MiR-22, a serum predictor of poor outcome and therapy response in diffuse large B-cell lymphoma patients.

Diffuse large B-cell lymphoma (DLBCL) is an aggressive, heterogeneous neoplasm where prognostication and therapeutic decision are challenging. The available prognostic tools are not able to identify all patients refractory to treatment. MicroRNAs, small RNAs frequently deregulated in cancer, stably circulate in biofluids, representing interesting candidates for non-invasive biomarkers. Here we validated serum miR-22, an evolutionarily conserved microRNA, as a prognostic/predictive biomarker in DLBCL. Moreover, we found that its expression and release from DLBCL cells are related to therapy response and adversely affect cell proliferation. These results suggest that miR-22 is a promising complementary or even independent non-invasive biomarker for DLBCL management.

Thymic carcinomas and thymic neuroendocrine tumors: a tribute to Dr. Juan Rosai.

Throughout his career, Dr. Juan Rosai greatly impacted our understanding of mediastinal tumors, both as a scientist and as a teacher. This review highlights his manifold contributions in the field of thymic carcinomas and thymic neuroendocrine tumors from a historical perspective.

Juan Rosai as master of our comprehensive understanding of thymus and thymoma.

In this study, the authors report on the activity of Juan Rosai, one of the pathologists most engaged in the definition of cells, diseases and tumors occurring in the thymus and in the mediastinum during the last 60 years. With his morphological skills and tireless interest in clarification of disease patterns, he contributed extraordinarily to expand our knowledge of the mediastinal diseases and to improve our diagnostic approach. He determined extraordinary advances also in trasmission electron microscopy and in immunohistochemistry as powerful diagnostic tools. Moreover, he proposed and promoted, together with an international panel of Pathologists, the World Health Classification of Thymic tumors as a definite progress in our comprehension and diagnostics of thymic epithelial tumors (TET). Our purpose is to review J. Rosai's achievements in thymic normal structure, in TET and particularly in the entity now definied as "thymoma", in distinction from the thymic carcinoma. To do this, our narrative will also be based on personal memories, longstanding collaborations and/or friendship with J. Rosai.

Association between CMV and Invasive Fungal Infections After Autologous Stem Cell Transplant in Lymphoproliferative Malignancies: Opportunistic Partnership or Cause-Effect Relationship?

Unlike allogeneic transplant, autologous stem cell transplantation (ASCT) represents a procedure with a low-risk of cytomegalovirus (CMV) symptomatic reactivation-infection/end-organ disease (CMV complications) and invasive fungal disease (IFD). However, novel drugs for the treatment of lymphoproliferative malignancies could cause an increase of such opportunistic infections, even after ASCT. To the best of our knowledge, there are no published data demonstrating an association between CMV and IFD in the autologous setting, while this association has been widely reported in allogeneic transplantation. We have reviewed our series of 347 ASCT in myeloma and lymphoma patients performed over a period of 14 years with the aim of investigating the descriptive and analytical epidemiology of bacterial, CMV and IFD complications, focusing on the association between CMV and IFD. Patients with myeloma have significantly fewer bacterial infections and IFD than patients with lymphoma, but a similar rate of CMV complications. Descriptive epidemiological data are consistent with the literature, indicating an overall incidence of 36%, 3.5% and 15.5% for bacterial infections, IFD and CMV complications, with a case mortality rate of 4%, 16.7% and 3.7%, respectively. A strong correlation between CMV and IFD exists, with 8 cases of IFD out of a total of 12 presenting a CMV complication. At multivariate analysis, a diagnosis of lymphoma, ≥3 previous treatment lines and age ≥60 years were found to be independent risk factors for IFD. Duration of neutropenia (ANC < 500/mm³) ≥7 days represents an independent risk factor for CMV complications, where neutropenia most likely represents a crude surrogate biomarker indicating a deeper and longer state of overall immunosuppression. From our data we conclude that (1) myeloma patients are at lower risk of bacterial infections and IFD as compared with lymphoma patients but are at equal risk of CMV complications, most likely as a consequence of a selective impact of bortezomib on Herpes Viruses infection control; (2) a significant association exists between CMV and IFD, although a possible cause-effect relationship remains to be determined; (3) IFD is a rare complication after ASCT but burdened by a mortality rate of about 17%, with peak rates in older lymphoma patients who underwent more intensive therapeutic regimens.

