Key components of chemotherapy for thymic malignancies: a systematic review and pooled analysis for anthracycline-, carboplatin- or cisplatin-based chemotherapy

China Anti-Cancer Association Guidelines for the diagnosis, treatment, and follow-up of thymic epithelial tumors (2023)

Background

Thymic epithelial tumors (TETs) are a relatively rare type of thoracic tumors with higher incidence in Asians. The diagnosis and treatment pattern has long been based mainly on clinical experience and expert consensus. In recent years, with an increasing number of TETs detected in physical examinations, there is an urgent need to develop the guidelines that apply to the Chinese population. Thus, we intend to develop a holistic integrative guideline for TETs.

Methods

Under the leadership of the Chinese Anti-Cancer Association (CACA) Mediastinal Tumor Committee, a multidisciplinary guideline development group was established. Systemic literature review and two rounds of questionnaires regarding key clinical issues were carried out. The grading of recommendations assessment, development and evaluation (GRADE) approach was used to rate the quality of evidence and the strength of recommendations.

Results

The CACA guideline provides recommendations for the clinical differential diagnosis of anterior mediastinal lesions, management of asymptomatic small anterior mediastinal nodules, pathological classification and staging systems of TETs, as well as principles of surgery, neoadjuvant and adjuvant therapies, systemic therapies for advanced TETs, and follow-up strategies after surgical resection.

Conclusions

This guideline provides holistic integrative management strategies for TETs and would be a useful tool for clinicians on decision-making.

Update on thymic epithelial tumors: a narrative review

Background and Objective

Thymoma, thymic carcinoma and thymic neuroendocrine tumors originate from the epithelial cells of the thymus and account for the thymic epithelial tumors (TETs). Although TETs are uncommon, they are the most frequent tumor type in the anterior mediastinum. Multidisciplinary approach is essential for their correct management. The aim of the present review is to summarize the update management for TETs.

Methods

For this review, we searched in Excerpta Medica database (EMBASE) and MEDLINE until 6 September 2023. The terms used in the search included thymoma, thymic carcinoma, thymic epithelial tumors, management, immunotherapy, multiple tyrosine kinases inhibitors.

Key Content and Findings

The therapeutic approach is based on histology and tumor stage and may involve surgery with or without neoadjuvant or adjuvant treatment. In the metastatic setting, platinum-based chemotherapy is the standard of care and patients who do not respond to first-line treatment have limited treatment options mainly because of the poor efficacy shown in subsequent lines of therapy.

Conclusions

Future research should focus on identifying predictive biomarkers for patients with TETs, and should implement multicenter collaborations and appropriate clinical trials tailored for rare tumor types. Immune check point inhibitors, mammalian target of rapamycin (mTOR) and antiangiogenic multikinase inhibitors have also been studied in this clinical setting.

A late relapse thymoma and pure red cell aplasia case with an over 5 years of clinical response under everolimus

Although several agents showed some clinical activity in patients with recurrent thymoma, there is no standard treatment option. Here, we report a late relapse thymoma and pure red cell aplasia case, responsive to everolimus with over 5 years of clinical benefit following multiple lines of treatment. Everolimus controlled the rapidly progressive disease in our patient without significant toxicity.

Personalized cancer avatars for patients with thymic malignancies: A pilot study with circulating tumor cell-derived organoids

BACKGROUND

Systemic therapy is the primary treatment for advanced thymic malignancies. However, there is an urgent need to improve clinical outcome. Personalized treatment based on predictive biomarkers is a potential approach to address this requirement. In this study, we aimed to show the correlation between drug sensitivity tests on CTCs-derived organoids and clinical response in patients with thymic malignancies. This approach carries the potential to create personalized cancer avatars and improve treatment outcome for patients.

METHODS

We previously reported potential treatment outcome prediction with patient-derived organoids (cancer avatars) in patients with pancreatic ductal adenocarcinoma. To further investigate the feasibility of this approach in advanced thymic malignancies, we conducted a study in which 12 patients were enrolled and 21 liquid biopsies were performed.

RESULTS

Cancer avatars were successfully derived in 16 out of 21 samples (success rate 76.2%). We found a sensitivity of 1.0 and specificity of 0.6 for drug sensitivity tests on the cancer avatars, and a two-tailed Fisher's exact test revealed a significant correlation between drug sensitivity tests and clinical responses (p = 0.0275).

CONCLUSION

This study supports the potential of circulating tumor cell-derived organoids to inform personalized treatment for advanced thymic malignancies. Further validation of this proof of concept finding is ongoing.

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.

Chinese expert consensus on the diagnosis and treatment of thymic epithelial tumors

Thymic epithelial tumors (TETs) are a relatively rare type of thoracic tumor, accounting for less than 1% of all tumors. The incidence of TETs is about 3.93/10000 in China, slightly higher than that of European and American countries. For resectable TETs, complete surgical resection is recommended. Radiotherapy or chemotherapy may be used as postoperative adjuvant treatment. Treatment for advanced, unresectable TETs consist mainly of radiotherapy and chemotherapy, but there is a lack of standard first- and second-line treatment regimens. Recently, targeted therapies and immune checkpoint inhibitors have shown promising outcomes in TETs. Based on the currently available clinical evidences and the opinions of the national experts, the Thymic Oncology Group of Yangtze River Delta Lung Cancer Cooperation Group (East China LUng caNcer Group, ECLUNG; Youth Committee) established this Chinese expert consensus on the clinical diagnosis and treatment of TETs, covering the epidemiology, diagnosis, treatment, prognosis and follow-up of TETs.

Molecular genetic characteristics of thymic epithelial tumors with distinct histological subtypes

BACKGROUND

Due to the low incidence and histological heterogeneity, the molecular features and underlying carcinogenic mechanisms of thymic epithelial tumors (TETs) are yet to be fully elucidated, especially for different subtypes of TETs.

METHODS

Tumor tissue samples of 43 TETs with distinct histological subtypes were collected. We analyzed the molecular characteristics in different subtypes based on whole exome sequencing data.

RESULTS

The mutational profiles of the different subtypes of TETs varied. Compared with thymomas, thymic carcinomas (TCs) had a higher mutation frequency of MYO16 (33% vs. 3%, p = 0.024) and a lower frequency of ZNF729 mutations (0% vs. 35%, p = 0.044). No significant difference was observed in the median tumor mutation burden across different subtypes. The value of copy number variation burden, weighted genome instability index, and the number of amplified segments were all higher in TCs than thymomas, and they also tended to be higher in B3 thymoma than in non-B3 thymomas, while they had no significant differences between B3 thymoma and TCs. Clustering analyses revealed that Wnt, MAPK, Hedgehog, AMPK, and cell junction assembly signaling pathways were exclusively enriched in non-B3 thymomas, lysine degradation pathway in B3 thymoma, and extracellular matrix-receptor (ECM-receptor) interaction, positive regulation of cell cycle process, and activation of innate immune response pathways in TCs.

CONCLUSIONS

This study revealed distinct molecular landscapes of different subtypes of TETs, suggesting diverse pathogenesis of non-B3 thymomas, B3 thymomas, and TCs. Our findings warrant further validation in future large-scale studies and may provide a theoretical basis for potential personalized therapeutic strategies.

