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.

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.

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.

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.

The Role of Chemotherapy Plus Immune Checkpoint Inhibitors in Oncogenic-Driven NSCLC: A University of California Lung Cancer Consortium Retrospective Study

Introduction

There is a paucity of data on immune checkpoint inhibitors (ICIs) plus doublet chemotherapy (C) in patients with advanced lung cancer whose tumor harbors an actionable mutation. We sought to provide insight into the role of this combination in relation to chemotherapy alone in this patient population.

Methods

We conducted a retrospective study at the five University of California National Cancer Institute-designated Comprehensive Cancer Centers. The primary end point was progression-free survival (PFS). Secondary end points included overall survival (OS) and significant adverse events. Adverse events in patients who received a tyrosine kinase inhibitor (TKI) post-ICI were also captured.

Results

A total of 246 patients were identified, 170 treated with C plus ICI and 76 treated with C alone. Driver alterations included EGFR (54.9%), KRAS (32.9%), ALK (5.3%), HER2/ERBB2 (2.9%), ROS1 (1.2%), MET (1.2%), RET (0.8%), and BRAF non-V600 (0.8%). The overall PFS and OS hazard ratios were not significant at 1.12 (95% confidence interval 0.83-1.51; p = 0.472) and 0.86 (95% confidence interval: 0.60-1.24, p = 0.429), respectively. No significant differences in PFS or OS were observed in the mutational subgroups. Grade 3 or greater adverse events were lower in the C plus ICI group. The multivariate analysis for PFS and OS revealed a performance status (Eastern Cooperative Oncology Group) score of 2, and previous TKI treatment was associated with poorer outcomes with C plus ICI.

Conclusions

Our study suggests that patients with oncogenic-driven NSCLC, primarily those with EGFR-driven tumors, treated with a TKI should not subsequently receive C plus ICI. Analysis from prospective clinical trials will provide additional information on the role of ICIs in this group of patients.

Single-cell chromatin profiling of the primitive gut tube reveals regulatory dynamics underlying lineage fate decisions

Development of the gastrointestinal system occurs after gut tube closure, guided by spatial and temporal control of gene expression. However, it remains unclear what forces regulate these spatiotemporal gene expression patterns. Here we perform single-cell chromatin profiling of the primitive gut tube to reveal organ-specific chromatin patterns that reflect the anatomical patterns of distinct organs. We generate a comprehensive map of epigenomic changes throughout gut development, demonstrating that dynamic chromatin accessibility patterns associate with lineage-specific transcription factor binding events to regulate organ-specific gene expression. Additionally, we show that loss of Sox2 and Cdx2, foregut and hindgut lineage-specific transcription factors, respectively, leads to fate shifts in epigenomic patterns, linking transcription factor binding, chromatin accessibility, and lineage fate decisions in gut development. Notably, abnormal expression of Sox2 in the pancreas and intestine impairs lineage fate decisions in both development and adult homeostasis. Together, our findings define the chromatin and transcriptional mechanisms of organ identity and lineage plasticity in development and adult homeostasis.

The primitive gut tube gives rise to all major internal organs, while underlying regulatory mechanisms are unclear. Here, the authors analyze its chromatin landscape at the single-cell level and define the epigenetic regulation of lineage fate decisions and plasticity in organ development and homeostasis.

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.

Risk of Acute Lung Injury after Esophagectomy

To develop a new approach for identifying acute lung injury (ALI) in surgical ward setting and to assess incidence rate, clinical outcomes, and risk factors for ALI cases after esophagectomy. We also compare the degree of lung injury between operative and non-operative sides. Consecutive esophageal cancer patients (n=1022) who underwent esophagectomy from Dec 2012 to Nov 2018 in our hospital were studied. An approach for identifying ALI was proposed that integrated radiographic assessment of lung edema (RALE) score to quantify degree of lung edema. Stepwise logistic regression identified risk factors for postoperative ALI incidence. The degree of bilateral lung injury was compared using the RALE score. The approach for identifying ALI in surgical ward setting was defined as acute onset, PaO₂/FiO₂≤300 mmHg, bilateral opacities on bedside chest radiograph with a RALE score≥16, and exclusion of cardiogenic pulmonary edema. Incidence rate of ALI was estimated to be 9.7%. ALI diagnosis was associated with multiple clinical complications, prolonged hospital stay, higher medical bills, and higher perioperative mortality. Nine risk factors including BMI, ASA class, DLCO%, duration of surgery, neutrophil percentage, high-density lipoprotein, and electrolyte disorders were identified. The RALE score of the lung lobes of the operative side was higher than the non-operative side. A new approach for identifying ALI in esophageal cancer patients receiving esophagectomy was proposed and several risk factors were identified. ALI is common and has severe outcomes. The lung lobes on the operative side are more likely to be affected than the non-operative side.

