The Society of Thoracic Surgeons General Thoracic Surgery Database: 2023 Update on Outcomes and Research

The Society of Thoracic Surgeons General Thoracic Surgery Database (GTSD) continues its trajectory of growth and enhancement, solidifying its stature as a premier global thoracic surgical database. The past year witnessed a notable expansion with the inclusion of 10 additional participating sites, now totaling 287, augmenting the database's repository to more than 800,000 procedures. A significant stride was made in refining the data audit process, thereby elevating the accuracy and completeness metrics, a testament to the relentless pursuit of data integrity. The GTSD further broadened its research apparatus, with 15 scholarly publications, a 50% uptick from the preceding year. These publications underscore the database's instrumental role in advancing thoracic surgical knowledge. In a concerted effort to alleviate data entry exigencies, the GTSD Task Force also instituted streamlined data submission protocols, a move lauded by participant sites. This report delineates the recent advancements, volume trajectories, and outcome metrics and encapsulates the prolific research output emanating from the GTSD, reflecting a year of substantial progress and academic fecundity.

Corrigendum: Iatrogenic air embolism: pathoanatomy, thromboinflammation, endotheliopathy, and therapies

[This corrects the article DOI: 10.3389/fimmu.2023.1230049.].

Conditional survival analysis of patients with resected non-small cell lung cancer

Background

Conditional survival (CS) analyses provide an estimate of survival accounting for years already survived after treatment. We aim to evaluate the difference between actuarial and conditional survival in patients following lung resection for non-small cell lung cancer (NSCLC). In addition, CS analyses are used to examine whether prognosticators of survival change over time following surgery.

Methods

Patients who underwent anatomic lung resection at a single institution for pathologic stage I-IIIA NSCLC between 2010 and 2021 were identified; those who underwent wedge resection for node-negative tumors ≤2 cm were also included. CS estimates were calculated as the probability of remaining disease-free after x years of nonrecurrence (CSx). Kaplan-Meier, log-rank, and Cox proportional hazard methods for examining CS were used for subgroup comparisons and assessing associations with baseline covariates.

Results

Overall, 863 patients met the study inclusion criteria, with a median follow-up of 44.1 months. Conditional overall survival (OS) and disease-free survival (DFS) were greater than actuarial rates at all time points after surgery. At the time of resection, male sex (hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.03 to 1.72; P = .032), tumor size >3 cm (HR, 1.17; 95% CI, 1.11-1.23; P < .001), node positivity (HR, 3.31; 95% CI, 2.52-4.33; P < .001), and American Joint Committee on Cancer stage (P < .001) were associated with DFS. However, if a patient lived 3 years without recurrence (CS3), these factors were no longer prognostic of DFS.

Conclusions

Conditional survival analyses provide dynamic assessments of OS and DFS after NSCLC resection. After 3 years without recurrence, certain characteristics associated with DFS at the time of surgery no longer prognosticate recurrence.

Iatrogenic air embolism: pathoanatomy, thromboinflammation, endotheliopathy, and therapies

Iatrogenic vascular air embolism is a relatively infrequent event but is associated with significant morbidity and mortality. These emboli can arise in many clinical settings such as neurosurgery, cardiac surgery, and liver transplantation, but more recently, endoscopy, hemodialysis, thoracentesis, tissue biopsy, angiography, and central and peripheral venous access and removal have overtaken surgery and trauma as significant causes of vascular air embolism. The true incidence may be greater since many of these air emboli are asymptomatic and frequently go undiagnosed or unreported. Due to the rarity of vascular air embolism and because of the many manifestations, diagnoses can be difficult and require immediate therapeutic intervention. An iatrogenic air embolism can result in both venous and arterial emboli whose anatomic locations dictate the clinical course. Most clinically significant iatrogenic air emboli are caused by arterial obstruction of small vessels because the pulmonary gas exchange filters the more frequent, smaller volume bubbles that gain access to the venous circulation. However, there is a subset of patients with venous air emboli caused by larger volumes of air who present with more protean manifestations. There have been significant gains in the understanding of the interactions of fluid dynamics, hemostasis, and inflammation caused by air emboli due to in vitro and in vivo studies on flow dynamics of bubbles in small vessels. Intensive research regarding the thromboinflammatory changes at the level of the endothelium has been described recently. The obstruction of vessels by air emboli causes immediate pathoanatomic and immunologic and thromboinflammatory responses at the level of the endothelium. In this review, we describe those immunologic and thromboinflammatory responses at the level of the endothelium as well as evaluate traditional and novel forms of therapy for this rare and often unrecognized clinical condition.

Baseline Electrocardiographic Abnormalities in Pre-Treatment Cancer Compared With Non-Cancer Patients: A Propensity Score Analysis

Background

Most studies have compared post-treatment electrocardiogram (ECG) abnormalities in cancer patients to the general population. To assess baseline cardiovascular (CV) risk, we compared pre-treatment ECG abnormalities in cancer patients with a non-cancer surgical population.

Methods

We conducted a combined prospective (n = 30) and retrospective (n = 229) cohort study of patients aged 18 - 80 years with diagnosis of hematologic or solid malignancy, compared with 267 pre-surgical, non-cancer, age- and sex-matched controls. Computerized ECG interpretations were obtained, and one-third of the ECGs underwent blinded interpretation by a board-certified cardiologist (agreement r = 0.94). We performed contingency table analyses using likelihood ratio Chi-square statistics, with calculated odds ratios. Data were analyzed after propensity score matching.

Results

The mean age of cases was 60.97 ± 13.86; and 59.44 ± 11.83 years for controls. Pre-treatment cancer patients had higher likelihood of abnormal ECG (odds ratio (OR): 1.55; 95% confidence interval (CI): 1.05 to 2.30), and more ECG abnormalities (χ² = 4.0502; P = 0.04) compared with non-cancer patients. ECG abnormalities were higher in black compared to non-black patients (P = 0.001). In addition, baseline ECGs among cancer patients prior to cancer therapy demonstrated less QT prolongation and intra-ventricular conduction defect (P = 0.04); but showed more arrhythmias (P < 0.01) and atrial fibrillation (AF) (P = 0.01) compared with the general patient population.

