Rare thoracic cancers, including peritoneum mesothelioma

Successful pembrolizumab treatment for microsatellite instability-high thymoma: A case report

Microsatellite instability (MSI) is a valuable biomarker for immune checkpoint inhibitors. We report the first case of MSI-high thymoma successfully treated with pembrolizumab. This patient had pleural dissemination and was treated with two cytotoxic chemotherapy regimens including carboplatin and paclitaxel combination therapy and pemetrexed, which did not have the desired effect. Because MSI status was high by using the surgical specimen, pembrolizumab was administered as 3rd line chemotherapy. After three courses, the pleural lesions dramatically shrunk, which confirmed a partial response. Although MSI-high thymoma is rare, our results suggest the necessity to evaluate MSI status in patients with thymoma.

Incidence of second malignancies in patients with thymic carcinoma and thymic neuroendocrine tumor

OBJECTIVES

Thymic carcinoma and thymic neuroendocrine tumor (NET) are rare and are more likely to develop second malignancies. The purpose of this study was to explore the incidence and lifetime risk of second malignancies in thymic carcinoma and thymic NET.

METHODS

The standardized incidence ratio (SIR) and the age-adjusted cancer incidence of the thymic carcinoma and thymic NET patients with second malignancies were retrospectively calculated by using the Surveillance, Epidemiology, and End Results (SEER) database. Prognosis results were also determined by Kaplan-Meier analysis and Cox regression.

RESULTS

1130 patients with thymic carcinoma (73 patients had second malignancies) and 263 patients with thymic NET (19 patients had second malignancies) from 2000 to 2018 are included. Patients with thymic carcinoma (SIR: 1.36, 95% CI 1.08-1.69) and with thymic NET (SIR: 1.73, 95% CI 1.13-2.54) demonstrate an increased overall risk of developing second malignancies in various organ systems. The age-adjusted cancer incidence of second malignancies in patients with thymic carcinoma is 3058.48 per 100,000 persons (4178.46 per 100,000 persons in patients with thymic NET). Age at diagnosis is a significant risk factor for the development of second malignancies.

CONCLUSION

The incidence of second malignancies in patients with thymic carcinoma and thymic NET is significantly higher than the patients in the normal population. The occurrence of second malignancies is not related to the use of different treatments. It is important to extend the follow-up period and add other screening methods.

Prognostic factors and role of postoperative radiotherapy in surgically resected thymomas

Objective

To investigate the prognostic factors in and role of postoperative radiotherapy (PORT) for surgically resected thymomas.

Methods

A total of 1540 patients with pathologically confirmed thymomas undergoing resection between 2000 and 2018 were identified retrospectively from the SEER (Surveillance, Epidemiology, and End Results) database. Tumors were restaged as local (limited to thymus), regional (invasion to mediastinal fat and other neighboring structures), or distant stage. Disease-specific survival (DSS) and overall survival (OS) were estimated by the Kaplan-Meier method and the log-rank test. Adjusted hazard ratios (HRs) with 95% CIs were calculated by Cox proportional hazards modeling.

Results

Tumor stage and histology were independent predictors of both DSS (regional: HR, 3.711; 95% CI, 2.006-6.864; distant: HR, 7.920; 95% CI, 4.061-15.446; type B2/B3: HR, 1.435; 95% CI, 1.008-2.044) and OS (regional: HR, 1.461; 95% CI, 1.139-1.875; distant: HR, 2.551; 95% CI, 1.855-3.509; type B2/B3: HR, 1.409; 95% CI, 1.153-1.723). For patients with regional stage and type B2/B3 thymomas, PORT was associated with better DSS after thymectomy/thymomectomy (HR, 0.268; 95% CI, 0.099-0.727), but the association was not significant after extended thymectomy (HR, 1.514; 95% CI, 0.516-4.44). Among patients with lymph node metastases, those who received PORT (HR, 0.372; 95% CI, 0.146-0.949), chemotherapy (HR, 0.843; 95% CI, 0.303-2.346), or both (HR, 0.296, 95% CI, 0.071-1.236) had a better OS.

Conclusions

The extent of invasion and tumor histology were independent predictors of worse survival following surgical resection of thymoma. Patients with regional invasion and type B2/B3 thymoma who undergo thymectomy/thymomectomy may benefit from PORT, while patients with nodal metastases may benefit from multimodal therapy, including PORT and chemotherapy.

Current Treatment Approaches for Thymic Epithelial Tumors

Thymic epithelial tumors (TETs), including thymoma, thymic carcinoma and neuroendocrine tumors, are uncommon tumors that originate from the epithelial cells of the thymus. Nevertheless, despite their rarity, they represent the most common tumor type located in the anterior mediastinum. Therapeutic choices based on staging and histology may include surgery with or without neoadjuvant or adjuvant therapy represented by chemotherapy, radiotherapy or chemo-radiotherapy. For patients with advanced or metastatic TETs, platinum-based chemotherapy remains the standard first-line treatment; however, some new drugs and combinations are currently under evaluation. In any case, proper management of patients with TETs requires a multidisciplinary team approach to personalize care for each patient.

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.

Incidental Detection of a Type B3 Thymoma on 68Ga-FAPI-04 PET/CT Imaging

ABSTRACT

18F-FDG PET/CT performed for staging of colon cancer in a 60-year-old woman revealed a thymic neoplasm with increased radiopharmaceutical uptake in the anterior mediastinum. 68Ga-FAPI PET/CT showed low FAPI uptake in the anterior mediastinal mass. The patient was diagnosed with type B3 thymoma by histopathologic evaluation. In this case, thymoma demonstrated lower uptake with FAPI than FDG. Larger studies are required for the differentiation of malignant and benign mediastinal masses with FAPI.

Comparison of Efficacy and Safety of Platinum-Based Chemotherapy as First-Line Therapy between B3 Thymoma and Thymic Carcinoma

BACKGROUND

B3 type thymoma is defined as a well-differentiated thymic carcinoma and is similar to a thymic carcinoma. However, the differences between them are not well defined. In addition, the data to compare the efficacy and safety of platinum-based chemotherapy as first-line therapy between B3 thymoma and thymic carcinoma are lacking.

METHODS

The efficacy and safety of platinum-based chemotherapy as first-line therapy was retrospectively compared between a group of 36 patients with type B3 thymoma and a group of 127 patients with thymic carcinoma treated between January 2009 and March 2022 at the Zhejiang Cancer Hospital. Objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and treatment-related adverse events were analyzed.

RESULTS

The ORRs for B3 thymoma and thymic carcinoma were 36.1% and 28.3%, respectively (p = 0.370). Among all patients, the difference in PFS between B3 thymoma and thymic carcinoma was not significant (11.3 vs. 10.1 months, p = 0.118). The squamous carcinoma subgroup did not exhibit any differences in PFS compared to B3 thymoma (11.7 vs. 11.3 months, p = 0.161). The result for the non-squamous carcinoma subgroup was similar (6.5 vs. 11.3 months, p = 0.128). Furthermore, the OS values for B3 thymoma and thymic carcinoma were not significantly different (58.3 vs. 35.1 months, p = 0.067). However, there were differences in OS between B3 thymoma and non-squamous carcinoma (58.3 vs. 30.6 months, p = 0.031).