Minimally invasive thymectomy for myasthenia gravis favours left-sided approach and low severity class

OBJECTIVES

Complete thymectomy is a key component of the optimal treatment for myasthenia gravis. Unilateral, minimally invasive approaches are increasingly utilized with debate about the optimal laterality approach. A right-sided approach has a wider field of view, while a left-sided approach accesses potentially more thymic tissue. We aimed to assess the impact of laterality on perioperative and medium-term outcomes, and to identify predictors of a 'good outcome' using standard definitions.

METHODS

We performed a multicentre review of 123 patients who underwent a minimally invasive thymectomy for myasthenia gravis between January 2000 and August 2015, with at least 1-year follow-up. The Myasthenia Gravis Foundation of America standards were followed. A 'good outcome' was defined by complete stable remission/pharmacological remission/minimal manifestations 0, and a 'poor outcome' by minimal manifestations 1-3. Univariate and multivariable logistic regression analyses were performed to assess factors associated with a 'good outcome'.

RESULTS

Ninety-two percent of thymectomies (113/123) were robotic-assisted. The left-sided approach had a shorter median operating time than a right-sided: 143 (interquartile range, IQR 110-196) vs 184 (IQR 133-228) min, P = 0.012. At a median of 44 (IQR 27-75) months, the left-sided approach achieved a 'good outcome' (46%, 31/68) more frequently than the right-sided (22%, 12/55); P = 0.011. Multivariable analysis identified a left-sided approach and Myasthenia Gravis Foundation of America class I/II to be associated with a 'good outcome'.

CONCLUSIONS

A left-sided thymectomy may be preferred over a right-sided approach in patients with myasthenia gravis given the shorter operating times and potential for superior medium-term symptomatic outcomes. A lower severity class is also associated with a 'good outcome'.

Initial and Longitudinal Cost of Surgical Resection for Lung Cancer

BACKGROUND

The longitudinal cost of treating patients with non-small cell lung cancer (NSCLC) undergoing surgical resection has not been evaluated. We describe initial and 4-year resource use and cost for NSCLC patients aged 65 years of age or greater who were treated surgically between 2008 and 2013.

METHODS

Using clinical data for NSCLC resections from The Society of Thoracic Surgeons General Thoracic Surgery Database linked to Medicare claims, resource use and cost of preoperative staging, surgery, and subsequent care through 4 years were examined ($2017). Cost of hospital-based care was estimated using cost-to-charge ratios; professional services and care in other settings were valued using reimbursements. Inverse probability weighting was used to account for administrative censoring. Outcomes were stratified by pathologic stage and by surgical approach for stage I lobectomy patients.

RESULTS

Resection hospitalizations averaged 6 days and cost $31,900. In the first 90 days, costs increased with stage ($12,430 for stage I to $26,350 for stage IV). Costs then declined toward quarterly means more similar among stages. Cumulative costs ranged from $131,032 (stage I) to $205,368 (stage IV). In the stage I lobectomy cohort, patients selected for minimally invasive procedures had lower 4-year costs than did thoracotomy patients ($120,346 versus $136,250).

CONCLUSIONS

The 4-year cost of surgical resection for NSCLC was substantial and increased with pathologic stage. Among stage I lobectomy patients, those selected for minimally invasive surgery had lower costs, particularly through 90 days. Potential avenues for improving the value of surgical resection include judicious use of postoperative intensive care and earlier detection and treatment of disease.

Prior tonsillectomy is associated with an increased risk of esophageal adenocarcinoma

BACKGROUND

Esophageal cancer is a deadly cancer with 5-year survival <20%. Although multiple risk factors for esophageal adenocarcinoma (EAC) including obesity, GERD and smoking have been identified, these risk factors do not fully explain the rising incidence of EAC. In this study, we evaluated the association between prior history of tonsillectomy and EAC. Our goal was to determine whether tonsillectomies were more frequent in patients with EAC (cases) than in our thoracic surgery controls.

METHODS

Cases included 452 esophagectomy cases, including 396 with EAC and 56 who underwent esophagectomy for Barrett's esophagus (BE) with high grade dysplasia (HGD). 1,102 thoracic surgery patients with surgical indications other than dysplastic BE or esophageal cancer represented the controls for our analysis. The association of tonsillectomy and HGD/EAC were primarily evaluated by using univariate tests and then verified by logistic regression analysis. Baseline demographics, medical history, and thoracic surgery controls were compared by using χ2 tests or 95% CIs. Significant risk factors were considered as covariates in the multivariate models while evaluating the association between tonsillectomy and HGD/EAC. P-values or odds ratios were estimated with 95% confidence limits to identify significances which was more appropriate.