Conclusions

Based on these findings, we recommend that all cancer patients receive an ECG, a low-cost and widely available tool, as part of their CV baseline screening, prior to cancer treatment.

Development of a Novel Circulating Autoantibody Biomarker Panel for the Identification of Patients with 'Actionable' Pulmonary Nodules

Due to poor compliance and uptake of LDCT screening among high-risk populations, lung cancer is often diagnosed in advanced stages where treatment is rarely curative. Based upon the American College of Radiology's Lung Imaging and Reporting Data System (Lung-RADS) 80-90% of patients screened will have clinically "non-actionable" nodules (Lung-RADS 1 or 2), and those harboring larger, clinically "actionable" nodules (Lung-RADS 3 or 4) have a significantly greater risk of lung cancer. The development of a companion diagnostic method capable of identifying patients likely to have a clinically actionable nodule identified during LDCT is anticipated to improve accessibility and uptake of the paradigm and improve early detection rates. Using protein microarrays, we identified 501 circulating targets with differential immunoreactivities against cohorts characterized as possessing either actionable (n = 42) or non-actionable (n = 20) solid pulmonary nodules, per Lung-RADS guidelines. Quantitative assays were assembled on the Luminex platform for the 26 most promising targets. These assays were used to measure serum autoantibody levels in 841 patients, consisting of benign (BN; n = 101), early-stage non-small cell lung cancer (NSCLC; n = 245), other early-stage malignancies within the lung (n = 29), and individuals meeting United States Preventative Screening Task Force (USPSTF) screening inclusion criteria with both actionable (n = 87) and non-actionable radiologic findings (n = 379). These 841 patients were randomly split into three cohorts: Training, Validation 1, and Validation 2. Of the 26 candidate biomarkers tested, 17 differentiated patients with actionable nodules from those with non-actionable nodules. A random forest model consisting of six autoantibody (Annexin 2, DCD, MID1IP1, PNMA1, TAF10, ZNF696) biomarkers was developed to optimize our classification performance; it possessed a positive predictive value (PPV) of 61.4%/61.0% and negative predictive value (NPV) of 95.7%/83.9% against Validation cohorts 1 and 2, respectively. This panel may improve patient selection methods for lung cancer screening, serving to greatly reduce the futile screening rate while also improving accessibility to the paradigm for underserved populations.

Predicting Non-home Discharge After Lung Surgery: Analysis of the General Thoracic Surgery Database

BACKGROUND

Anticipating the need for non-home discharge (NHD) enables improved patient counseling and expedites placement, potentially reducing length of stay and hospital readmission. The objective of this study was to create a simple, preoperative, clinical prediction tool for NHD using The Society of Thoracic Surgeons General Thoracic Surgery Database (STS GTSD).

METHODS

The STS GTSD was queried for patients who underwent elective anatomic lung cancer resection between 2009 and 2019. Exclusion criteria included age <18 years, percentage predicted diffusion capacity of the lung for carbon monoxide <20% or >150%, N3 or M1 disease, incomplete datasets, and mortality. The primary outcome was defined as discharge to an extended care, transitional care, rehabilitation center, or another hospital. Multivariable logistic regression was used to select risk factors and a nomogram for predicting risk of NHD was developed. The approach was cross-validated in 100 replications of a training set consisting of randomly selected two-thirds of the cohort and a validation set of remaining patients.

RESULTS

A total of 35 948 patients from the STS GTSD met inclusion criteria. Final model variables used to derive the nomogram for NHD risk prediction included age (P < .001), percentage predicted diffusion capacity of the lung for carbon monoxide (P < .001), open surgery (P < .001), cerebrovascular history (P < .001), and Zubrod score (P < .001). The receiver operating characteristic curve, using sensitivities and specificities of the model, yielded area under the curve of 0.74. In 100 replicated cross-validations, out-of-sample area under the curve ranged from 0.72-0.76.

CONCLUSIONS

Using readily available preoperative variables, our nomogram prognosticates the risk of NHD after anatomic lung resection with good discriminatory ability. Such risk stratification can enable improved patient counseling and facilitate better planning of patients' postoperative needs.

The Society of Thoracic Surgeons General Thoracic Surgery Database: 2022 Update on Outcomes and Research

The Society of Thoracic Surgeons General Thoracic Surgery Database (STS GTSD) remains the largest and most robust thoracic surgical database in the world. Participating sites receive risk-adjusted performance reports for benchmarking and quality improvement initiatives. The GTSD also provides several mechanisms for high-quality clinical research using data from 274 participant sites and 781,000 procedures since its inception in 2002. Participant sites are audited at random annually for completeness and accuracy. Over the last year and a half, the GTSD Task Force continued to refine the data collection process, implementing an updated data collection form in July 2021, ensuring high data fidelity while minimizing data entry burden. In addition, the STS Workforce on National Databases has supported a robust GTSD-based research program, which led to eight scholarly publications in 2021. This report provides an update on volume trends, outcomes, and database initiatives as well as a summary of research productivity resulting from the GTSD over the preceding year.

Consensus for Thoracoscopic Lower Lobectomy: Essential Components and Targets for Simulation

BACKGROUND

Despite demonstration of its clear benefits relative to open approaches, a video-assisted thoracic surgery technique for pulmonary lobectomy has not been universally adopted. This study aims to overcome potential barriers by establishing the essential components of the operation and determining which steps are most useful for simulation training.

METHODS

After randomly selecting experienced thoracic surgeons to participate, an initial list of components to a lower lobectomy was distributed. Feedback was provided by the participants, and modifications were made based on anonymous responses in a Delphi process. Components were declared essential once at least 80% of participants came to an agreement. The steps were then rated based on cognitive and technical difficulty followed by listing the components most appropriate for simulation.

RESULTS

After 3 rounds of voting 18 components were identified as essential to performance of a video-assisted thoracic surgery for lower lobectomy. The components deemed the most difficult were isolation and division of the basilar and superior segmental branches of the pulmonary artery, isolation and division of the lower lobe bronchus, and dissection of lymphovascular tissue to expose the target bronchus. The steps determined to be most amenable for simulation were isolation and division of the branches of the pulmonary artery, the lower lobe bronchus, and the inferior pulmonary vein.

