Tolerability and Feasibility of the Upper Esophageal Sphincter Assist Device in Preventing Acute and Chronic Allograft Rejection Among Lung Transplant Recipients.

GOALS: We aimed to evaluate a novel upper esophageal sphincter (UES) assist device loaner program for the prevention of acute cellular rejection and chronic lung allograft dysfunction among lung transplant (LTx) recipients. BACKGROUND: Laryngopharyngeal reflux can lead to chronic microaspiration and LTx rejection. The UES assist device applies external pressure at the level of UES to decrease reflux. STUDY: We prospectively enrolled and issued UES assist devices to consecutive transplant patients referred for gastrointestinal motility testing from 2016 to 2020. Device tolerability was defined by successful utilization as a bridge to ambulatory pH monitoring and/or antireflux procedure, or as permanent therapy. Incidence of rejection was analyzed before, during, and after device implementation. RESULTS: Twenty-six participants were issued devices (15 pathologic, 5 physiological, 6 unknown reflux status), none of whom developed acute rejection episodes or chronic lung allograft dysfunction while using the device. Thirteen adopted the device promptly after transplantation (mean 1.7 mo) and remained free of rejection episodes over a mean 24.7 months of follow-up. Among those with pathologic reflux, lag time to device adoption strongly correlated with the development of rejection ( r =0.8, P =0.0006). There was no such correlation among those with physiological reflux. Five developed acute rejection after device return. CONCLUSIONS: The device was tolerated by a majority of LTx patients and appears feasible as a barrier measure in the prevention of rejection. Delayed treatment of laryngopharyngeal reflux may lead to early allograft failure; therefore, the UES assist device should be given important consideration in transplant protection.

NCCN Guidelines® Insights: Lung Cancer Screening, Version 1.2022.

The NCCN Guidelines for Lung Cancer Screening recommend criteria for selecting individuals for screening and provide recommendations for evaluation and follow-up of lung nodules found during initial and subsequent screening. These NCCN Guidelines Insights focus on recent updates to the NCCN Guidelines for Lung Cancer Screening.

The cell of origin and subtype of K-Ras-induced lung tumors are modified by Notch and Sox2.

Cell type-specific conditional activation of oncogenic K-Ras is a powerful tool for investigating the cell of origin of adenocarcinomas in the mouse lung. Our previous studies showed that K-Ras activation with a CC10(Scgb1a1)-CreER driver leads to adenocarcinoma in a subset of alveolar type II cells and hyperplasia in the bronchioalveolar duct region. However, no tumors develop in the bronchioles, although recombination occurs throughout this region. To explore underlying mechanisms, we simultaneously modulated either Notch signaling or Sox2 levels in the CC10+ cells along with activation of K-Ras. Inhibition of Notch strongly inhibits adenocarcinoma formation but promotes squamous hyperplasia in the alveoli. In contrast, activation of Notch leads to widespread Sox2+, Sox9+, and CC10+ papillary adenocarcinomas throughout the bronchioles. Chromatin immunoprecipitation demonstrates Sox2 binding to NOTCH1 and NOTCH2 regulatory regions. In transgenic mouse models, overexpression of Sox2 leads to a significant reduction of Notch1 and Notch2 transcripts, while a 50% reduction in Sox2 leads to widespread papillary adenocarcinoma in the bronchioles. Taken together, our data demonstrate that the cell of origin of K-Ras-induced tumors in the lung depends on levels of Sox2 expression affecting Notch signaling. In addition, the subtype of tumors arising from type II cells is determined in part by Notch activation or suppression.

Readmission After Lobectomy for Lung Cancer: Not All Complications Contribute Equally.