Thymic Epithelial Tumors phenotype relies on miR-145-5p epigenetic regulation.

BACKGROUND: Thymoma and thymic carcinoma are the most frequent subtypes of thymic epithelial tumors (TETs). A relevant advance in TET management could derive from a deeper molecular characterization of these neoplasms. We previously identified a set of microRNA (miRNAs) differentially expressed in TETs and normal thymic tissues and among the most significantly deregulated we described the down-regulation of miR-145-5p in TET. Here we describe the mRNAs diversely regulated in TETs and analyze the correlation between these and the miRNAs previously identified, focusing in particular on miR-145-5p. Then, we examine the functional role of miR-145-5p in TETs and its epigenetic transcriptional regulation. METHODS: mRNAs expression profiling of a cohort of fresh frozen TETs and normal tissues was performed by microarray analysis. MiR-145-5p role in TETs was evaluated in vitro, modulating its expression in a Thymic Carcinoma (TC1889) cell line. Epigenetic transcriptional regulation of miR-145-5p was examined by treating the TC1889 cell line with the HDAC inhibitor Valproic Acid (VPA). RESULTS: Starting from the identification of a 69-gene signature of miR-145-5p putative target mRNAs, whose expression was inversely correlated to that of miR-145-5p, we followed the expression of some of them in vitro upon overexpression of miR-145-5p; we observed that this resulted in the down-regulation of the target genes, impacting on TETs cancerous phenotype. We also found that VPA treatment of TC1889 cells led to miR-145-5p up-regulation and concomitant down-regulation of miR-145-5p target genes and exhibited antitumor effects, as indicated by the induction of cell cycle arrest and by the reduction of cell viability, colony forming ability and migration capability. The importance of miR-145-5p up-regulation mediated by VPA is evidenced by the fact that hampering miR-145-5p activity by a LNA inhibitor reduced the impact of VPA treatment on cell viability and colony forming ability of TET cells. Finally, we observed that VPA was also able to enhance the response of TET cells to cisplatin and erlotinib. CONCLUSIONS: Altogether our results suggest that the epigenetic regulation of miR-145-5p expression, as well as the modulation of its functional targets, could be relevant players in tumor progression and treatment response in TETs.

Dataset for reporting of thymic epithelial tumours: recommendations from the International Collaboration on Cancer Reporting (ICCR).

AIMS: The International Collaboration on Cancer Reporting (ICCR) is a not-for-profit organization formed by the Royal Colleges of Pathologists of Australasia and the United Kingdom, the College of American Pathologists, the Canadian Association of Pathologists-Association Canadienne des Pathologists in association with the Canadian Partnership Against Cancer, and the European Society of Pathology. Its goal is to produce standardized, internationally agreed, evidence-based datasets for use throughout the world. METHODS AND RESULTS: This article describes the development of a cancer dataset by the multidisciplinary ICCR expert panel for the reporting of thymic epithelial tumours. The dataset includes 'required' (mandatory) and 'recommended' (non-mandatory) elements, which are validated by a review of current evidence and supported by explanatory text. Seven required elements and 12 recommended elements were agreed by the international dataset authoring committee to represent the essential information for the reporting of thymic epithelial tumours. CONCLUSIONS: The use of an internationally agreed, structured pathology dataset for reporting thymic tumours provides all of the necessary information for optimal patient management, facilitates consistent and accurate data collection, and provides valuable data for research and international benchmarking. The dataset also provides a valuable resource for those countries and institutions that are not in a position to develop their own datasets.

Induction Therapy versus Initial Surgery in Advanced Thymic Tumors: Perioperative and Oncological Outcome.

