TET) are rare malignancies and lack well-defined biomarkers for neoadjuvant therapy. This study aimed to evaluate the clinical utility of artificial intelligence (AI)-powered tumor-infiltrating lymphocyte (TIL) analysis in TET.

METHODS

Patients initially diagnosed with unresectable thymoma or thymic carcinoma who underwent neoadjuvant therapy between January 2004 and December 2021 formed our study population. Hematoxylin and eosin-stained sections from the initial biopsy and surgery were analyzed using an AI-powered spatial TIL analyzer. Intratumoral TIL (iTIL) and stromal TIL (sTIL) were quantified and their immune phenotype (IP) was identified.

RESULTS

Thirty-five patients were included in this study. The proportion of patients with partial response to neoadjuvant therapy was higher in the group with nondesert IP in preneoadjuvant biopsy (63.6% vs. 17.6%, p = 0.038). A significant increase in both iTIL (median 22.18/mm2 vs. 340.69/mm2 , p < 0.001) and sTIL (median 175.19/mm2 vs. 531.02/mm2 , p = 0.004) was observed after neoadjuvant therapy. Patients with higher iTIL (>147/mm2 ) exhibited longer disease-free survival (median, 29 months vs. 12 months, p = 0.009) and overall survival (OS) (median, 62 months vs. 45 months, p = 0.002). Patients with higher sTIL (>232.1/mm2 ) exhibited longer OS (median 62 months vs. 30 months, p = 0.021).

CONCLUSIONS

Nondesert IP in initial biopsy was associated with a better response to neoadjuvant therapy. Increased infiltration of both iTIL and sTIL in surgical specimens were associated with longer OS in patients with TET who underwent resection followed by neoadjuvant therapy.

Intuitive evaluation of contemporary management strategies in thymoma - the largest Indian experience

Background

The aim was perusal of the treatment strategies, clinical outcomes and factors impacting these outcomes in thymoma.

Materials and methods

A total of 119 patients diagnosed and treated cases of thymoma, at our hospital, were taken for analysis. Thirty-one patients were excluded due to inadequate medical records. Descriptive statistics were used to report demographic and clinical characteristics. Time period between diagnosis and death was defined as overall survival (OS). Multivariate analysis (MVA), using cox regression modelling, was done by including clinicopathological factors in a bid to identify prognostic factors influencing OS. SPSS version 26 was used for statistical analysis.

Results

The mean age of the patients was 52.17 years and 39 (44.3%), 19 (21.6%), 17 (1.3%) and 13 (4.8%) patients presented with Masaoka stage II, IV, III and I, respectively. Surgery was done in 64 (72.7%) of the patients as a part of the treatment strategy. Radiotherapy was administered to a total of 57 patients with a median dose of 50.4 Gy. Early Masaoka stage at presentation and use of surgery in the treatment plan were statistically significant prognostic factors for a better overall survival on multivariate analysis.

Conclusion

Judicious use of radiotherapy and chemotherapy in locally advanced cases may render them resectable. In a bid to gain good survival rates, aggressive multimodality treatment should be offered to the patients.

Risk factor analysis of thymoma resection and its value in guiding clinical treatment

BACKGROUND

In this study, relationships between clinicopathologic characteristics and progression-free survival (PFS) of patients after thymomectomy were analyzed to provide valuable suggestions regarding the treatment of thymoma.

METHODS

Data from 187 thymoma patients undergoing surgery at Beijing Tongren Hospital between January 1, 2006, and December 31, 2015, were retrospectively reviewed. We explored the risk factors for PFS among sex, age, thymoma-associated MG, completeness of resection, histologic type and TNM stage, and investigated their interrelationship.

RESULTS

Among the 187 patients, 18 patients (9.63%) had tumor recurrence/metastasis, and all of whom had in situ recurrence or pleural metastasis, and most of them (10 of 18 patients) had MG symptoms that reappeared or were aggravated. Fifteen patients (8.02%) died, and myasthenic crisis was a leading cause. Based on Cox regression analysis, only age (HR = 3.16; 95% CI: 1.44-6.91; p = 0.004) and the completeness of resection (HR = 9.03; 95% CI: 2.58-31.55; p = 0.001) were independent risk factors for PFS. Furthermore, we found that the completeness of resection was related to the histologic type (p = 0.009) and TNM stage (p < 0.001) by Fisher's exact test.

CONCLUSIONS

The results of this cohort study remind us that we should pay attention to the reappearance or aggravation of MG after thymoma resection, because it is the leading cause of death and may indicate tumor progression. Furthermore, completeness of resection was related to the histologic type and TNM stage, but it was the independent risk factors of thymoma. Therefore, R0 resection is critical to the prognosis of thymoma.

Unradical Surgery for Locally-Advanced Thymoma: Is it time to evolve Perspectives?

OBJECTIVES

Nearly-one-third of thymomas are locally-advanced at diagnosis. The traditional dogma that surgery is justified in case a complete resection can be achieved has remained unmovable until today. This study aimed to investigate feasibility and oncologic efficacy of incomplete resection for locally-advanced thymomas in a contest of multimodality therapy.

MATERIALS AND METHODS

A retrospective analysis was conducted using data of prospectively maintained thymomas database in a single high-volume centre. Data on 285 consecutive patients undergoing surgery for stage III and IVa thymomas between 1995 and 2019 were reviewed. Patients who underwent incomplete resection with curative-intent (removal of at least 90% of tumour burden) were included. Long-term outcomes and predictors of cancer-specific survival (CSS) and progression-free survival (PFS) were analyzed. Secondary endpoint was to assess adjuvant therapy efficacy.

RESULTS

The study included 79 patients, 60 with microscopic residual tumour (76%, R1) and 19 with macroscopic residual disease (24%, R2). Masaoka-Koga stage was: III in 41 patients (52%) and IVa in 38 (48%). Histology was B2-thymomas (n = 31, 39.2%) followed by B3 (n = 27, 34.2%). Five- and 10-years CSS was 88% and 80%. Seventy patients (90%) underwent adjuvant treatment; they showed CSS comparable to radical resected patients (5-years: 89.1% vs 98.9%, respectively; 10-years: 81.8% vs 92.7%, respectively, p = 0.43). The site of residual disease, Masaoka-Koga stage and WHO histology did not affect prognosis. Stepwise multivariable analysis confirmed adjuvant therapy as a favourable CSS prognostic factor (HR, 0.51; 95% CI, 0.33-0.79, p = 0.003). Stratifying by subgroups, R2-patients who received postoperative chemo(radio)therapy (pCRT) showed a significantly better prognosis than R2-patients treated by consolidation radiotherapy alone (10-years CSS: 60%, p < 0.001).

CONCLUSION

In locally-advanced thymomas, whenever a radical surgery cannot be achieved, incomplete resection has proved to be effective in a contest of multimodality strategy, independently of WHO histology, Masaoka-Koga stage and site of residual disease.

Thymoma and Thymic Carcinoma: Surgical Resection and Multidisciplinary Treatment

Thymoma and thymic carcinoma are the most common tumors of the anterior mediastinum and a relatively rare type of thoracic cancer. The prerequisite for surgery is clinical staging and operative evaluation, both of which are based on medical imaging. The best strategy for treating a thymic epithelial tumor is surgical resection of the organ and surrounding tissue. Thymectomy modalities vary, including open surgery and minimally invasive surgery, and surgeons have used various innovations to better meet the needs of the procedure; therefore, it is critical to select the appropriate procedure based on the patient's characteristics. Evaluation of resectability is the first step of surgical resection for thymic tumors without distant metastasis. The decision regarding unresectability should be made carefully. During subsequent chemotherapy or chemoradiotherapy, reevaluation of whether an area is resectable or not remains essential. Despite numerous technological advances in the surgical treatment of thymic tumors, several contentious issues remain, including the selection of surgical approaches for difficult cases, the selection of video-assisted thoracoscopic approaches, the evaluation of resectability, minimally invasive surgery for locally advanced thymic tumors, lymphadenectomy in thymic tumors, neoadjuvant therapy for thymic tumors, debulking surgery, and salvage surgery. In solving these problems, the surgeon's judgment, surgical experience, and surgical skills are especially important.