CONCLUSIONS

B3 thymoma and especially squamous carcinoma patients may be treated using a similar therapy scheme as that utilized for thymic carcinoma.

Gastroparesis, Thymoma, and Asymptomatic Myasthenia: A Rare Clinical Scenario

Background: Paraneoplastic gastroparesis is a gastrointestinal syndrome that rarely precedes a tumor diagnosis. To increase awareness of this rare clinical entity, we present a case of severe gastroparesis, which was later proven to be associated with a thymoma. Case report: A 55-year old man had the sudden onset of severe abdominal cramps and abdominal distension, early satiety with postprandial nausea, acid regurgitation, belching, and flatulence. He lost about 20 pounds. The physical and imaging examination revealed stomach distension, gastroparesis, and the presence of a solid mass in the anterior mediastinum. Radical surgery was performed to remove the thymoma and, given the high value of Mib-1, the patient was submitted to postoperative chest radiation therapy. After thymectomy, a diagnosis of paraneoplastic myasthenia gravis with subacute autonomic failure was made. Conclusion: Autoimmune gastroparesis should be considered as a potential paraneoplastic syndrome in patients with thymoma, myasthenia gravis, and delayed gastric emptying in the absence of mechanical obstruction.

Lymphatic Node Metastasis Risk Scoring System: A Novel Instrument for Predicting Lymph Node Metastasis After Thymic Epithelial Tumor Resection

BACKGROUND

The authors aimed to create a novel model to predict lymphatic metastasis in thymic epithelial tumors.

METHODS

Data of 1018 patients were collected from the Surveillance, Epidemiology, and End Results database from 2004 to 2015. To construct a nomogram, the least absolute shrinkage and selection operator (LASSO) regression model was used to select candidate features of the training cohort from 2004 to 2013. A simple model called the Lymphatic Node Metastasis Risk Scoring System (LNMRS) was constructed to predict lymphatic metastasis. Using patients from 2014 to 2015 as the validation cohort, the predictive performance of the model was determined by receiver operating characteristic (ROC) curves.

RESULTS

The LASSO regression model showed that age, extension, and histology type were significantly associated with lymph node metastasis, which were used to construct the nomogram. Through analysis of the area under the curve (AUC), the nomogram achieved a AUC value of 0.80 (95 % confidence interval [Cl] 0.75-0.85) in the training cohort and 0.82 (95 % Cl 0.70-0.93) in the validation cohort, and had closed calibration curves. Based on the nomogram, the authors constructed the LNMRS model, which had an AUC of 0.80 (95 % Cl 0.75-0.85) in the training cohort and 0.82 (95% Cl 0.70-0.93) in the validation cohort. The ROC curves indicated that the LNMRS had excellent predictive performance for lymph node metastasis.

CONCLUSION

This study established a nomogram for predicting lymph node metastasis. The LNMRS model, constructed to predict lymphatic involvement of patients, was more convenient than the nomogram.

Robotic thymectomy for thymomas: a retrospective follow-up study in the Netherlands

BACKGROUND

The Maastricht University Medical Center+ (MUMC+) is a Dutch center of expertise, appointed by the Netherlands Federation of University Medical Centres (NFU), for the treatment of thymomas. The aim of this study was to investigate the long-term oncological-, surgical-, and neurological outcomes of all patients who underwent a robotic thymectomy for a thymoma at the MUMC+.

METHODS

We retrospectively analyzed the clinical-pathological data of all consecutive patients with a thymoma who underwent robotic thymectomy using the DaVinci® Robotic System at the MUMC+ between April 2004 and December 2018. Follow-up data were collected from 60 referring Dutch hospitals.

RESULTS

In total, 398 robotic thymectomies were performed and 130 thymomas (32.7%) were found. Median follow-up time, procedure time and hospitalization were 46 months, 116 minutes and 3 days, respectively. In 8.4% of the patients a conversion was performed and in 20.8% a complication was registered. The majority of myasthenic patients with a thymoma went into remission, mostly within 12 to 24 months after thymectomy (81.0%). No statistical difference was found in the number of complications, conversions, incomplete resections or deaths between patients with myasthenia gravis and nonmyasthenic patients. Thirty-six patients (27.7%) underwent postoperative radiotherapy. The recurrence rate was 9.1% and the five-year thymoma-related survival rate was 96.6% .

CONCLUSIONS

Robotic thymectomy was found to be safe and feasible in early-stage thymomas, most advanced-stage thymomas and thymomatous myasthenia gravis. A national guideline could contribute to the improvement of the oncological follow-up of thymic epithelial tumors in the Netherlands.

An autophagy-related lncRNA prognostic risk model for thyroid cancer

PURPOSE

Thyroid cancer (TC) is the most common malignancy of the endocrine system and its incidence is gradually rising. Research has demonstrated a close link between autophagy and thyroid cancer. We constructed a prognostic model of autophagy-related long non-coding RNA (lncRNA) in thyroid cancer and explored its prognostic value.

METHODS

The data used in this study were all obtained from The Cancer Genome Atlas (TCGA) database and the Human Autophagy Database (HADb). We construct a co-expression network by autophagy-related genes and lncRNA to obtain autophagy-related lncRNAs. After univariate Cox regression analysis and multivariate Cox regression analysis, autophagy-related lncRNAs significantly associated with prognosis were identified. Based on the risk score of lncRNA, thyroid cancer patients are divided into high-risk group and low-risk group.

RESULTS

A total of 14,142 lncRNAs and 212 autophagy-related genes (ATGs) were obtained from the TCGA database and the HADb, respectively. We performed lncRNA-ATGs correlation analysis and finally obtained 1,166 autophagy-associated lncRNAs. Subsequently, we conducted univariate Cox regression analysis and multivariate Cox regression analysis, nine autophagy-related lncRNAs (AC092279.1, AC096677.1, DOCK9-DT, LINC02454, AL136366.1, AC008063.1, AC004918.3, LINC02471 and AL162231.2) significantly associated with prognosis were identified. Based on these autophagy-related lncRNAs, a risk model was constructed. The area under the curve (AUC) of the risk score was 0.905, proving that the accuracy of risk signature was superior. In addition, multiple regression analysis showed that risk score was a significant independent prognostic risk factor for thyroid cancer.

CONCLUSION

In this study, nine autophagy-related lncRNAs in thyroid cancer were established to predict the prognosis of thyroid cancer patients.

[Expression and Diagnostic Value of NPTX1 in Thymoma Patients]

BACKGROUND

Thymomas are the most common primary malignant tumors of anterior mediastinal. However, there are no specific laboratory indicator for the diagnosis the diagnosis of thymoma. The aim of this study was to screen out a tumor marker for diagnosis of thymoma by mRNA microarray analysis and confirmed it.