RESULTS

Tonsillectomy was more common in cases than controls and was found to have a significant association with esophageal cancer (19.9% vs. 12.7%; p-value = 0.0003). This significant association persisted after controlling for other known risk factors/covariates.

CONCLUSION

A prior history of tonsillectomy was significantly associated with HGD/EAC and may represent an independent risk factor for the development of EAC. However, the underlying biology driving this association remains unclear.

A 37-Year-Old Man With Pleuritic Chest Pain

CASE PRESENTATION

A 37-year-old man with poorly controlled type 2 diabetes presented with severe right-sided pleuritic chest pain, respiratory splinting, and cough. Two weeks earlier, he had been evaluated at an urgent care for cough and was prescribed a 5-day course of azithromycin for bronchitis. He then presented to our ED reporting mild, right-sided pleuritic chest pain. Vital signs were normal, and his chest radiograph showed a trace right pleural effusion (Fig 1A). He was discharged with naproxen for pleurisy. Three days later, he returned, reporting a dramatic increase in the severity of his pleuritic chest pain and a cough that had become productive of yellow-brown sputum. He denied fever, but endorsed chills and night sweats. His medications included atorvastatin, lisinopril, metformin, and saxagliptin. His parents were from Guam, although he was born and raised in San Diego, CA. He was employed as a social worker and denied any history of cigarette smoking, alcohol, or drug use.

Equivalent Survival Between Lobectomy and Segmentectomy for Clinical Stage IA Lung Cancer

BACKGROUND

The oncologic efficacy of segmentectomy is controversial. We compared long-term survival in clinical stage IA (T1N0) Medicare patients undergoing lobectomy and segmentectomy in The Society of Thoracic Surgeons database.

METHODS

The Society of Thoracic Surgeons General Thoracic Surgery Database was linked to Medicare data in 14,286 lung cancer patients who underwent segmentectomy (n = 1654) or lobectomy (n = 12,632) for clinical stage IA disease from 2002 to 2015. Cox regression was used to create a long-term survival model. Patients were then propensity matched on demographic and clinical variables to derive matched pairs.

RESULTS

In Cox modeling segmentectomy was associated with survival similar to lobectomy in the entire cohort (hazard ratio, 1.04; 95% confidence interval, 0.89-1.20; P = .64) and in the matched subcohort. A subanalysis restricted to the 2009 to 2015 population (n = 11,811), when T1a tumors were specified and positron emission tomography results and mediastinal staging procedures were accurately recorded in the database, also showed that segmentectomy and lobectomy continue to have similar survival (hazard ratio, 1.00; 95% confidence interval, 0.87-1.16). Subanalysis of the pathologic N0 patients demonstrated the same results.

CONCLUSIONS

Lobectomy and segmentectomy for early-stage lung cancer are equally effective treatments with similar survival. Surgeons from The Society of Thoracic Surgeons database appear to be selecting patients appropriately for sublobar procedures.

International expert consensus on the management of bleeding during VATS lung surgery

Intraoperative bleeding is the most crucial safety concern of video-assisted thoracic surgery (VATS) for a major pulmonary resection. Despite the advances in surgical techniques and devices, intraoperative bleeding is still not rare and remains the most common and potentially fatal cause of conversion from VATS to open thoracotomy. Therefore, to guide the clinical practice of VATS lung surgery, we proposed the International Interest Group on Bleeding during VATS Lung Surgery with 65 experts from 10 countries in the field to develop this consensus document. The consensus was developed based on the literature reports and expert experience from different countries. The causes and incidence of intraoperative bleeding were summarised first. Seven situations of intraoperative bleeding were collected based on clinical practice, including the bleeding from massive vessel injuries, bronchial arteries, vessel stumps, and bronchial stumps, lung parenchyma, lymph nodes, incisions, and the chest wall. The technical consensus for the management of intraoperative bleeding was achieved on these seven surgical situations by six rounds of repeated revision. Following expert consensus statements were achieved: (I) Bleeding from major vascular injuries: direct compression with suction, retracted lung, or rolled gauze is useful for bleeding control. The size and location of the vascular laceration are evaluated to decide whether the bleeding can be stopped by direct compression or by ligation. If suturing is needed, the suction-compressing angiorrhaphy technique (SCAT) is recommended. Timely conversion to thoracotomy with direct compression is required if the operator lacks experience in thoracoscopic angiorrhaphy. (II) Bronchial artery bleeding: pre-emptive clipping of bronchial artery before bronchial dissection or lymph node dissection can reduce the incidence of bleeding. Bronchial artery bleeding can be stopped by compression with the suction tip, followed by the handling of the vascular stump with energy devices or clips. (III) Bleeding from large vessel stumps and bronchial stumps: bronchial stump bleeding mostly comes from accompanying bronchial artery, which can be clipped for hemostasis. Compression for hemostasis is usually effective for bleeding at the vascular stump. Otherwise, additional use of hemostatic materials, re-staple or a suture may be necessary. (IV) Bleeding from the lung parenchyma: coagulation hemostasis is the first choice. For wounds with visible air leakage or an insufficient hemostatic effect of coagulation, suturing may be necessary. (V) Bleeding during lymph node dissection: non-grasping en-bloc lymph node dissection is recommended for the nourishing vessels of the lymph node are addressed first with this technique. If bleeding occurs at the site of lymph node dissection, energy devices can be used for hemostasis, sometimes in combination with hemostatic materials. (VI) Bleeding from chest wall incisions: the chest wall incision(s) should always be made along the upper edge of the rib(s), with good hemostasis layer by layer. Recheck the incision for hemostasis before closing the chest is recommended. (VII) Internal chest wall bleeding: it can usually be managed with electrocoagulation. For diffuse capillary bleeding with the undefined bleeding site, compression of the wound with gauze may be helpful.