Invasive thymoma metastases to the pancreas: A case report

INTRODUCTION AND IMPORTANCE

Thymoma is the most common type of tumor that develops in the thymic epithelial cells. Although thymomas can invade surrounding organs in the chest cavity, extrathoracic metastasis is very rare, and little is known about the prognosis and effective treatments for such tumors. Herein, we report a case of an invasive thymoma metastasizing to the pancreas after incomplete resection.

CASE PRESENTATION

A 47-year-old man presented to our hospital with an anterior mediastinal mass. Although a thymic tumor was suspected, complete resection was not achieved because the tumor had invaded the pulmonary artery trunk, superior pulmonary vein, and left brachiocephalic vein. The pathological diagnosis was a Type B3 thymoma. The patient underwent chemotherapy and radiotherapy after surgery. Three years after surgery, computed tomography indicated a pancreatic mass suggestive of pancreatic cancer. Distal pancreatectomy was performed after neoadjuvant chemotherapy and radiotherapy. The pancreatic mass was diagnosed as Type B3 thymoma metastasis. Thirteen months after surgery for the pancreatic lesion, the patient underwent resection of the bilateral lung metastases.

CLINICAL DISCUSSION

To the best of our knowledge, only four cases of metastatic thymic tumors in the pancreas have been reported. All patients who underwent surgical resection for pancreatic metastasis survived for >6 months including our case.

CONCLUSION

In cases of thymic tumors with metastasis to extra-thoracic organs, complete resection of the metastatic lesions can contribute to prolonged survival.

Prognostic value of preoperative chemotherapy for thymic epithelial tumors: A propensity-matched analysis based on the SEER database

Background

The aim of this study was to assess the impact of preoperative chemotherapy on long-term survival (≥1 month) in patients with thymic epithelial tumors (TETs) and conditions suitable for chemotherapy using data from surveillance, epidemiology, and end-result databases.

Methods

This retrospective study controlled for confounding factors by propensity score matching (PSM), analyzed overall survival (OS) and cancer-specific survival (CSS) by Kaplan-Meier methods, and analyzed factors affecting the prognosis of patients undergoing surgery for thymic epithelial tumors by univariate and multifactorial Cox regression.

Results

A total of 2,451 patients who underwent surgery for TETs were identified from the Surveillance, Epidemiology, and End Results database. Preoperative chemotherapy significantly improved OS and CSS in patients with stage III/IV TETs compared to patients without preoperative chemotherapy. Subgroup analysis showed that patients younger than 60 years of age with TETs, patients with thymic carcinoma, and patients with TETs with multiple cancers were more likely to benefit from preoperative chemotherapy.

Conclusion

This study found that preoperative chemotherapy is a viable option for advanced thymoma with favorable overall and cancer-specific survival rates, but patient history and physical condition should be fully considered in conjunction with diagnostic imaging findings to assess patient tolerance to chemotherapy.

Postoperative clinical outcomes of patients with thymic epithelial tumors after over-3-year follow-up at a single-center

BACKGROUND

To evaluate postoperative clinical outcomes and analyze influencing factors for patients with thymic epithelial tumors over 3 years after operation.

METHODS

Patients with thymic epithelial tumors (TETs) who underwent surgical treatment in the Department of Thoracic Surgery at Beijing Hospital from January 2011 to May 2019 were retrospectively enrolled in the study. Basic patient information, clinical, pathological, and perioperative data were collected. Patients were followed up by telephone interviews and outpatient records. Statistical analyses were performed using SPSS version 26.0.

RESULTS

A total of 242 patients (129 men, 113 women) with TETs were included in this study, of which 150 patients (62.0%) were combined with myasthenia gravis (MG) and 92 patients (38.0%) were not. 216 patients were successfully followed up and their complete information was available. The median follow-up period was 70.5 months (range, 2-137 months). The 3-year overall survival (OS) rate of the whole group was 93.9%, and the 5-year OS rate was 91.1%. The 3-year relapse-free survival (RFS) rate of the whole group was 92.2%, and the 5-year relapse-free survival rate was 89.8%. Multivariable COX regression analysis indicated that recurrence of thymoma was an independent risk factor for OS. Younger age, Masaoka-Koga stage III + IV, and TNM stage III + IV were independent risk factors for RFS. Multivariable COX regression analysis indicated that Masaoka-Koga staging III + IV, WHO type B + C were independent risk factors for postoperative improvement of MG. For patients with MG, the postoperative complete stable remission (CSR) rate was 30.5%. And the result of multivariable COX regression analysis showed that thymoma patients with MG with Osserman staging IIA + IIB + III + IV were not prone to achieving CSR. Compared with patients without MG, MG was more likely to develop in patients with WHO classification type B, and patients with myasthenia gravis were younger, with longer operative duration, and more likely to develop perioperative complications.

CONCLUSIONS

The 5-year overall survival rate of patients with TETs was 91.1% in this study. Younger age and advanced stage were independent risk factors for RFS of patients with TETs, and recurrence of thymoma were independent risk factors for OS. In patients with MG, WHO classification type B and advanced stage were independent predictors of poor outcomes of MG treatment after thymectomy.

Risk factors for postoperative myasthenia gravis in patients with thymoma without myasthenia gravis: A systematic review and meta-analysis

Introduction

According to the principle, thymomas combined with myasthenia gravis (MG) require surgical treatment. However, patients with non-MG thymoma rarely develop MG and early- or late-onset MG after surgery is called postoperative MG (PMG). Our study used a meta-analysis to examine the incidence of PMG and risk factors.

Methods

Relevant studies were searched for in the PubMed, EMBASE, Web of Science, CNKI,and Wanfang databases. Investigations that directly or indirectly analyzed the risk factors for PMG development in patients with non-MG thymoma were included in this study. Furthermore, risk ratios (RR) with 95% confidence intervals (CI) were pooled using meta-analysis, and fixed-effects or random-effects models were used depending on the heterogeneity of the included studies.

Results

Thirteen cohorts containing 2,448 patients that met the inclusion criteria were included. Metaanalysis revealed that the incidence of PMG in preoperative patients with non-MG thymoma was 8%. Preoperative seropositive acetylcholine receptor antibody (AChR-Ab) (RR = 5.53, 95% CI 2.36 - 12.96, P<0.001), open thymectomy (RR =1.84, 95% CI 1.39 - 2.43, P<0.001), non-R0 resection (RR = 1.87, 95% CI 1.36 - 2.54, P<0.001), world health organization (WHO) type B (RR =1.80, 95% CI 1.07 - 3.04, P= 0.028), and postoperative inflammation (RR = 1.63, 95% CI 1.26 - 2.12, P<0.001) were the risk factors for PMG in patients with thymoma. Masaoka stage (P = 0.151) and sex (P = 0.777) were not significantly associated with PMG.

Discussion

Patients with thymoma but without MG had a high probability of developing PMG. Although the incidence of PMG was very low, thymectomy could not completely prevent the occurrence of MG. Preoperative seropositive AChR-Ab level, open thymectomy, non-R0 resection, WHO type B, and postoperative inflammation were risk factors for PMG.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022360002.

Giant thymoma with complete superior vena cava obstruction

Thymomas are rare epithelial tumors of the mediastinum with relatively good prognosis compared to other thoracic malignancies. Surgery is considered the best treatment and the most important determinant of long-term survival even in advanced stages. Nevertheless, complete resection may be challenging and require a multimodality approach. We present a case of a stage IVa thymoma surgically treated. The superior vena cava was completely occluded and, after resection, reconstruction was deemed unnecessary due to sufficient venous return through the azygos-inferior vena cava system. In our opinion, despite the morbidity of surgery in advanced thymomas, it should always be considered in expert hands.

Neoadjuvant radiotherapy plus single-incision thoracoscopic surgery in the treatment of type B3 thymomas

Background

Although minimally invasive surgery is the standard treatment for thymomas, minimally invasive thymectomy is difficult for patients with type B3 thymomas, especially for giant or aggressive lesions. These tumors are frequently treated with radical radiation therapy or surgery plus adjuvant radiotherapy. Few studies, however, have tested the efficacy of neoadjuvant radiotherapy prior to thoracoscopic surgery.