Analysis of the efficacy and safety of immunotherapy in advanced thymoma patients

BACKGROUND

Immunotherapy has exhibited efficacy in thymic carcinoma patients; however, there are insufficient data to confirm this efficacy in thymoma. The toxicity of immunotherapy also remains to be determined.

METHODS

The efficacy and safety of immunotherapy were analyzed in 11 thymoma patients who received PD-1 inhibitors according to a range of relevant indexes including the objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and immunotherapy-related adverse events.

RESULTS

The PFS and OS rates for all patients were 12.8 and 56.5 months, respectively. No difference in efficacy was detected between monotherapy and combination therapy (PFS: 12.8 vs 2.2 months, P = 0.787; OS: 73.8 vs 56.5 months, P = 0.367). The ORRs and DCRs for all patients were 27.3% and 90.9%, respectively. The incidence of adverse events was 45.5% among the 11 thymoma patients, including immune-related myocarditis (36.4%), immune-related liver damage (18.2%), and myasthenia gravis (18.2%). In the whole cohort of patients, the rate of adverse events of grade 3 or higher was 36.4%. The rates of adverse events of grade 3 or 4 in B3-type and non-B3-type thymoma patients were 0% and 62.5%, respectively.

CONCLUSIONS

Immunotherapy elicited a response in thymoma patients; however, more attention should be paid to the immune-related adverse events.

Efficacy and safety of treatments for advanced thymic carcinoma after failure of first-line platinum-based chemotherapy: A systematic literature review and meta-analysis

Thymic carcinoma (TC) is a rare cancer and patients failing initial chemotherapy (relapse/refractory) face limited therapeutic options given no approved options or consensus standard of care. This study aimed to identify and summarize clinical outcomes of all regimens evaluated in clinical trials of relapsed or refractory patients. Interventional trials enrolling advanced TC patients who failed first-line chemotherapy and reported outcomes in this group were eligible for inclusion in our systemic literature review (SLR). Between-study heterogeneity was assessed to determine the feasibility of pooling specific studies and treatments. Objective response rate (ORR), overall survival (OS), progression-free survival (PFS), and duration of response (DOR) endpoints were of interest for meta-analysis. Nineteen trials were identified in the SLR. Three trials with one or two TC patients were removed from our assessment to reduce publication bias. Response rates among studies with at least ten TC patients varied from 9 % to 38 %. Pooled ORRs in patients receiving S-1 (46 patients), sunitinib (46 patients), or pembrolizumab (66 patients) were 28 %, 24 %, and 21 %, respectively. Prolonged duration of response with pembrolizumab was observed with a pooled median of 23.8 months (95 % confidence interval [CI]: 12, not reached). Median PFS of five months or greater was reported in patients treated with sunitinib, lenvatinib, pembrolizumab, capecitabine + gemcitabine, everolimus, or S-1. Median OS of 20 months or greater was reported in trials evaluating S-1 or pembrolizumab; this endpoint was not reached in trials evaluating lenvatinib, regorafenib, or sunitinib. Generalizability of treatment effects is challenging in the research of rare diseases and meta-analysis of clinical outcomes may help to increase precision and relevance of results to the larger TC population. Our study found limited treatment options upon relapse, demonstrating a need for further investigations into novel therapeutics and well-powered clinical trials to better inform on optimal treatments.

Principles of medical and oncological management of giant masses of the mediastinum: a narrative review

Background and Objective

Giant mediastinal tumors are represented by well-defined histological variants originating from different structures and compartments while their clinical presentation may be similar and characterized by the same set of symptoms, the well-known mediastinal syndrome (MS). In 80% of cases the MS is caused by malignant neoplasms, such as lung tumors, in 10-18% of cases by hematological neoplasms and in 2-3% by benign causes. In this review we investigated the medical treatment of main giant mediastinal tumors, focusing our interest on the objective response rate (ORR), as it represents the most suitable parameter to predict the volumetric reduction of the neoplasm and, consequently, the regression of their most severe complication, the MS. We will also cover the supportive and symptomatic treatment of MS.

Methods

We performed a deep analysis of the recent international literature published on PUBMED, UpToDate and Medline. The literature search was undertaken from origin until November 30th, 2021, and we only considered publications in English.

Key Content and Findings

Considering the variety of pathologies that can occur in the mediastinum, a rapid histological characterization of the neoplasm is mandatory. In fact, the treatment of these neoplasms includes different approaches, sometimes used in combination, which include chemotherapy, radiotherapy, and surgery. The vena cava syndrome (VCS), due to its high mortality, is considered an oncological emergency and, therefore, requires effective treatments carried out urgently, evaluated in multidisciplinary meeting.

Conclusions

The treatment of MS includes both antiblastic treatments and therapies directed to the symptoms. Among the former, chemotherapy, target therapy, radiation and surgery may be used, according to the etiology of MS. Among the latters, supportive therapies, interventional radiology procedures such as stenting may help manage this syndrome, despite the prognosis is poor in most cases and linked to the histology of the tumor, which therefore represents the most important prognostic factor.

Treatment outcomes and prognosis of immune checkpoint inhibitors therapy in patients with advanced thymic carcinoma: A multicentre retrospective study

BACKGROUND

Immunotherapy has demonstrated good efficacy and survival outcomes in solid tumours. However, efficacy data for immune checkpoint inhibitors (ICIs) in advanced thymic carcinoma are lacking. The present study aimed to assess the activity of ICIs in advanced thymic carcinoma.

METHODS

A multicentre retrospective study was conducted to explore the efficacy and safety of ICIs for advanced thymic carcinoma. Objective response rate (ORR), progression-free survival (PFS), overall survival, and immune-related adverse events (irAEs) were analysed. In addition, factors independently associated with treatment efficacy and survival outcomes were evaluated.

RESULTS

A total of 77 patients with advanced thymic carcinoma were enrolled between March 2016 and September 2021. The ORR was existing the difference between ICIs monotherapy (n = 23) and ICIs combined with chemotherapy (n = 54) (17.4% versus 44.4%, P = 0.024). The ICIs combination treatments were associated with better median PFS (mPFS) compared to ICIs monotherapy (12.7 months versus 2.1 months, P < 0.001). Notably, liver or brain metastasis was a poor prognostic factor of mPFS (1.8 months versus 3.5 months, P = 0.012) in the ICIs monotherapy group. In addition, mPFS for the first-line treatment (n = 27) was longer than that for ICIs as the second- or posterior-line treatment (n = 50) (P < 0.001). The incidence of irAEs was 54.5% (42/77) in the 77 enrolled patients. The incidence of grade 3-4 irAE was 15.6% (12/77).

CONCLUSIONS

Immunotherapy is effective in advanced thymic carcinoma, especially for combination with chemotherapy showed promising antitumour activity, which indicates worthy of combination treatment strategy for further study. IrAEs also require close monitoring and management.

Second-line treatment options in advanced thymic carcinoma after failure of platinum-based chemotherapy: A multicenter retrospective study

BACKGROUND

Currently there is no standard therapy recommended for second-line treatment for thymic carcinoma. Our study compared multidrug chemotherapy, single-agent chemotherapy, and PD-1 inhibitors in patients diagnosed with advanced thymic carcinoma who had previous platinum-based chemotherapy at the clinic.