Transcriptional signature primes human oral mucosa for rapid wound healing

Oral mucosal wound healing has long been regarded as an ideal system of wound resolution. However, the intrinsic characteristics that mediate optimal healing at mucosal surfaces are poorly understood, particularly in humans. We present a unique comparative analysis between human oral and cutaneous wound healing using paired and sequential biopsies during the repair process. Using molecular profiling, we determined that wound-activated transcriptional networks are present at basal state in the oral mucosa, priming the epithelium for wound repair. We show that oral mucosal wound-related networks control epithelial cell differentiation and regulate inflammatory responses, highlighting fundamental global mechanisms of repair and inflammatory responses in humans. The paired comparative analysis allowed for the identification of differentially expressed SOX2 (sex-determining region Y-box 2) and PITX1 (paired-like homeodomain 1) transcriptional regulators in oral versus skin keratinocytes, conferring a unique identity to oral keratinocytes. We show that SOX2 and PITX1 transcriptional function has the potential to reprogram skin keratinocytes to increase cell migration and improve wound resolution in vivo. Our data provide insights into therapeutic targeting of chronic and nonhealing wounds based on greater understanding of the biology of healing in human mucosal and cutaneous environments.

Minimally Invasive Lung Cancer Surgery Performed by Thoracic Surgeons as Effective as Thoracotomy

Purpose The prevalence of minimally invasive lung cancer surgery using video-assisted thoracic surgery (VATS) has increased dramatically over the past decade, yet recent studies have suggested that the lymph node evaluation during VATS lobectomy is inadequate. We hypothesized that the minimally invasive approach to lobectomy for stage I lung cancer resulted in a longitudinal outcome that was not inferior to thoracotomy. Patients and Methods Patients > 65 years of age who had undergone lobectomy for stage I lung cancer between 2002 and 2013 were analyzed within the Society of Thoracic Surgeons General Thoracic Surgery Database, which had been linked to Medicare data, as part of a retrospective-cohort, noninferiority study. Results A total of 10,597 patients with clinical stage I lung cancer who underwent lobectomy were evaluated (4,448 patients underwent thoracotomy, and 6,149 underwent VATS). VATS patients had a more favorable distribution of all health-related variables, including pulmonary function (59% of VATS patients had intact spirometry v 51% of thoracotomy patients; P < .001). Cox proportional hazards models were performed over two eras to account for an evolving practice standard. The mortality risk associated with the VATS approach was not greater than thoracotomy in either the earlier era (2002 to 2008; hazard ratio, 0.97; 95% CI, 0.87 to 1.09; P = .62) or the more recent era (2009 to 2013; hazard ratio, 0.84; 95% CI, 0.75 to 0.93; P < .001). Kaplan-Meier survival estimates of 2,901 propensity-matched VATS-thoracotomy pairs demonstrated that the 4-year survival associated with VATS (68.6%) was modestly superior to thoracotomy (64.8%; P = .003). The analyses detailed above were replicated in a separate cohort of pathologic stage I patients with similar findings. Conclusion The long-term efficacy of lobectomy for stage I lung cancer performed using the VATS approach by board-certified thoracic surgeons does not seem to be inferior to that of thoracotomy.

Prediction of Long-Term Survival After Lung Cancer Surgery for Elderly Patients in The Society of Thoracic Surgeons General Thoracic Surgery Database

BACKGROUND

Prior risk models using the STS General Thoracic Surgery database (STS-GTSD) have been limited to 30-day outcomes. We have now linked STS data to Medicare data and sought to create a risk prediction model for long-term mortality after lung cancer resection in patients older than 65 years.