Background Despite the intense debate concerning management of advanced thymic tumors, no specific oncological strategies have been yet recommended. We report our 13 years' experience to investigate this issue. Methods From 01/2001 to 12/2013, the clinical data of 28 patients treated for Masaoka stages III-IV thymic tumors were retrospectively reviewed. Eleven potentially nonresectable patients (Group A) underwent induction chemotherapy plus surgery, while immediate surgery was performed in 17 patients (Group B). The endpoint was to compare the two groups on (1) surgical resectability; (2) postoperative course; (3) disease-free survival; and (4) overall survival. Results Both groups were comparable in terms of age, gender, clinical stage, clinical tumor size, histology, and adjuvant therapy. Length of surgery was statistically longer in Group A (p = 0.015). Combined surgery and R0 resection was similarly performed in both groups (p = 0.14 and p = 0.99, respectively). The 3-year overall survival was 71.4% for Group A and 93.3% for Group B (p = 0.84). On the other hand, 3-year disease-free survival was 40.5 and 53.7% for Group A and B, respectively (p = 0.67). At multivariate analysis, gender was the strongest predictor for recurrence (hazard ratio = 5.71 [1.22; 26.67], p = 0.03). Conclusion Our results suggest that induction therapy allows obtaining acceptable clinical responses as well as resectability, survival, and recurrence rates. In selected patients with "clinically resectable" stage III-IV cancers, surgery (as first step of a multimodality therapy) could be a feasible treatment option.

Tumor genetics and survival of thymic neuroendocrine neoplasms: a multi-institutional clinicopathologic study.

Thymic neuroendocrine tumors (TNET) are rare primary epithelial neoplasms of the thymus. This study aimed to determine clinically relevant parameters for their classification and for therapeutic decisions. We performed a comprehensive histological, clinical, and genetic study of 73 TNET cases (13 thymic typical carcinoids [TTC], 40 thymic atypical carcinoids [TAC], and 20 high-grade neuroendocrine carcinomas [HGNEC] of the thymus), contributed by multiple institutions. The mean number of chromosomal imbalances per tumor was 0.8 in TTC (31% aberrant cases) versus 1.1 in TAC (44% aberrant cases) versus 4.7 in HGNEC (75% aberrant cases). Gains of 8q24 (MYC gene locus) were the most frequent alteration and one of the overlapping features between carcinoids and HGNEC. The 5-year survival rates for TTC, TAC, and HGNEC were 100, 60, and 30%. The 10-year survival rates for TTC and TAC were 50 and 30% (P = 0.002). Predictive mitotic cut-off values for TTC versus TAC were 2.5 per 10 high-power fields (HPF; indicating a higher death rate, P = 0.062) and 15 per 10 HPF (indicating higher risk of recurrence, P = 0.036) for separating HGNEC from TAC. We conclude that the current histopathologic classifications of TNET reflect tumor biology and provide important information for therapeutic management.

Capecitabine plus gemcitabine in thymic epithelial tumors: final analysis of a Phase II trial.

BACKGROUND: A multi-institutional Phase II trial was initiated in 2005 to test the combination gemcitabine and capecitabine in patients with thymic epithelial malignancies (TETs). PATIENTS & METHODS: Patients with histologic confirmation of TET diagnosis by central review who had received >1 systemic chemotherapy treatment were included. Patients received oral capecitabine (650 mg/mq twice daily on days 1-14) and intravenous gemcitabine (1000 mg/mq on days 1 and 8 every 3 weeks). RESULTS: Of the 30 patients included (18 men, 12 women; median age: 57 years, range: 48-61 years), the majority (73%) had thymoma, and the remaining thymic carcinoma. Eight patients developed grade 3-4 neutropenia. A total of 12 patients had a response. Median progression-free survival was 11 months (range: 6.5-16.5). CONCLUSION: Capecitabine and gemcitabine is highly active in TETs.

The International Association for the Study of Lung Cancer Staging Project for Lung Cancer: Proposals for the Revision of the M Descriptors in the Forthcoming Ninth Edition of the TNM Classification for Lung Cancer.