METHODS

By mRNA microarray analysis of 31 thymomas and peritumoral thymic tissues, we found that the transcription level of neuronal pentraxin 1 (NPTX1) gene was up-regulated more than 4 times in thymomas. To further verify the above results, we detected the transcription and expression level of NPTX1 in 60 thymoma and 30 thymic cyst patients by quantitative Real-Time polymerase chain reaction (PCR), immunohistochemistry and enzyme-linked immunosorbent assay (ELISA). Furthermore, the diagnostic value of NPTX1 in thymoma by receiver operating characteristic curve (ROC) was analyzed.

RESULTS

The transcription level of NPTX1 mRNA in thymoma tissues was significantly higher than that in the thymic tissues of control group [(2.88±1.02) vs (1.35±0.47), P<0.001); The expression level of NPTX1 in thymoma tissues was significantly higher than that in the thymic tissues of control group (2 vs 1, P<0.001); The preoperative serum level of NPTX1 protein in thymoma patients were significantly higher than that in the thymic cyst patients of control group [(1,018.29±209.38) pg/mL vs (759.95±66.02) pg/mL, P<0.001]; At the threshold of 842.22 pg/mL, sensitivity and specificity of NPTX1 as a serologic marker were 85.00% and 93.33%, respectively for thymoma. ROC showed that the area the under curve (AUC) of NPTX1 was 0.902.

CONCLUSIONS

NPTX1 was highly expressed in thymoma patients, and had diagnostic value for thymoma.

Thymoma and Tuberculoma: Unexpected Coexistence

Mediastinal tumours can be incidental findings on chest x-ray or present with systemic symptoms and/or direct effect of the mediastinal mass. We report the case of a woman with symptomatic thymoma B1 and simultaneous thymus tuberculosis.

LEARNING POINTS

The association of tuberculosis (TB) of the thymus and thymoma is extremely rare.The differential diagnosis of a mediastinal mass should include TB, particularly in endemic regions.Mediastinal mass resection or biopsy can be of great value in diagnostic work-up.

How to Better Understand the Influence of Host Genetics on Developing an Effective Immune Response to Thoracic Cancers

Thoracic cancers pose a significant global health burden. Immune checkpoint blockade therapies have improved treatment outcomes, but durable responses remain limited. Understanding how the host immune system interacts with a developing tumor is essential for the rational development of improved treatments for thoracic malignancies. Recent technical advances have improved our understanding of the mutational burden of cancer cells and changes in cancer-specific gene expression, providing a detailed understanding of the complex biology underpinning tumor-host interactions. While there has been much focus on the genetic alterations associated with cancer cells and how they may impact treatment outcomes, how host genetics affects cancer development is also critical and will greatly determine treatment response. Genome-wide association studies (GWAS) have identified genetic variants associated with cancer predisposition. This approach has successfully identified host genetic risk factors associated with common thoracic cancers like lung cancer, but is less effective for rare cancers like malignant mesothelioma. To assess how host genetics impacts rare thoracic cancers, we used the Collaborative Cross (CC); a powerful murine genetic resource designed to maximize genetic diversity and rapidly identify genes associated with any biological trait. We are using the CC in conjunction with our asbestos-induced MexTAg mouse model, to identify host genes associated with mesothelioma development. Once genes that moderate tumor development and progression are known, human homologues can be identified and human datasets interrogated to validate their association with disease outcome. Furthermore, our CC-MexTAg animal model enables in-depth study of the tumor microenvironment, allowing the correlation of immune cell infiltration and gene expression signatures with disease development. This strategy provides a detailed picture of the underlying biological pathways associated with mesothelioma susceptibility and progression; knowledge that is crucial for the rational development of new diagnostic and therapeutic strategies. Here we discuss the influence of host genetics on developing an effective immune response to thoracic cancers. We highlight current knowledge gaps, and with a focus on mesothelioma, describe the development and application of the CC-MexTAg to overcome limitations and illustrate how the knowledge gained from this unique study will inform the rational design of future treatments of mesothelioma.

Immunotherapy in malignant pleural mesothelioma: a review of literature data

Malignant pleural mesothelioma (MPM) is a rare, aggressive cancer of the pleural surface, associated with asbestos exposure, whose incidence is still growing in some areas of the world. MPM is still considered a rare and an orphan disease with an unchanged median overall survival (OS) ranging from 8 to 14 months and no treatment advances in the last 15 years both in local and advanced disease. In the recent years, chronic inflammation of the mesothelium together with local tumor suppression plays a major role in the malignant transformation. Also, significant heterogeneity in both tumor and the microenvironment is at the basis of MPM biology. Preclinical data have demonstrated the immunogenicity and the lack of an effective antitumor response by the immune system in MPM thus paving the way to the development of immune therapeutics in this disease. Still there is no clear evidence of any predictive biomarker so that, given the close interaction between the immune infiltrate and mesothelial cells, a number of trials are ongoing to investigate the role and prognostic value of the immune microenvironment. In this review we summarize the rationale for immune therapeutics development in MPM, as well as, the relevant literature and ongoing trials of immune checkpoint inhibitors (ICIs) and vaccines used as both first-line treatment and beyond.

Thymic epithelial tumours in 51 dogs: Histopathologic and clinicopathologic findings

Canine thymic epithelial tumours (TET) are uncommon and little is known about their behaviour. Previous attempts at histologic classification have varied, and as such reliable prognostic information is unavailable. The aim of this retrospective multi-institutional study was to evaluate cases of canine TETs, irrespective of subtype, in order to identify useful histopathologic and clinicopathologic prognostic factors. Cases were included if the tumour arose from the cranial mediastinum and a diagnosis of TET was made on the basis of histopathology. Fifty-one dogs were included. In addition to clinicopathologic data, histology samples were reviewed for the following features: mitotic count, percentage of necrosis, presence of Hassall's corpuscles, lymphocytic infiltrate, cellular pleomorphism and vascular or capsular invasion. The median survival time for all dogs was 449 days. The 1- and 2-year survival rate was 52.6% and 26.3% respectively. On multivariable analysis surgical excision of the thymic tumour was associated with significantly prolonged survival; the presence of metastasis, myasthenia gravis and moderate or marked cellular pleomorphism were associated with significantly reduced survival. Additional studies are needed to further evaluate prognostic factors to aid treatment recommendations.

Autogenous pericardial angioplasty for thymic malignancies: a narrative review

Locally advanced thymic tumor usually invades adjacent great vessels, while the optimal treatment strategy for vessels resection and prosthetic replacement is still in controversial. We hereby present our series of patients undergoing autologous pericardial angioplasty for thymic malignancies. For invasive thymic tumors involving the superior vena cava (SVC), the replacement vessel was prepared by autologous pericardium and placed between the right atrium and distal left innominate vein stump to establish a SVC bypass. Then, the distal right innominate vein and proximal SVC were blocked, and the thymic tumor and involved vessel were completely resected, followed by SVC reconstruction using pericardium. We retrospectively analyzed the clinical characteristics and short-term outcomes of six related patients with autologous pericardial angioplasty. Due to the homologous advantages of autologous pericardial transplantation, those patients didn't need to receive anticoagulant therapy during the perioperative period, so as to avoid the occurrence of hemorrhage, embolism and other graft-related complications. There were no postoperative long-term thoracic drainage (>7 days), anastomotic bleeding, reconstructed vascular stenosis, embolism or even secondary thoracotomy and other related complications occurred in this case series. The application of autologous pericardium for the replacement of mediastinal great vessels in the surgery of locally advanced thymoma is a safe and effective technique. Compared with former artificial materials, such as polytetrafluoroethylene synthetic prosthesis, autologous pericardial transplantation avoids the occurrence of high risk graft-related complications such as postoperative hemorrhage and vascular stenosis, and its clinical application prospect is worth expecting.