METHODS

The STS-GTSD was linked to Medicare data for lung cancer resections from 2002 to 2013 as previously reported. Successful linkage was performed in 29,899 lung cancer resection patients. Cox proportional hazards modeling was used to create a long-term survival model. Variable selection was performed using statistically significant univariate factors and known clinical predictors of outcome. Calibration was assessed by dividing the cohort into deciles of predicted survival and discrimination assessed with a C-statistic corrected for optimism via 1,000 bootstrap replications.

RESULTS

Median age was 73 years (interquartile range, 68 to 78 years), and 48% of the patients were male. Of the 29,094 patients with nonmissing pathologic stage, 69% were stage I, 18% stage II, 11% stage III, and 2% stage IV. Procedure performed was lobectomy in 69%, bilobectomy in 3%, pneumonectomy in 3%, segmentectomy in 7%, sleeve lobectomy in 1%, and wedge resection in 17%. Thoracoscopic approach was performed in 47% of resections. The final Cox model reveals that stage and age are the strongest predictors of long-term survival. Even after controlling for stage, wedge resection, segmentectomy, bilobectomy, and pneumonectomy are all associated with increased hazard of death in comparison with lobectomy. Thoracoscopic approach is associated with improved long-term survival in comparison with thoracotomy. Other modifiable predictive factors include smoking and low body mass index. Calibration of the model demonstrates excellent performance across all survival deciles and a C-statistic of 0.694.

CONCLUSIONS

The STS-GTSD-Medicare long-term risk model includes several novel factors associated with mortality. Although medical factors predict long-term survival, age and stage are the strong predictors. Despite this, procedure choice and thoracoscopic/open approach are potentially modifiable predictors of long-term survival after lung cancer resection.

High-LET Radiation Increases Tumor Progression in a K-Ras-Driven Model of Lung Adenocarcinoma

High-linear energy transfer (LET) radiation encountered by astronauts in space generates clustered DNA damage that is potentially oncogenic. Analysis of the impact of exposure to space radiation on cancer formation is necessary to determine the best ways to prepare astronauts for space travel so they are protected for the duration of the space mission. A mouse model of lung adenocarcinoma driven by oncogenic K-Ras was used to ascertain the effect of low- and high-LET radiation on tumor formation. We observed increased tumor progression and tumor cell proliferation after single dose or fractionated high-LET doses, which was not observed in mice exposed to low-LET radiation. Location of the tumor nodules was not affected by radiation, indicating that the cell of origin of K-Ras-driven tumors was the same in irradiated or nonirradiated mice. Gene expression analysis revealed an upregulation of genes involved in cell proliferation and DNA damage repair. This study provides evidence that exposure to a single dose or fractionated doses of high-LET radiation induces molecular and cellular changes that accelerate lung tumor growth.

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.

Surgically Managed Clinical Stage IIIA-Clinical N2 Lung Cancer in The Society of Thoracic Surgeons Database

BACKGROUND

The role of surgical resection in patients with clinical stage IIIA-N2 positive (cIIIA-N2) lung cancer is controversial, partly because of the variability in short- and long-term outcomes. The objective of this study was to characterize the management of cIIIA-N2 lung cancer in The Society of Thoracic Surgeons General Thoracic Surgery Database (STS-GTSD).

METHODS

The STS-GTSD was queried for patients who underwent operations for cIIIA-N2 lung cancer between 2002 and 2012. A subset of patients aged older than 65 years was linked to Medicare data.

RESULTS

Identified were 3,319 surgically managed, cIIIA-N2 patients, including 1,784 (54%) treated with upfront resection (treatment naïve upfront surgery group, and 1,535 (46%) with induction therapy. A positron emission tomography scan was documented in 93% of patients, and 51% of patients were coded in STS-GTSD as having undergone invasive mediastinal staging. Nodal overstaging (cN2→pN0/N1) was observed in 43% of upfront surgery patients. Lobectomy was performed in 69% of patients and pneumonectomy in 11%. Operative mortality was similar between patients treated with upfront surgery (1.9%) and induction therapy (2.5%, p = .2583). The unadjusted Kaplan-Meier estimate of 5-year survival of cIII-N2 patients treated with induction therapy then resection was 35%.

CONCLUSIONS

STS surgeons achieve excellent short- and long-term results treating predominantly lobectomy-amenable cIIIA-N2 lung cancer. However, prevalent overstaging and abstention from induction therapy suggest "overcoding" of false positives on imaging or variable compliance with current guidelines for cIIIA-N2 lung cancer. Efforts are needed to improve clinical stage determination and guideline compliance in the GTSD for this cohort.