CONCLUSIONS

Using a Delphi process a list of essential components for a video-assisted thoracic surgery for lower lobectomy was established. Furthermore 3 components were identified as most appropriate for simulation-based training, providing insights for future simulation development.

The association between thoracic sarcopenia and survival is gender specific in early-stage lung cancer

Background

Sarcopenia, as measured at the 3rd lumbar (L3) level, has been shown to prognosticate survival in cancer patients. However, many patients with early-stage non-small cell lung cancer (NSCLC) do not undergo abdominal imaging. We hypothesized that preoperative thoracic sarcopenia is associated with survival in patients undergoing lung resection for early-stage NSCLC.

Methods

Patients who underwent anatomic resection for NSCLC between 2010-2019 were retrospectively identified. Exclusion criteria included induction therapy, less than 90 days of follow-up, and absence of computed tomography (CT) imaging. Cross sectional skeletal muscle area was calculated at the fifth thoracic vertebra (T5), twelfth thoracic vertebra (T12), and L3 level. Gender-specific lowest quartile values and previously defined values were used to define sarcopenia. Overall survival and disease-free survival were assessed using the Kaplan-Meier method.

Results

Overall, 221 patients met inclusion criteria with a median body mass index (BMI) of 26.5 kg/m² [interquartile range (IQR), 23.3-29.9 kg/m²], age of 69 years (IQR, 62.4-74.9 years), and follow-up of 46.9 months (IQR, 25.0-70.7 months). At the T5 level, sarcopenic males demonstrated worse overall survival [median 41.0 (IQR, 13.8-53.7) vs. 42.0 (IQR, 23.1-55.1) months, P=0.023] and disease-free survival [median 15.8 (IQR, 8.4-30.78) vs. 34.8 (IQR, 20.1-50.5) months, P=0.007] when compared to non-sarcopenic males. There was no difference in survival between sarcopenic and non-sarcopenic females when assessed at T5. Sarcopenia at T12 or L3 was associated with worse overall survival (P<0.05).

Conclusions

Sarcopenia at T5 is associated with worse survival in males, but not females. When using upper thoracic vertebral levels to assess for sarcopenia, it is necessary to account for gender.

The Choice between Plasma-Based Common Coagulation Tests and Cell-Based Viscoelastic Tests in Monitoring Hemostatic Competence: Not an either-or Proposition

There has been a significant interest in the last decade in the use of viscoelastic tests (VETs) to determine the hemostatic competence of bleeding patients. Previously, common coagulation tests (CCTs) such as the prothrombin time (PT) and partial thromboplastin time (PTT) were used to assist in the guidance of blood component and hemostatic adjunctive therapy for these patients. However, the experience of decades of VET use in liver failure with transplantation, cardiac surgery, and trauma has now spread to obstetrical hemorrhage and congenital and acquired coagulopathies. Since CCTs measure only 5 to 10% of the lifespan of a clot, these assays have been found to be of limited use for acute surgical and medical conditions, whereby rapid results are required. However, there are medical indications for the PT/PTT that cannot be supplanted by VETs. Therefore, the choice of whether to use a CCT or a VET to guide blood component therapy or hemostatic adjunctive therapy may often require consideration of both methodologies. In this review, we provide examples of the relative indications for CCTs and VETs in monitoring hemostatic competence of bleeding patients.

Paired tumor/normal sequencing to overcome racial differences in tumor mutational burden (TMB)

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Background: TMB is routinely reported in cancer patients tested with broad-panel next generation sequencing and has become a predictive biomarker associated with response to checkpoint inhibitor (CPI) therapy. Sequencing of paired tumor and normal specimens allows correction of TMB estimates with patient-specific germline variants. When a paired normal specimen is unavailable, TMB estimates are corrected using germline variant annotations derived from population-scale germline variant surveys. Germline variants do not generate neoantigens, which is the putative target of the immune response in CPI treated patients. To evaluate TMB differences in paired sequencing (PS) and tumor-only sequencing (TOS), we compared TMB assessments—stratified by race—in two common malignancies. Methods: Using de identified records from the Tempus clinico-genomic database, cohorts of patients with non-small cell lung cancer (NSCLC) and breast cancer sequenced using the Tempus xT NGS platform (DNA-seq of 595-648 genes at 500x coverage, whole exome capture RNA-seq) and noted to not have microsatellite instability, were identified for analyses. The Kruskall-Wallis test was used to compare TMB distributions. Results: Among 4,817 NSCLC patients with race information (13% Black (B), 5% Asian (A), 82% White (W), 3,052 had PS, and 1,765 had TOS performed. Median TMB for B, A, and W patients was 5.8, 2.6, and 4.7 (within group p < 0.0001), respectively in patients with PS, and 9.5, 6, and 7.4 (within group p < 0.0001), in patients with TOS. Comparisons across PS and TOS were highly significant (p < 0.0001). The absolute difference in median TMB was 3.7, 3.4, and 2.5, respectively. Among 3,191 patients with breast cancer (17% B, 4% A, 78% W), 2,220 had PS, and 971 had TOS. Median TMB for B, A, and W patients was 2.6, 2.1, and 2.6 (within group p = 0.11), respectively, in patients with PS, and 6.3, 5.8, and 4.7 (within group p < 0.0001) in patients with TOS. Comparisons across PS and TOS were highly significant (p < 0.0001). The absolute difference in median TMB was 3.7, 3.7, and 2.1, respectively. Conclusions: PS reduces estimated TMB compared to TOS across all racial groups with a pronounced difference in Black and Asian racial groups. This is expected as population databases of germline variation are based on cohorts predominantly from individuals of European ancestry, leading to artifactually high TMB in minorities tested with TOS. As a result, artifactually elevated TMB estimates from TOS may promote treatment with CPI in patients with a low probability of response which could exacerbate known race-based outcome disparities. PS provides a more accurate estimate of TMB regardless of race and could reduce the use of CPI in patients with a low likelihood of response.