METHODS

The study included patients with thymic carcinoma who failed first-line platinum-based chemotherapy. Kaplan-Meier methods were applied in the study for estimating the progression-free survival (PFS) and overall survival (OS) curves. Pearson chi-square or Fisher's exact chi-square test was adopted to make comparisons of the objective response rate (ORR) between treatment groups. Cox regression was used for the multivariate analyses in PFS and OS.

RESULTS

Among the 92 patients enrolled, multidrug chemotherapy was used in 51 (55.4%) patients for second-line therapy. Thirty-six patients (35.9%) received single-agent chemotherapy, and eight patients (8.7%) underwent PD-1 inhibitors. The multidrug chemotherapy group showed better efficacy than the other two groups, with an ORR of 35.3% (p = 0.006). The median PFS of multidrug chemotherapy, single-agent chemotherapy and PD-1 inhibitors were 5.0 months, 3.0 months, and 4.0 months, respectively (p = 0.008). Patients in the multidrug chemotherapy group also showed an advantage in OS in comparison with the other two treatment groups (p = 0.045), with a median OS of 30.4 months. Multivariate analysis showed that second-line treatment was independent factor for both PFS (p = 0.035) and OS (p = 0.037). Grade 3-4 AEs were mostly detected in patients receiving multidrug chemotherapy and were primarily hematologic. Treatment-related mortality was not found in any of the groups.

CONCLUSIONS

Multidrug chemotherapy had a trend toward a more positive response rate and outcomes in longer survival time than single-agent chemotherapy and PD-1 inhibitors. Multidrug chemotherapy is a choice worth considering for second-line therapy in patients with thymic carcinoma if tolerable.

Transformation from Small Cell to Squamous Cell Carcinoma in a Thymic Carcinoma Patient with a Durable Response to Anlotinib: A Case Report

The most common pathologic type of thymic carcinoma (TC) is squamous cell carcinoma (SCC). Small cell carcinoma is relatively rare, accounting for approximately 2% to 5% of all thymic tumors. Histologic transformation of TC has not yet been reported. Available treatments for TC patients who progress after first-line therapy are limited, which contributes to their poor prognosis. We reported an extraordinary case of a 66-year-old man who was diagnosed with thymic small cell carcinoma that transformed into SCC after third-line treatment. Surprisingly, the patient had a progression-free survival (PFS) of 25 months and an overall survival (OS) of 10 years on anlotinib as fourth-line therapy. The tolerance was well. Thus, anlotinib may be a safe and promising treatment for TC patients, especially those who undergo histologic transformation.

Cisplatin and Irinotecan as First-Line Chemotherapy for Previously Untreated Metastatic Thymic Carcinoma: Updated Analysis

Platinum-based chemotherapy is the de facto standard treatment for metastatic or unresectable thymic carcinoma. The optimal chemotherapy regimen has not yet been determined, including whether this should be combined with a second- or third-generation anti-cancer agent. We retrospectively evaluated the data of patients with metastatic or unresectable thymic carcinoma who were treated with a combination of cisplatin and irinotecan as first-line chemotherapy between 2002 and 2021 (trial registration UMIN000012175). The primary endpoint was response rate according to the RECIST criteria version 1.1. Secondary endpoints were disease control rate, progression-free survival (PFS), overall survival (OS), and toxicity (adverse events). Some patients analyzed in this study were also included in the previous trial, which was terminated early. For this analysis, we included 18 patients with a median age of 56 years and an Eastern Cooperative Oncology Group performance status of 0 or 1. All patients had clinical stage IVa or IVb thymic carcinoma according to the Masaoka-Koga staging system. The response rate was 44% and the disease control rate was 89%. The median PFS was 8.4 months (95% confidence interval (CI): 2.7–11.6 months) and the median OS was 45.6 months (95% CI: 15.7–69.1 months). Grade 3 or worse hematological toxicity was observed in 5 patients and grade 3 or worse non-hematological toxicity was observed in 3 patients. None of the patients developed febrile neutropenia, and no treatment-related deaths occurred. Thus, the combination of cisplatin and irinotecan as first-line chemotherapy for metastatic thymic carcinoma showed efficacy and acceptable toxicity.

Thymic tumours and their special features

Thymic tumours are rare thoracic malignancies, that may be aggressive and difficult to treat. The pillars of the management include pathological review, consideration of differential diagnoses, staging and multidisciplinary discussion. Assessment of resectability is key to drive the treatment sequencing. Association with autoimmune diseases, especially myasthenia gravis, is observed, which impacts the oncological management. Networks are being built at the national and international levels. This article provides an overview of the most recent findings in the diagnosis, staging, histology, and management strategies of thymic tumours.

Thymic tumours are rare and heterogeneous tumours. Management is based on multidisciplinary discussion and networking.https://bit.ly/3kYAZ7u

Resound Trial: A phase 2 study of regorafenib in patients with thymoma (type B2-B3) and thymic carcinoma previously treated with chemotherapy

BACKGROUND

Angiogenesis has an important role in thymic epithelial tumors (TETs). Regorafenib inhibits vascular endothelial growth factor receptors (VEGFRs), platelet-derived growth factor receptor β (PDGFR-β), and fibroblast growth factor receptors (FGFRs). This study explored the activity of regorafenib as monotherapy in patients with advanced or recurrent B2-B3 thymoma (T) and thymic carcinoma (TC) previously treated with platinum-containing chemotherapy.

METHODS

A Fleming single-arm, single-stage, phase 2 trial to evaluate the activity of regorafenib (160 mg once a day by mouth for 3 weeks on/1 week off) was planned. The study was designed to reject the null hypothesis of an 8-week progression-free survival (PFS) rate ≤25% with a type I error of 0.10 and a statistical power of 80% at the alternative hypothesis of an 8-week PFS rate of ≥50% (≥8 of 19 evaluable patients progression-free at 2 months).

RESULTS

From June 2016 to November 2017, 19 patients were enrolled (11T/8TC). We observed partial response (PR) in 1 patient (1T) (5.3%), stable disease (SD) in 14 patients (9T/5TC) (73.7%), and progressive disease in 2 patients (1T/1TC) (10.5%), with a disease control rate of 78.9%. According to Choi-criteria, 13 patients (68.4%) achieved PR, and 2 patients SD (10.5%). The median PFS was 9.6 months whereas median overall survival was 33.8 months. The 8-week PFS rate was 78.9% (15 of 19 patients). Grade 3-4 treatment-related adverse events were observed in 10 patients (52.6%).

CONCLUSIONS

The primary end point of this study was reached. The high rate of PR (Choi-criteria) suggests antitumor activity of regorafenib in TETs. On the basis of survival outcomes, the efficacy of regorafenib should be further evaluated in larger studies.