Methods

Patients with type B3 thymomas >5 cm or with infiltrates into vital organs on CT-guided puncture biopsy who underwent neoadjuvant radiotherapy followed by single-incision minimally invasive thymectomy from March 2016 to July 2020 were retrospectively evaluated. Reduction ratios, TNM stage changes according to WHO stage criteria, resectability, long-term survival, and the response in terms of RECIST v1.1 criteria achieved by preoperative RT were analyzed.

Results

The 11 patients who underwent neoadjuvant radiotherapy plus minimally invasive thymectomy included five men and six women, of mean age 49.5 years. Four patients had myasthenia gravis. Neoadjuvant radiotherapy consisted of 50 Gy in 25 fractions, with all patients showing varying degrees of lesion reduction after radiotherapy. Surgery was performed about 1 month after neoadjuvant radiotherapy, with none of these patients having severe radiation pneumonitis. All patients underwent radical resection of the tumor and adjacent tissue, with none experiencing tumor seeding or rupture during surgery. The median postoperative hospital stay was 3 days (range: 2-6 days) and the frequency of additional regular analgesics (including those for wound pain and neuralgia) was 2.5 times per person. On follow-up, one patient experienced pleural metastasis and one experienced pulmonary metastasis, with the other nine patients showing no evidence of tumor recurrence.

Conclusion

Neoadjuvant radiotherapy followed by minimally invasive surgery was a safe and efficacious procedure for the treatment of type B3 thymomas, with less postoperative pain and faster recovery. This strategy, of tumor shrinkage prior to surgery, may make possible the easier removal of type B3 thymomas by single-incision thoracoscopy.

Myasthenia gravis with achalasia secondary to thymoma: a case report and literature review

Background

Myasthenia gravis is an autoimmune neuromuscular junction disorder characterized by fatigable muscle weakness and autoantibodies. Frequent associations exist between myasthenia gravis and thymic abnormalities, including hyperplasia and thymoma. Several autoimmune illnesses have been identified to be associated with thymoma; however, a few case reports have linked thymoma and achalasia, and the underlying mechanism is unknown.

Case report

A 43-year-old man with thymoma-associated myasthenia gravis presented with dysphagia that was refractory to conventional treatment of myasthenia gravis. This dysphagia was challenging to diagnose even after multiple gastroenterology consults and upper endoscopy. The diagnosis of achalasia type II was established after a comprehensive evaluation, including upper endoscopy, barium swallow, and high-resolution esophageal manometry. The patient underwent elective pneumatic balloon dilatation, which successfully alleviated his dysphagia.

Conclusion

This case confirmed the association between myasthenia gravis secondary to thymoma and achalasia and showed how the diagnosis of achalasia was challenging. Awareness of this association is crucial for early diagnosis and treatment, improving affected patients' quality of life.

An Updated Review on Radiation Treatment Management in Thymus Cancers

This narrative review aims to summarize the currently available evidence for the role of radiation in the treatment of thymus cancers. Thymus cancers are rare, heterogeneous tumors with limited evidence to guide their clinical management. There remains some controversy over the role of radiation in the adjuvant and induction/definitive setting. We performed a systematic search of the MEDLINE/PubMed database, focusing on studies published within the last 30 years. Our search queried "thymoma [OR] thymic carcinoma [AND] radiation" and was limited only to prospective and retrospective studies and metanalyses, omitting books, documents, and reviews. Our search resulted in 174 total references, of which only 31 references were within the scope of interest ranging from 1988 to 2021. For resectable disease, there is prospective evidence to support the avoidance of postoperative radiation (PORT) in completely resected Masaoka stage I thymoma, but there is a lack of prospective evidence guiding the use of PORT in other situations. Several retrospective studies and metanalyses have suggested a benefit with PORT for positive margins and advanced stage disease, although it remains controversial whether PORT is beneficial for all completely resected Masaoka stage II thymoma. For unresectable disease, induction chemotherapy followed by reassessment of resectability is the preferred management. Prospective evidence exists to support the use of induction chemoradiation for patients unable to tolerate anthracycline-based chemotherapy and the use of definitive chemoradiation for those unable to undergo surgery. An effective multidisciplinary approach is the optimal strategy for achieving the best outcomes in patients with thymus cancers.

Effect of myasthenia gravis on the surgical outcomes of patients with thymoma

BACKGROUND

Myasthenia gravis (MG) is the most common paraneoplastic syndrome in thymoma. However, the association between MG and postoperative outcomes is controversial. Therefore, we examined the effect of MG on the surgical outcomes of patients with thymoma.

METHODS

This study enrolled 145 consecutive patients with thymoma who underwent surgical resection at our institution between January 2000 and December 2020. The patients were classified into thymoma with MG (MG group) and without MG (non-MG group). Data about characteristics of patients, surgical outcomes, and prognostic factors were compared between the two groups.

RESULTS

Of 145 patients, 47 (32%) presented with MG and 98 (68%) did not. There was no significant difference in terms of the incidence of postoperative complications, overall survival (OS), and recurrence-free survival (RFS) between the two groups. The deaths were not caused by thymoma. Among the patients aged >60 years, the MG group had a lower survival rate than the non-MG group. In the univariate analysis, age ≥60 years was a poor prognostic factor for OS, whereas in the multivariate analysis, Masaoka stage III and IV classifications were poor prognostic factors for RFS.

CONCLUSION

The incidence of postoperative complications did not differ between patients with thymoma and without MG. In the MG group, age ≥60 years was a poor prognostic factor for OS. The postoperative follow-up of patients aged ≥60 years with thymoma with MG should focus on not only recurrence but also progression of diseases other than thymoma.

Unilateral video-assisted thoracoscopic thymoma resection – Indications, early and mid-term results

Introduction. Thymoma is the most common tumour of the anterior mediastinum. Video-Assisted Thoracic Surgery technique of thymoma resection is spreading world-wide, but the thoracoscopic method is still contentious in many ways. Authors evaluate the early and mid-term results of a 17 years period of VATS unilateral approach at 2 Hungarian thoracic surgical centers. Method. Depending on the anatomical situation of the thymoma, we performed thymectomy, or partial thymectomy (thymomectomy) for the Masaoka–Koga I–II–III stage thymoma from the right or left side through 2 or 3 intercostal ports. We managed the operations with ultrasonic dissector and electrocauter. By using international standards we evaluated perioperative morbidity, mid-term oncological results and clinical symptoms of myasthenia. Results. 23 of the 54 patients were man, 31 were woman, the average age was 58 (26–79) years, 23 of them had myasthenia. The conversion rate was 11,5% (7/61). The average operation time was 84 (39–150) minutes. The average hospitalisation time was 5.5 (3–19) days. The average size of the thymomas was 46 (18–90) mm. The histology resulted thymoma type A in 2 cases, AB in 19 cases, B1/2/3 in 11/11/1 cases, mixed B in 10 cases. The examination of the resection line was R0/1/2 in 42/11/1 cases. The Masaoka–Koga stages were: I (17), IIA (28), IIB (2), III (7). There was 25 thymomectomies, and 29 thymectomies. In seven cases there were extension of the operation to the pericardium (2), to the lung (2), to the phrenic nerve (6), and to innominate vein (1). The in-hospital mortality over 30 day was in 1 case (1.85%). The morbidity was 11/54 (20.4%). The average follow-up time was 62.56 (5–198) months. In the group with myasthenia the effectivity of the operation was 18/21 (85.7%), including complete remission of 5/21 (23.8%). Post-thymectomy myasthenia gravis developed in 2/31 cases (6.5%). The average 5 years survival was 100%, tumour-free 5 years survival was 96%. Conclusions. The higher proportion of the thymomectomy in the early results, higher conversion rate and lower R0 proportion might be in connection with the attitude of the surgeons, with the learning curve and with the limitations of the unilateral method. After a longer follow-up time late results may become more real and comparable. Instead of unilateral VATS technique we have changed to the subxyphoideal approach of VATS because of its better visualisation.