Identifying biomarkers associated with disease-free survival in stage I non–small cell lung cancer

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Background: Patients with early stage, non-small cell lung cancer (NSCLC) with solitary pulmonary lesions ≤4 cm typically have favorable outcomes. However, disease recurrence impacts up to 30% of patients, leading to either additional surgical or systemic interventions. New methods to risk stratify patients based on clinical and molecular parameters may improve our ability to select cases that would benefit from more frequent surveillance or enrollment in clinical trials evaluating systemic therapy. Methods: We retrospectively analyzed data from 179 patients with early stage (T1a-2aN0M0) NSCLC from a single institution. All patients had anatomic resection, negative margins, and systematic nodal sampling. Clinical and demographic data were abstracted from patient charts and tumor samples were molecularly profiled using the Tempus xT solid tumor assay (DNA-seq of 595-648 genes at 500x coverage, whole exome-capture RNA-seq). Pathogenic alterations (single nucleotide variants and insertion/deletions) and RNA expression were examined. Bivariate Cox-proportional Hazards models were used to assess the association of individual clinical, demographic, and molecular variables with recurrence-free survival, defined as the time from surgery until recurrence or death. Results: Our dataset included 166 stage IA1-3 patients and 13 stage IB patients, of which 36 patients experienced a recurrence or death event after surgery. Clinical and DNA-seq data was available for all patients, and RNA expression data was available for 172 patients. Across all patients, the most common somatically mutated genes were TP53 (33% of tumors) and KRAS (16% of tumors), consistent with previous studies. Increasing log10-RNA expression for NTRK1 (HR: 5.95; 95% CI, 1.16-30.4; p = 0.027) and CD274 (PD-L1) (HR: 7.88; 95% CI, 1.61-38.6; p = 0.013) and decreasing log10-RNA expression for EGFR (HR: 0.24; 95% CI, 0.05-1.21; p = 0.071) and ERBB2 (Her2) (HR: 0.20; 95% CI, 0.04-0.97; p = 0.042) were associated with increased risk of recurrence or death. Conclusions: Increased expression of NTRK1 and CD274 (PD-L1) and decreased expression of EGFR and ERBB2 (Her2) were associated with a increased risk for recurrence following surgery. This may have mechanistic implications for heightened tumor aggressiveness and/or metastatic potential. Future work will expand our cohort and validate our findings in a broader set of early-stage NSCLC patients.

Textbook outcome following oesophagectomy for cancer: international cohort study

Background

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

Methods

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

Results

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter ‘no major postoperative complication’ had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P &lt; 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P &lt; 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

Conclusion

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Textbook outcome following oesophagectomy for cancer: international cohort study

BACKGROUND

Textbook outcome has been proposed as a tool for the assessment of oncological surgical care. However, an international assessment in patients undergoing oesophagectomy for oesophageal cancer has not been reported. This study aimed to assess textbook outcome in an international setting.

METHODS

Patients undergoing curative resection for oesophageal cancer were identified from the international Oesophagogastric Anastomosis Audit (OGAA) from April 2018 to December 2018. Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. A multivariable binary logistic regression model was used to identify factors independently associated with textbook outcome, and results are presented as odds ratio (OR) and 95 per cent confidence intervals (95 per cent c.i.).

RESULTS

Of 2159 patients with oesophageal cancer, 39.7 per cent achieved a textbook outcome. The outcome parameter 'no major postoperative complication' had the greatest negative impact on a textbook outcome for patients with oesophageal cancer, compared to other textbook outcome parameters. Multivariable analysis identified male gender and increasing Charlson comorbidity index with a significantly lower likelihood of textbook outcome. Presence of 24-hour on-call rota for oesophageal surgeons (OR 2.05, 95 per cent c.i. 1.30 to 3.22; P = 0.002) and radiology (OR 1.54, 95 per cent c.i. 1.05 to 2.24; P = 0.027), total minimally invasive oesophagectomies (OR 1.63, 95 per cent c.i. 1.27 to 2.08; P < 0.001), and chest anastomosis above azygous (OR 2.17, 95 per cent c.i. 1.58 to 2.98; P < 0.001) were independently associated with a significantly increased likelihood of textbook outcome.

CONCLUSION

Textbook outcome is achieved in less than 40 per cent of patients having oesophagectomy for cancer. Improvements in centralization, hospital resources, access to minimal access surgery, and adoption of newer techniques for improving lymph node yield could improve textbook outcome.

Safety and efficacy of vagus nerve preservation technique during minimally invasive esophagectomy

Background

This study aimed to assess the feasibility, efficacy and safety of McKeown surgery with vagal-sparing using minimally invasive esophagectomy (MIE).

Methods

McKeown surgery with vagal-sparing technique using MIE was adopted on patients diagnosed with resectable esophageal cancer. From June 2020 to January 2021, a total of 20 patients from the Department of Thoracic Surgery of the National Clinical Research Center for Cancer were enrolled.

Results

The study group included 17 (85%) males and 3 (15%) females, with an average age of 62.6 (±7.1) years. The most common tumor location was lower thoracic esophagus (n=9, 45%), followed by middle thoracic esophagus (n=8, 40%) and upper thoracic esophagus (n=3, 15%). Nine (45%) patients had T1b disease, followed by T2 (n=8, 40%), T1a (n=2, 10%), and Tis (n=1, 5%). The average operation time was 221.5 (±61.2) minutes. Postoperative complications were as follow: 2 (10%) with hoarseness, 2 (10%) with pulmonary infection, 1 (5%) with arrhythmia, 1 (5%) with anastomotic leakage, 1 (5%) with delayed gastric emptying, 1 (5%) with pleural effusion, and 1 (5%) with diarrhea. Dumping syndrome, cholestasis, and chylothorax were not observed, and there was no perioperative death.

Conclusions

MIE with vagus nerve preservation is a feasible and safe technique, with the possibility to be an alternative for esophageal carcinoma. Further study is needed to explore the functional outcome of preserving vagus nerve.

The role of IGF-pathway biomarkers in determining risks, screening, and prognosis in lung cancer

Background: Detection rates of early-stage lung cancer are traditionally low, which contributes to inconsistent treatment responses and high rates of annual cancer deaths. Currently, low-dose computed tomography (LDCT) screening produces a high false discovery rate. This limitation has prompted research to identify biomarkers to more clearly define eligible patients for LDCT screening, differentiate indeterminate pulmonary nodules, and select individualized cancer therapy. Biomarkers within the Insulin-like Growth Factor (IGF) family have come to the forefront of this research.