Future Perspective of Chemotherapy and Pharmacotherapy in Thymic Carcinoma

Simple Summary

Thymic carcinoma is a rare cancer, and its biology remains largely unknown. Although complete surgical resection is a standard treatment for thymic carcinoma, systemic chemotherapy is frequently administered in metastatic or recurrent cases. Given the rarity, therapeutic agents are often confirmed on the basis of the results of phase II trials or retrospective studies. Platinum-based combination chemotherapy has long been employed for treating thymic carcinoma. Recently, biomarkers have been explored, and molecular profiles and major oncogenic pathways have gradually been revealed by next-generation sequencing, resulting in the development of targeted therapies. Moreover, clinical trials assessing combination therapy with immune checkpoint inhibitors are ongoing and are expected to be efficacious for treating thymic epithelial tumors. We reviewed the current role of systemic chemotherapy, including targeted therapies and immune checkpoint inhibitors, considering recent findings regarding its biology.

Abstract

Thymic carcinoma is a rare cancer that arises from thymic epithelial cells. Its nature and pathology differ from that of benign thymoma, presenting a poorer prognosis. If surgically resectable, surgery alone or surgery followed by chemoradiotherapy or radiotherapy is recommended by the National Comprehensive Cancer Network Guidelines. Metastatic and refractory thymic carcinomas require systemic pharmacotherapy. Combined carboplatin and paclitaxel, and cisplatin and anthracycline-based regimens have been shown a fair response rate and survival to provide a de facto standard of care when compared with other drugs employed as first-line chemotherapy. Cytotoxic agents have been pivotal for treating thymic carcinoma, as little is known regarding its tumorigenesis. In addition, genetic alterations, including driver mutations, which play an important role in treatments, have not yet been discovered. However, molecular pathways and biomarker studies assessing thymic epithelial tumors have been reported recently, resulting in the development of new agents, such as molecular targeted agents and immune checkpoint inhibitors. As treatment options are currently limited and the prognosis remains poor in metastases and recurrent thymic carcinoma, genetic alterations need to be assessed. In the present review, we focused on the current role of targeted therapies and immune checkpoint inhibitors in treating thymic carcinoma.

Systemic treatments for thymic tumors: a narrative review

Thymic epithelial tumours (TETs) are rare tumours originating from the thymus. Considering the rarity of this disease, the management of TETs is still challenging and difficult. In fact, all the worldwide clinical practice guidelines are based on data from retrospective analyses, prospective single arm trials or experts' opinions. The results of combined modality therapy (chemotherapy, surgery, radiotherapy) in thymic malignancies are reasonably good in less advanced cases whereas in case of advanced (unsuitable for surgery) or metastatic disease, a platinum-based chemotherapy is considered standard of care. Unfortunately, chemotherapy in the palliative setting has modest efficacy. Moreover, due to the lack of known oncogenic molecular alterations, no targeted therapy has been shown to be efficient for these tumours. In order to offer the best diagnostic and therapeutic tools, patients with TETs should be managed with a continuous and specific multidisciplinary expertise at any step of the disease, especially in the era of a novel coronavirus disease (COVID-19). Current evidences show that cancer patients might have more severe symptoms and poorer outcomes from COVID-19 infection than general population. With the exception of the patients carrying a Good's syndrome, there is no evidence that patients with TETs present a higher risk of infection compared with other cancer patients and their management should be the same. The aim of this review is to summarize the existing literature about systemic treatments for TETs in all clinical setting (local and locally advanced/metastatic disease) exploring how these therapeutic strategies have been managed in the COVID-19 era.

Narrative review of immunotherapy in thymic malignancies

Thymomas and thymic carcinomas (TCs) (also known as Thymic Epithelial Tumors or TETs) are rare cancers and the most frequent masses of the anterior mediastinum. These tumors appear in the epithelial component of the thymus, a primary lymphoid organ, and they have reported a high risk of auto-immunity due to a unique biology. Indeed, up to 30% of patients with TETs could present an autoimmune disorder (AID), the most frequent being Myasthenia Gravis (MG). Moreover, AIDs have been reported not only at tumor diagnosis but before and during the follow-up. These tumors have a lack of specific therapeutic targets for metastatic setting. Immune checkpoint inhibitors (ICI) may defeat cancer cells' capacity to evade the immune system and proliferate. The long-term benefit of ICIs in the metastatic setting in several tumors, such as melanoma or non-small cell lung cancer (NSCLC), let to evaluate ICI approaches in TETs. The high rate of AIDs and distribution of autoimmune events among TET's histological subtypes may have an influence on the decision regarding a treatment based on ICI due to the increased risk of toxicity. We summarize the current evidence for the efficacy of ICI in thymoma and TC and discuss several unresolved challenges and concerns for the use of this agents in TETs.

Radiotherapy for thymic epithelial tumours: a review

Thymic epithelial tumours (TETs) represent a rare disease, yet they are the most common tumours of the anterior mediastinum. Due to the rare occurrence of TETs, evidence on optimal treatment is limited. Surgery is the treatment of choice in the management of TETs, while the role of postoperative radiotherapy (PORT) remains unresolved. PORT remains debated for thymomas, especially in completely resected stage II tumours, for which PORT may be more likely to benefit in the presence of aggressive histology (WHO subtype B2, B3) or extensive transcapsular invasion (Masaoka-Koga stage IIB). For stage III thymoma, evidence suggests an overall survival (OS) benefit for PORT after complete resection. For incompletely resected thymomas stage II or higher PORT is recommended. Thymic carcinomas at any stage with positive resection margins should be offered PORT. Radiotherapy plays an important role in the management of unresectable locally advanced TETs. Induction therapy (chemotherapy or chemoradiation) followed by surgery may be useful for locally advanced thymic malignancies initially considered as unresectable. Chemotherapy only is offered in patients with unresectable, metastatic tumours in palliative intent, checkpoint inhibitors may be promising for refractory diseases. Due to the lack of high-level evidence and the importance of a multidisciplinary approach, TETs should be discussed within a multidisciplinary team and the final recommendation should reflect individual patient preferences.

Perspective of Immune Checkpoint Inhibitors in Thymic Carcinoma

Simple Summary

Thymic carcinoma is a rare neoplasm with a poor outcome, and there are no established therapeutic regimens for metastatic or recurrent disease. Immune checkpoint inhibitors (ICIs), such as PD-1/PD-L1 antibodies, are approved in several human cancers, however, ICIs are not approved in thymic carcinoma. Thus, several clinical trials have been undertaken to demonstrate if they are therapeutically effective for patients with thymic carcinoma. In our review, three prospective phase II studies and several case series were discussed in thymic carcinoma. We found that the objective response rate, disease control rate, and progression-free survival in PD-1 blockade monotherapy were approximately 20%, 73%, and four months, respectively. The therapeutic efficacy of PD-1 blockade monotherapy is still limited in patients with thymic carcinoma. Future perspectives focus on the therapeutic implication of tyrokinase inhibitors plus ICIs or new experimental agents plus ICIs alongside several ongoing experimental studies.

Abstract

Thymic carcinoma is a rare neoplasm with a dismal prognosis, and there are no established therapeutic regimens for metastatic or recurrent disease. Immune checkpoint inhibitors (ICIs), such as PD-1/PD-L1 antibodies, are widely approved in several human cancers, contributing to prolonging survival in thoracic tumors. Thymic carcinoma exhibits histologic properties of squamous cell carcinoma (SQC), and resembles the SQC of the lung. ICIs are not approved in thymic carcinoma. Thus, several clinical trials have been undertaken to demonstrate if they are therapeutically effective for patients with thymic carcinoma. In our review, three prospective phase II studies and several case series were discussed in thymic carcinoma. We found that the objective response rate, disease control rate, and progression-free survival in PD-1 blockade monotherapy were approximately 20%, 73%, and four months, respectively. Two exploratory investigations indicated that PD-L1 within tumor cells exhibits a possibility of the therapeutic prediction of PD-1 blockade in thymic carcinoma. Several case reports, alongside their treatment content, have also been reviewed. The therapeutic efficacy of PD-1 blockade monotherapy is still limited in patients with thymic carcinoma. Future perspectives focus on the therapeutic implication of tyrokinase inhibitors plus ICIs or new experimental agents plus ICIs alongside several ongoing experimental studies.