INTRODUCTION: This study analyzed all metastatic categories of the current TNM classification of NSCLC to propose modifications of the M component in the next edition (ninth) of the classification. METHODS: A database of 124,581 patients diagnosed between 2011 and 2019 was established; of these, 14,937 with NSCLC in stages IVA to IVB were available for this analysis. Overall survival was calculated using the Kaplan-Meier method, and prognosis was assessed using multivariable-adjusted Cox proportional hazards regression. RESULTS: The eighth edition M categories revealed good discrimination in the ninth edition data set. Assessments revealed that an increasing number of metastatic lesions were associated with decreasing prognosis; because this seems to be a continuum and adjustment for confounders was not possible, no specific lesion number was deemed appropriate for stage classification. Among tumors involving multiple metastases, decreasing prognosis was found with an increasing number of organ systems involved. Multiple assessments, including after adjustment for potential confounders, revealed that M1c patients who had metastases to a single extrathoracic organ system were prognostically distinct from M1c patients who had involvement of multiple extrathoracic organ systems. CONCLUSIONS: These data validate the eighth edition M1a and M1b categories, which are recommended to be maintained. We propose the M1c category be divided into M1c1 (involvement of a single extrathoracic organ system) and M1c2 (involvement of multiple extrathoracic organ systems).

The International Association for the Study of Lung Cancer Lung Cancer Staging Project: Proposals for Revision of the Classification of Residual Tumor After Resection for the Forthcoming (Ninth) Edition of the TNM Classification of Lung Cancer.

INTRODUCTION: The goal of surgical resection is to completely remove a cancer; it is useful to have a system to describe how well this was accomplished. This is captured by the residual tumor (R) classification, which is separate from the TNM classification that describes the anatomic extent of a cancer independent of treatment. The traditional R-classification designates as R0 a complete resection, as R1 a macroscopically complete resection but with microscopic tumor at the surgical margin, and as R2 a resection that leaves gross tumor behind. For lung cancer, an additional category encompasses situations in which the presence of residual tumor is uncertain. METHODS: This paper represents a comprehensive review of evidence regarding these R categories and the descriptors thereof, focusing on studies published after the year 2000 and with adjustment for potential confounders. RESULTS: Consistent discrimination between complete, uncertain, and incomplete resection is revealed with respect to overall survival. Evidence regarding specific descriptors is generally somewhat limited and only partially consistent; nevertheless, the data suggest retaining all descriptors but with clarifications to address ambiguities. CONCLUSION: On the basis of this review, the R-classification for the ninth edition of stage classification of lung cancer is proposed to retain the same overall framework and descriptors, with more precise definitions of descriptors. These refinements should facilitate application and further research.

The International Association for the Study of Lung Cancer Thymic Epithelial Tumors Staging Project: Proposals for the N and the M Components for the Forthcoming (Ninth) Edition of the TNM Classification of Malignant Tumors.

INTRODUCTION: Stage classification is an important underpinning of management in patients with cancer and rests on a combination of three components-T for tumor extent, N for nodal involvement, and M for distant metastases. This article details the revision of the N and the M components of thymic epithelial tumors for the ninth edition of the TNM classification of malignant tumors proposed by the Thymic Domain of the International Association for the Study of Lung Cancer Staging and Prognostic Factors Committee. METHODS: The N and M components of the eighth edition staging system were verified by a large international collaborative data source through a data-driven analysis. A total of 9147 cases were included for analysis, including 7662 thymomas, 1345 thymic carcinomas, and 140 neuroendocrine thymic tumors. RESULTS: Lymph node involvement rates were 1.5% in thymomas and 17.6% and 27.7% in thymic carcinomas and neuroendocrine thymic tumors, respectively. Rates of lymph node metastasis were increasingly higher in tumors with higher T stage and higher-grade histologic type. Survival analysis validated the differences in the N and M categories proposed in the eighth edition staging system. Good discrimination in overall survival was detected among pathologic (p)N and pM categories in patients with thymoma and thymic carcinoma. CONCLUSIONS: No changes are proposed from the eighth edition for the N and M components. The proposed stage classification will provide a useful tool for management of the disease among the global thymic community.

Extraskeletal Ewing's sarcoma of the mediastinum: Case report.