Primary thymus tumors: retrospective case analysis at a reference center in Latin America, 2011-2019

BACKGROUND

Thymic tumors are unusual neoplasms, representing 0.2 to 1.5% of tumors in humans, but correspond to 20% of mediastinal tumors and 50% of those that occur in the anterior mediastinum. They tend to appear around the fourth and fifth decades of life without gender predilection. Up to 30% of patients are asymptomatic, therefore many are incidentally diagnosed. Radical thymectomy is the treatment of choice with high survival rates when detected in the early stages.

METHODS

This was a retrospective descriptive study, including 18 adult patients' diagnosis of thymic neoplasm, who were managed with surgical resection from 2011 to 2019. Information about demographics, clinical characteristics, imaging findings, surgical and medical management, plus histological findings was obtained and reported.

RESULTS

18 patients with thymic tumors were included, of which specific histologic studies reveled thymomas, carcinomas, neuroendocrine tumors, thymolipoma and thymic cyst. Mean age was 52.7 years, with a predominance of male population. The main symptom was dyspnea, followed by cough and chest pain. Paraneoplastic syndromes such as myasthenia gravis, aplastic anemia and Cushing syndrome were reported. 89% of cases were treated by radical thymectomy alone, while only 2 cases required chemotherapy and radiotherapy. There were no surgical complications. Mean hospital stay length was 11. 9 days, with only 1 mortality during hospital admission. 5-year survival rate was 81%.

CONCLUSIONS

The treatment of choice is radical thymectomy, which has been shown to positively impact patient mortality. Early detection is key to improve patient outcomes.

Pembrolizumab as a novel therapeutic option for patients with refractory thymic epithelial tumor: A case report

BACKGROUND

Thymic epithelial carcinomas are rare and have a poor prognosis. Treatment of thymic epithelial carcinoma is multimodal and includes surgery, post-operative radiation therapy, adjuvant and neoadjuvant chemotherapy, or exclusive chemotherapy based on disease resectability. However, there is currently no standard treatment regimen for metastatic and recurrent thymic carcinoma.

CASE SUMMARY

A 45-year-old Caucasian male, with no past medical history, presented with hepatalgia and a cervical mass. A computed tomography (CT) scan showed multiple suspect lesions in the lungs, liver, and anterior mediastinum associated with mediastinal and cervical adenopathy. CT-guided percutaneous biopsies of the liver lesions and anterior mediastinal mass were performed, confirming the histopathology of thymic epithelial carcinoma. Management consisted of several chemotherapy regimens and radiation therapy, administered between April 2016 and December 2018. The patient achieved complete metabolic response. Fluorodeoxyglucose positron emission tomography/CT performed in June 2019 showed disease relapse, with reappearance of a large hypermetabolic hepatic mass and involvement of mediastinal and axillary lymph nodes. Intravenous pembrolizumab (200 mg, every 3 wk) was administered after two prior systemic therapies. The patient’s response to treatment was last documented on March 5, 2020.

CONCLUSION

Pembrolizumab was successful in treatment of a patient with programmed death-ligand 1-negative metastatic thymic carcinoma, pretreated with chemotherapy.

Chemotherapy-induced myasthenic crisis in thymoma treated with primary chemotherapy with curative intent on mechanical ventilation: a case report and review of the literature

Background

Thymoma is an uncommon cancer often associated with myasthenia gravis, an autoimmune disorder of the neuromuscular junction characterized by muscular fatigability. In patients with advanced nonmetastatic thymoma, primary chemotherapy may be required to induce tumor shrinkage and to achieve radical resection. Cancer chemotherapy has been anecdotally reported as a trigger factor for worsening of myasthenia gravis in thymic epithelial cancers. The study of uncommon cases of chemotherapy-related myasthenic crisis is warranted to gain knowledge of clinical situations requiring intensive care support in the case of life-threatening respiratory failure.

Case presentation

We report a case of an 18-year-old Caucasian woman with advanced Masaoka-Koga stage III type B2 thymoma and myasthenia gravis on treatment with pyridostigmine, steroids and intravenous immunoglobulins, who developed a myasthenic crisis 2 hours after initiation of cyclophosphamide/doxorubicin/cisplatin primary chemotherapy. Because of severe acute respiratory failure, emergency tracheal intubation, mechanical ventilation, and temporary (2 hours) discontinuation of chemotherapy were needed. Considering the curative intent of the multimodal therapeutic program, we elected to resume primary chemotherapy administration while the patient remained on mechanical ventilation. After 24 hours, the recovery of adequate respiratory function allowed successful weaning from respiratory support, and no further adverse events occurred. After 3 weeks, upon plasma exchange initiation with amelioration of myasthenic symptoms, a second course of chemotherapy was given, and in week 6, having documented partial tumor remission, the patient underwent radical surgery (R0) and then consolidation radiation therapy with 50.4 Gy in 28 fractions in weeks 15–20.

Conclusions

This case report, together with the only four available in a review of the literature, highlights that chemotherapy may carry the risk of myasthenic crisis in patients affected by thymoma and myasthenia gravis. To our knowledge, this is the first reported case of chemotherapy continuation on mechanical ventilation in a patient with chemotherapy-induced myasthenic crisis requiring tracheal intubation. The lesson learned from the present case is that, in selected cases of advanced thymoma, the paradoxical worsening of myasthenia gravis during chemotherapy should not be considered an absolute contraindication for the continuation of primary chemotherapy with curative intent.

Epidemiology of thymoma

Thymic tumours are a heterogeneous group of malignancies with a range of clinical presentations. The most common types are thymoma and thymic carcinoma, but overall it remains a rare cancer, and one without a clear aetiology. In this review of the epidemiology of the disease, the relationship between sex, age, and ethnicity is reviewed, along with limited evidence on the genetics of the condition. In terms of risk factors and potential causative factors, environmental exposures such as tobacco, radiation, alcohol, or diet, seem to be irrelevant, but there is some evidence linking the development of thymoma and thymic carcinoma with viral conditions, including Epstein Barr Virus. But data is not conclusive, and in the absence of large patient numbers, it is difficult to prove causation. There has been good research looking at the link between thymoma and other malignancies, either before or after the diagnosis. There does not appear to be a significant increased likelihood of thymoma following other malignancies. But, there is a suggestion, in several papers, that there is an increased risk of other malignancies following the diagnosis of thymoma, although the magnitude of this risk is disputed. There does appear to be an increased risk of non-Hodgkins Lymphoma after a diagnosis of thymoma, and this could be related to a disruption in T-cell function caused by either the disease process or the treatment directed at the thymoma. In summary though, it is a rare malignant process with a variety of presentations, often limited to the anterior mediastinum, and without an aggressive disease profile.