Phase II trial of S-1 treatment as palliative-intent chemotherapy for previously treated advanced thymic carcinoma

Thymic carcinoma (TC) is a rare cancer with minimal evidence of survival following palliative-intent chemotherapy. Sunitinib, everolimus, and pembrolizumab have been proposed as active agents based on previous phase II trials. In this phase II study, TC patients previously treated with platinum-based chemotherapy were enrolled. The patients received S-1 orally twice daily at a dose of 40-60 mg/m² for 4 weeks, followed by 2 weeks off until the progression of the disease or the presence of unacceptable toxicities. The primary endpoint was the objective response rate (ORR), and secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. The sample size of 26 patients was planned to reject the ORR of 10% under the expectation of 30% with a power of 0.80 and a type I error of 0.05 (one-sided). Twenty-six patients were recruited between 2013 and 2016; 23 patients had squamous cell carcinoma and 10 had an ECOG performance status of 0. One patient showed complete response and seven patients showed partial responses, resulting in a 30.8% response rate (90% confidence interval [CI], 18.3-46.9) and an 80.8% disease control rate (90% CI, 65.4-90.3). The median PFS was 4.3 months (95% CI, 2.3-10.3 months) and median OS was 27.4 months (95% CI, 16.6-34.3). Adverse events of grade ≥ 3 included neutropenia (12%), skin rash (8%), elevated alanine aminotransferase, and fatigue (4%). No treatment-related death was observed. S-1 confirmed clinical activity with tolerability in patients with previously treated TC. (UMIN000010736).

Thymic epithelial tumors: From biology to treatment

In the last few years, meaningful advances have been made in the knowledge of the biology of Thymic Epithelial Tumors (TETs). Data available suggest that in most cases, the different histological subtypes could be distinct biological entities, characterized by specific molecular aberrations, rather than representing a histological continuum of diseases. Recurrent gene mutations in Thymomas and Thymic Carcinoma have been identified, but we still do not know the exact role played by these mutations in TETs pathogenesis. Relevant new data are now available on the pathogenetic mechanisms underlying the association between TETs and autoimmune diseases that warrant further investigations for the potential therapeutic implications. The progress in knowledge of the molecular pathways involved in TETs pathogenesis, allowed to identify and to test target therapies potentially active in such diseases. Platinum-based chemotherapy remains the standard first line treatment for patients with advanced or metastatic TETs. However, some promising data have been reported on the activity of new target therapies, including anti-angiogenic drugs, Cycline Dependent Kinases and PI3K/mTOR inhibitors, as well as of Immune-checkpoint inhibitors. A number of new drugs and combinations are currently under evaluation. The efficacy of new drugs should be balanced with their toxicity profiles, in such complex patients that seem to be more susceptible to develop drug-related toxicities, in particular with immunotherapies.

Next-generation sequencing in thymic epithelial tumors uncovered novel genomic aberration sites and strong correlation between TMB and MSH6 single nucleotide variations

Thymic epithelial tumors (TET) including thymomas and thymic carcinomas are rare, but they are common primary tumors in the anterior mediastinum. The etiology and tumorigenesis of TET remain unclear. To better understand the novel aberrations of this rare tumor and provide more significant mutation sites for targeted therapy, we performed next-generation sequencing detection on 55 patients with TET. Our results showed that most genes in 12 core pathways harbored aberrations of indeterminate potential. In 4 genes (ARID1A, KMT2C, TGFBR2 and MAP3K1), the indel frequency was above 90%. Dozens of genes, including TGFBR2, KMT2C, PRKDC, ATR, CHD2, SDHA, KDM5A, CHEK1, MSH6 and POLE, possessed frameshift indel with different frequencies in different hotspot sites, which could be the new targets of therapy for TET. For the first time, we revealed a strong correlation between the tumor mutational burden and single nucleotide variations, but not frameshift, on DNA mismatch repair gene MSH6 in TET.

Effect of Suramin on Renal Proximal Tubular Cells Damage Induced by Cisplatin in Rats (Histological and Immunohistochemical Study)

Background:

Renal toxicity is the most common complication of cispaltin therapy that has broad-spectrum antitumor activity against a variety of human solid tumor. Suramin, a Food and Drug Administration-approved old drug is a polysulfonated compound of napthylurea originally designed to treat trypanosomiasis.

Aim:

The current work aimed to investigate the possible protective effect of different doses of suramin against cisplatin-induced renal proximal tubular cells (RPTCs) damage.

Material and Methods:

Fifty adult male rats were used and divided into five equal groups. Group I served as a control, group II received suramin alone (10 mg/kg). Groups III, IV and V were administered cisplatin once (5 mg/kg, intraperitoneally) alone or combined with low dosage suramin (5 mg/kg) or high dosage suramin (10 mg/kg) once intravenously respectively.

Results:

Compared with control rats, cisplatin administration caused proximal tubules damage, RPTCs vacuolation with pyknotic nuclei, loss of brush border and widespread caspase-3 immunostaining. Cisplatin-induced RPTCs toxicity was further confirmed morphometrically (a significantly decreased proximal tubular epithelium height and increased mean number of caspase-3-immunopositive cells). These changes were accompanied by biochemical alteration manifested as a significant increase of blood urea nitrogen and serum creatinine. Simultaneous administration of high-dose but not low-dose suramin to the cisplatin-treated rats improved the deleterious morphological and morphometrical effects on RPTCs and restored the aforementioned biochemical parameters to control values.

Conclusion:

In conclusion suramin in a dose dependant manner protects RPTCs from damage induced by cisplatin.

Phase II trial of single agent amrubicin in patients with previously treated advanced thymic malignancies

OBJECTIVES

There are limited treatment options for patients with thymic malignancies. Here we present data supporting treatment with single agent amrubicin, a third generation anthracycline and topoisomerase II inhibitor.

MATERIALS AND METHODS

This was a phase 2 open-label, single arm trial of amrubicin in patients with thymoma (T) or thymic carcinoma (TC), conducted at two academic institutions. Patients were included if they had received at least one prior chemotherapy regimen. The first 18 patients received amrubicin at 40 mg/m2 IV days 1-3 repeated every 3-weeks. Due to the high incidence of febrile neutropenia, dosing was subsequently amended to 35 mg/m2 for the final 15 patients.