Main Body: Multiple biomarkers within the IGF family have been investigated, most notably IGF-I and IGF binding protein 3. However, newer studies seek to expand this search to other molecules within the IGF axis. Certain studies have demonstrated these biomarkers are useful when used in combination with lung cancer screening, but other findings were not as conclusive, possibly owing to measurement bias and non-standardized assay techniques. Research also has suggested IGF biomarkers may be beneficial in the prognostication and subsequent treatment via systemic therapy. Despite these advances, additional knowledge of complex regulatory mechanisms inherent to this system are necessary to more fully harness the potential clinical utility for diagnostic and therapeutic purposes.

Conclusions: The IGF system likely plays a role in multiple phases of lung cancer; however, there is a surplus of conflicting data, especially prior to development of the disease and during early stages of detection. IGF biomarkers may be valuable in the screening, prognosis, and treatment of lung cancer, though their exact application requires further study.

Neoadjuvant programmed cell death 1 blockade combined with chemotherapy for resectable esophageal squamous cell carcinoma

BACKGROUND

Programmed cell death 1 (PD-1) blockade induces tumor regression in patients with advanced esophageal squamous cell carcinoma (ESCC); however, little is known about the efficacy of PD-1 blockade as neoadjuvant therapy in resectable ESCC. We aim to assess the safety and feasibility of using the combination of neoadjuvant PD-1 blockade with chemotherapy in patients with ESCC.

METHODS

Patients with previously untreated, resectable (stage II or III) ESCC were enrolled. Each patient received two 21-day cycles of neoadjuvant treatment with camrelizumab, nab-paclitaxel, and carboplatin before undergoing surgical resection approximately 6-9 weeks after the first cycle.

RESULTS

Between January 2020 and September 2020, 37 patients were screened, of whom 23 were enrolled. The neoadjuvant therapeutic regimen had an acceptable side effect profile, and no delays in surgery were observed. Severe (grade 3-4) treatment-related adverse events included neutropenia (9 of 23, 39.1%) and leukopenia (2 of 23, 8.7%). The objective response and disease control rates were 90.5% and 100%, respectively. Twenty patients received surgery, and R0 resection was achieved in all cases. Five (25%) patients had a pathological complete response (PCR) and 10 (50%) patients had a major pathological response. The proportion of patients with a high tumor mutation burden and a high expression of programmed death-ligand 1 (PD-L1) in primary tumor was significantly higher in the PCR group than in the non-PCR group (p=0.044). The number of infiltrating PD-L1+ CD163+ cells was significantly lower in the PCR group than in the non-PCR group after treatment (p=0.017).

CONCLUSIONS

Neoadjuvant camrelizumab plus carboplatin and nab-paclitaxel had manageable treatment-related adverse effects and induced an objective response in 90.5% of patients, demonstrating its antitumor efficacy in resectable ESCC.

TRIAL REGISTRATION NUMBER

ChiCTR2000028900.

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND

The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting.

METHODS

Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups.

RESULTS

Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005).

CONCLUSION

Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery.

Robotic vs. Thoracoscopic Anatomic Lung Resection in Obese Patients: A Propensity Adjusted Analysis

BACKGROUND

Minimally-invasive lung resections can be particularly challenging in obese patients. We hypothesized robotic surgery (RTS) is associated with less conversion to thoracotomy than thoracoscopic surgery (VATS) in obese populations.

METHODS

The STS GTSD, Epithor French National Database, and McMaster University Database were queried for obese (BMI≥30 kg/m²) patients who underwent VATS or RTS lobectomy or segmentectomy for clinical T1-2, N0-1 NSCLC between 2015-2019. Propensity score adjusted logistic regression analysis was used to compare the rate of conversion to thoracotomy between the VATS and RTS cohorts.

RESULTS

Overall, 8,108 patients (STS GTSD: n=7,473; Epithor: n=572; McMaster: n=63) met inclusion criteria with a mean age of 66.6 years (SD 9 years) and BMI of 34.7 kg/m² (SD 4.5 kg/m²). After propensity score adjusted multivariable analysis, patients who underwent VATS were over 5 times more likely to experience conversion to thoracotomy than those who underwent RTS (OR=5.33; 95% CI 4.14, 6.81, p<0.001). There was a linear association between degree of obesity and odds ratio of VATS conversion to thoracotomy compared to RTS. The VATS cohort had a longer mean length of stay (5.0 vs. 4.3 days, p<0.001), higher rate of respiratory failure (2.8% [168/5975] vs. 1.8% [39/2133], p=0.026), and were less likely to be discharged to their home (92.5% [5,525/5,975] vs. 94.3% [2,012/2,133]; p=0.013) compared to RTS patients.

CONCLUSIONS

In obese patients, RTS anatomic lung resection is associated with a lower rate of conversion to thoracotomy than VATS.

Pulmonary metastasectomy in bone and soft tissue sarcoma with metastasis to the lung

 

OBJECTIVES

This study investigated the outcomes of sarcoma patients with lung metastases who underwent pulmonary metastasectomy (PM), compared to patients who underwent medical management alone. The secondary objective was to compare survival after PM between variables of interest.

METHODS

This was a retrospective review of 565 sarcoma patients with confirmed, isolated pulmonary metastasis identified from the Surveillance, Epidemiology and End Results database between 2010 and 2015. 1:4 propensity score matching was used to select PM and non-PM groups. The multivariable Cox proportional hazards model was used to analyse prognostic factors of disease-free survival (DFS).

RESULTS

Of the eligible 565 patients, 59 PM patients were matched to 202 non-PM patients in a final ratio of 3.4. After propensity matching, there were no significant differences in baseline characteristics between PM and non-PM patients. The median DFS after PM was 32 months (interquartile range 18–59), compared to 20 months (interquartile range 7–40) in patients without PM (P = 0.032). Using a multivariable Cox proportional hazards model, metastasectomy (hazard ratio 0.536, 95% confidence interval 0.33–0.85; P = 0.008) was associated with improved DFS. In a subset analysis of patients who underwent PM only, the median DFS was longer in males compared to females (P = 0.021), as well as in bone sarcoma compared to soft tissue sarcoma (P = 0.014).

CONCLUSIONS

For sarcoma patients with metastatic lung disease, PM appears to improve the prognosis compared to medical management. Furthermore, there may be a survival association with gender and tumour origin in patients who underwent PM. These data may be used to inform the surgical indications and eligibility criteria for metastasectomy in this setting.