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.

Paclitaxel-loaded expansile nanoparticles improve survival following cytoreductive surgery in pleural mesothelioma xenografts

OBJECTIVE

Malignant pleural mesothelioma is a lethal malignancy with poor survival and high local recurrence rates despite multimodal therapy with cytoreduction and chemoradiation. We evaluated the antitumor efficacy of a paclitaxel-loaded pH-responsive expansile nanoparticle (PTX-eNP) in 2 clinically relevant murine xenograft models of malignant pleural mesothelioma.

METHODS

Luciferase-transfected MSTO-211H human mesothelioma cells were injected into the thoracic cavity of immunodeficient Nu/J mice. Tumor burden was monitored by bioluminescent imaging. Animals were randomized into 2 models of disease treatment chemotherapy with PTX-eNPs alone delivered locally for early limited disease or cytoreductive surgery plus local PTX-eNP chemotherapy for advanced disease. Within each disease model, anti-tumor efficacy of PTX-eNP was compared against standard formulation paclitaxel and drug-empty nanoparticles. Influence on survival was calculated. Fluorescently labeled PTX-eNPs and immunohistochemistry evaluated in vivo drug localization to tumor.

RESULTS

Intrathoracic injection of MSTO-211H resulted in large tumor deposits distributed within the pleural space of the murine thoracic cavity. Local multidose treatment with PTX-eNPs alone in limited stage disease more than doubled survival compared with drug-empty nanoparticles (P ≤ .0001) and standard formulation paclitaxel (P = .0004). In the model of advanced disease, local multidose treatment with PTX-eNPs following cytoreductive surgery also prolonged survival by 126% and 69.4% compared with drug-empty nanoparticles (P = .0018) and standard formulation paclitaxel (P = .03457), respectively. Immunohistology demonstrated PTX-eNP accumulation within tumor cells in vitro and in vivo.

CONCLUSIONS

Local delivery of paclitaxel via eNPs confers prolonged survival in a murine model of malignant pleural mesothelioma as single modality treatment for limited disease and in combination with cytoreductive surgery for advanced disease.

Pembrolizumab in a Patient With Heavily Pre-Treated Squamous Cell Thymic Carcinoma and Cardiac Impairment: A Case Report and Literature Review

Immunotherapy directed at the programmed cell death-1 receptor (PD-1) or its ligand PD-L1 has proven effective in solid malignancies such as melanoma, non-small cell lung cancer (NSCLC), urothelial cancer, renal cell carcinoma, and head and neck cancer. Compared with cytotoxic chemotherapy, radiotherapy, or molecular targeted agents, immunotherapy is an innovative strategy for treating malignancies, with durable clinical responses and manageable adverse events. Thymic carcinomas are extremely rare, constituting only 0.06% of all malignancies, are much more aggressive tumours than thymomas and have a worse prognosis. Nowadays, first line platinum-based chemotherapy for metastatic tumours are the cornerstone of treatment. However, the results of further therapeutic lines for metastatic or relapsed thymic carcinoma are unsatisfactory, with no regimen showing a consistent benefit. Moreover, the rarity of these tumours makes it difficult to carry out clinical trials. Herein we report a remarkable result of 1 year stable disease with good quality of life and no side effects obtained from the use of immunotherapy with pembrolizumab in a case of heavily pre-treated squamous cell thymic carcinoma and cardiac impairment. We also include a literature review of clinical trials on PD-1/PD-L1 inhibitors for the treatment of thymic epithelial cancers, taking a close look at cardiac toxicity.

Thymic Epithelial Tumors as a Model of Networking: Development of a Synergistic Strategy for Clinical and Translational Research Purposes

Among the group of thymic epithelial tumors (TET), thymomas often show either uncertain or explicit malignant biological behavior, local invasiveness, and intrathoracic relapse and are often difficult to manage. From the initial stages, thymic carcinomas tend to show aggressive behavior and extrathoracic spread. Moreover, the interplay of epithelial cells and thymocytes in thymomas causes complex immune derangement and related systemic autoimmune diseases. Due to their rare occurrence and to the limited funding opportunities available for rare tumors, it is challenging to make advances in clinical and translational research in TET. The authors of this paper are all members of a multidisciplinary clinical and research thoracic tumor team. Strong input was given to the team by long-standing expertise in TET in the Pathology Department. In addition, thanks to the collaboration between research units at our Institute as well as to national collaborations, over the last 10 years we were able to perform several tissue-based research studies. The most recent studies focused on microRNA and on functional studies on the thymic carcinoma cell line 1889c. The recent implementation of our biobank now provides us with a new tool for networking collaborative research activities. Moreover, the participation in a worldwide community such as ITMIG (International Thymic Malignancy Interest Group) has allowed us to significantly contribute toward fundamental projects/research both in tissue-based studies (The Cancer Genome Atlas) and in clinical studies (TNM staging of TET). Our achievements derive from constant commitment and long-standing experience in diagnosis and research in TET. New perspectives opened up due to the establishment of national [the Italian Collaborative Group for ThYmic MalignanciEs (TYME)] and European reference networks such as EURACAN, for an empowered joint clinical action in adult solid rare tumors. The challenge we face still lies in the advancement of clinical and basic science in thymic epithelial malignancies.

Volumetric modulated arc therapy versus intensity-modulated proton therapy in the postoperative irradiation of thymoma

BACKGROUND

To investigate the role of intensity-modulated proton therapy (IMPT) compared to volumetric modulated arc therapy (VMAT) for the radiation treatment of thymoma cancer.

METHODS

Twenty patients were retrospectively planned for IMPT [with (IMPT_R1 or IMPT_R2 according to the approach adopted) and without robust optimization] and VMAT. The results were compared according to dose-volume metrics on the clinical and planning target volumes (CTV and PTV) and the main organs at risk (heart, breasts, lungs, spinal cord and oesophagus). Estimates of the excess absolute risk (EAR) of secondary cancer induction were determined for the oesophagus, the breasts and the composite lungs. For the heart, the relative risk (RR) of chronic heart failure (CHF) was assessed.

RESULTS

IMPT and VMAT plans resulted equivalent in terms of target coverage for both the CTV and the PTV. The CTV homogeneity index resulted in 0.03 ± 0.01 and 0.04 ± 0.01 for VMAT and all IMPT plans, respectively. The conformality index resulted in 1.1 ± 0.1 and 1.2 ± 0.1 for VMAT and all IMPT plans. The mean dose to the breasts resulted in 10.5 ± 5.0, 4.5 ± 3.4, 4.7 ± 3.5 and 4.6 ± 3.4 Gy for VMAT, IMPT, IMPT_R1 and IMPT_R2. For the lungs, the mean dose was 9.6 ± 2.3, 3.5 ± 1.5, 3.6 ± 1.6 and 3.8 ± 1.4 Gy; for the heart: 8.7 ± 4.4, 4.3 ± 1.9, 4.5 ± 2.0 and 4.4 ± 2.4 Gy and for the oesophagus 8.2 ± 3.5, 2.2 ± 3.4, 2.4 ± 3.6 and 2.5 ± 3.5 Gy. The RR for CHF was 1.6 ± 0.3 for VMAT and 1.3 ± 0.2 for IMPT (R1 or R2). The EAR was 3.6 ± 0.v vs 1.0 ± 0.6 or 1.2 ± 0.6 (excess cases/10,000 patients year) for the oesophagus; 17.4 ± 6.5 vs 5.7 ± 3.2 or 6.1 ± 3.8 for the breasts and 24.8 ± 4.3 vs 8.1 ± 2.7 or 8.7 ± 2.3 for the composite lungs for VMAT and IMPT_R, respectively.

