Impact of the COVID-19 Pandemic on Lung Cancer Screening Processes in a Northeast Tertiary Health Care Network.

ABSTRACT: The coronavirus disease 2019 (COVID-19) pandemic disrupted health care systems, including implementation of lung cancer screening programs. The impact and recovery from this disruption on screening processes is not well appreciated. Herein, the radiology database of a Northeast tertiary health care network was reviewed before and during the pandemic (2013-2022). In the 3 months before the pandemic, an average of 77.3 lung cancer screening with computed tomography scans (LCS-CT) were performed per month. The average dropped to 23.3 between April and June of 2020, whereas COVID-19 hospitalizations peaked at 1604. By July, average hospitalizations dropped to 50, and LCS-CTs rose to >110 per month for the remaining year. LCS-CTs did not decline during COVID-19 surges in December of 2021 and 2022. The LCS-CT performance grew by 4.5% in 2020, 69.6% in 2021, and 27.0% in 2022, exceeding projected growth by 722 examinations. This resiliency indicates a potentially smaller impact of COVID-19 on lung cancer diagnoses than initially feared.

Thymus-derived B cell clones persist in the circulation after thymectomy in myasthenia gravis.

Myasthenia gravis (MG) is a neuromuscular, autoimmune disease caused by autoantibodies that target postsynaptic proteins, primarily the acetylcholine receptor (AChR) and inhibit signaling at the neuromuscular junction. The majority of patients under 50 y with AChR autoantibody MG have thymic lymphofollicular hyperplasia. The MG thymus is a reservoir of plasma cells that secrete disease-causing AChR autoantibodies and although thymectomy improves clinical scores, many patients fail to achieve complete stable remission without additional immunosuppressive treatments. We speculate that thymus-associated B cells and plasma cells persist in the circulation after thymectomy and that their persistence could explain incomplete responses to resection. We studied patients enrolled in a randomized clinical trial and used complementary modalities of B cell repertoire sequencing to characterize the thymus B cell repertoire and identify B cell clones that resided in the thymus and circulation before and 12 mo after thymectomy. Thymus-associated B cell clones were detected in the circulation by both mRNA-based and genomic DNA-based sequencing. These antigen-experienced B cells persisted in the circulation after thymectomy. Many circulating thymus-associated B cell clones were inferred to have originated and initially matured in the thymus before emigration from the thymus to the circulation. The persistence of thymus-associated B cells correlated with less favorable changes in clinical symptom measures, steroid dose required to manage symptoms, and marginal changes in AChR autoantibody titer. This investigation indicates that the diminished clinical response to thymectomy is related to persistent circulating thymus-associated B cell clones.

Quality Versus Quantity: The Potential Impact of Public Reporting of Hospital Safety for Complex Cancer Surgery.

OBJECTIVE: To estimate the potential mortality reduction if patients chose the safest hospitals for complex cancer surgery. BACKGROUND: Mortality after complex oncologic surgery is highly variable across hospitals, and directing patients away from unsafe hospitals could potentially improve survivorship. Hospital quality measures are becoming increasingly accessible at a time when patients are more engaged in choosing providers. It is currently unclear what information to share with patients to maximally capitalize on patient-centered realignment. METHODS: The National Cancer Database was queried for adults undergoing 5 complex cancer surgeries (pulmonary lobectomy, pneumonectomy, esophagectomy, gastrectomy, and colectomy) for a primary cancer between 2008 and 2012. Risk-standardized mortality rate (RSMR) methodology, currently used by Medicare-based hospital rating systems, was used to classify hospitals as "safest" and "least safe" by procedure. Patients were modeled moving from "least safe" to "safest" hospitals and the potential number of lives saved through patient realignment determined. As surgical volume has historically been used to distinguish safe hospitals, comparisons were made to models moving patients from low-volume to high-volume hospitals. RESULTS: A total of 292,040 patients were analyzed. In an optimally modeled scenario, realignment using RSMR would result in a greater number of lives saved (3592 vs 2161, P < 0.01) and require only 15 patients to change hospitals to save a life, compared to 78 patients using volume models (P < 0.01). CONCLUSIONS: Public reporting of hospital safety, specifically based on RSMR instead of volume, has the potential to lead to meaningful reductions in surgical mortality after complex cancer surgery, even in the setting of a modest patient realignment.

Medical and Surgical Management of Empyema.