Background: Ewing sarcoma (ES) represents the second most common malignant bone tumor in children and young adults. ES is not a frequent finding in sites different from the skeletal. Common sites of appearance of ES are lower extremities, the pelvis, paravertebral spaces and head and neck. Primary extraskeletal ES located in the anterior mediastinum are very rare. These neoplasms should be discussed in specialized contests with a high volume of patients treated. Here, we present an uncommon mediastinal mass challenging in its characterization and management. Case description: A thirty-year-old woman performed a thoracic CT scan for dyspnea and persistent cough. Imaging showed a solid mass of 14 x 11 cm involving the left thorax with mediastinal deviation to the right side. Patient underwent an en bloc resection of the mass. Initial histological examination was suggestive for B3 thymoma/thymic carcinoma. Patient was then referred to our rare tumor reference center where a histological review excluded the diagnosis of thymic/thymoma neoplasms meanwhile a third revision assessed a diagnosis of ES. Patient refused adjuvant chemotherapy due to her desire of maternity and radiation therapy was not indicated because surgery was performed too many months earlier. A close follow-up was considered. After a few months the patient relapsed and first line chemotherapy was proposed. She reached a complete response at the first evaluation maintained also at the end of the protocol. In order to consolidate the obtained response, high dose chemotherapy followed by autologous stem cell transplantation (HDCT/ASCT) was suggested and the patient agreed. Conclusions: This case underlined that, potentially, ES can arise from any soft tissue site in the body, even in rare sites such as mediastinum. The evaluation of expert centers was critical to establish a correct diagnosis and therapeutic approach in this complex case. Taking into account the time lasting from the diagnosis and the aggressiveness of this kind of neoplasm, frequently relapsing, the patient after a multidisciplinary discussion was a candidate for a multimodal treatment.

The International Association for the Study of Lung Cancer Thymic Epithelial Tumor Staging Project: A Re-Assessment of the International Thymic Malignancy Interest Group/International Association for the Study of Lung Cancer Lymph Node Map for Thymic Epithelial Tumors for the Forthcoming Ninth Edition of the TNM Classification of Malignant Tumors.

INTRODUCTION: A lymph node map is the pillar on which accurate assignment and documentation of nodal classification stands. The International Thymic Malignancy Interest Group created the first map for thymic epithelial malignancies in conjunction with the eighth edition of the TNM classification, representing the first official TNM classification of thymic epithelial malignancies. The map was based on clinical experience and published studies, but it was largely empirical because of limited available data. Dissemination of the map and implementation of a standard thymic stage classification across the world in 2017 have provided more consistent and granular data. METHODS: More than twice as many cases of node involvement are available for analysis in the current database compared with that of the eighth edition database, allowing validation of many aspects of the eighth edition map. This article details the process and considerations for refinement of the thymic map for the ninth TNM used by the Thymic Domain of the Staging and Prognostic Factors Committee of the International Association for the Study of Lung Cancer. The committee evaluated a large international collaborative data set, published anatomical and clinical studies pertaining to lymph node spread from thymic epithelial tumors, in conjunction with the analysis underlying refinements of the TNM components for the ninth edition TNM classification. RESULTS: The node map boundaries of the N1 and N2 categories remain unchanged. Visual clarifications have been added to the nomenclature of nodal stations within these regions. CONCLUSIONS: On the basis of the recommendation to keep the N component unchanged for the ninth edition TNM classification, the lymph node map remains unchanged as well; however, clarifications have been added to facilitate clinical use.

The International Association for the Study of Lung Cancer Thymic Epithelial Tumors Staging Project: Proposal for a Stage Classification for the Forthcoming (Ninth) Edition of the TNM Classification of Malignant Tumors.

INTRODUCTION: A TNM-based system for all types of thymic epithelial tumors was introduced in the eighth edition of the TNM classification of thoracic malignancies. The Thymic Domain of the Staging and Prognostic Factors Committee of the International Association for the Study of Lung Cancer, composed of multispecialty international experts, was charged to develop proposals for the ninth edition. This article outlines the proposed definitions for the T, the N, and the M components and their combination into stage groups. METHODS: A large central database of 11,347 patients with thymic epithelial tumors was assembled thanks to the contribution of the major thymic organizations worldwide and analyses were carried out for the T, the N, and the M components and the stage groups. Overall survival was the outcome measure for patients with completely and incompletely resected tumors, and recurrence for those with complete resection. When the number of patients was sufficient, analyses were performed separately for thymomas, thymic carcinomas, and neuroendocrine thymic tumors. RESULTS: Tumor size is included in the T1 category as T1a (≤5cm) and T1b (>5 cm); the mediastinal pleura is dropped as a T descriptor; invasion of the lung or phrenic nerve is reclassified as T2 (instead of T3). No changes are proposed for the N and the M components from the eighth edition. The stage groups remain the same. CONCLUSIONS: The proposed changes for the ninth edition of the TNM classification set the stage for further progress in the future for these rare tumors.