RESULTS

A total of 33 patients (14 T/19 TC) were enrolled from 2011 to 2014. Median number of prior therapies was 2. Best response included 6 partial responses, 21 stable disease, and 6 progressive disease (all TC). Objective response rate was 18% (90% exact binomial CI 8.2%-32.8%; T = 4/14 (29%), TC = 2/19 (11%)). Median progression-free survival was 7.7 months (T: 8.3 months; TC: 7.3) and median overall survival was 29.7 months (T: 54.1 months; TC: 18 months). There was a high rate of febrile neutropenia (7 patients) that occurred despite a reduction in amrubicin dose and one related death. Five patients had reduction in LVEF below 50% during the course of treatment resulting in treatment discontinuation in one patient.

CONCLUSION

Amrubicin shows promise as a single agent in heavily pre-treated patients with thymic malignancies. Notable side effects include febrile neutropenia and the use of growth factor support is essential. Further investigation of this agent is warranted.

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.

Clinical Outcomes of Up-front Surgery Versus Surgery After Induction Chemotherapy for Thymoma and Thymic Carcinoma: A Retrospective Study

INTRODUCTION

Although induction chemotherapy improves the resectability of thymic neoplasms, it is unclear whether surgery after induction chemotherapy can improve outcomes. We compared long-term outcomes of surgery with and without induction chemotherapy in patients with thymic neoplasms.

PATIENTS AND METHODS

We retrospectively investigated the clinical information of patients with thymic neoplasms at the National Taiwan University Hospital between 2005 and 2013.

RESULTS

Of 204 patients, 119 underwent direct surgery (group 1), 45 underwent surgery after induction chemotherapy (group 2), and 40 underwent no surgery (group 3). The 5-year overall survival rates of groups 1, 2, and 3 were as follows: for 204 patients, 96.3%, 76.4%, and 35.5% (P < .001); for 119 thymoma patients, 96.6%, 88.9%, and 100.0% (P = .835); for 85 thymic carcinoma patients, 94.7%, 69.7%, and 17.7% (P < .001); for 36 American Joint Committee on Cancer (AJCC) stage III-IVA thymoma patients, 92.9%, 83.3%, and 100% (P = .833); and for 28 stage III-IVA thymic carcinoma patients, 75.0%, 76.2%, and 62.5%, (P = .160). Univariate analysis showed that for group 2 (P = .0208) and group 3 (P < .0001), thymic carcinoma pathology type (P = .0010) and stage IVB disease (P < .0001) were poor prognostic factors. Multivariate analysis found thymic carcinoma (P = .0026) and stage IVB disease (P = .0449) to be poor prognostic factors.

CONCLUSION

Up-front surgery leads to best overall survival, and induction chemotherapy followed by surgery may improve resectability and outcomes. Only thymic carcinoma and stage IVB disease were poor prognostic factors in multivariate analysis.

A bimodal approach to thymic carcinoma with pericardial sac invasion

Thymic carcinoma is a rare tumour of the thymus, representing less than 1% of thymic malignancies. ¹ It has an annual incidence of 0.15-0.32 per 1 00 000 person-years. ² It is found incidentally in 30% of the patients as an opacity on chest X-ray or with non-specific complaints of persistent cough, chest pain, fatigue, shortness of breath, arm and facial swelling, and upper airway congestion related to tumour extension. We present the case of a 59-year-old man with a history of Graves' disease status post radiation treatment presenting with cough and left lingual opacity on chest X-ray, confirmed to be thymic carcinoma with pericardial invasion and lymph node metastasis. We aim to discuss the presentation, treatment modalities and outcome associated with this rare tumour.

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.

Best practices for the management of thymic epithelial tumors: A position paper by the Italian collaborative group for ThYmic MalignanciEs (TYME)

Thymic epithelial tumors (TETs) are a heterogenous group of rare tumors, with a complex histopatological classification. Furthermore, the recent introduction of the first TNM staging system, that is scheduled to replace the Masaoka-Koga system, may create further difficulties in TET management, that remains challenging. Several guidelines for treatment of TETs are available and provide recommendations based mainly on non randomized trials and retrospective or limited series. Often the lack of evidence leads to formulation of indications based on expert opinions. As for other rare cancers it is crucial to create networks to coordinate the work among centres involved in treatment of these diseases in order to offer the best diagnostic and therapeutic tools. For this purpose, in 2014 a network named TYME (ThYmic MalignanciEs), was founded in Italy with the aim of improving care and research in TETs. In September 2017 a panel of multidisciplinary experts from TYME network and from other Italian centres strongly involved in TET diagnosis and treatment convened a first Italian Expert meeting together with representatives of association for patients affected by rare thoracic cancers Tu.To.R, to explore how these tumors are managed in the different centres of Italy compared to ESMO guidelines. In this paper we summarize the issues discussed during that meeting and we propose recommandations based on Masaoka Koga and the new TNM staging system.

Systemic Therapy in Advanced Thymic Epithelial Tumors: Insights from the RYTHMIC Prospective Cohort

INTRODUCTION

Thymic epithelial tumors (TETs) are rare malignancies that may be aggressive and difficult to treat. In the advanced setting, systemic treatments may be delivered as primary therapy before surgery or definitive radiotherapy, as exclusive treatment when no focal treatment is feasible, or in the setting of recurrences. Réseau tumeurs THYMIques et Cancer (RYTHMIC) is the nationwide network for TETs in France. The objective of the study was to describe the modalities and analyze the efficacy of systemic treatments for patients with advanced TETs included in the RYTHMIC prospective database hosted by the French Thoracic Cancer Intergroup.

METHODS

All consecutive patients for whom systemic treatment was discussed at the RYTHMIC multidisciplinary tumor board from 2012 to 2015 and who received at least one cycle of treatment were included. The main end points were objective response and progression-free survival (PFS).

RESULTS

A total of 236 patients were included in this analysis. Of those 236 patients, 91 received primary chemotherapy, leading to response rates of 83% for thymomas and 75% for thymic carcinomas and a median PFS of 23.2 months. A strong predictor of longer PFS was histologic type of thymoma (p < 0.001). Exclusive chemotherapy was delivered to 54 patients. The response rates were 31% for thymomas and 37% for thymic carcinomas. The median PFS was 6.2 months, and it was correlated to response rate (p = 0.001). Systemic therapy for a first, second, third, and fourth recurrence was delivered to 114, 81, 51, and 27 patients, respectively. The response rates ranged between 15% and 39% for thymomas and 4% to 21% for thymic carcinomas. The median PFS times were 7.7, 6.2, 5.9, and 6.5 months, respectively.

CONCLUSION

Patients with advanced thymic malignancies may receive multiple lines of systemic therapy, with an opportunity for clinically relevant PFS rates for which objective response may be a surrogate. Our real-life study provides landmark efficacy data that are needed when designing clinical trials to assess innovative agents.

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.