Infection of the pleural space is an ancient and common clinical problem, the incidence which is on the rise. Advances in therapy now present clinicians of varying disciplines with an array of therapeutic options ranging from thoracentesis and chest tube drainage (with or without intrapleural fibrinolytic therapies) to video-assisted thoracic surgery (VATS) or thoracotomy. A framework is provided to guide decision making, which involves weighing multiple factors (clinical history and presentation, imaging characteristics, comorbidities); multidisciplinary collaboration and active management are needed as the clinical course over a few days determines subsequent refinement. The initial choice of antibiotics depends on whether the empyema is community-acquired or nosocomial, and clinicians must recognize that culture results often do not reflect the full disease process. Antibiotics alone are rarely successful and can be justified only in specific circumstances. Early drainage with or without intrapleural fibrinolytics is usually required. This is successful in most patients; however, when surgical decortication is needed, clear benefit and low physiologic impact are more likely with early intervention, expeditious escalation of interventions, and care at a center experienced with VATS.

Incorporating Coexisting Chronic Illness into Decisions about Patient Selection for Lung Cancer Screening. An Official American Thoracic Society Research Statement.

BACKGROUND: Lung cancer screening (LCS) has the potential to reduce the risk of lung cancer death in healthy individuals, but the impact of coexisting chronic illnesses on LCS outcomes has not been well defined. Consideration of the complex relationship between baseline risk of lung cancer, treatment-related harms, and risk of death from competing causes is crucial in determining the balance of benefits and harms of LCS. OBJECTIVES: To summarize evidence, identify knowledge and research gaps, prioritize topics, and propose methods for future research on how best to incorporate comorbidities in making decisions regarding LCS. METHODS: A multidisciplinary group of international clinicians and researchers reviewed available data on the effects of comorbidities on LCS outcomes, focusing on the juxtaposition of lung cancer risk and competing risks of death, consideration of benefits and risks in patients with chronic obstructive pulmonary disease, communication of risk, and treatment of screen-detected lung cancer. RESULTS: This statement identifies gaps in knowledge regarding how comorbidities and competing causes of death impact outcomes in LCS, and we have developed questions to help guide future research efforts to better inform patient selection, education, and implementation of LCS. CONCLUSIONS: There is an urgent need for further research that can help guide clinical decision-making with patients who may not benefit from LCS owing to coexisting chronic illness. This statement establishes a research framework to address essential questions regarding how to incorporate and communicate risks of comorbidities into patient selection and decisions regarding LCS.

Recommendations for the Appropriate Structure, Communication, and Investigation of Tobacco Harm Reduction Claims. An Official American Thoracic Society Policy Statement.

RATIONALE: The tobacco harm reduction literature is replete with vague language, far-reaching claims, and unwarranted certainty. The American Thoracic Society has increasingly recognized the need for a framework for reliably making such claims. Evidence-based standards improving the scientific value and transparency of harm reduction claims are expected to improve their trustworthiness, clarity, and consistency. METHODS: Experts from relevant American Thoracic Society committees identified key topic areas for discussion. Literature search strategy included English language articles across Medline, Google Scholar, and the Cochrane Collaborative databases, with expanded search terms including tobacco, addiction, smoking, cigarettes, nicotine, and harm reduction. Workgroup members synthesized their evidentiary summaries into a list of candidate topics suitable for inclusion in the final report. Breakout groups developed detailed content maps of each topic area, including points to be considered for suggested recommendations. Successive draft recommendations were modified using an iterative consensus process until unanimous approval was achieved. Patient representatives ensured the document's relevance to the lay public. RESULTS: Fifteen recommendations were identified, organized into four framework elements dealing with: estimating harm reduction among individuals, making claims on the basis of population impact, appropriately careful use of language, and ethical considerations in harm reduction. DISCUSSION: This statement clarifies important principles guiding valid direct and inferential harm reduction claims. Ideals for effective communication with the lay public and attention to unique ethical concerns are also delineated. The authors call for formal systems of grading harm reduction evidence and regulatory assurances of longitudinal surveillance systems to document the impact of harm reduction policies.

The Significance of Upfront Knowledge of N2 Disease in Non-small Cell Lung Cancer.