CONCLUSION

The data from this in-silico study suggest that intensity-modulated proton therapy could be significantly advantageous in the treatment of thymoma patients with particular emphasis to a substantial reduction of the risk of cardiac failure and secondary cancer induction. Robust planning is a technical pre-requisite for the safety of the delivery.

Trends in the incidence of thymoma, thymic carcinoma, and thymic neuroendocrine tumor in the United States

This study aimed to identify the trends in the incidence of thymic cancer, i.e., thymoma, thymic carcinoma, and thymic neuroendocrine tumor, in the United States. Data from the United States Cancer Statistics (USCS) database (2001-2015) and those from the Surveillance, Epidemiology, and End Results (SEER) database (SEER 9 [1973-2015], SEER 13 [1992-2015], and SEER 18 [2000-2015]) were used in this study. All incidences were per 100,000 population at risk. The trends in incidence were described as annual percent change (APC) using the Joinpoint regression program. Data from the USCS (2001-2015) database showed an increase in thymic cancer diagnosis with an APC of 4.89% from 2001 to 2006, which is mainly attributed to the significant increase in the incidence of thymoma and thymic carcinoma particularly in women. The incidence of thymic cancer did not increase from 2006 to 2015, which may be attributed to the increase in the diagnosis of thymic carcinoma from 2004 to 2015, with a concomitant decrease in thymoma from 2008 to 2015. Before declining, the age-specific incidence of thymic cancer peaked at ages 70-74 years, with a peak incidence at 1.06 per 100,000 population, and decreased in older age groups. The incidence of thymic cancer was higher in men than in women. Asian/Pacific Islanders had the highest incidence of thymoma, followed by black and then white people. The incidence of thymic carcinoma increased from 2004 to 2015, with a concomitant decrease in thymoma from 2008 to 2015. Asian/Pacific Islanders had the highest incidence of thymoma than other races.

A case of thymoma in myasthenia gravis: Successful outcome after thymectomy

INTRODUCTION

Thymic abnormalities occur as hyperplasia and thymoma. Myasthenia gravis is commonly present in thymoma. Thymectomy possesses risk due to anatomical proximity with vital thoracic structures and myasthenia crisis.

PRESENTATION OF CASE

Forty five years female with complaints of difficulty swallowing and weakness of upper limb muscles upon investigation showed mass in mediastinum and antibody test for myasthenia gravis positive. Medical management was done for a month followed by thymectomy. There were no intra and postoperative complications. Medical management was stopped one month after surgery and she is symptom free.

DISCUSSION

Thymectomy is the standard of care where median sternotomy is the mainstay approach to surgery. Various other surgical approaches and complications revolving around surgery has been discussed.

CONCLUSION

Surgical removal of thymoma cured myasthenia gravis in our case. We focused on proper preoperative optimization of myasthenia gravis symptoms before thymectomy.

Cardiotoxicity of mediastinal radiotherapy

Aim

To explore available recent literature related to cardiotoxicity following mediastinal radiation.

Background

Radiotherapy-related heart injury is well documented, with no apparent safety threshold dose. The number of long-term cancer survivors exposed to mediastinal radiotherapy at some point of their treatment is increasing. Heart dosimetric parameters are of great importance in developing a treatment plan, but few data are available regarding radiosensitivity and dose-volume constraints for specific heart structures.

Materials and Methods

In October 2018, we identified articles published after 1990 through a PubMed/MEDLINE database search. The authors examined rough search results and manuscripts not relevant for the topic were excluded. We extracted clinical outcomes following mediastinal radiotherapy of childhood cancers, lymphoma, medulloblastoma, thymic cancers and hematopoietic cell transplantation survivors and evaluated treatment planning data, whenever available.

Results

A total of 1311 manuscripts were identified in our first-round search. Of these manuscripts, only 115 articles, matching our selection criteria, were included.

Conclusions

Studies uniformly show a linear radiation dose-response relationship between mean absorbed dose to the heart (heart-D_mean) and the risk of dying as a result of cardiac disease, particularly when heart-D_mean exceeds 5 Gy. Limited data are available regarding dose-volume predictors for heart substructures and the risk of subsequent cardiac toxicity. An individual patient's cardiotoxicity risk can be modified with advanced treatment planning techniques, including deep inspiration breath hold. Proton therapy is currently showing advantages in improving treatment planning parameters when compared to advanced photon techniques in lymphoma, thymic malignancies, malignant mesothelioma and craniospinal irradiation.

Optimal management of thymic malignancies: current perspectives

Thymic epithelial tumors (TETs) belong to orphan oncology. The incidence of TETs is about 1.3–3.2 cases per million worldwide. Following pathology, evolution and prognosis are variable. The World Health Organization classification distinguishes thymomas and thymic carcinomas. TETs are composed of thymic epithelial tumoral cells and normal lymphocytes. The mean age at diagnosis is 50–60 years-old. There are no identified risk factors. TETs are frequently associated with paraneoplastic syndromes as myasthenia gravis. The complete R₀ surgical resection is the most significant prognosis factor on survival. In 2010, the French National Institute of Cancer labeled the RYTHMIC network as a specific tumor board including thoracic surgeons, oncologist, and radiation therapist to define standard of care for the management of TETs. The aim of the review was to update knowledge to optimize the standard of care.

Incidence and survival of peritoneal malignant mesothelioma between 1989 and 2015: A population-based study

BACKGROUND

Peritoneal malignant mesothelioma is a rare disease for which few population-based studies are available. The aim of this study was to describe the evolution of the incidence and survival of peritoneal malignant mesothelioma in France between 1989 and 2015, using data derived from the French network of cancer registries.

METHODS

Age world-standardized incidence rates and overall survival were calculated using data from 16 French cancer registries. Log-linear Poisson regression analysis was used to estimate the average annual percentage change in incidence rates. Overall survival was performed using age-adjusted Cox proportional hazards model.

RESULTS

In French men, the incidence has increased quietly over the reporting period from 0.07 to 0.10 with a maximum of 0.16 per 100,000 persons-years in 2001-2003. For women, the increase in incidence has been lower than for men over the period 1989-2015, ranging from 0.04 to 0.11. A better prognosis was associated with a diagnosis made after 2000 (HR = 1.76; p = 0.013), the epithelioid histological type (p = 0.003), and the fact of being a woman, which has a 5-year risk of death half that of men (HR = 0.55; p = 0.001), regardless of age, diagnosis period or histology.