Phase II Study of Everolimus in Patients With Thymoma and Thymic Carcinoma Previously Treated With Cisplatin-Based Chemotherapy

Purpose No effective salvage treatments are available for patients with advanced/recurrent thymoma (T) or thymic carcinoma (TC) who have progressed after platinum-based chemotherapy. This study evaluated the activity of everolimus in patients with advanced/recurrent T or TC previously treated with cisplatin-containing chemotherapy. Patients and Methods This was a single-arm, single-stage, open-label, multicenter, phase II trial. Patients received oral everolimus 10 mg/d until disease progression, unacceptable toxicity, or patient refusal. A Fleming phase II trial was designed. The null hypothesis of a true disease control rate (DCR) of 40% was tested against a one-sided alternative of a true DCR of 60% (α = β = 0.10): If disease control were achieved in ≥ 21 of the first 41 evaluable patients, everolimus could be recommended for further evaluation. Progression-free survival, overall survival, and safety were also evaluated. Results From 2011 to 2013, 51 patients were enrolled (T, n = 32; TC, n = 19). Complete remission was observed in one patient with TC, partial response in five patients (T, n = 3; TC, n = 2), and stable disease in 38 patients (T, n = 27; TC, n= 11), with a DCR of 88% (T,: 93.8%; TC, 77.8%). With a median follow up of 25.7 months, median progression-free survival was 10.1 months (T,: 16.6 months; TC, 5.6 months), and median overall survival was 25.7 months (T, not reached; TC, 14.7 months). Fourteen patients had a serious drug-related adverse event; of these patients, nine permanently discontinued treatment. Three patients died of pneumonitis while in the study. Immunohistochemical positivity for p4E-BP1 or insulin-like growth factor-1 receptor was statistically significantly related to a shorter survival. Conclusion Everolimus may induce durable disease control in a high percentage of patients with T or TC, albeit with a potential high risk of fatal pneumonitis.

Thymic Carcinoma With Endobronchial Metastasis: A Case Report

Thymic carcinoma is a rare cancer, accounting for only 1% to 4% of thymic epithelial tumors. Endobronchial metastasis is a rare presentation of these tumors. A 64-year-old man presented with a cough. Lung cancer was suspected because a chest radiograph showed a 7-cm mass in the left pulmonary hilum. Computed tomography showed a mass in the anterior mediastinum and an infiltrate in the upper lobe of the left lung. Bronchoscopy demonstrated bilateral polypoid tumors in the left B bronchus and the right B bronchus. Endobronchial biopsies of both lesions resulted in a diagnosis of squamous cell carcinoma that was positive for c-KIT by immunohistochemical staining. The patient was eventually found to have thymic squamous cell carcinoma with bilateral endobronchial metastases (stage IVb according to the Masaoka-Koga staging system) by diagnostic video-assisted thoracoscopic surgery. He was subsequently treated with platinum-doublet chemotherapy and achieved a partial response for 18.8 months.

CD52, CD22, CD26, EG5 and IGF-1R expression in thymic malignancies

BACKGROUND

Thymic epithelial tumours are rare cancers for which new treatment options are required. Identification of putative predictive markers is important for developing clinical trials. We studied the expression of five putative predictive biomarkers, potentially actionable by approved experimental drugs.

METHODS

CD52, CD22, CD26, EG5, and IGF-1R expression were investigated by immunohistochemistry in formalin-fixed surgical samples of thymic epithelial tumour patients. All samples containing 10% positive epithelial tumour cells, independent of tumour cell intensity, were considered as positive. Correlation with histological subtype was performed.

RESULTS

106 surgical samples (89 thymomas, 12 thymic carcinoma, and 5 thymic neuroendocrine tumours) were evaluated. Overall, CD52, CD22, CD26, EG5 and IGF-1R expression was observed in 7%, 42%, 25%, 42% and 77% of samples, respectively. CD52 expression was more frequent in B2 and B3 thymoma. All TET subtypes stained for CD22, mainly AB thymoma (68%). CD26 expression also correlated with AB thymoma (68%), and A thymoma (50%) subtype, while IGFR1 was the most common marker expressed by thymic carcinoma samples (92%), followed by EG5 (60%). Only EG5 expression was significantly higher in thymic carcinomas than in thymomas (75% vs. 38%, p=0.026).

CONCLUSIONS

Our data were consistent with a previous study of IGF-1R expression. Based on their expression, activity of agents targeting CD52, CD 22, CD26 and EG5 could be further explored in TET patients.

Dexmedetomidine protects against cisplatin-induced acute kidney injury in mice through regulating apoptosis and inflammation

OBJECTIVE AND DESIGN

Cisplatin-based chemotherapy has been widely used in the perioperative period of cancer surgery, which exacerbates the risk of renal injury. In this study, we examined whether dexmedetomidine (DEX), a commonly used anesthetic adjuvant, shows a protective effect against cisplatin-induced acute kidney injury.

MATERIALS

Acute kidney injury in mice was induced by cisplatin.

TREATMENTS

Mice were administered with DEX 25 μg/kg or atipamezole 250 μg/kg (once a day, for 3 days) after cisplatin treatment.

METHODS

The renal function and tubular damage score were evaluated at 72 h following cisplatin administration. Apoptotic tubular cells were detected by TUNEL assay. Caspase-3, p53, Bax, F4/80⁺ macrophages, CD3⁺ T cells, and NF-κB were examined by immunohistochemistry staining or Western blot. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and monocyte chemoattractant protein (MCP)-1 in kidney were measured using real-time polymerase chain reaction.

RESULTS

DEX treatment preserved renal function and reduced tubular damage score of mice after cisplatin administration. Mice treated with DEX exhibited less apoptotic tubular cells in response to cisplatin insult, which was associated with decreased Bax and reduced activation of p53 and caspase-3. DEX suppressed the infiltration of macrophages and T cells into the kidneys following cisplatin treatment, which was involved in the inhibition of NF-κB activation and decreased expression of TNF-α, IL-1β, IL-6, and MCP-1. Furthermore, we showed that the renoprotective effect conferred by DEX may be related to α₂ adrenoceptor-dependent pathway.

CONCLUSION

We demonstrate that DEX protects the kidney against cisplatin-induced AKI by the regulation of apoptosis and inflammatory response.

Isolated splenic metastasis from a thymic carcinoma: A case report

Thymic carcinomas are rare tumors that arise in the anterior mediastinum. Most of these malignancies develop local metastases limited in the thorax. Splenic metastases from thymic carcinomas are extremely rare. Here we report a case of isolated splenic metastasis from a 38-year-old female patient with Stage IV thymic carcinoma, who was treated with chemoradiotherapy. At twenty-2 months follow-up, the patient was found to have an isolated spleen metastasis, which was treated by Cyberknife with a reduced size of the metastasis, representing a partial response. Although splenic metastasis is a rare phenomenon, physicians need to be aware of the possibility of such metastases.

Expression of programmed death 1 (PD-1) and its ligand (PD-L1) in thymic epithelial tumors: Impact on treatment efficacy and alteration in expression after chemotherapy

BACKGROUNDS

To understand the clinical impact of PD-1/L1 expression in thymoma (TM) and thymic carcinoma (TC), we evaluated the frequency of PD-1/L1 expression in pre/post chemotherapy specimens and the correlation with the treatment efficacy.

METHODS

The expression of PD-1/L1 was evaluated using immunohistochemistry in patients with TM or TC treated with chemotherapy between 2000 and 2014. Using formalin-fixed, paraffin-embedded tissue samples and a PD-L1 antibody, the expression of PD-L1 in the TM and TC specimens was reported in terms of the H-score (0-300), with a score ≥1 being defined as positive. The PD-1 expression in the tumor-infiltrating immune cells was evaluated based on the intensity (0-3) of staining using a PD-1 antibody. The objective response rate, progression-free survival, and the difference in PD-1/L1 expression between the pre/post chemotherapy were evaluated.