Literature Review of Percutaneous Stenting for Palliative Treatment of Malignant Superior Vena Cava Syndrome (SVCS)

RATIONALE AND OBJECTIVES

To assess the efficacy and safety of percutaneous stenting for the palliative treatment of malignant superior vena cava syndrome (SVCS).

METHODS AND MATERIALS

Literature review of retrospective studies was performed regarding direct procedural complications (fatal and non-fatal), clinical effectiveness, and patency rates (primary and secondary) of percutaneous transluminal stenting for the palliative treatment of malignant SVCS. Pooled rates and 95% confidence intervals were calculated for fatal complications, non-fatal complications, clinical effectiveness, primary patency, and secondary patency. Pooled rates were presented overall and by stent types (Wallstent, Nitinol stents, Steel stents and Stent Graft). Odds ratios and 95% confidence intervals were calculated to compare rates by stent type.

RESULTS

Overall fatal complications rate was 1.46%, 95% CI [0.91 -2.23], non-fatal complications rate was 8.28%, 95% CI [6.91 -9.83], clinical effectiveness was 90.50%, 95% CI [88.86 -91.97], primary patency rate was 86.18%, 95% CI [84.06-88.12], secondary patency rate was 94.05 %, 95% CI [91.82 -95.82]. Primary patency rate of the Wallstent group was 83.38%, 95% CI [79.34 -86.90], and significantly higher for the Nitinol group 94.87%, 95% CI [87.40 -98.60], OR = 3.67, p = 0.01, and for the Stent Graft group 96.10%, 95% CI [89.00 -99.20], OR = 4.92, p = 0.01. Secondary patency rate for the Wallstent group was 93.33%, 95% CI [88.87 -96.40] and significantly lower for the Steel group 77.42%, 95% CI [58.90 -90.41], OR = 0.25, p = 0.01.

CONCLUSION

Percutaneous stenting is a safe option for palliative treatment of patients with malignant SVCS with greater than 90% of patients experiencing immediate relief of symptoms, low rates of fatal complications (1.46%) and high patency rates (86.18% primary patency and 94.05% secondary patency).

Maximal Thymectomy via Mini Sternotomy with Pleural Preservation

Gaurav PatelBackground  There are different surgical techniques used for maximal thymectomy. Each technique has its own advantages and disadvantages. We propose a mini sternotomy with pleural preservation approach for complete maximal thymectomy. Methods  Over time range of 5 years, 32 patients with diagnosis of thymoma with or without myasthenia gravis (MG) underwent maximal thymectomy by mini sternotomy in our institute. Patient records were examined for the following parameters: age, sex, preoperative medication, symptoms of MG as per Myasthenia Gravis Foundation of America grading system, operating time, duration of postoperative ventilation, length of stay in the intensive care unit, overall length of hospitalization, and postoperative complications. Results  The mean age of patients in our study was 43.66. Sex ratio in this study was almost equal. Sixty-nine percent of patients were stage I thymoma according to Masaoka staging. Size of the tumor ranged from 3 to 8 cm with mean size being 4.54 cm. Complete resection with negative tumor margins was possible in all the cases. Four patients had intraoperative pleural injury out of which two patients required intercostal tube insertion. We did not have any serious postoperative complications with no perioperative mortality. Conclusions  Mini sternotomy allows maximal removal of thymus through a less invasive approach and is associated with a significantly smoother postoperative course, less overall complications, and good clinical outcome. It is a simple technique that can be performed by any thoracic and surgical oncologists especially in Indian subcontinent where facilities of video-assisted thoracoscopic surgery and robotic video-assisted thoracoscopic surgery are not available in all areas and are expensive.

Can the Ratio SUVmax of the Lesion/SUVmax of Mediastinal Tissues Guide the Choice of Surgical Access for the Resection of Thymic Epithelial Tumors?

Background

There are studies showing the utility of the 18-fluorodeoxyglucose positron emission tomography (18FDG PET) scan in the management of patients with thymic epithelial tumors. It seems to be a correlation between the standard uptake value (SUVmax) of thymic epithelial tumors and the histological type and the stage. This study aims to use the ratio of the SUVmax of the lesion to the SUVmax of the adjacent mediastinal tissues in order to guide the choice of the surgical access.

Methods

All patients who presented an anterior mediastinal lesion with a high suspicion of being of thymic origin were included in a prospective database. A ratio inferior to 1 could predict a benign nature and less aggressive behavior, and a minimally invasive approach was performed. A ratio superior to 1 suggested a malignant and aggressive behavior, and a median sternotomy (or a thoracotomy) was performed.

Results

There were 15 male (mean age 44.6 ± 16.26 years, range 25–73) and 15 female patients (mean age 50.1 ± 16.94 years, range 25–76). When the ratio is inferior to 1, it predicts benign disease in 80% of cases. When it is superior to 1, it predicts in half of cases advanced histological types (high risk thymomas and thymic carcinomas). On the contrary, it can quite accurately predict advanced Masaoka–Koga stages.

Conclusions

The protocol of this study is in accordance with the current literature showing the utility of 18FDG PET scan in the treatment of thymic epithelial tumors. This study goes one step further since the choice of surgical access is based on the SUVmax values. The ratio SUVmax of the lesion/SUVmax of the mediastinal tissues could be a new marker, more pertinent than absolute SUVmax values.

Thymic tumours: a single center surgical experience and literature review on the current diagnosis and management of thymic malignancies

OBJECTIVE

This study aimed to provide an extensive overview of clinical and pathological findings along with various therapeutic options analyzing in addiction, retrospectively, the surgical outcomes of a single center cohort.

BACKGROUND

Thymic neoplasms are rare thoracic tumors which commonly are located in the anterior mediastinum and are associated with a wide spectrum of clinical presentations. They may run an indolent course or could present a very aggressive biologic progression with infiltration of mediastinal structures and presence of distant metastases. The pathogenesis of these tumors is so far not completely clear. Several treatment modalities in a multidisciplinary setting have to be considered in order to provide the best treatment for patients affected by thymic tumors.

METHODS

We conducted a retrospective cohort analysis of all patients who underwent surgery due to thymic tumor in a university hospital located in Switzerland (Bern University Hospital) and then we performed a narrative review of the English literature using PubMed, Embase, Cochrane Database of Systematic Reviews and Scopus.

CONCLUSIONS

Minimally invasive techniques play an important role in the treatment of thymic tumors. A careful patients selection in a multidisciplinary setting is mandatory in order to offer the best treatment for patients affected by thymic tumors.

Partial Versus Complete Thymectomy in Non-Myasthenic Patients With Thymoma: A Systematic Review and Meta-Analysis of Clinical Outcomes

The optimal extent of surgical resection for non-myasthenic patients with thymoma is controversial. The objective of this meta-analysis was to compare complete to partial thymectomy in non-myasthenic patients for oncological and postoperative clinical outcomes. We performed a PubMed and EMBASE search (from inception to January 2020) for English-language studies directly comparing partial to complete thymectomy for thymoma resection. Clinical endpoints studied included overall and disease-free survival, Masaoka and World Health Organization staging, adjuvant therapy, postoperative complications, postoperative drainage, length of hospital stay, thymoma-related deaths, postresection development of myasthenia gravis, incomplete resection, and recurrence. Random effects meta-analyses across all clinical endpoints was done. There was no statistically significant difference between the two approaches with regard to recurrence (odds ratio [OR], 1.22; 95% confidence interval [CI], 0.78-1.92), completeness of resection (OR, 1.17; 95% CI, 0.66-2.10), adjuvant therapy (OR, 0.71; 95% CI, 0.40-1.26), or thymoma-related deaths (OR, 0.76; 95% CI, 0.12-4.66). There was a statistically significant decrease in postoperative complications (OR, 0.61; 95% CI, 0.39-0.97), drainage (mean difference [MD], -0.99; 95% CI, -1.98 to -0.01), and length of hospital length (MD, -1.88; 95% CI, -3.39 to -0.36) with partial thymectomy. The evidence appeared to suggest that partial thymectomy is oncologically equivalent to complete thymectomy for non-myasthenic patients with early-stage thymoma. There is an additional advantage of reduced postoperative complications and decreased length of hospital stay with partial thymectomy.