OBJECTIVE: The aim of this study was to identify independent predictors of hospital readmission for patients undergoing lobectomy for lung cancer. SUMMARY BACKGROUND DATA: Hospital readmission after lobectomy is associated with increased mortality. Greater than 80% of the variability associated with readmission after surgery is at the patient level. This underscores the importance of using a data source that includes detailed clinical information. METHODS: Using the Society of Thoracic Surgeons (STS) General Thoracic Surgery Database (GTSD), we conducted a retrospective cohort study of patients undergoing elective lobectomy for lung cancer. Three separate multivariable logistic regression models were generated: the first included preoperative variables, the second added intraoperative variables, and the third added postoperative variables. The c statistic was calculated for each model. RESULTS: There were 39,734 patients from 277 centers. The 30-day readmission rate was 8.2% (n = 3237). In the final model, postoperative complications had the greatest effect on readmission. Pulmonary embolus {odds ratio [OR] 12.34 [95% confidence interval (CI),7.94-19.18]} and empyema, [OR 11.66 (95% CI, 7.31-18.63)] were associated with the greatest odds of readmission, followed by pleural effusion [OR 7.52 (95% CI, 6.01-9.41)], pneumothorax [OR 5.08 (95% CI, 4.16-6.20)], central neurologic event [OR 3.67 (95% CI, 2.23-6.04)], pneumonia [OR 3.13 (95% CI, 2.43-4.05)], and myocardial infarction [OR 3.16 (95% CI, 1.71-5.82)]. The c statistic for the final model was 0.736. CONCLUSIONS: Complications are the main driver of readmission after lobectomy for lung cancer. The highest risk was related to postoperative events requiring a procedure or medical therapy necessitating inpatient care.

It's not always too late: a case for minimally invasive salvage esophagectomy.

INTRODUCTION: Standard of care for locally advanced esophageal carcinoma is neoadjuvant chemoradiation (nCRT) and surgical resection 4-8 weeks after completion of nCRT. It is recommended that the CRT to surgery interval not exceed 90 days. Many patients do not undergo surgery within this timeframe due to patient/physician preference, complete clinical response, or poor performance status. Select patients are offered salvage esophagectomy (SE), defined in two ways: resection for recurrent/persistent disease after complete response to definitive CRT (dCRT) or esophagectomy performed > 90 days after completion of nCRT. Salvage esophagectomy reportedly has higher postoperative morbidity and poor survival outcomes. In this study, we assessed outcomes, overall, and disease-free survival of patients undergoing salvage esophagectomy by both definitions (recurrent/persistent disease after dCRT and/or > 90 days), compared to planned (resection after nCRT/within 90 days) esophagectomy (PE). MATERIALS AND METHODS: Retrospective review of a prospectively maintained database identified patients who underwent minimally invasive esophagectomy at a single institution from 2009 to 2019. Esophagectomy for benign disease and patients who did not receive nCRT were excluded. Outcomes included postoperative complications, length of stay (LOS), disease-free survival, and overall survival. RESULTS: 97 patients underwent minimally invasive esophageal resection for esophageal carcinoma. 89.7% of patients were male. Mean age was 64.9 years (range 36-85 years). 94.8% of patients had adenocarcinoma, with 16 transthoracic and 81 transhiatal approaches. On comparing planned esophagectomy (n = 87) to esophagectomy after dCRT failure (n = 10), no significant differences were identified in overall survival (p = 0.73), disease-free survival (p = 0.32), 30-day or major complication rate, anastomotic leak, or LOS. Similarly, when comparing esophagectomy < 90 days after CRT (n = 62) to > 90 days after CRT completion (n = 35), no significant differences were identified in overall survival (p = 0.39), disease-free survival (p = 0.71), 30-day or major complication rate, LOS, or anastomotic leak rate between groups. In this comparison, local recurrence was noted to be elevated with SE as compared to PE (64.3% vs. 25.0%, p = 0.04). CONCLUSION: Overall survival and disease-free survival were equivalent between SE and PE. Local recurrence was noted to be increased with SE, though this did not appear to affect survival. Although planned esophagectomy remains the standard of care, salvage esophagectomy has comparable outcomes and is appropriate for selected patients.

Sox2 expression in Schwann cells inhibits myelination in vivo and induces influx of macrophages to the nerve.

Correct myelination is crucial for the function of the peripheral nervous system. Both positive and negative regulators within the axon and Schwann cell function to ensure the correct onset and progression of myelination during both development and following peripheral nerve injury and repair. The Sox2 transcription factor is well known for its roles in the development and maintenance of progenitor and stem cell populations, but has also been proposed in vitro as a negative regulator of myelination in Schwann cells. We wished to test fully whether Sox2 regulates myelination in vivo and show here that, in mice, sustained Sox2 expression in vivo blocks myelination in the peripheral nerves and maintains Schwann cells in a proliferative non-differentiated state, which is also associated with increased inflammation within the nerve. The plasticity of Schwann cells allows them to re-myelinate regenerated axons following injury and we show that re-myelination is also blocked by Sox2 expression in Schwann cells. These findings identify Sox2 as a physiological regulator of Schwann cell myelination in vivo and its potential to play a role in disorders of myelination in the peripheral nervous system.