RESULTS

Thirty patients (TM/TC 12/18) were evaluated. PD-L1 positivity were TM/TC 67%/41%. Within the PD-L1 positive/negative populations, the objective response rates were 50%/0% for TM and 14%/20% for TC. No significant differences in progression-free survival were seen according to the PD-L1 expression status. Increases in both the PD-L1 and PD-1 scores were observed after chemotherapy in six serial pre/post chemotherapy TM specimens, with a mean PD-L1 score and a median PD-1 intensity of 42/93, and 0/2.5, respectively.

CONCLUSIONS

The substantially high expression of PD-L1 and the increase in PD-L1 and PD-1 expression after chemotherapy supports anti-PD-1/L1 drugs therapy for TM and TC as well as the development of a strategy for its sequential use after chemotherapy.

Correlation between S-1 treatment outcome and expression of biomarkers for refractory thymic carcinoma

BACKGROUND

Thymic carcinoma is a rare cancer with minimal evidence of a survival benefit following chemotherapy. An oral fluoropyrimidine of S-1, however, is the recommended active cytotoxic chemotherapy agent for refractory thymic carcinoma based on a case series, whereas sunitinib or everolimus are recommended as molecular-targeted agents based on Phase II trials. We retrospectively investigated the efficacy of S-1 for refractory thymic carcinoma and performed a biomarker analysis.

METHODS

We assessed the clinicopathological variables of 14 consecutive patients who underwent S-1 for refractory thymic carcinoma and correlated the clinical outcomes with potential biomarkers using paraffin-embedded cancer tissues of eight patients in the cohort.

RESULTS

A total of 178 thymic malignancies were identified, of whom 14 patients included 12 cases of squamous cell carcinoma, one lymphoepithelioma-like carcinoma, and one undifferentiated carcinoma. Six patients exhibited a partial response (42.9 %: 95 % confidence interval [CI], 21.4-67.4) and the disease control rate was 85.7 % (60.0-96.0 %). After a median follow-up of 24.2 months, the median progression-free survival was 8.1 months (range, 2.6-12.2 months), and median overall survival was 30.0 months (range, 6.2-41.9 months). No significant correlation between biomarker expression and response was noted. However, thymidine synthase (TS)/dihydropyrimidine dehydrogenase and TS/orotate phosphoribosyltransferase were observed.

CONCLUSIONS

S-1 for refractory thymic carcinoma offered clinical activity and achieved an 85 % disease control rate. Although the biomarkers did not correlate with clinical outcome, the study results showed efficacy of S-1 as a cytotoxic chemotherapy for refractory thymic carcinoma, which warrants future investigation.

Adjuvant Therapy for Thymic Carcinoma--A Decade of Experience in a Taiwan National Teaching Hospital

Background

Thymic carcinomas are rare tumors for which surgical resection is the first treatment of choice. The role of adjuvant treatment after surgery is unknown because of limited available data. The present study evaluated the efficacy of post-surgery adjuvant chemotherapy or radiotherapy in patients with thymic carcinoma.

Methods

To evaluate the role of adjuvant therapy in patients with thymic carcinoma, we retrospectively reviewed the records of patients with thymic carcinoma who were diagnosed and treated between 2004 and 2014.

Results

Among 78 patients with thymic carcinoma, 30 patients received surgical resection. Progression-free survival (PFS) and overall survival (OS) were significantly longer among these patients than among patients who received other treatments (PFS: 88.4 months vs 9.1 months, p<0.001; OS: 134.9 months vs 60.9 months; p = 0.003). Patients with stage III thymic carcinoma who received surgery had a longer OS than patients who did not receive surgery (70.1 months vs 23.9 months; p = 0.017, n = 11). Among 47 patients with stage IV carcinoma, 12 patients who received an extended thymothymectomy had a longer PFS than 35 patients who did not receive surgery (18.9 months vs 8.7 months; p = 0.029). Among 30 patients (with stage I- IV carcinoma) who received primary lesion surgery, 19 patients received an R0 resection and 9 patients of the 19 patients received adjuvant radiotherapy. These patients had longer PFS (50.3 months) than 2 patients who received adjuvant chemotherapy (5.9 months) or 4 patients who received concurrent chemoradiotherapy (7.5 months) after surgery (p = 0.003).

Conclusions

Surgical resection should be considered for patients with thymic carcinoma, even for patients with locally advanced or stage IV carcinoma. Adjuvant radiotherapy resulted in a better PFS after R0 resection.

Gemcitabine in patients previously treated with platinum-containing chemotherapy for refractory thymic carcinoma: radiographic assessment using the RECIST criteria and the ITMIG recommendations

BACKGROUND

The key drugs for chemotherapy of thymic carcinoma are gradually being revealed in phase II and conventional retrospective studies. Gemcitabine is regarded as one of these key drugs according to the findings of clinical trials in which it was combined with capecitabine. However, the activity of single-agent gemcitabine concerning refractory thymic carcinoma remains unclear.

PATIENTS AND METHODS

We conducted a retrospective review of the medical records of refractory thymic carcinoma patients previously treated with platinum-containing chemotherapy between 1980 and 2014.

RESULTS

Of all 11 patients in this study, the objective response rate regarding gemcitabine was 36.4 % [95 % confidence interval (CI) 15.2-64.6] using the RECIST criteria and the response criteria proposed by the ITMIG. The median progression-free survival time was 4.3 months (95 % CI 0.7-11.0). The survival time from the start of gemcitabine treatment was 28.5 months (95 % CI 5.5-47.8), and from the start of first-line chemotherapy was 46.5 months (95 % CI 7.3-47.8).

CONCLUSIONS

Gemcitabine achieved a moderate response and has the potential to be used as a key drug for thymic carcinoma. Some patients treated with gemcitabine demonstrated prolonged cancer control even in later lines of chemotherapy.

Efficacy and safety of the combination of paclitaxel and platinum in advanced thymic carcinoma

This study aimed to assess the efficacy and safety of a combination of paclitaxel and cisplatin/carboplatin for the treatment of advanced thymic carcinoma. Thirty‐seven patients (23 men and 14 women, median age 47 years, performance status score ≤2) with pathologically or cytologically diagnosed advanced thymic carcinoma were recruited. Patients received 175 mg/m² paclitaxel on day 1 and 75 mg/m² cisplatin or 300 mg/m² carboplatin on day 2 of a 21 day cycle for at least two cycles to evaluate efficacy and adverse events. No complete response (CR) was observed; 11 patients had a partial response (PR), 16 patients had no change (NC), and 10 had progressive disease, resulting in an overall response rate of 29.7%, a stable rate of 43.2%, and a disease control rate (CR + PR + NC) of 72.9%. Grade I/II and III/IV neutropenia were observed in 21 (56.7%) and 13 (35.1%) patients, respectively. Four (10.8%) patients developed grade I/II thrombocytopenia. Grade I/II and III/IV nausea and vomiting were observed in 19 (51.2%) and five (13.5%) patients, respectively. Grade I/II liver dysfunction was observed in seven (18.9%) patients. Two patients with grade III liver dysfunction recovered after hepatoprotective treatment. The combination of paclitaxel and platinum was effective and well tolerated in patients with advanced thymic carcinoma.