CONCLUSION

Our results are similar to those currently available for other countries. In France, peritoneal mesothelioma remains a rare and fatal cancer with a small increase in the incidence rate since 1989 and a median survival of 1 year; it seemed to develop equally in women and men over this period of time.

Efficacy and toxicities of gemcitabine and cisplatin combined with endostar in advanced thymoma and thymic carcinoma

BACKGROUND

Thymoma and thymic carcinoma are rare thymic epithelial tumors. We investigated the efficacy of first-line gemcitabine and cisplatin (GP) chemotherapy versus gemcitabine and cisplatin chemotherapy combined with the anti-angiogenic drug endostar (GP + E) in advanced thymoma and thymic carcinoma.

METHODS

The records of 45 patients with invasive metastatic thymomas or thymic carcinomas treated with GP as first-line therapy between August 2008 and July 2017 at the Department of Respiratory Medicine, Peking University Cancer Hospital and Institute were retrospectively reviewed.

RESULTS

Eighteen patients (75%) in the GP + E group achieved a partial response and six (25%) had stable disease. In GP only group, nine (42.8%) patients achieved a partial response, 11 (52.4%) had stable disease, and one (4.8%) had progressive disease. The GP + E group had a significantly higher overall response rate (75% vs. 42.9%; P = 0.028), and median progression-free survival (PFS) and overall survival (OS) of 19 and 76 months, respectively. In the GP only group, median PFS and OS were 16 and 29 months, respectively. PFS and OS were not significantly different between the groups.

CONCLUSIONS

GP has moderate efficacy and could represent a suitable first-line therapy for thymic carcinoma and thymoma. Chemotherapy combined with endostar could improve the overall response rate, but did not prolong PFS or OS.

Systemic treatments for thymoma and thymic carcinoma: A systematic review

Thymic tumours are rare diseases that for most of the cases are cured with surgery and eventually adjuvant radiotherapy. However, about 30% of patients present with advanced stage or relapsing tumours, which require administration of chemotherapy. While cisplatin-adriamycin-cyclophosphamide combination is regularly prescribed, other drugs have been assessed in the literature. Our aim is to evaluate the effectiveness (response rate) of systemic treatments, whatever the therapeutic line, including chemotherapy, targeted therapies and immunotherapies, in thymoma and thymic carcinoma, using the principles of evidence-based medicine. A systematic review was designed using the PICO system, by an experienced librarian and clinicians' experts in thoracic oncology, through the Ovid Medline system. Only phase II-IV trials and retrospective studies including at least 14 patients treated with the same regimen were considered. Articles were independently selected by at least two investigators. Fifty-five eligible articles were retrieved. Sixty% were dealing with platinum-based regimens, mainly cisplatin, and showed overall similar activity (mostly response rate above 50%) independently of the line of treatment or histological type (thymoma versus thymic carcinoma). Non-platinum based regimens included octreotide-prednisone and capecitabine-gemcitabine. Promising data of immunotherapy with antiPDL1 antibody (pembrolizumab) requires confirmation. Based on available data, the most popular and active regimens are cisplatin-anthracycline (CAP or ADOC) or cisplatin-etoposide combinations that should be recommended when considering first-line chemotherapy in thymoma or thymic carcinoma.

EGFR exon 20 insertion mutation in advanced thymic squamous cell carcinoma: Response to apatinib and clinical outcomes

Thymic carcinoma (TC) is a rare malignant tumor of the mediastinum with occult onset, rapid development, and poor prognosis. Surgery is the main treatment for early TC, but the majority of patients are diagnosed at Masaoka‐Koga stage III or IV with local invasion or distant metastasis. Platinum and anthracyclines are currently considered key components of first‐line chemotherapy for advanced TC; however, there are no standard treatment plans for patients who are refractory to first‐line and further chemotherapy. The clinical effect is also unsatisfactory. Apatinib has been successfully applied as third‐line treatment for advanced gastric cancer and has shown high efficacy in the treatment of various cancers, such as lung, liver, and colorectal cancers. Herein we report a case of advanced thymic squamous cell carcinoma harboring EGFR exon 20 insertion in which apatinib was administered after multi‐line chemotherapy and radiotherapy and a partial response was achieved after five months of treatment. To date, a five month overall response and 10 months of progression‐free survival have been achieved. Adverse reactions can be controlled and the patient's quality of life has improved. Apatinib provides a new option for clinicians to treat patients with advanced TC.

The role of postoperative radiation therapy for completely resected stage III thymoma and effect of higher heart radiation dose on risk of cardiovascular disease: A retrospective cohort study

OBJECTIVES

This study aimed to assess the efficacy of radiation therapy (RT) in patients with completely resected stage III thymoma and evaluate the relationship between higher heart dose and risk of cardiovascular disease (CVD).

PATIENTS AND METHODS

A total of 130 consecutive patients with Masaoka stage III thymoma were retrospectively reviewed from January 2003 to December 2013. Of these, 99 underwent complete tumor resection [74 received postoperative radiation therapy (S + R) and 25 received surgery alone (S alone)] and 31 patients underwent RT alone (16 due to inoperable tumors and 15 due to high surgical risk or patient refusal; R alone). Three-dimensional conformal RT/intensity-modulated RT was used for patients receiving RT.

RESULTS

The median follow-up for all patients was 70 months. The 5- and 8-year overall survival (OS) rates were 95.6% and 93.9% for S + R, 84.0% and 67.2% for S alone, and 73.3% and 73.3% for R alone (excluding patients with inoperable tumors), respectively (P = 0.004). A trend of improved disease-specific survival (DSS) was also observed in the S + R group compared with the other two groups. CVD was the main nonmalignant cause of death (3/6, 50%). The median time of CVD diagnosis was 101 months after treatment. The mean heart dose was an independent risk factor for CVD.

CONCLUSIONS

Postoperative RT after complete resection improved the survival compared with surgery alone and RT alone for patients with stage III thymoma. A higher heart dose was related to increased risk of CVD in long-term survivors.

Clinical characteristics, risk factors, and outcomes after adjuvant radiotherapy for patients with thymoma in the United States: analysis of the Surveillance, Epidemiology, and End Results (SEER) Registry (1988-2013)

PURPOSE

The surgery with adjuvant radiation for the treatment of thymoma is still debated. The aim of this study was to examine the efficacy of postoperative radiotherapy (PORT) in a population-based registry of patients with thymoma.

MATERIALS AND METHODS

We conducted a retrospective analysis of the Surveillance, Epidemiology, and End Results database to compare the outcomes of patients with thymoma who received surgery with or without PORT.

RESULTS

Among the 2234 patients of this study, the surgery with PORT group had a longer mean overall survival (OS) and cancer-specific survival (CSS) than did the surgery without PORT group (OS: 172.3 vs. 155.3 months, p = .005; CSS: 247.3 vs. 241.8 months, p = .04). PORT significantly improved OS and CSS of patients with stage III/IV disease, but decreased CSS for those with stage I/IIA disease. Although the surgery with PORT group had a higher rate of secondary cancers, the between-group difference in the disease-free interval was not significant.