Percutaneous Right Ventricular Assist Device Using the TandemHeart ProtekDuo: Real-World Experience

BACKGROUND

Acute right ventricular (RV) failure is challenging to treat and mechanical circulatory support devices are limited. The TandemHeart ProtekDuo (THPD; TandemLife) is a novel percutaneous RV assist device that can provide 4.0 liters per minute of blood flow through venovenous extracorporeal life support. It allows venous drainage from the right atrium and reinfusion of blood into the main pulmonary artery via internal jugular vein access. We aim to provide real-world insight into disease characteristics resulting in the use of THPD for mechanical support and enhance knowledge of best practice regarding clinical management weaning and removal/exit strategies.

METHODS

We retrospectively collected data of consecutive patients who received a THPD device at our center for acute RV failure between August 2015 and February 2018.

RESULTS

Eleven patients were diagnosed with acute RV failure and required placement of THPD. The hospital length of stay ranged from 12 to 223 days. The average length of support ranged from 11 to 154 days. We observed complications such as stroke (18.2%), sepsis (63.6%), massive gastrointestinal bleed (45.5%), and heparin-induced thrombocytopenia (54.5%). These patients received on average 85 units of blood products. Survival was 82% at 30 days and 72% at 180 days. Six of the patients were successfully weaned from the THPD devices and 1 patient required venovenous extracorporeal life support.

CONCLUSIONS

This real-world experience, despite high morbidity, continues to suggest benefits of THPD for patients with severe acute RV failure.

Cannabis Use Is Associated With Recurrence After Primary Spontaneous Pneumothorax

Purpose: Primary spontaneous pneumothorax (PSP) is a frequently encountered entity that carries a high rate of recurrence. The current study aims to investigate if cannabis use at time of initial PSP is associated with disease recurrence.

Methods: Patients presenting with PSP between 2010 and 2018 at a single institution were identified. Exclusion criteria included secondary pneumothorax, severe chronic lung disease, lung cancer, and lost to follow-up. Patients were compared relative to their cannabis usage with Fisher's exact test, Wilcoxon rank-sum test, and logistic regression.

Results: Overall, 67 patients (53 male) met inclusion criteria with a median body mass index (BMI) of 21.5 kg/m² (IQR 19.1–25.2) and age of 34 years (IQR 22–53). Initial treatment consisted of chest tube in 42 patients (63%), video-assisted thoracoscopic surgery wedge resection in 19 patients (28%), and observation in 6 patients (9%). Cannabis users (n = 28; 42%) had a higher rate of tobacco use (79 vs. 38%; p = 0.005), lower BMI [21.0 kg/m² (IQR 18.3–23.1) vs. 22.2 kg/m² (IQR 19.9–28.6), p = 0.037], and were more likely to require intervention at first presentation compared with non-marijuana users. Cannabis use was associated with PSP recurrence when adjusting for tobacco use, BMI, and height (OR 1.85, 95% CI 1.38–18.3, p = 0.014).

Conclusion: There is a high rate of cannabis usage in patients presenting with PSP. Cannabis usage is associated with PSP recurrence and eventual need for operative intervention.

Comparison of short-term outcomes from the International Oesophago-Gastric Anastomosis Audit (OGAA), the Esophagectomy Complications Consensus Group (ECCG), and the Dutch Upper Gastrointestinal Cancer Audit (DUCA)

BACKGROUND

The Esophagectomy Complications Consensus Group (ECCG) and the Dutch Upper Gastrointestinal Cancer Audit (DUCA) have set standards in reporting outcomes after oesophagectomy. Reporting outcomes from selected high-volume centres or centralized national cancer programmes may not, however, be reflective of the true global prevalence of complications. This study aimed to compare complication rates after oesophagectomy from these existing sources with those of an unselected international cohort from the Oesophago-Gastric Anastomosis Audit (OGAA).

METHODS

The OGAA was a prospective multicentre cohort study coordinated by the West Midlands Research Collaborative, and included patients undergoing oesophagectomy for oesophageal cancer between April and December 2018, with 90 days of follow-up.

RESULTS

The OGAA study included 2247 oesophagectomies across 137 hospitals in 41 countries. Comparisons with the ECCG and DUCA found differences in baseline demographics between the three cohorts, including age, ASA grade, and rates of chronic pulmonary disease. The OGAA had the lowest rates of neoadjuvant treatment (OGAA 75.1 per cent, ECCG 78.9 per cent, DUCA 93.5 per cent; P < 0.001). DUCA exhibited the highest rates of minimally invasive surgery (OGAA 57.2 per cent, ECCG 47.9 per cent, DUCA 85.8 per cent; P < 0.001). Overall complication rates were similar in the three cohorts (OGAA 63.6 per cent, ECCG 59.0 per cent, DUCA 62.2 per cent), with no statistically significant difference in Clavien-Dindo grades (P = 0.752). However, a significant difference in 30-day mortality was observed, with DUCA reporting the lowest rate (OGAA 3.2 per cent, ECCG 2.4 per cent, DUCA 1.7 per cent; P = 0.013).

CONCLUSION

Despite differences in rates of co-morbidities, oncological treatment strategies, and access to minimal-access surgery, overall complication rates were similar in the three cohorts.

Redefining the Risk of Surgery for Clinical Stage IIIA (N2) Non-Small Cell Lung Cancer: A Pooled Analysis of the STS GTSD and ESTS Registry

BACKGROUND

Management of clinical stage IIIA-N2 (cIIIA-N2) non-small cell lung cancer (NSCLC) remains controversial. We evaluated treatment strategies and outcomes in cIIIA-N2 NSCLC patients who underwent pulmonary resection in The Society of Thoracic Surgeons General Thoracic Surgery Database (STS GTSD) and the European Society of Thoracic Surgeons (ESTS) Registry.

METHODS

The STS GTSD and ESTS Registry were queried for patients who underwent pulmonary resection for cIIIA-N2 NSCLC between 2012 and 2016. Demographic variables, treatment strategies, and outcome measures were collected and analyzed. Significance of differences was determined using the χ² test for categorical variables and the Wilcoxon rank sum test for continuous variables.