Polymorphisms of the centrosomal gene (FGFR1OP) and lung cancer risk: a meta-analysis of 14,463 cases and 44,188 controls.

Centrosome abnormalities are often observed in premalignant lesions and in situ tumors and have been associated with aneuploidy and tumor development. We investigated the associations of 9354 single-nucleotide polymorphisms (SNPs) in 106 centrosomal genes with lung cancer risk by first using the summary data from six published genome-wide association studies (GWASs) of the Transdisciplinary Research in Cancer of the Lung (TRICL) (12,160 cases and 16 838 controls) and then conducted in silico replication in two additional independent lung cancer GWASs of Harvard University (984 cases and 970 controls) and deCODE (1319 cases and 26,380 controls). A total of 44 significant SNPs with false discovery rate (FDR) ≤ 0.05 were mapped to one novel gene FGFR1OP and two previously reported genes (TUBB and BRCA2). After combined the results from TRICL with those from Harvard and deCODE, the most significant association (P combined = 8.032 × 10(-6)) was with rs151606 within FGFR1OP. The rs151606 T>G was associated with an increased risk of lung cancer [odds ratio (OR) = 1.10, 95% confidence interval (95% CI) = 1.05-1.14]. Another significant tagSNP rs12212247 T>C (P combined = 9.589 × 10(-6)) was associated with a decreased risk of lung cancer (OR = 0.93, 95% CI = 0.90-0.96). Further in silico functional analyzes revealed that rs151606 might affect transcriptional regulation and result in decreased FGFR1OP expression (P trend = 0.022). The findings shed some new light on the role of centrosome abnormalities in the susceptibility to lung carcinogenesis.

Impact of pretreatment imaging on survival of esophagectomy after induction therapy for esophageal cancer: who should be given the benefit of the doubt?: esophagectomy outcomes of patients with suspicious metastatic lesions.

PURPOSE: We examined survival of patients who underwent esophagectomy for locally advanced esophageal cancer with foci that were suspicious for metastatic disease on initial imaging but whose disease did not progress after induction chemoradiation treatment (CRT). METHODS: The impact of pre- and posttherapy staging characteristics on survival of patients who underwent esophagectomy after CRT between 2003 and 2009 was evaluated using multivariable logistic regression. Survival of patients with and without possible metastatic disease on initial imaging was compared with the log-rank test. RESULTS: During the study period, 71 (32%) of 220 patients who underwent CRT followed by esophagectomy had possible distant metastatic disease on initial imaging. Patients with initial suspicion of metastases had a 5-year survival of 24.8%. Overall survival of patients with and without possible metastatic disease on initial imaging was not significantly different (p = 0.4), but pretreatment positron emission tomography (PET) suggesting a liver lesion (hazard ratio [HR] 3.2, p = 0.003) predicted worse survival. Additional predictors of worse survival were clinical T4 status (HR 3.1, p = 0.001), post-CRT pathologic nodal status (HR 1.6, p = 0.04), and pathologically confirmed metastatic disease at or before resection (HR 3.1, p = 0.01). None of 10 patients with pathologic metastatic disease at resection lived longer than 2.5 years. CONCLUSIONS: Patients with possible liver metastases on pretreatment PET and patients with confirmed metastatic disease at the time of surgery do not benefit from resection. However, patients with pretreatment imaging that shows possible metastatic disease in sites other than the liver still have reasonable long-term survival after resection.

Evidence for type II cells as cells of origin of K-Ras-induced distal lung adenocarcinoma.

Identifying the cells of origin of lung cancer may lead to new therapeutic strategies. Previous work has focused upon the putative bronchoalveolar stem cell at the bronchioalveolar duct junction as a cancer cell of origin when a codon 12 K-Ras mutant is induced via adenoviral Cre inhalation. In the present study, we use two "knock-in" Cre-estrogen receptor alleles to inducibly express K-RasG12D in CC10(+) epithelial cells and Sftpc(+) type II alveolar cells of the adult mouse lung. Analysis of these mice identifies type II cells, Clara cells in the terminal bronchioles, and putative bronchoalveolar stem cells as cells of origin for K-Ras-induced lung hyperplasia. However, only type II cells appear to progress to adenocarcinoma.

The contemporary role of minimally invasive esophagectomy in esophageal cancer.