The International Association for the Study of Lung Cancer Thymic Epithelial Tumors Staging Project: An Overview of the Central Database Informing Revision of the Forthcoming (Ninth) Edition of the TNM Classification of Malignant Tumors.

INTRODUCTION: In 2014, a TNM-based system for thymic epithelial tumors was proposed. The TNM stage classification system was published as a result of a joint project from the International Association for the Study of Lung Cancer and the International Thymic Malignancy Interest Group for the eighth edition of the American Joint Commission on Cancer and the Union for International Cancer Control stage classification system. The Thymic Domain of the Staging and Prognostic Factors Committee of the International Association for the Study of Lung Cancer received the mandate to make proposals for the ninth edition of the TNM stage classification. METHODS: A central thymic database was collected by the Cancer Research And Biostatistics with the contribution of the major thymic associations in the world. RESULTS: A total of 11,347 patients were collected. Submitting organizations were the following: Japanese Association for Research in the Thymus, European Society of Thoracic Surgeons, Chinese Alliance for Research in Thymoma, Korean Association for Research in the Thymus, International Thymic Malignancy Interest Group, and Réseau tumeurs THYMiques et Cancer. Additional contributions came from centers in the United States, United Kingdom, Turkey, Australia, Spain, and Italy. A total of 9147 cases were eligible for analysis. Eligible cases for analysis came from Asia and Australia (5628 cases, 61.5%), Europe (3113 cases, 34.0%), and North America (406 cases, 4.4%). CONCLUSIONS: This report provides an overview of the database that has informed the proposals for the updated T, N, and M components and the stage groups for the ninth TNM of malignant tumors.

The International Association for the Study of Lung Cancer Thymic Epithelial Tumor Staging Project: Proposal for the T Component for the Forthcoming (Ninth) Edition of the TNM Classification of Malignant Tumors.

INTRODUCTION: A TNM-based stage classification system of thymic epithelial tumors was adopted for the eighth edition of the stage classification of malignant tumors. The Thymic Domain of the Staging and Prognostics Factor Committee of the International Association for the Study of Lung Cancer developed a new database with the purpose to make proposals for the ninth edition stage classification system. This article outlines the proposed definitions for the T categories for the ninth edition TNM stage classification of thymic malignancies. METHODS: A worldwide collective database of 11,347 patients with thymic epithelial tumors was assembled. Analysis was performed on 9147 patients with available survival data. Overall survival, freedom-from-recurrence, and cumulative incidence of recurrence were used as outcome measures. Analysis was performed separately for thymomas, thymic carcinomas, and neuroendocrine thymic tumors. RESULTS: Proposals for the T categories include the following: T1 category is divided into T1a (≤5 cm) and T1b (>5 cm), irrespective of mediastinal pleura invasion; T2 includes direct invasion of the pericardium, lung, or phrenic nerve; T3 denotes direct invasion of the brachiocephalic vein, superior vena cava, chest wall, or extrapericardial pulmonary arteries and veins; and T4 category remains the same as in the eighth edition classification, involving direct invasion of the aorta and arch vessels, intrapericardial pulmonary arteries and veins, myocardium, trachea, or esophagus. CONCLUSIONS: The proposed T categories for the ninth edition of the TNM classification provide good discrimination in outcome for the T component of the TNM-based stage system of thymic epithelial tumors.

Long Non-Coding RNAs in the Cell Fate Determination of Neoplastic Thymic Epithelial Cells.