RESULTS

Pulmonary resection was performed in 4279 cIIIA-N2 NSCLC patients (2928 STS GTSD; 1351 ESTS). Induction therapy was administered to 49%. Lobectomy was performed in 67.1% and pneumonectomy in 13%. Lobectomy was associated with 19.2% major morbidity and 1.6% operative mortality, while pneumonectomy was associated with 34.1% and 5%, respectively. Induction therapy was associated with a higher rate of major morbidity or mortality than upfront surgery (23.2% vs 19.5%, p = 0.004), driven by pneumonectomy (40.7% vs 30.3%, p = 0.012) rather than lobectomy (20.3% vs 18.8%, p = 0.31).

CONCLUSIONS

Pulmonary resection for cIIIA-N2 NSCLC is associated with low rates of operative morbidity and mortality, with lobectomy having lower morbidity and mortality than pneumonectomy. Induction therapy, particularly chemoradiotherapy, is associated with a higher rate of composite morbidity or mortality than upfront surgery in pneumonectomy patients but not lobectomy patients.

Benign Endobronchial Tumors: A Clinicopathologic Review

Purpose: Benign endobronchial tumors are rare entities that can be difficult to diagnose because they often present with non-specific symptoms and vague radiographic findings. The current study reviews the clinical, radiologic and pathologic features, diagnosis, and treatment of patients with benign endobronchial tumors. Methods: We examined the charts of all patients who presented with biopsy-proven benign endobronchial tumors at a tertiary-care academic medical center between 1993 and 2018. Pertinent clinicopathologic and radiologic data were analyzed, with particular attention paid to treatment modalities and mean overall patient survival. Results: A total of 28 cases were identified. The most common benign neoplasm was hamartoma (37%), followed by lipoma (19%), squamous papilloma (11%), pleomorphic adenoma (7%), mucin gland adenoma (7%), papillary adenoma (3%), hemangioma (3%), neurofibroma (3%), leiomyoma (3%), and papillomatosis (3%). Cough (58%), shortness of breath (44%), and hemoptysis (15%) were the most frequent presentations. Most cases demonstrated well-defined submucosal or pedunculated endobronchial lesions with segmental pneumonia or atelectasis on imaging. Histologic diagnosis was obtained by endobronchial resection in 43% of patients, thoracoscopic lobectomy in 36%, endobronchial biopsy in 18%, and thoracoscopic wedge resections in 3%. All procedures were performed with no intraoperative or in-hospital deaths (mean overall survival: 20.2 years). Conclusion: Benign endobronchial tumors typically present as well-defined submucosal and/or pedunculated lesions, and may lead to post-obstructive complications. Endobronchial resection is the preferred strategy for diagnosis and treatment of these tumors.

Sarcopenia after induction therapy is associated with reduced survival in patients undergoing esophagectomy for locally-advanced esophageal cancer

Background

The impact of sarcopenia on the outcome of esophageal cancer patients remains unknown in North American populations. The current study aims to investigate if sarcopenia at the time of esophagectomy for locally-advanced esophageal cancer (LAEC) is associated with survival.

Methods

Patients who underwent induction therapy followed by esophagectomy for LAEC between 2010–2018 at a single institution were identified. Exclusion criteria included follow-up less than 90 days and distant metastatic disease at the time of surgery. Demographic, treatment, and outcome data were retrospectively collected. Computed tomography (CT) scans following induction therapy were analyzed to calculate skeletal muscle index (SMI). Overall survival (OS) and disease-free survival (DFS) were examined using Kaplan-Meier and Cox Proportional Hazard regression analysis.

Results

Overall, 52 patients met inclusion criteria with a median BMI of 25 (IQR, 22.4–29.1) kg/m² and age of 65 (IQR, 57–70) years. Sarcopenia was present in 75% (39/52) of patients at the time of surgery. Sarcopenic patients had a lower median BMI and higher median age when compared to non-sarcopenic patients. There was no difference in gender, race, stage, operative technique, post-operative complications, or hospital length of stay between sarcopenic and non-sarcopenic patients. With a median follow-up of 24.9 months, patients with sarcopenia at the time of esophagectomy had worse OS [median 24.3 (IQR, 9.9–34.5) vs. 50.9 (IQR, 25.6–50.9) months, P=0.0292] and DFS [median 11.7 (IQR, 6.4–25.8) vs. 29.4 (IQR, 12.8–26.7) months, P=0.0387] compared to non-sarcopenic patients.

Conclusions

Sarcopenia is associated with reduced overall and DFS in patients undergoing esophagectomy for LAEC.

Variability in Smoking Status for Lobectomy Among Society of Thoracic Surgeons Database Participants

BACKGROUND

Current smokers undergoing lobectomy are at greater risk of complications than are former smokers. The Society of Thoracic Surgeons (STS) composite score for rating program performance for lobectomy adjusts for smoking status, a modifiable risk factor. This study examined variability in the proportion of current smokers undergoing lobectomy among STS database participants. Additionally, the study determined whether each participant's rating changed if smoking was excluded from the risk adjustment model.

METHODS

This is a retrospective analysis of the STS cohort used to develop the composite score for rating program performance for lobectomy. The study summarized the variability among STS database participants for performing lobectomy on current smokers and compared star ratings developed from models with and without smoking status.

RESULTS

There were 24,912 patients with smoking status data: 23% current smokers, 62% former smokers, and 15% never smokers. There was significant variability among participants in the proportion of current smokers undergoing lobectomy (3% to 48.6%; P < .001). Major morbidity or mortality (composite) was greater in current smokers (12.1%) than in former smokers (8.6%) and never smokers (4.2%) (P < .001). Using the current risk adjustment model, participant star ratings were as follows: 1 star, n = 6 (3.2%); 2 stars, n = 170 (91.4%); and 3 stars, n = 10 (5.4%). When smoking status was excluded from the model, 1 participant shifted from a 2-star to a 3-star program.

CONCLUSIONS

There is substantial variability among STS database participants with regard to the proportion of current smokers undergoing lobectomy. However, exclusion of smoking status from the model did not significantly affect participant star rating.

Understanding barriers to lung cancer screening in primary care

Background

Low-dose computed tomography (LDCT) scan for lung cancer screening is underutilized. Studies suggest that up to one-third of providers do not know the current lung cancer screening guidelines. Thus, identifying the barriers to utilization of LDCT scan is essential.