Open surgical resection via transhiatal or transthoracic, including McKeown, access is the most viable option for curing esophageal cancer; however, the extensive nature of open surgery in both the chest and abdomen results in significant rates of morbidity and mortality. A natural response was the introduction of minimally invasive esophagectomy (MIE) and, later, endoscopic resection. In the hands of experienced surgeons, MIE can achieve equivalent or better perioperative mortality, morbidity, and oncologic outcomes as compared to open surgery. This review starts with an overview of open esophagectomy before delving into the evolving body of evidence on MIE outcomes and practices.

Integrin αvß3 Upregulation in Response to Nutrient Stress Promotes Lung Cancer Cell Metabolic Plasticity.

Cancer stem/tumor-initiating cells display stress tolerance and metabolic flexibility to survive in a harsh environment with limited nutrient and oxygen availability. The molecular mechanisms underlying this phenomenon could provide targets to prevent metabolic adaptation and halt cancer progression. Here, we showed in cultured cells and live human surgical biopsies of non-small cell lung cancer that nutrient stress drives the expression of the epithelial cancer stem cell marker integrin αvß3 via upregulation of the ß3 subunit, resulting in a metabolic reprogramming cascade that allows tumor cells to thrive despite a nutrient-limiting environment. Although nutrient deprivation is known to promote acute, yet transient, activation of the stress sensor AMP-activated protein kinase (AMPK), stress-induced αvß3 expression via Src activation unexpectedly led to secondary and sustained AMPK activation. This resulted in the nuclear localization of peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC1α) and upregulation of glutamine metabolism, the tricarboxylic acid cycle, and oxidative phosphorylation. Pharmacological or genetic targeting of this axis prevented lung cancer cells from evading the effects of nutrient stress, thereby blocking tumor initiation in mice following orthotopic implantation of lung cancer cells. These findings reveal a molecular pathway driven by nutrient stress that results in cancer stem cell reprogramming to promote metabolic flexibility and tumor initiation. SIGNIFICANCE: Upregulation of integrin αvß3, a cancer stem cell marker, in response to nutrient stress activates sustained AMPK/PGC1α signaling that induces metabolic reprogramming in lung cancer cells to support their survival. See related commentary by Rainero, p. 1543.

A Multidisciplinary Minimally Invasive Approach Is Necessary for the Contemporary Management of Esophageal Diverticula.

Background: Esophageal diverticula were traditionally treated with open surgery, which is associated with significant morbidity and mortality rates. Management has shifted to minimally invasive approaches with several advantages. We examine outcomes in patients with esophageal diverticula treated with minimally invasive techniques by a multidisciplinary surgical team at a single center. Materials and Methods: A retrospective review of a prospectively maintained database was performed for patients who underwent minimally invasive surgery for esophageal diverticula at our institution from June 2010 to December 2022. Primary outcomes were 30-day morbidity and mortality rates. Secondary outcomes were symptom resolution, length of stay (LOS), readmission, and need for reintervention. Results: A total of 28 patients were identified. Twelve patients had pharyngeal diverticula, 7 patients had midesophageal diverticula, and 9 patients had epiphrenic diverticula. Thirty-day morbidity and readmission rates were 10.7% (3 patients), 1 pharyngeal (sepsis), 1 midesophageal (refractory nausea), and 1 epiphrenic (poor oral intake). There were no esophageal leaks. Average LOS was 2.3 days, with the pharyngeal group experiencing a significantly shorter LOS (1.3 days versus 3.4 days for midesophageal, P < .01 versus 2.8 days for epiphrenic, P < .05). Symptom resolution after initial operation was 78.6%. Reintervention rate was 17.9%, and symptom resolution after reintervention was 100%. There were no mortalities. Conclusion: This study demonstrates that esophageal diverticula can be repaired safely and efficiently when performed by a multidisciplinary team utilizing advanced minimally invasive endoscopic and robotic surgical techniques. We advocate for the management of this rare condition at a high-volume center with extensive experience in foregut surgery.

A randomized phase II study of immunization with dendritic cells modified with poxvectors encoding CEA and MUC1 compared with the same poxvectors plus GM-CSF for resected metastatic colorectal cancer.