Evaluation of Surgical Therapy in Advanced Thymic Tumors

A complete resection of thymic tumors is known to be the most important prognostic factor, but it is often difficult to perform, especially in advanced stages. In this study, 73 patients with advanced thymic tumors of UICC stages III and IV who underwent radical resection were examined retrospectively. The primary endpoint was defined as the postoperative resection status. Secondary endpoints included postoperative morbidity, mortality, recurrence/progression-free, and overall survival. In total, 31.5% of patients were assigned to stage IIIa, 9.6% to stage IIIb, 47.9% to stage IVa, and 11% to stage IVb. In stages III a R0 resection was achieved in 53.3% of patients. In stages IV a R0/R1 resection was documented in 76.7% of patients. Surgical revision was necessary in 17.8% of patients. In-hospital mortality was 2.7%. Median recurrence/progression-free interval was 43 months (p = 0.19) with an overall survival of 79 months. The 5-year survival rate was 61.3%, respectively. Median survival after R2 resection was 25 months, significantly shorter than after R0 or R1 resection (115 months; p = 0.004). Advanced thymic tumors can be resected with an acceptable risk of complications and low mortality. In stage III as well as in stage IV the promising survival rates are dependent on the resection-status.

Central Nervous System Metastases in Thymic Epithelial Tumors: A Brief Report of Real-World Insight From RYTHMIC

Thymic epithelial tumors (TETs) are rare malignancies ranging from indolent thymoma A to aggressive thymic carcinomas (TCs). Brain metastases are extremely infrequent for TETs and have only been described in case reports or small single-center series. RYTHMIC (Réseau tumeurs THYMiques et Cancer) is a French nationwide network mandated to systematically review every TET case and prospectively includes all consecutive patients discussed by national or regional tumor boards. We analyzed patients with TETs and central nervous system (CNS) metastasis during their cancer history from this large French registry. In an 8-year period, 2909 patients were included in the database, including 248 TCs (8.5%). A total of 14 patients had CNS metastases, five (36%) at diagnosis and nine (64%) at relapse. Among them, 12 patients (86%) had a diagnosis of TC and two (14%) had thymoma A and B3. Surgical biopsies were performed, and the histologic subtype for non-TC tumors was centrally confirmed. Median overall survival was 22 months (95% confidence interval [CI]: 9.8-34.2), with longer, albeit not significant, overall survival when CNS metastases were present at diagnosis versus relapse (not reached versus 17 mo; p = 0.29); median progression-free survival was 13 versus 8 months (p = 0.06), respectively. A higher risk of death (hazard ratio = 5.34, 95% CI: 1.3-21.9, p = 0.02) and relapse (hazard ratio = 1.89, 95% CI: 0.9-3.7, p = 0.06) was observed for patients suffering from TC with brain metastases compared with those without CNS extension. CNS disease was extremely rare in our TET cohort (0.48%), reported at both diagnosis and progression, present primarily in TC, with prevalence rising to 4.9%.

Induction Strategy for Locally Advanced Thymoma

Surgery remains cornerstone for the management of thymoma. Complete surgical resection (R0), is recognized as the constant and significant factor for prognosis. However, in locally advanced (Masaoka-Koga stages III-IVa) thymomas, achieving R0 resection remains challenging due to local-regional invasion of the disease. Induction treatment, with the aim of reducing bulky tumor mass, offers new strategy to facilitate totally surgical resection. Herein, we reviewed recent progress and provided a comprehensive overview of induction strategy in locally advance thymoma.

The International Thymic Malignancy Interest Group Classification of Thymoma Recurrence: Survival Analysis and Perspectives

INTRODUCTION

The International Thymic Malignancy Interest Group (ITMIG) classifies thymoma recurrences on the basis of the topographic location, but its effectiveness in prognosis prediction has not been well investigated yet. Aims of this study are to analyze survival outcome of patients surgically treated for thymoma recurrence according to the ITMIG recurrence classification and to investigate possible alternatives.

METHODS

From January 1, 1990, to January 7, 2017, data on 135 surgically treated patients for thymoma recurrence from three high-volume centers were collected and retrospectively analyzed. Patients were classified according to the ITMIG classification as local, regional, and distant. The ITMIG classification and alternative classifications were correlated to overall survival (OS).

RESULTS

According to the ITMIG classification, recurrence was local in 17 (12.5%), regional in 97 (71.8%), and distant in 21 (15.7%) patients, with single localization in 38 (28.2%) and multiple localizations in 97 (71.8%). The 5- and 10-year OS were 79.9% and 49.7% in local, 68.3% and 52.6% in regional, and 66.3% and 35.4% in distant recurrences, respectively, but differences were not statistically significant (p = 0.625). A significant difference in survival was present considering single versus multiple localizations: 5- and 10-year OS of 86.2% and 81.2% versus 61.3% and 31.5% (p = 0.005, hazard ratio = 7.22, 95% confidence interval: 0.147-0.740), respectively. Combining the localization number with the recurrence site, ITMIG locoregional single recurrence had a statistically significant better survival compared with patients with ITMIG locoregional multiple recurrence or ITMIG distant recurrence (p = 0.028). Similarly, a significant difference was present considering intrathoracic single versus intrathoracic multiple versus distant recurrence (p = 0.024).

CONCLUSIONS

The ITMIG classification for thymoma recurrence did not have significant survival differences comparing local, regional, and distant recurrences. Integrating this classification with the number of the localizations may improve its effectiveness in prognosis prediction.

Identification and Characterization of Non-Coding RNAs in Thymoma

BACKGROUND Thymoma is the most common tumor of the anterior mediastinum, and can be caused by infrequent malignancies arising from the epithelial cells of the thymus. Unfortunately, blood-based diagnostic markers are not currently available. High-throughput sequencing technologies, such as RNA-seq with next-generation sequencing, have facilitated the detection and characterization of both coding and non-coding RNAs (ncRNAs), which play significant roles in genomic regulation, transcriptional and post-transcriptional regulation, and imprinting and epigenetic modification. The knowledge about fusion genes and ncRNAs in thymomas is scarce. MATERIAL AND METHODS For this study, we gathered large-scale RNA-seq data belonging to samples from 25 thymomas and 25 healthy thymus specimens and analyzed them to identify fusion genes, lncRNAs, and miRNAs. RESULTS We found 21 fusion genes, including KMT2A-MAML2, HADHB-REEP1, COQ3-CGA, MCM4-SNTB1, and IFT140-ACTN4, as the most frequent and significant in thymomas. We also detected 65 differentially-expressed lncRNAs in thymomas, including AFAP1-AS1, LINC00324, ADAMTS9-AS1, VLDLR-AS1, LINC00968, and NEAT1, that have been validated with the TCGA database. Moreover, we identified 1695 miRNAs from small RNA-seq data that were overexpressed in thymomas. Our network analysis of the lncRNA-mRNA-miRNA regulation axes identified a cluster of miRNAs upregulated in thymomas, that can trigger the expression of target protein-coding genes, and lead to the disruption of several biological pathways, including the PI3K-Akt signaling pathway, FoxO signaling pathway, and HIF-1 signaling pathway. CONCLUSIONS Our results show that overexpression of this miRNA cluster activates PI3K-Akt, FoxO, HIF-1, and Rap-1 signaling pathways, suggesting pathway inhibitors may be therapeutic candidates against thymoma.

Vascular Involvement in Thymic Epithelial Tumors: Surgical and Oncological Outcomes

BACKGROUND

The involvement of mediastinal great vessels is common in advanced stage thymic tumors, which makes their surgical resection challenging. Moreover, the impact of vascular involvement on the oncological prognosis is still unclear. The aim of this study is to investigate the surgical and oncological outcomes and the impact of vascular involvement in a population of patients operated for advanced stage thymic tumors.

METHODS

A retrospective analysis on four hundred and sixty-five patients undergoing resection for advanced stage (Masaoka III-IV) thymic tumors in a single high-volume center was performed. One hundred forty-four patients met the inclusion criteria and were eligible for the study. Patients were divided in two groups according to the presence or absence of vascular involvement.