Immune profiling of circulating T cells and TILs following neoadjuvant ipilimumab and chemotherapy in non-small cell lung cancer (NSCLC)

26

Background: Ipilimumab (Ipi) is a humanized CTLA-4 antibody that blocks binding of CTLA-4 to B7, permitting T cell activation through CD28. Phased in Ipi added to chemotherapy (C) may enhance efficacy in NSCLC. Methods: Patients with stage 2 or 3A NSCLC received neoadjuvant carboplatin AUC6 plus paclitaxel 200 mg/m2 every 21 days for 3 cycles and Ipi (10 mg/kg) was given on day 1 for cycles 2 and 3. Blood for immune profiling of circulating T cells was collected at baseline, after chemotherapy alone, and after chemotherapy plus Ipi. Tumor infiltrating lymphocytes (TIL) were derived from 7 available tumors. Polychromatic flow cytometry (PFC) analyses were performed on peripheral blood mononuclear cells (PBMC) and TIL. Objective response rates were assessed according to RECIST 1.1 criteria. Results: Of the 24 patients enrolled on this study, objective responses after 3 cycles of neoadjuvant C plus ipi included 2 PD, 8 SD, and 14 PR. Phenotypic analyses revealed that PBMC from all 24 patients were highly activated following two cycles of Ipi (cycle 3) as evidenced by significantly increased frequencies of CD28, ICOS, HLA-DR, PD-1, and CTLA-4 expressing CD4+ cells; and ICOS, HLA-DR, and CTLA-4 expressing CD8+ cells. The frequencies of Tregs were highly variable among the 24 participants. Two of the 24 participants had levels of MDSC cells above 15%. TIL contained far greater frequencies of activated CD4+ and CD8+ cells than found in the PBMC at cycle 3. Tumor associated antigen (TAA)-specific CD4+ or CD8+ cells were detected at baseline in 4 patients (24%), but their relative frequencies remained unaltered by Ipi therapy. No patients developed detectable de novo TAA reactivities while on Ipi therapy. Conclusions: Combined neoadjuvant Ipi plus chemotherapy produced significantly increased frequencies of highly activated CD4+ and CD8+ populations in the peripheral blood and the tumor microenvironment. TAA-specific CD4+ or CD8+ cells were detected in PBMC at baseline in a subset of patients. No TAA-reactive T cells were detected among the 7 TIL samples analyzed. Analysis for predictive or pharmacodynamic biomarkers is ongoing. Clinical trial information: NCT01820754.

Inactivation of ABL kinases suppresses non-small cell lung cancer metastasis

Current therapies to treat non-small cell lung carcinoma (NSCLC) have proven ineffective owing to transient, variable, and incomplete responses. Here we show that ABL kinases, ABL1 and ABL2, promote metastasis of lung cancer cells harboring EGFR or KRAS mutations. Inactivation of ABL kinases suppresses NSCLC metastasis to brain and bone, and other organs. ABL kinases are required for expression of prometastasis genes. Notably, ABL1 and ABL2 depletion impairs extravasation of lung adenocarcinoma cells into the lung parenchyma. We found that ABL-mediated activation of the TAZ and β-catenin transcriptional coactivators is required for NSCLC metastasis. ABL kinases activate TAZ and β-catenin by decreasing their interaction with the β-TrCP ubiquitin ligase, leading to increased protein stability. High-level expression of ABL1, ABL2, and a subset of ABL-dependent TAZ- and β-catenin-target genes correlates with shortened survival of lung adenocarcinoma patients. Thus, ABL-specific allosteric inhibitors might be effective to treat metastatic lung cancer with an activated ABL pathway signature.

A Risk Score to Assist Selecting Lobectomy Versus Sublobar Resection for Early Stage Non-Small Cell Lung Cancer

BACKGROUND

The long-term survival benefit of lobectomy over sublobar resection for early-stage non-small cell lung cancer must be weighed against a potentially increased risk of perioperative mortality. The objective of the current study was to create a risk score to identify patients with favorable short-term outcomes following lobectomy.

METHODS

The 2005-2012 American College of Surgeons National Surgical Quality Improvement Program database was queried for patients undergoing a lobectomy or sublobar resection (either segmentectomy or wedge resection) for lung cancer. A multivariable logistic regression model was utilized to determine factors associated with 30-day mortality among the lobectomy group and to develop an associated risk score to predict perioperative mortality.

RESULTS

Of the 5,749 patients who met study criteria, 4,424 (77%) underwent lobectomy, 1,098 (19%) underwent wedge resection, and 227 (4%) underwent segmentectomy. Age, chronic obstructive pulmonary disease, previous cerebrovascular event, functional status, recent smoking status, and surgical approach (minimally invasive versus open) were utilized to develop the risk score. Patients with a risk score of 5 or lower had no significant difference in perioperative mortality by surgical procedure. Patients with a risk score greater than 5 had significantly higher perioperative mortality after lobectomy (4.9%) as compared to segmentectomy (3.6%) or wedge resection (0.8%, p < 0.01).