BACKGROUND: Previous literature suggests that patients with non-small cell lung cancer (NSCLC) and unsuspected N2 disease (cN0, pN2) represent a distinct subgroup associated with improved overall survival compared to patients with N2 disease identified prior to resection (cN2, pN2). METHODS: Retrospective analysis of the National Cancer Database of patients from 2004 to 2011 with cN0 and cN2 status found to be pathologic stage III-N2 NSCLC after surgical resection. Comparison of 5-year survival of patients with unsuspected N2 disease versus those with known N2 disease after surgical resection using Kaplan-Meier analysis was made. The independent effect of unsuspected N2 disease on mortality was analyzed using multivariate analysis. RESULTS: A total of 3271 patients with pathologic stage III-N2 NSCLC underwent curative intent surgical resection with or without adjuvant chemotherapy or chemotherapy and radiation. Unsuspected N2 disease was identified in 48% of patients. Patients with unsuspected N2 disease were more likely to have T1 tumors (37 vs. 32%, p < 0.001). Unsuspected N2 disease did not impact 5-year overall survival compared with known N2 when adjuvant therapy was utilized (40 vs. 37%, p = 0.167). Multivariate analysis identified older age, higher comorbidity score, and treatment with surgery alone as independent risk factors for mortality. The presence of unsuspected N2 disease was not significant in this model. CONCLUSIONS: The findings of this study suggest that unsuspected N2 disease is associated with equivalent 5-year survival compared to cN2 disease when adjuvant therapy is employed. These results support the use of adjuvant chemotherapy and radiation therapy when confronted with unsuspected N2 disease after surgical resection for stage IIIA-NSCLC.

Stakeholder Research Priorities for Smoking Cessation Interventions within Lung Cancer Screening Programs. An Official American Thoracic Society Research Statement.

RATIONALE: Smoking cessation counseling in conjunction with low-dose computed tomography (LDCT) lung cancer screening is recommended in multiple clinical practice guidelines. The best approach for integrating effective smoking cessation interventions within this setting is unknown. OBJECTIVES: To summarize evidence, identify research gaps, prioritize topics for future research, and propose standardized tools for use in conducting research on smoking cessation interventions within the LDCT lung cancer screening setting. METHODS: The American Thoracic Society convened a multistakeholder committee with expertise in tobacco dependence treatment and/or LDCT screening. During an in-person meeting, evidence was reviewed, research gaps were identified, and key questions were generated for each of three research domains: (1) target population to study; (2) adaptation, development, and testing of interventions; and (3) implementation of interventions with demonstrated efficacy. We also identified standardized measures for use in conducting this research. A larger stakeholder panel then ranked research questions by perceived importance in an online survey. Final prioritization was generated hierarchically on the basis of average rank assigned. RESULTS: There was little consensus on which questions within the population domain were of highest priority. Within the intervention domain, research to evaluate the effectiveness in the lung cancer screening setting of evidence-based smoking cessation interventions shown to be effective in other contexts was ranked highest. In the implementation domain, stakeholders prioritized understanding strategies to identify and overcome barriers to integrating smoking cessation in lung cancer screening settings. CONCLUSIONS: This statement offers an agenda to stimulate research surrounding the integration and implementation of smoking cessation interventions with LDCT lung cancer screening.

Length of Stay From the Hospital Perspective: Practice of Early Discharge Is Not Associated With Increased Readmission Risk After Lung Cancer Surgery.

OBJECTIVE: To determine if hospitals that routinely discharge patients early after lobectomy have increased readmissions. BACKGROUND: Hospitals are increasingly motivated to reduce length of stay (LOS) after lung cancer surgery, yet it is unclear if a routine of early discharge is associated with increased readmissions. The relationship between hospital discharge practices and readmission rates is therefore of tremendous clinical and financial importance. METHODS: The National Cancer Database was queried for patients undergoing lobectomy for lung cancer from 2004 to 2013 at Commission on Cancer-accredited hospitals, which performed at least 25 lobectomies in a 2-year period. Facility discharge practices were characterized by a facility's median LOS relative to the median LOS for all patients in that same time period. RESULTS: In all, 59,734 patients met inclusion criteria; 2687 (4.5%) experienced an unplanned readmission. In a hierarchical logistic regression model, a routine of early discharge (defined as a facility's tendency to discharge patients faster than the population median in the same time period) was not associated with increased risk of readmission (odds ratio 1.12, 95% confidence interval 0.97-1.28, P = 0.12). In a risk-adjusted hospital readmission rate analysis, hospitals that discharged patients early did not experience more readmissions (P = 0.39). The lack of effect of early discharge practices on readmission rates was observed for both minimally invasive and thoracotomy approaches. CONCLUSIONS: It is possible for hospitals to develop early discharge practices without increasing readmissions. Further study is needed to identify the critical practice elements that have enabled hospitals to aggressively discharge patients without increasing readmission risk.

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.

Gender, Age, and Comorbidity Status Predict Improved Survival with Adjuvant Chemotherapy Following Lobectomy for Non-small Cell Lung Cancers Larger than 4 cm.