RESULTS

the two groups did not differ for the baseline characteristics and showed comparable surgical outcomes. Vascular involvement was not associated with worse overall survival but with an increased recurrence rate (p = 0.03). Multivariable analysis demonstrated a higher risk of recurrence in patients without R0 resection (HR 0.11, 0.02-0.54, p = 0.006) and with thymic carcinoma (HR 2.27, 1.22-4.24, p = 0.01).

CONCLUSIONS

resection of thymic tumors with vascular involvement can be performed with optimal surgical results in a high volume center. From the oncological point of view, the involvement of the great vessels seems to be associated with a higher recurrence rate without affecting long-term survival.

A Retrospective Study on Using a Novel Single Needle Cone Puncture Approach for the Iodine-125 Seed Brachytherapy in Treating Patients With Thoracic Malignancy

Background

Patients with progressive thoracic malignancy characterized by large irregular tumors with necrosis and life-threatening symptoms lack effective treatments. We set out to develop a single needle cone puncture method for the Iodine-125 seed (SNCP-¹²⁵I) brachytherapy, and aim to report the initial results.

Methods

294 patients with advanced thoracic malignancy were treated with local SNCP-¹²⁵I brachytherapy between March 2009 and July 2020, followed by thorough evaluation of clinical outcome, overall survival (OS), progression-free survival (PFS) and procedure-related complications after treatment.

Results

The overall response rate (ORR) among the treated patients was 81.0% (238/294). Life-threatening symptoms due to tumor oppression, hemoptysis and large irregular tumor with necrosis were successfully alleviated after the SNCP-¹²⁵I treatment with a remission rate at 91% to 94%. The median OS and PFS were 13.6 months and 5.8 months, respectively. Procedure-related side effects including pneumothorax (32/294), blood-stained sputum (8/294), subcutaneous emphysema (10/294), puncture site bleeding (16/294) and chest pain (6/294) were observed. Patients who were able to follow with chemotherapy or immunotherapy experienced extended OS and PFS, as compared with patients who opted to receive hospice care (16.5 months Vs. 11.2 months). Further pathological and immunological analysis showed that SNCP-¹²⁵I induced tumor lymphocytes infiltration and long-term tumor necrosis.

Conclusion

SNCP-¹²⁵I brachytherapy effectively eliminates life-threatening symptoms due to local tumor oppression, hemoptysis and large irregular and necrotic tumors in patients with unresectable chest malignancy and significantly induces local tumor regression. SNCP-¹²⁵I brachytherapy combines with chemotherapy significantly prolong OS and PFS compare with SNCP-¹²⁵I brachytherapy alone.

3D DenseNet Deep Learning Based Preoperative Computed Tomography for Detecting Myasthenia Gravis in Patients With Thymoma

Background

Myasthenia gravis (MG) is the most common paraneoplastic syndromes of thymoma and closely related to thymus abnormalities. Timely detecting of the risk of MG would benefit clinical management and treatment decision for patients with thymoma. Herein, we developed a 3D DenseNet deep learning (DL) model based on preoperative computed tomography (CT) as a non-invasive method to detect MG in thymoma patients.

Methods

A large cohort of 230 thymoma patients in a hospital affiliated with a medical school were enrolled. 182 thymoma patients (81 with MG, 101 without MG) were used for training and model building. 48 cases from another hospital were used for external validation. A 3D-DenseNet-DL model and five radiomic models were performed to detect MG in thymoma patients. A comprehensive analysis by integrating machine learning and semantic CT image features, named 3D-DenseNet-DL-based multi-model, was also performed to establish a more effective prediction model.

Findings

By elaborately comparing the prediction efficacy, the 3D-DenseNet-DL effectively identified MG patients and was superior to other five radiomic models, with a mean area under ROC curve (AUC), accuracy, sensitivity, and specificity of 0.734, 0.724, 0.787, and 0.672, respectively. The effectiveness of the 3D-DenseNet-DL-based multi-model was further improved as evidenced by the following metrics: AUC 0.766, accuracy 0.790, sensitivity 0.739, and specificity 0.801. External verification results confirmed the feasibility of this DL-based multi-model with metrics: AUC 0.730, accuracy 0.732, sensitivity 0.700, and specificity 0.690, respectively.

Interpretation

Our 3D-DenseNet-DL model can effectively detect MG in patients with thymoma based on preoperative CT imaging. This model may serve as a supplement to the conventional diagnostic criteria for identifying thymoma associated MG.

Meta-Analysis of Limited Thymectomy versus Total Thymectomy for Masaoka Stage I and II Thymoma

Background

This meta-analysis aimed to evaluate the incidence of tumor recurrence, postoperative myasthenia gravis, postoperative complications, and overall survival after limited versus total thymectomy for Masaoka stage I and II thymoma.

Methods

A systematic search of the literature was conducted using the PubMed, Embase, MEDLINE, and Cochrane databases to identify relevant studies that compared limited and total thymectomy in Masaoka stage I-II patients. The quality of the included observational studies was assessed using the Newcastle-Ottawa Scale. The results of the meta- analysis were expressed as log-transformed odds ratios (log ORs), with 95% confidence intervals (CIs).

Results

Seven observational studies with a total of 2,310 patients were included in the meta-analysis. There was an overall non-significant difference in favor of total thymectomy in terms of tumor recurrence (pooled log OR, 0.40; 95% CI, -0.07 to 0.87; p=0.10; I²=0%) and postoperative myasthenia gravis (pooled log OR, 0.12; 95% CI, -1.08 to 1.32; p=0.85; I²=22.6%). However, an overall non-significant difference was found in favor of limited thymectomy with respect to postoperative complications (pooled log OR, -0.21; 95% CI, -1.08 to 0.66; p=0.64; I²=36.1%) and overall survival (pooled log OR, -0.01; 95% CI, -0.68 to 0.66; p=0.98; I²=47.8%).

Conclusion

Based on the results of this systematic review and meta-analysis, limited thymectomy as a treatment for stage I and II thymoma shows similar oncologic outcomes to total thymectomy.

[Case report of an osseous (and lymphogenic) thymic carcinoma in an adult]

A Thymic carcinoma in adults is rare. We present the case of a 47-year-old man, who was treated conservatively for spondylolisthesis L5/S1 in our institution for several years. In the further course, the patient complained about pain exacerbation with acute lower back pain. Cross-sectional scanning showed a tumor of the lumbar vertebral body three. A biopsy of this mass revealed a metastatic thymic carcinoma of the squamous cells. After palliative therapy, the patient died 9 months after initial diagnosis.

Anterior Mediastinal Lesion Segmentation Based on Two-Stage 3D ResUNet With Attention Gates and Lung Segmentation

OBJECTIVES

Anterior mediastinal disease is a common disease in the chest. Computed tomography (CT), as an important imaging technology, is widely used in the diagnosis of mediastinal diseases. Doctors find it difficult to distinguish lesions in CT images because of image artifact, intensity inhomogeneity, and their similarity with other tissues. Direct segmentation of lesions can provide doctors a method to better subtract the features of the lesions, thereby improving the accuracy of diagnosis.

METHOD

As the trend of image processing technology, deep learning is more accurate in image segmentation than traditional methods. We employ a two-stage 3D ResUNet network combined with lung segmentation to segment CT images. Given that the mediastinum is between the two lungs, the original image is clipped through the lung mask to remove some noises that may affect the segmentation of the lesion. To capture the feature of the lesions, we design a two-stage network structure. In the first stage, the features of the lesion are learned from the low-resolution downsampled image, and the segmentation results under a rough scale are obtained. The results are concatenated with the original image and encoded into the second stage to capture more accurate segmentation information from the image. In addition, attention gates are introduced in the upsampling of the network, and these gates can focus on the lesion and play a role in filtering the features. The proposed method has achieved good results in the segmentation of the anterior mediastinal.

RESULTS

The proposed method was verified on 230 patients, and the anterior mediastinal lesions were well segmented. The average Dice coefficient reached 87.73%. Compared with the model without lung segmentation, the model with lung segmentation greatly improved the accuracy of lesion segmentation by approximately 9%. The addition of attention gates slightly improved the segmentation accuracy.