CONCLUSIONS

PORT provides a significant benefit for patients with thymoma, particularly those with advanced disease. However, it also increases the risk of a second malignancy. We suggest that treatment guidelines should adopt a more positive stance on the use of PORT.

Thymic Carcinoma Treated by CyberKnife Stereotactic Body Radiotherapy

The standard treatment for advanced thymic carcinoma has not yet been established. Most patients have no symptoms until the advanced stage. Radiation therapy has been used for advanced stage cancer, usually in combination with surgery or chemotherapy; however, the survival rates are 30%-50%. We performed hypofractionated stereotactic radiotherapy with CyberKnife (Accuray, Sunnyvale, CA, USA) for 10 cases of advanced thymic cancer. All cases reached at least partial remission (PR) in two months with progression-free irradiated lesions and minimal radiation-related toxicity. It took only seven to 12 days for each therapy that did not require admission. CyberKnife is beneficial for patients even at the terminal stage.

Postoperative Radiotherapy in Locally Invasive Malignancies of the Thymus: Patterns of Care and Survival

INTRODUCTION

Our purpose was to determine the overall survival (OS) benefit of postoperative radiotherapy (PORT) in patients with advanced thymic malignancies and the associated predictors of PORT receipt.

METHODS

We queried the National Cancer Data Base for all stage II to III thymic malignancies. Trends in PORT use over time were analyzed using least squares linear regression. Factors predictive of PORT and OS were identified by using multivariate logistic and Cox regression analysis, respectively.

RESULTS

We identified 1156 patients between 2004 and 2012 who met the inclusion criteria. The utilization of PORT was found to increase over the study period by 41% (37% to 52% [p = 0.01]). On multivariate analysis, the factors found to be the most predictive of receipt of PORT were positive surgical margins (adjusted OR = 1.98 [p < 0.01]) and treatment at a nonacademic facility (adjusted OR = 1.44 [p = 0.01]). The 5-year OS was superior for patients receiving PORT compared with for those who did not (83% versus 79%, p = 0.03). Receipt of PORT was associated with a trend toward decreased risk for death on multivariate analysis (hazard ratio = 0.75 [p = 0.09]). In addition, a positive macroscopic margin was the most important predictor of survival (hazard ratio = 3.48 [p < 0.01]). On subgroup analysis, patients with thymic carcinoma and WHO histologic types A and AB were associated with an OS benefit with PORT, whereas types B1, B2, and B3 were not. Patients with positive margins were not associated with an OS benefit with PORT.

CONCLUSIONS

The use of PORT in patients with advanced thymic malignancies is increasing over time and is determined by both clinical and demographic factors. Receipt of PORT was associated with improved OS. The OS benefit with PORT was dependent on the WHO histologic type.

Thymoma and thymic carcinomas

Thymomas (Ts) and thymic carcinomas (TCs) are rare tumours of the mediastinum with an incidence rate of 1.7/million per year in Europe. Histological classification is based on rate of non-malignant-appearing thymic epithelial cells and proportions of lymphocytes (A, AB, B1, B2, B3, and C), while staging system concerns localisation of the involved areas. Surgery is the mainstay of treatment with a 10-year survival of 80%, 78%, 75%, and 42% for stages I, II, III and IV, respectively, with an R0 resection. Radiotherapy has a role in selected cases (stage III patients or R1-2 residual) and platinum-based chemotherapy remains the standard of care for patients with advanced disease. A multimodality approach would be advisable when surgery is not recommended. Since molecular aberrations are poorly understood and few responses are reported, targeted therapies are yet being studied. In this review, we describe key aspects of clinical management for Ts and TCs.

Malignant Peritoneal Mesothelioma in an Adolescent Male With BAP1 Deletion

Diffuse malignant peritoneal mesotheliomas in children are uncommon, aggressive tumors with a grave prognosis. We herein report the clinical, radiologic, and pathologic findings of a 16-year-old male. The adolescent presented with a history of abdominal pain, nausea and daily, nonbilious, nonbloody emesis for 3 weeks. Radiographic imaging suggested small bowel obstruction. The diagnostic work-up and differential diagnoses are discussed. Histologically, the tumor was composed of epithelioid cells with a papillary and glandular architectural pattern. A few glands appeared to produce mucinous material. Histochemistry revealed PAS diastase resistant mucin, an inconspicuous finding in diffuse malignant peritoneal mesothelioma. An extensive immunohistochemistry panel (calretinin, WT-1, D2-40, CK 7, CAM 5.2, CK 5/6, CEA, B72.3, CK 20, CD10, CD30, CD15, CD117, PLAP, S100, TFE3, and EMA) confirmed the diagnosis. Of special interest, BAP1 staining was cytoplasmic and consistent with 3p deletion detected by conventional cytogenetics. The ultrastructural analysis demonstrated long microvilli, desmosomes, and intercellular junctions which further supported the diagnosis.

Available evidence and new biological perspectives on medical treatment of advanced thymic epithelial tumors

Thymic epithelial tumors (TETs) are rare primary mediastinal tumors arising from thymic epithelium. Their rarity and complexity hinder investigations of their causes and therapy development. Here, we summarize the existing knowledge regarding medical treatment of these tumors, and thoroughly review the known genetic aberrations associated with TETs and the present status of potential biological treatments. Epidermal growth factor receptor (EGFR), stem-cell factor receptor, insulin-like growth factor-1 receptor (IGF1R), and vascular endothelial growth factors (VEGF-A, VEGF-B, and VEGF-2) are overexpressed in TETs. EGFR overexpression in TETs is associated with higher stage, and IGF1R overexpression has poor prognostic value. Data indicate that anti-IGF1R monoclonal antibodies, and inhibitors of angiogenesis, somatostatin receptors, histone deacetylase, mammalian target of rapamycin, and cyclin-dependent kinases may be active against TETs. Continued investigations in this field could lead to advancement of targeted and biological therapies for TETs.

New histone deacetylase inhibitors improve cisplatin antitumor properties against thoracic cancer cells

Histone deacetylase inhibitors (HDACi) have shown promising antitumor effects on numerous cancer cells including malignant pleural mesothelioma (MPM) and lung adenocarcinoma (ADCA) cells. However, clinical trials using these compounds alone have shown limited efficacy against solid tumors. Therefore, new molecules are being developed and combinations with classical chemotherapeutic drugs are being tested. Here, we have evaluated on three MPM and three lung ADCA cell lines the antitumor potential of four new HDACi compounds, either alone or in combination with cisplatin. These effects were compared with those of vorinostat, an HDACi approved for cancer treatments. First, we characterized the HDAC mRNA expression profiles of tumor cells and showed an increase of the classI/classII HDAC ratio. We then treated cancer cells with these new HDACi and observed a cell-death induction and an increase of HDACi target genes and proteins expression. This was particularly evident for NODH compound (pan-HDACi) which had similar effects at nanomolar concentrations as micromolar concentrations of vorinostat. Interestingly, we observed that the HDACi/cisplatin combination strongly increased cell-death and limited resistance-phenotype emergence as compared with results obtained when the drugs were used alone. These results could be exploited to develop MPM and lung ADCA treatments combining chemotherapeutic approaches.