OBJECTIVE: To determine whether 1 of 2 vaccines based on dendritic cells (DCs) and poxvectors encoding CEA (carcinoembryonic antigen) and MUC1 (PANVAC) would lengthen survival in patients with resected metastases of colorectal cancer (CRC). BACKGROUND: Recurrences after complete resections of metastatic CRC remain frequent. Immune responses to CRC are associated with fewer recurrences, suggesting a role for cancer vaccines as adjuvant therapy. Both DCs and poxvectors are potent stimulators of immune responses against cancer antigens. METHODS: Patients, disease-free after CRC metastasectomy and perioperative chemotherapy (n = 74), were randomized to injections of autologous DCs modified with PANVAC (DC/PANVAC) or PANVAC with per injection GM-CSF (granulocyte-macrophage colony-stimulating factor). Endpoints were recurrence-free survival overall survival, and rate of CEA-specific immune responses. Clinical outcome was compared with that of an unvaccinated, contemporary group of patients who had undergone CRC metastasectomy, received similar perioperative therapy, and would have otherwise been eligible for the study. RESULTS: Recurrence-free survival at 2 years was similar (47% and 55% for DC/PANVAC and PANVAC/GM-CSF, respectively) (χ P = 0.48). At a median follow-up of 35.7 months, there were 2 of 37 deaths in the DC/PANVAC arm and 5 of 37 deaths in the PANVAC/GM-CSF arm. The rate and magnitude of T-cell responses against CEA was statistically similar between study arms. As a group, vaccinated patients had superior survival compared with the contemporary unvaccinated group. CONCLUSIONS: Both DC and poxvector vaccines have similar activity. Survival was longer for vaccinated patients than for a contemporary unvaccinated group, suggesting that a randomized trial of poxvector vaccinations compared with standard follow-up after metastasectomy is warranted. (NCT00103142).

Cell of origin of lung cancer.

Lung cancer is the leading cause of cancer deaths worldwide, and current therapies are disappointing. Elucidation of the cell(s) of origin of lung cancer may lead to new therapeutics. In addition, the discovery of putative cancer-initiating cells with stem cell properties in solid tumors has emerged as an important area of cancer research that may explain the resistance of these tumors to currently available therapeutics. Progress in our understanding of normal tissue stem cells, tumor cell of origin, and cancer stem cells has been hampered by the heterogeneity of the disease, the lack of good in vivo transplantation models to assess stem cell behavior, and an overall incomplete understanding of the epithelial stem cell hierarchy. As such, a systematic computerized literature search of the MEDLINE database was used to identify articles discussing current knowledge about normal lung and lung cancer stem cells or progenitor cells. In this review, we discuss what is currently known about the role of cancer-initiating cells and normal stem cells in the development of lung tumors.

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.

Racial and ethnic variation in referral times for thoracic oncologic surgery in a major metropolitan area.

OBJECTIVE: The study objective was to understand the impact of race/ethnicity on access to thoracic surgical care for patients undergoing lung resection for cancer. METHODS: We performed a retrospective analysis on 206 consecutive patients who underwent lung resection for cancer (120 female, 86 male; median age 66 years), with respect to how race and ethnicity impact time to referral for thoracic surgery to a major healthcare center. Time between initial radiographic appearance of a lung nodule/mass 1 cm or greater to surgical referral and time from surgical referral to operation were evaluated for 121 White, 30 Asian, 26 Hispanic, 12 African American, and 17 mixed or other race patients. The impact of age, sex, median income of patient's household, national and state Area Deprivation Indices, insurance type, and distance between the patient's domicile and our hospital was evaluated. The influence of the referring physician's practice (hospital-based, hospital-affiliated, or private), internal or external referral, race/ethnicity, and level of specialization was also studied. RESULTS: African American, Asian, Hispanic, and mixed/other race patients had significantly longer wait times between initial radiographic finding of a lung nodule/mass 1 cm or greater and surgical referral compared with White individuals (median days: African American, 78; Asian, 95; Hispanic, 92; mixed or other, 65; White, 35). Multiple linear regression analysis demonstrated that race/ethnicity was the only significant predictor of prolonged time to surgical referral when adjusted for age, sex, median household income level, national and state Area Deprivation Indices, insurance type, and distance between patient's home and our hospital. The referring physician's type of practice and internal versus external referral were not significant. However, the physician's race/ethnicity and level of specialization had an impact on referral times, with nonspecialists referring patients sooner to thoracic surgery compared with specialists who ordered more workup tests. For all patient races/ethnicities, there was no difference in time between surgical referral and day of operation. CONCLUSIONS: Race and ethnicity have a major impact on the time from initial radiographic appearance of a lung nodule/mass 1 cm or greater to referral for surgical resection for cancer. This study suggests the need to develop strategies to reduce minority wait times and improve timely access to surgery for patients with thoracic malignancies. VIDEO ABSTRACT: Discussion of how race and ethnicity impact referral time to thoracic surgery discussed by Dr Moises Hernandez.