CONCLUSION

The proposed automatic segmentation method has achieved good results in clinical data. In clinical application, automatic segmentation of lesions can assist doctors in the diagnosis of diseases and may facilitate the automated diagnosis of illnesses in the future.

Single-center evaluation of prognostic factors for thymoma treated by surgery: a retrospective study

BACKGROUND

This study aimed to retrospectively evaluate the clinical, pathological, and treatment-related factors associated with survival in patients with surgically treated thymomas.

METHODS

Sixty patients with thymomas who underwent treatment at our institution between 2004 and 2015 were included. Survival analysis was performed based on curves that were obtained using the Kaplan-Meier method. The Wilcoxon test was used for all comparisons, and p < 0.05 was considered statistically significant.

RESULTS

Forty-seven, four, three, four, and two patients presented tumor stages I, II, III, IVa, and IVb (according to the Masaoka classification), respectively, while six, 14, 11, 22, and seven patients had type A, AB, B1, B2, and B3 thymomas, respectively. Furthermore, 53 and eight patients underwent complete resection and required additional resection of adjacent organs, respectively, and no patients died from surgery-related complications. The five-year survival and recurrence-free survival (RFS) rates were 96 and 86%, respectively. The five-year survival rate for all stages was 100% except for those with stage IVb tumors (Masaoka classification); the survival rate for those patients was 0%. Separately, the five-year RFS rates for tumor stages I, II, III, IVa, and IVb were 100, 91, 91, 81, and 71%, respectively. Finally, the five-year survival rates in cases with complete and incomplete resections were 100 and 71%, respectively, indicating that the latter group had a significantly poorer prognosis (p < 0.001).

CONCLUSIONS

These findings suggest that complete resection and the Masaoka pathological stage are significant predictors of prognosis in patients with thymomas. Surgery should aim to achieve complete resection; however, advanced cases may require multimodality therapy.

Case Report: MDM4 Amplified in a Thymoma Patient With Autoimmune Enteropathy and Myocarditis

INTRODUCTION

Thymoma is a type of mediastinal malignant tumors which always associated with autoimmune diseases. Although surgery is the predominant treatment method for thymoma, the pathogenesis of thymoma and thymoma-associated autoimmune diseases is still unknown. However, the case study here provided a possible pathogenesis and treatment to cure the thymoma with autoimmune enteropathy and myocarditis.

CASE PRESENTATION

A thymoma case with autoimmune enteropathy and myocarditis undergoing surgery was reported. The symptoms and laboratory results of the patient had dramatically fluctuated after tumor resection and gradually alleviated. The whole exome sequencing found MDM4 amplified in tumor cells. Immunohistochemistry indicated that thymoma cells were positive for MDM4. The result of drug sensitivity tests showed thymoma cells were highly sensitive to Nutlin-3a.

CONCLUSION

MDM4 could play an important role in the pathogenesis of this thymoma case with autoimmune enteropathy and myocarditis. This discovery may provide a novel idea of pathogenesis and treatment for thymoma and autoimmune diseases.

Effect of Postoperative Radiotherapy in Thymoma Patients: A SEER-Based Study

INTRODUCTION

The role of postoperative radiation therapy (PORT) for thymoma is under debate, especially in patients aged ≥60 years with an advanced stage (Masaoka stages III and IV). We aimed to evaluate the efficacy of PORT for thymoma in a population-based registry.

METHODS

A retrospective analysis of the Surveillance, Epidemiology, and End Results (SEER) database was conducted to compare the outcomes of thymoma patients with or without PORT. The primary outcomes were overall survival (OS) and cancer-specific survival (CSS). Conditional inference tree analyses were performed for risk classification according to the study variables. Cox regression was performed to evaluate the prognostic effect of PORT in the specific subgroups.

RESULTS

A total of 2,236 patients were included. The conditional inference tree analysis identified that an age ≥60, a Masaoka stage ≥3, and the year of diagnosis were important factors when classifying patients into prognostic subgroups. PORT was found to be a protective predictor of OS in patients aged ≥60 years, those with a Masaoka stage III-IV, and those diagnosed after 2005. Further subgroup analyses revealed that PORT was significantly associated with a better OS (HR = 0.77) in patients aged ≥60 years, whereas it was not significantly associated with CSS.

CONCLUSIONS

An older age (≥60 years) is critical for predicting survival outcomes in thymoma patients. Moreover, patients aged ≥60 years could benefit from PORT in terms of OS.

Classification and staging of thymoma

The appropriate therapy and prognosis of patients with thymic malignancies is decisively influenced by the local extent and dissemination of the tumor. For this reason, a staging system that reflects these factors is essential. Mainly the Masaoka-Koga classification, which was introduced in 1994, has been applied for this purpose. The rarity of thymic malignancies makes it difficult not only to establish internationally standardized diagnostics and treatment, but also to progress staging. Besides, efforts were made to adapt the classification into a tumor-node-metastasis-based (TNM) system for standardization with the staging of other tumor entities. The 2017 published 8th edition of the TNM Classification of Malignant Tumors introduced several adjustments based on a proposal of the International Association for the Study of Lung Cancer (IASLC) and the International Thymic Malignancy Interest Group (ITMIG). Compared to the Masaoka-Koga classification, surgically good resectable tumor involvements like pericardium, mediastinal fat or mediastinal pleura have been shifted to lower stages. Thus, even more than in Masaoka-Koga classification, tumors are basically divided into completely resectable and thus surgically treatable tumors (stage I, II, IIIA) and advanced stages (stage IIIB, IVA and IVB) that require multimodal therapy.

Myasthenia Gravis Is Not an Independent Prognostic Factor of Thymoma: Results of a Propensity Score Matching Trial of 470 Patients

Objective

The association between the prognosis of thymoma and MG remains controversial. Differences in clinical characteristics and treatments between patients with and without MG may affect the findings of those studies. We designed this propensity score matching trial to investigate whether MG is an independent prognostic predictor in thymoma.

Methods

Patients with pathologically diagnosed thymoma and MG were enrolled in the MG group. Moreover, the propensity score matching method was used to select patients who were diagnosed with thymoma without MG from the database of two participating centers. Matched factors included sex, age, Masaoka stage, pathological subtypes, and treatments. Matched patients were enrolled in the non-MG group. Chi-squared test was used to compare the characteristics of the two groups. Overall survival, local-regional relapse-free survival, distant metastasis-free survival, progression-free survival, and cancer-specific survival were calculated from the diagnosis of thymoma using the Kaplan–Meier method.

Results

Between April 1992 and October 2018, 235 patients each were enrolled in the MG and non-MG groups (1:1 ratio). The median ages of patients in the MG and non-MG groups were 46 years old. The World Health Organization pathological subtypes were well balanced between the two groups (B2 + B3: MG vs. non-MG group, 63.0 vs. 63.4%, p = 0.924). Most patients in both groups had Masaoka stages I–III (MG vs. non-MG group, 90.2 vs. 91.5%, p = 0.631). R0 resections were performed in 86.8 and 90.2% of the MG and non-MG groups, respectively (p = 0.247). The median follow-up time of the two groups was 70.00 months (MG vs. non-MG group, 73.63 months vs. 68.00 months). Five-year overall survivals were 92.5 and 90.3%, 8-year overall survivals were 84.2 and 84.2%, and 10-year overall survivals were 80.2 and 81.4% (p = 0.632) in the MG and non-MG groups, respectively. No differences were found in the progression-free survival, distant metastasis-free survival, and local-regional relapse-free survival between the two groups.

Conclusion

MG is not an independent or direct prognostic factor of thymoma, although it might be helpful in diagnosis thymoma at an early stage, leading indirectly to better prognosis.

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.

Report from the European Society of Thoracic Surgeons prospective thymic database 2017: a powerful resource for a collaborative global effort to manage thymic tumours

OBJECTIVES

We queried the European Society of Thoracic Surgeons (ESTS) prospective thymic database for descriptive analysis and for comparison with the ESTS retrospective thymic database (1990-2010).