PURPOSE: To identify pretreatment prognostic factors associated with improved outcomes in patients with non-small cell lung cancer (NSCLC) tumors larger than 4 cm receiving adjuvant chemotherapy following surgery versus surgery alone. METHODS: Information was collected from the National Cancer Data Base on adults diagnosed with NSCLC who underwent lobectomy with or without adjuvant chemotherapy for pathologic T2 tumors measuring at least 4 cm, with no lymph node involvement or distant metastasis. The data were analyzed using model-based recursive partitioning for survival. RESULTS: Patients who underwent chemotherapy following surgery experienced a survival benefit compared with patients who were treated with surgery alone (5-year survival of 66 vs. 49 %, p<0.0001). Overall, women had improved 5-year survival relative to men (60 vs. 47 %, p<0.0001). Despite this observation, three groups of women experienced no benefit from adjuvant chemotherapy:women 65-72 years with a Charlson-Deyo (CD) score ≥1 (5-year survival: 51 vs. 58 %, p = 0.29), women >72 with a CD score = 0 (5-year survival: 53 vs. 56 %, p = 0.57), and women >72 with a CD score ≥1 (5-year survival: 40 vs. 56 %, p = 0.04). By contrast, all groups of men identified by recursive partitioning analysis demonstrated improved survivals with adjuvant chemotherapy. CONCLUSIONS: Adjuvant chemotherapy appears to increase survival for patients with resected NSCLC tumors larger than 4 cm. Women with NSCLC experience improved survival relative to men regardless of treatment. However,there are certain groups of women over 65 years old who do not benefit from adjuvant chemotherapy.

Resection of oligometastatic lung cancer to the pancreas may yield a survival benefit in select patients--a systematic review.

OBJECTIVES: To conduct a systematic review of the existing literature regarding surgical therapy for oligometastatic lung cancer to the pancreas. METHODS: Data was collected on patients with singular pancreatic metastases from lung cancer from papers published between January 1970 and June 2014. This was performed following the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) guidelines. Kaplan-Meier and Cox Regression analyses were then used to determine and compare survival. RESULTS: There were 27 papers that fulfilled the search criteria, from which data on 32 patients was collected. Non-small cell lung cancer (NSCLC) was the most prevalent type of primary lung malignancy, and metachronous presentations of metastases were most common. Lesions were most frequently located in the pancreatic head and consequently the most common curative intent metastasectomy was pancreaticoduodenectomy. There was a statistically significant survival benefit for patients whose metastasis were discovered incidentally by surveillance CT as opposed to those whose metastasis were discovered during a work up for new somatic complaints (p = 0.024). The overall median survival for patients undergoing curative intent resection was 29 months, with 2-year and 5-year survivals of 65% and 21% respectively. Palliative surgery or medical only management was associated with a median survival of 8 months and 2-year and 5-year survivals of 25% and 8% respectively. CONCLUSIONS: Curative intent resection of isolated pancreatic metastasis from lung cancer may be beneficial in a select group of patients.

What's new in thymic neoplasms.

PURPOSE OF REVIEW: The past 5 years have been marked with major developments in the field of thymic malignancies. RECENT FINDINGS: A lack of progress over decades has been transformed into dramatic advancements over the past 5 years through the creation of the International Thymic Malignancy Interest Group (ITMIG). ITMIG has brought together an engaged worldwide community interested in this field. An unprecedented global database has been developed and is being actively analyzed. Standard definitions have been established to allow collaboration; the histologic classification has been revised and the first formal stage classification system developed. Clinical trials and innovative research approaches are being implemented. The creation of the ITMIG infrastructure has yielded many successes and provides a solid foundation for future progress. SUMMARY: Clinicians and researchers should be aware of the knowledge, structure and tools that have been established. ITMIG provides an engaged community for collaboration and progress.

Pediatric thymomas: report of two cases and comprehensive review of the literature.

PURPOSE: Thymomas are rare pediatric malignancies with indolent behavior. There are fewer than 50 reported cases and no comprehensive review. We sought to evaluate our recent experience with pediatric thymomas, and comprehensively review the extant literature. METHODS: A systematic search of the PubMed database was performed using keywords: "thymoma", "pediatric", "juvenile", "childhood", and "child". Additional studies were identified by a manual search of the reference list. RESULTS: We report two patients with thymomas. We identified 22 case reports or series that described 48 patients; 62 % were male, 15 % presented with myasthenia gravis. Fifty percent were Masaoka Stage I, 15 % were Stage II, 13 % were Stage III, and 23 % were Stage IV. Four patients with early stage (I or II) disease were treated with adjuvant therapies in addition to surgical excision, while five patients with late stage (III or IV) disease treated with surgical excision alone. Of studies reporting at least 2-year follow-up, survival was 71 %. CONCLUSION: Pediatric thymomas are rare tumors with a slight male predominance. Wide variations were observed in the treatment of thymomas across all stages. Our review indicates a need for large database and multi-institutional studies to clearly elucidate clinical course, prognostic factors and outcome.