Activation of KrasG12D in Subset of Alveolar Type II Cells Enhances Cellular Plasticity in Lung Adenocarcinoma.

We have previously identified alveolar type II cell as the cell-of-origin of KrasG12D-induced lung adenocarcinoma using cell lineage-specific inducible Cre mouse models. Using gain-of-function and loss-of-function genetic models, we discovered that active Notch signaling and low Sox2 levels dictate the ability of type II cells to proliferate and progress into lung adenocarcinoma upon KrasG12D activation. Here, we examine the phenotype of type II cells after Kras activation and find evidence for proliferation of cells that coexpress type I and type II markers. Three-dimensional organoid culture and transplantation studies determine that these dual-positive cells are highly plastic and tumor initiating in vivo. RNA sequencing analysis reveals that these dual-positive cells are enriched in Ras/MAPK, EGFR, and Notch pathways. Furthermore, the proliferation of these cells requires active Notch signaling and is inhibited by genetic/chemical Sox2 upregulation. Our findings could provide new therapeutic strategies to target KRAS-activated lung adenocarcinomas. SIGNIFICANCE: Identification of progenitor like tumor-initiating cells in KRAS-mutant lung adenocarcinoma may allow development of novel targeted therapeutics.

Thoracoscopic lobectomy has increasing benefit in patients with poor pulmonary function: a Society of Thoracic Surgeons Database analysis.

OBJECTIVE: Using a national database, we asked whether video-assisted thoracoscopic surgery (VATS) lobectomy is beneficial in high-risk pulmonary patients. BACKGROUND: Single-institution series demonstrated benefit of VATS lobectomy over lobectomy via thoracotomy in poor pulmonary function patients [FEV1 (forced expiratory volume in 1 second) or DLCO (diffusion capacity of the lung to carbon monoxide) <60% predicted]. METHODS: The STS General Thoracic Database was queried for patients having undergone lobectomy by either thoracotomy or VATS between 2000 and 2010. Postoperative pulmonary complications included those defined by the STS database. RESULTS: In the STS database, 12,970 patients underwent lobectomy (thoracotomy, n = 8439; VATS, n = 4531) and met inclusion criteria. The overall rate of pulmonary complications was 21.7% (1832/8439) and 17.8% (806/4531) in patients undergoing lobectomy with thoracotomy and VATS, respectively (P < 0.0001). In a multivariable model of pulmonary complications, thoracotomy approach (OR = 1.25, P < 0.001), decreasing FEV1% predicted (OR = 1.01 per unit, P < 0.001) and DLCO% predicted (OR = 1.01 per unit, P < 0.001), and increasing age (1.02 per year, P < 0.001) independently predicted pulmonary complications. When examining pulmonary complications in patients with FEV1 less than 60% predicted, thoracotomy patients have markedly increased pulmonary complications when compared with VATS patients (P = 0.023). No significant difference is noted with FEV1 more than 60% predicted. CONCLUSIONS: Poor pulmonary function predicts respiratory complications regardless of approach. Respiratory complications increase at a significantly greater rate in lobectomy patients with poor pulmonary function after thoracotomy compared with VATS. Planned surgical approach should be considered while determining whether a high-risk patient is an appropriate resection candidate.

Basal cells as stem cells of the mouse trachea and human airway epithelium.

The pseudostratified epithelium of the mouse trachea and human airways contains a population of basal cells expressing Trp-63 (p63) and cytokeratins 5 (Krt5) and Krt14. Using a KRT5-CreER(T2) transgenic mouse line for lineage tracing, we show that basal cells generate differentiated cells during postnatal growth and in the adult during both steady state and epithelial repair. We have fractionated mouse basal cells by FACS and identified 627 genes preferentially expressed in a basal subpopulation vs. non-BCs. Analysis reveals potential mechanisms regulating basal cells and allows comparison with other epithelial stem cells. To study basal cell behaviors, we describe a simple in vitro clonal sphere-forming assay in which mouse basal cells self-renew and generate luminal cells, including differentiated ciliated cells, in the absence of stroma. The transcriptional profile identified 2 cell-surface markers, ITGA6 and NGFR, which can be used in combination to purify human lung basal cells by FACS. Like those from the mouse trachea, human airway basal cells both self-renew and generate luminal daughters in the sphere-forming assay.