Methods

Primary care providers in three different healthcare settings in the United States were surveyed to assess provider knowledge of LDCT scan screening criteria, lung cancer screening practices, and barriers to the utilization of LDCT scan screening. Fisher’s Exact, Chi-Squared, and Kruskal-Wallis tests were used to compare provider responses. Multivariable logistic regression was used to test the association between provider characteristics and the likelihood of utilizing LDCT scan for lung cancer screening.

Results

The survey was sent to 614 providers, with a 15.7% response rate. Overall, 29.2% of providers report never ordering LDCT scans for eligible patients. Providers practicing at a community or academic hospital more frequently order LDCT scans than those practicing at a safety net hospital. Academic- and community-based providers received a significantly higher mean knowledge score than safety net-based providers [academic 6.84 (SD 1.33), community 6.72 (SD 1.46), safety net 5.85 (SD 1.38); P<0.01]. Overall, only 6.2% of respondents correctly identified all six Centers for Medicare and Medicaid Services eligibility criteria when challenged with three incorrect criteria. Common barriers to utilization of LDCT scan included failure of the electronic medical record (EMR) to notify providers of eligible patients (54.7%), patient refusal (37%), perceived high false-positive rate leading to unnecessary procedures (18.9%), provider time constraints (16.8%), and lack of insurance coverage (13.7%).

Conclusions

Provider knowledge of lung cancer screening guidelines varies, perhaps contributing to underutilization of LDCT scan for lung cancer screening. Improved provider education at safety net hospitals and improving EMR-based best practice alerts may improve the rate of lung cancer screening.

Heart dose and coronary artery calcification in patients receiving thoracic irradiation for lung cancer

Background

Thoracic irradiation (TIR) is associated with an increased risk of coronary artery disease (CAD) and coronary-related death. Lung cancer patients receive considerable doses of TIR, making them a high-risk population that may benefit from post-therapy surveillance. Coronary artery calcium (CAC) is a known biomarker of CAD development and may serve as a useful indicator of disease progression in this population. We hypothesized greater CAC progression in lung cancer patients subjected to higher whole heart radiation doses.

Methods

CAC progression (pre- and >2 years post-TIR) from chest CT scans of lung cancer patients were evaluated. A 2:1 matched control population was established controlling for age, gender, race, and CT scan interval. Vessel-specific CAC presence, progression, and extension in pre- and post-interval CT studies was evaluated by two blinded reviewers using the ordinal method. Dosimetric treatment files were restored and contours of the whole heart and proximal left anterior descending artery (LAD) were created within existing plans to compute radiation doses (Pinnacle Treatment Planning Software). Binary logistic regression analysis identified factors predictive for CAC development. Multiple logistic regression analysis with hierarchal method was used to assess covariates.

Results

Thirty-five patients and 65 controls (50% female) were evaluated; mean age 57 years, mean follow-up post-radiation 4.9±2.2 years. Average mean and maximum left anterior descending coronary artery (LAD) radiation doses were 19.9 Gy (95% CI, 14.1–25.7) and 30.7 Gy (95% CI, 23.8–37.5), respectively; 91.6% inter-observer variability. There was greater incidence of coronary calcification in irradiated patients (48.6% vs. 24.6%; P=0.01). In interval CT scans, a greater proportion of radiated patients demonstrated new coronary calcification (P=0.007) and extension within the LAD (P=0.003). Radiation exposure was the only independent predictor of new calcification (OR 3.1; 95% CI: 1.09–9.2).

Conclusions

We identified both an increase in the development and progression of CAC in lung cancer patients receiving TIR. Future studies utilizing alternative cancer populations and larger sample sizes are necessary to further correlate radiographic and dosimetric observations to cardiovascular events.

A Case of Vanishing Thymoma

Cystic thymoma is a rare clinicopathologic entity. Chronic inflammation within and around these tumors has been suggested to compromise the vascular supply, leading to hemorrhage into the lesion and necrosis. This can result in rapid expansion of the tumor and symptoms owing to local compression. We present the case of a patient with a biopsy-proven lymphocytic-predominant thymoma who underwent resection to reveal a hemorrhagic, necrotic mediastinal cyst adjacent to a focus of organizing pneumonia, with no residual thymoma.

Quantitative FDG PET/CT may help risk-stratify early-stage non-small cell lung cancer patients at risk for recurrence following anatomic resection

BACKGROUND

Preoperative identification of non-small cell lung cancer (NSCLC) patients at risk for disease recurrence has proven unreliable. The extraction of quantitative metrics from imaging based on tumor intensity and texture may enhanced disease characterization. This study evaluated tumor-specific 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computerized tomography (PET/CT) uptake patterns and their association with disease recurrence in early-stage NSCLC.

METHODS

Sixty-four stage I/II NSCLC patients who underwent anatomic resection between 2001 and 2014 were examined. Pathologically or radiographic confirmed disease recurrence within 5 years of resection comprised the study group. Quantitative imaging metrics were extracted within the primary tumor volume. Squamous cell carcinoma (SCC) (N=27) and adenocarcinoma (AC) (N=41) patients were compared using a Wilcoxon signed-rank test. Associations between imaging and clinical variables with 5-year disease-free survival (DFS) and overall survival (OS) were evaluated by Cox proportional-hazards regression.

RESULTS

Clinical and pathologic characteristics were similar between recurrence (N=34) and patients achieving 5-year DFS (N=30). Standardized uptake value (SUV)max and SUVmean varied significantly by histology, with SCC demonstrating higher uptake intensity and heterogeneity patterns. Entropy-grey-level co-occurrence matrix (GLCM) was a significant univariate predictor of DFS (HR =0.72, P=0.04) and OS (HR =0.65, P=0.007) independent of histology. Texture features showed higher predictive ability for DFS in SCC than AC. Pathologic node status and staging classification were the strongest clinical predictors of DFS, independent of histology.

CONCLUSIONS

Several imaging metrics correlate with increased risk for disease recurrence in early-stage NSCLC. The predictive ability of imaging was strongest when patients are stratified by histology. The incorporation of 18F-FDG PET/CT texture features with preoperative risk factors and tumor characteristics may improve identification of high-risk patients.