CONCLUSIONS

In this study, we have developed a risk model that predicts relative operative mortality from a sublobar resection as compared to a lobectomy. Among patients with a risk score of 5 or less, lobectomy confers no additional perioperative risk over sublobar resection.

Impact of patient selection and treatment strategies on outcomes after lobectomy for biopsy-proven stage IIIA pN2 non-small cell lung cancer

OBJECTIVES

We evaluated the impact of patient selection and treatment strategies on long-term outcomes of patients who had lobectomy after induction therapy for stage IIIA pN2 non-small cell lung cancer (NSCLC).

METHODS

The impact of various patient selection, induction therapy and operative strategies on survival of patients with biopsy-proven stage IIIA pN2 NSCLC who received induction chemotherapy ± radiation followed by lobectomy from 1995 to 2012 was assessed using Cox proportional hazards analysis.

RESULTS

From 1995 to 2012, 111 patients had lobectomy for stage IIIA pN2 NSCLC after chemotherapy ± radiation with an overall 5-year survival of 39%. The use of induction chemoradiation decreased over time; from 1996 to 2007, 46/65 (71%) patients underwent induction chemoradiation, whereas from 2007 to 2012, 36/46 (78%) patients underwent induction chemotherapy. The use of video-assisted thoracoscopic surgery (VATS) increased over the time period of the study, from 0/26 (0%) in 1996-2001, to 4/39 (10%) in 2002-07 to 33/46 (72%) in 2008-12. Compared with patients given induction chemotherapy alone, patients given additional induction radiation were more likely to have complete pathologic response (30 vs 11%, P = 0.01) but had worse 5-year survival in univariable analysis (31 vs 48%, log-rank P = 0.021). Patients who underwent pathologic mediastinal restaging following induction therapy but prior to resection had an improved overall survival compared with patients who did not undergo pathologic mediastinal restaging {5-year survival: 45.2 [95% confidence interval (CI): 33.9-55.9] vs 13.9% (95% CI: 2.5-34.7); log-rank, P = 0.004}. In multivariable analysis, the particular induction therapy strategy and the surgical approach used, as well as the extent of mediastinal disease were not important predictors of survival. However, pathologic mediastinal restaging was associated with improved survival (HR 0.39; 95% CI: 0.21-0.72; P = 0.003).

CONCLUSIONS

For patients with stage IIIA pN2 NSCLC, the VATS approach or the addition of radiation to induction therapy can be selectively employed without compromising survival. The strategy of assessing response to induction therapy with pathologic mediastinal restaging allows one to select appropriate patients for complete resection and is associated with a 5-year overall survival of 39% in this population.

Toxicity of definitive and post-operative radiation following ipilimumab in non-small cell lung cancer

To determine the feasibility and toxicity of radiation therapy, delivered either as definitive treatment or following surgery, following neo-adjuvant immune checkpoint inhibition for locally advanced NSCLC sixteen patients who received neo-adjuvant chemotherapy including ipilimumab as part of a phase II study were identified. Patients were analyzed by intent of radiation and toxicity graded based on CTCAE 4.0. There were seven patients identified who received definitive radiation and nine who received post-operative radiation. There was no grade 3 or greater toxicity in the definitive treatment group although one patient stopped treatment early due to back pain secondary to progression outside of the treatment field. In the post-operative treatment group, one patient required a one week break due to grade 2 odynophagia and no grade 3 or greater toxicity was observed. In this study of radiation as definitive or post-operative treatment following neo-adjuvant chemotherapy including ipilimumab for locally advanced NSCLC was feasible and well tolerated with limited toxicity.

Minimally Invasive Versus Open Esophagectomy for Esophageal Cancer: A Population-Based Analysis

BACKGROUND

The objective of this study was to evaluate outcomes of minimally invasive approaches to esophagectomy using population-level data.

METHODS

Multivariable regression modeling was used to determine predictors associated with the use of minimally invasive approaches for patients in the National Cancer Data Base who underwent resection of middle and distal clinical T13N03M0 esophageal cancers from 2010 to 2012. Perioperative outcomes and 3-year survival were compared between propensity-matched groups of patients with esophageal cancer who underwent minimally invasive esophagectomy (MIE) or open esophagectomy (OE). A subgroup analysis was performed to evaluate the impact of using robotic-assisted operations as part of the minimally invasive approach.

RESULTS

Among 4,266 patients included, 1,308 (30.6%) underwent MIE. It was more likely to be used in patients treated at academic (adjusted odds ratio [OR], 10.1; 95% confidence interval [CI], 4.2-33.1) or comprehensive cancer facilities (adjusted OR, 6.4; 95% CI, 2.6-21.1). Compared with propensity-matched patients who underwent OE, patients who underwent MIE had significantly more lymph nodes examined (15 versus 13; p = 0.016) and shorter hospital lengths of stay (10 days versus 11 days; p = 0.046) but similar resection margin positivity, readmission, and 30-day mortality (all p > 0.05). Survival was similar between the matched groups at 3 years for both adenocarcinoma and squamous cell carcinoma (p > 0.05). Compared with MIE without robotic assistance, use of a robotic approach was not associated with any significant differences in perioperative outcomes (p > 0.05).