METHODS

Data were retrieved (January 2007-November 2017) for 1122 patients from 75 ESTS institutions.

RESULTS

There were 484 (65%) thymomas, 207 (28%) thymic carcinomas and 49 (7%) neuroendocrine thymic tumours. Staging (Masaoka) included 483 (67%) stage I and II, 100 (14%) stage III and 70 (10%) stage IV tumours. The new International Association for the Study of Lung Cancer/International Thymic Malignancies Interest Group tumour, node and metastasis (TNM) classification was available for 224 patients and including 177 (85%) stage I-II, 37 (16%) stage IIIA and 10 (4%) stage IIIB tumours. Chemotherapy as induction and adjuvant treatment was used in 14% and 15% of the patients. Radiotherapy was almost exclusively used postoperatively (24%). A minimally invasive surgical approach (video-assisted thoracic surgery/robotic-assisted thoracic surgery) was used in 276 (33%) patients. The overall recurrence rate was 10.8% (N = 38). Compared to the ESTS retrospective database, the increased prevalence of thymic carcinomas (from 9% to 28%) and neuroendocrine thymic tumours (from 2% to 7%), an increase in the use of minimally invasive techniques (from 6% to 34%) and a wider use of chemotherapy as induction (from 9% to 15%) and adjuvant (from 2% to 16%) treatment were observed in the prospective database. The introduction of a set of variables considered essential for the data use ('minimum dataset') resulted in an increased average completeness rate.

CONCLUSIONS

The reported data from the ESTS prospective thymic database confirm the recent trends in the management of thymic tumours. The ESTS prospective thymic database represents a powerful resource open to all ESTS members for the global effort to manage these rare tumours.

Radiologic response of chemotherapy alone versus radiation and chemotherapy in the treatment of locally-advanced or advanced thymic epithelial tumors

Background

Here, we investigated radiological responses following chemotherapy alone as compared to both radiation/chemotherapy (chemoRT) in patients with thymic epithelial tumors (TETs) who did not receive upfront surgery.

Methods

TETs treated at a tertiary academic cancer center between January 2007 and July 2018 were identified. Patients received chemotherapy or chemoRT as initial therapy and pre‐ and post‐treatment scans were available. Student's t‐test, Wilcoxon rank‐sum tests, and Cox proportional hazards method were used to compare clinical details and survival between groups. The primary outcome was change in tumor size, which was compared between groups using linear mixed‐effects regression models, adjusting for baseline tumor size, age, and histology.

Results

A total of 24 of 114 patients with TETs identified met the inclusion criteria. The majority of patients had 67% thymoma (67%, n = 16) and AJCC8 III–IVA disease (58%, n = 14). Median age was 58.5 years (range: 33–76), median initial tumor volume was 187.1 cc (range: 28.7–653.6) and diameter was 8.5 cm (range: 4.5–14.3). Half of the patients received upfront chemotherapy (n = 12: 83% cisplatin/adriamycin/cyclophosphamide) or chemoRT (n = 12: 58% carboplatin/paclitaxel; median RT dose: 63 Gy [range: 60–70 Gy]). At a median imaging follow‐up of 15 months (range: 0–86): ChemoRT was associated with increased average radiological response compared to chemotherapy alone (volume: −47.0 cc more, P < 0.001; diameter: −0.8 cm more, P = 0.03). In eight patients who received chemotherapy, 33% saw further tumor shrinkage (median volume: −42.3%, P = 0.03; diameter: −3.0%, P = 0.049) with additional radiation/chemoradiation. Median survival increased for patients ultimately receiving surgery versus those who did not (46 month, range: 16–127 vs. 14 month, range: 6–82; P < 0.01).

Conclusions

ChemoRT produced a greater radiologic response compared to chemotherapy alone in patients with TETs not suitable for upfront resection.

Key points

Significant findings of the study

We found that chemoRT was associated with a greater radiologic response compared to patients who received chemotherapy alone.

What this study adds

What this study adds: In patients with TET not amenable to upfront resection, chemoRT may be a feasible strategy for cytoreduction.

A single-center experience: management of patients with thymic epithelial tumors

Background

Thymic epithelial tumors are rare neoplasias. There are no internationally accepted standards to treat this complex oncological disease. The studies on which our knowledge is based frequently have methodological weaknesses. If the tumor is resectable, complete surgical excision is currently the first-line therapy. Thymic epithelial tumors respond to radiation. The therapeutic benefit of adjuvant radiotherapy depends on tumor stage. To validate and improve treatment, we share our current experiences with clinical management and surgical intervention.

Methods

This single-center retrospective study included 40 patients with primarily resectable thymic epithelial tumors who underwent resection with curative intent. The survival data was collected and presented according to Kaplan-Meier. Single- and multiple predictor survival analyses were carried out using the log-rank test and Cox proportional hazards model.

Results

Single-predictor survival analysis showed survival to be dependent on the Masaoka-Koga classification, WHO histological classification, resection status, surgical technique, and Clavien-Dindo grade for postoperative complications. Multiple predictor analysis confirms that the Masaoka-Koga stage (HR = 4.876, P = 0.032) and Clavien-Dindo grade (HR = 4.904, P = 0.011) are independent prognostic factors for survival.

Conclusion

In addition to the Masaoka stage, the occurrence of severe postoperative complications represents an independent prognostic factor. Given the tumor’s sensitivity to radiation, the use of neoadjuvant radiotherapy can be considered to downstage Masaoka-Koga stages III and higher, thus reducing surgical risks. Further prospective multicenter studies are urgently needed.

Thymic Malignancy-Updates in Staging and Management

Thymomas are relatively indolent tumors that present with locally advanced disease in 30% of the patients. Thymic carcinoma is a more aggressive histology with shorter disease-free and overall survival. Early-stage tumors are managed best with complete resection. Multimodal therapy is the standard of care for locally advanced tumors and neoadjuvant therapy may help improve respectability. Stage and complete resection are the strongest prognostic factors for long-term survival. Based on early experience, targeted and immunotherapies have shown limited promise in advanced disease.

[Extended Resection of Locally Advanced Thymic Tumours in Stage III]

In the treatment of locally advanced thymic tumours, specific diagnostic testing is required, with a multimodal therapeutic approach consisting of surgery, radio- and/or chemotherapy. The complete resection of the tumour represents the most important prognostic factor with regard to recurrence-free and long-term survival. Local invasive growth of malignant thymic tumours into neighbouring mediastinal structures is classified as Masaoka-Koga stage III. Surgical resection can be performed primarily or after induction therapy, depending on the extent of the tumour. However, in some cases these tumours must be classified as non-resectable, so that only palliative radio-/chemotherapy remains as therapeutic option. TNM classification for malignant thymic tumours has been recently introduced. This resembles the established Masaoka-Koga classification in many aspects, but also includes some therapy-relevant changes. A differentiation is made between stages IIIA and IIIB, with the aim of assessing the resectability of advanced thymic tumours in a more differentiated manner and consequent planning of the therapy concept. Besides the thymus, thymoma, perithymic tissue, mediastinal pleura (stage I) or pericardium (stage II), all infiltrated structures should be removed "en bloc", if possible in stage III tumours. While the lung, brachiocephalic vessels or extrapericardial pulmonary vessels can still be resected and reconstructed if necessary, infiltration of the aorta or intrapericardial pulmonary vessels often limits macroscopically complete resection.

Application of flow cytometry in the analysis of lymphoid disease in the lung and pleural space

Various types of lymphoid neoplasms can occur in the lung. Lung parenchyma, the pleura or the pleural cavity can be the primary site of a lymphoid neoplasm or can be involved secondarily as a result of systemic dissemination from a separate primary site. Recognition of pulmonary lymphoid neoplasms (PLN) has increased secondary to technological advances in the medical field. Multiparameter flow cytometry (FC) is a one of the diagnostic tools that serves an essential role in the detecting and categorizing PLNs. FC allows for rapid identification and immunophenotypic characterization of PLN. In this article, we discuss the role of FC in the diagnosis of the most commonly encountered PLNs as well as their basic clinicopathologic features. We briefly discuss the role of FC in identifying non-hematolymphoid neoplasms in lung specimens as well.