Thymic Epithelial Tumors (TETs) arise from epithelial cells of the thymus and are very rare neoplasms comprising Thymoma, Thymic carcinoma, and Thymic Neuroendocrine tumors that still require in-depth molecular characterization. Long non-coding RNAs (lncRNAs) are emerging as relevant gene expression modulators involved in the deregulation of several networks in almost all types of human cancer, including TETs. LncRNAs act at different control levels in the regulation of gene expression, from transcription to translation, and modulate several pathways relevant to cell fate determination under normal and pathological conditions. The activity of lncRNAs is strongly dependent on their expression, localization, and post-transcriptional modifications. Starting from our recently published studies, this review focuses on the involvement of lncRNAs in the acquisition of malignant traits by neoplastic thymic epithelial cells, and describes the possible use of these molecules as targets for the design of novel therapeutic approaches specific for TET. Furthermore, the involvement of lncRNAs in myasthenia gravis (MG)-related thymoma, which is still under investigation, is discussed.

The International Association for the Study of Lung Cancer Staging Project: Methods and Guiding Principles for the Development of the Ninth Edition TNM Classification.

INTRODUCTION: Stage classification provides a consistent and concise nomenclature about the anatomic extent of the cancer. This is a fundamental cornerstone in the management of patients; it enables reporting results and facilitates comparing one treatment to another and judging how closely clinical trial results apply to an individual patient. A nomenclature must be relatively static; however, periodical refinement is needed to adjust to a changing landscape of clinical relevance. Changes must be well justified and thoughtfully developed to maintain the ability to communicate clearly and facilitate comparisons across time. METHODS: For thoracic malignancies (lung, pleura, thymus, and esophagus), the International Association for the Study of Lung Cancer (IASLC) has leveraged its worldwide multidisciplinary reach, permitting a sophisticated approach to this process. Refinement of stage classification for the ninth edition of TNM is underway; this article describes the approach adopted by the IASLC Staging and Prognostic Factors Committee. RESULTS: Key guiding principles include the ability to maintain communication over time, a classification that discriminates homogeneous cohorts of tumors consistently across the world in multiple settings, treatment approaches, and patient characteristics, including clinical relevance and practical applicability. The IASLC has again assembled a large international database to permit multifaceted analysis. Providing confidence that the classification performs consistently in multiple settings, treatments, and patients requires consistent discrimination in multiple subset analyses. Although observed outcomes of patients in the 2011 to 2019 database are essential, considerations about how the classification will be used are also important to ensure clinical relevance and applicability. CONCLUSIONS: The strategy developed by the Staging and Prognostic Factors Committee is carefully designed to provide useful refinements to the stage classification of thoracic malignancies for the ninth edition of TNM classification of cancers.

The therapeutic relevance of a BRCA2 mutation in a patient with recurrent thymoma: a case report.

Background: Thymomas are characterized by a low tumor mutation burden and a paucity of actionable mutations. Clinical behavior can vary from relatively indolent to very aggressive and impact survival. Platinum-based chemotherapy is the primary treatment modality for inoperable disease and is palliative in intent. Patients with advanced thymoma frequently experience disease recurrence after frontline therapy. Treatment options for relapsed thymoma are relatively limited. A case of recurrent thymoma harboring a breast cancer gene 2 (BRCA2) mutation was presented for multidisciplinary discussion at the International Thymic Malignancy Interest Group (ITMIG) Tumor Board meeting. Case Description: A 63-year-old female presented with Tumor Node Metastasis (TNM) stage I, World Health Organization (WHO) subtype B1 thymoma at diagnosis and underwent surgical resection. First recurrence occurred in the left costophrenic recess and was treated with preoperative external beam radiotherapy (EBRT), surgical excision, and post-operative chemotherapy. Histology was consistent with WHO subtype B2 thymoma and genomic analysis of the resected tumor detected a BRCA2 mutation. Second recurrence occurred in the mediastinum and bilateral pleurae. Mediastinal disease was treated with EBRT, and the pleural deposits were observed initially. However, upon further progression, the case was discussed at the ITMIG tumor board meeting to determine optimal second line therapy for this patient. Conclusions: A potential role of poly (ADP-ribose) polymerase (PARP) inhibitors versus cytotoxic chemotherapy for treatment of BRCA2-mutated recurrent thymoma merits discussion. However, due to the absence of data to support the functional and therapeutic significance of BRCA2 mutations in patients with thymoma, the potential for severe toxicity associated with PARP inhibitors, and availability of other safe and effective alternatives, other treatment options should be considered. PARP inhibitors can be considered for treatment of BRCA2-mutated thymomas as part of a clinical trial or when other treatment options have been exhausted.