So Now We Know-Reflections on the Extent of Resection for Stage I Lung Cancer.

Lobectomy has been the standard treatment for stage I lung cancer in healthy patients, largely based on a randomized trial published in 1995. Nevertheless, research has continued regarding the role of sublobar resection. Three additional randomized trials addressing resection extent in healthy patients have recently been published. These 4 trials involve differences in design, eligibility, interventions, and intraoperative processes. Patients were ineligible if intraoperative assessment demonstrated stage > IA or inadequate resection margins. All trials consistently show no differences in perioperative morbidity, mortality, and postoperative changes in lung function between sublobar resection and lobectomy-consistent with other nonrandomized evidence. Long-term outcomes are generally encouraging of lesser resection, but some inconsistencies are apparent. The 2 larger recent trials demonstrated no overall survival difference while the others suggested better survival after lobectomy versus sublobar resection. Recurrence-free survival was found to be the same after lobectomy versus sublobar resection in 3 trials, despite higher locoregional recurrences after sublobar resection. The low 5-year recurrence-free survival (64%, regardless of resection extent) in 1 recent trial highlights the need for further optimization. Thus, there is high-level evidence that sublobar resection is a reasonable alternative to lobectomy in healthy patients. However, variability in long-term results suggests that aspects of patients, tumors and interventions need to be better understood. Therefore, we propose to apply sublobar resection cautiously; especially because there are no short-term benefits. Sublobar resection requires careful attention to intraoperative details (nodes, margins), and may be best suited for less aggressive (eg, ground glass, slow growing) tumors.

The Proposed 9th Edition TNM Classification of Lung Cancer.

A universal nomenclature of the anatomic extent of lung cancer has been critical for individual patient care as well as research advances. As progress occurs, new details emerge that need to be included in a refined system that aligns with contemporary clinical management issues. The 9th edition TNM classification of lung cancer, which is scheduled to take effect in January of 2025, addresses this need. It is based on a large international database, multidisciplinary input and extensive statistical analyses. Key features of the 9th edition include validation of the significant changes in the T component introduced in the 8th edition, subdivision of N2 after exploration of fundamentally different ways of categorizing the N component, and further subdivision of the M component. This has led to reordering of the TNM combinations included in stage groups, primarily involving stage groups IIA, IIB, IIIA and IIIB. This paper summarizes the analyses and revisions for the TNM classification of lung cancer to familiarize the broader medical community and facilitate implementation of the 9th edition system.

Completeness of Resection and Long-Term Survival of Patients Undergoing Resection for Pathologic T3 NSCLC: An International Association for the Study of Lung Cancer Analysis.

INTRODUCTION: Currently, tumors with different histopathologic characteristics and oncologic outcomes comprise the T3 category of the eight edition TNM classification for lung cancers. To better understand the T3 category, we evaluated completeness of resection and long-term survival in patients undergoing resection for T3 NSCLC. METHODS: The International Association for the Study of Lung Cancer 1999 to 2010 database was queried for patients with pathologic T3N0M0 NSCLC who underwent lobectomy or pneumonectomy. The primary outcome evaluated was overall survival (OS) stratified by T3 descriptors and completeness of resection. RESULTS: Of 1448 patients with T3N0M0 tumors, 1187 (82.0%) had a single descriptor defining them as T3. T3 tumors with chest wall infiltration (CWI) or parietal pleura infiltration (PL3) had the highest rates of incomplete resection (9.8% and 8.4%, respectively), and those classified as T3 by size only had the lowest rate of incomplete resection (2.9%). Individual T3 descriptors were associated with significant differences in OS (p = 0.005). When tumors with similar survival and complete resection rates were grouped, patients with T3 tumors characterized by size or the presence of a separate nodule (SN) in the same lobe had better 5-year OS than patients with tumors characterized by PL3 or CWI (size/SN 60% versus CWI/PL3 53%, p = 0.017) independent of completeness of resection. CONCLUSIONS: Significant differences in 5-year OS were associated with size, SN, PL3, or CWI T3 descriptors. Subdividing pathologic T3N0M0 tumors according to the presence or absence of CWI or PL3 may increase the prognostic accuracy of tumor staging.

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

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

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

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