CONCLUSIONS

The use of minimally invasive techniques to perform esophagectomy for esophageal cancer is associated with modestly improved perioperative outcomes without compromising survival.

Role of Adjuvant Therapy in a Population-Based Cohort of Patients With Early-Stage Small-Cell Lung Cancer

PURPOSE

Data on optimal adjuvant therapy after complete resection of small-cell lung cancer (SCLC) are limited, and in particular, there have been no studies evaluating the role of adjuvant chemotherapy, with or without prophylactic cranial irradiation, relative to no adjuvant therapy for stage T1-2N0M0 SCLC. This National Cancer Data Base analysis was performed to determine the potential benefits of adjuvant chemotherapy with and without prophylactic cranial irradiation in patients who undergo complete resection for early-stage small-cell lung cancer.

PATIENTS AND METHODS

Overall survival of patients with pathologic T1-2N0M0 SCLC who underwent complete resection in the National Cancer Data Base from 2003 to 2011, stratified by adjuvant therapy regimen, was evaluated using Kaplan-Meier and Cox proportional hazards analysis. Patients treated with induction therapy and those who died within 30 days of surgery were excluded from analysis.

RESULTS

Of 1,574 patients who had pT1-2N0M0 SCLC during the study period, 954 patients (61%) underwent complete R0 resection with a 5-year survival of 47%. Adjuvant therapy was administered to 59% of patients (n = 566), including chemotherapy alone (n = 354), chemoradiation (n = 190, including 99 patients who underwent cranial irradiation), and radiation alone (n = 22). Compared with surgery alone, adjuvant chemotherapy with or without radiation was associated with significantly improved survival. In addition, multivariable Cox modeling demonstrated that treatment with adjuvant chemotherapy (hazard ratio [HR], 0.78; 95% CI, 0.63 to 0.95) or chemotherapy with radiation directed at the brain (HR, 0.52; 95% CI, 0.36 to 0.75) was associated with improved survival when compared with no adjuvant therapy.

CONCLUSION

Patients with pT1-2N0M0 SCLC treated with surgical resection alone have worse outcomes than those who undergo resection with adjuvant chemotherapy alone or chemotherapy with cranial irradiation.

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.

Long-term survival following open versus thoracoscopic lobectomy after preoperative chemotherapy for non-small cell lung cancer

OBJECTIVES

Video-assisted thoracoscopic (VATS) lobectomy is increasingly accepted for the management of early-stage non-small cell lung cancer (NSCLC), but its role for locally advanced cancers has not been as well characterized. We compared outcomes of patients who received induction therapy followed by lobectomy, via VATS or thoracotomy.

METHODS

Perioperative complications and long-term survival of all patients with NSCLC who received induction chemotherapy (ICT) (with or without induction radiation therapy) followed by lobectomy from 1996-2012 were assessed using Kaplan-Meier and Cox proportional hazard analysis. Propensity score-matched comparisons were used to assess the potential impact of selection bias.

RESULTS

From 1996 to 2012, 272 patients met inclusion criteria and underwent lobectomy after ICT: 69 (25%) by VATS and 203 (75%) by thoracotomy. An 'intent-to-treat' analysis was performed. Compared with thoracotomy patients, VATS patients had a higher clinical stage, were older, had greater body mass index, and were more likely to have coronary disease and chronic obstructive pulmonary disease. Induction radiation was used more commonly in thoracotomy patients [VATS 28% (n = 19) vs open 72% (n = 146), P < 0.001]. Thirty-day mortality was similar between the VATS [3% (n = 2)] and open [4% (n = 8)] groups (P = 0.69). Seven (10%) of the VATS cases were converted to thoracotomy due to difficulty in dissection from fibrotic tissue and adhesions (n = 5) or bleeding (n = 2); none of these conversions led to perioperative deaths. In univariate analysis, VATS patients had improved 3-year survival compared with thoracotomy (61% vs 43%, P = 0.010). In multivariable analysis, the VATS approach showed a trend towards improved survival, but this did not reach statistical significance (hazard ratio, 0.56; 95% confidence interval, 0.32-1.01; P = 0.053). Moreover, a propensity score-matched analysis balancing patient characteristics demonstrated that the VATS approach had similar survival to an open approach (P = 0.56).

CONCLUSIONS

VATS lobectomy in patients treated with induction therapy for locally advanced NSCLC is feasible and effective and does not appear to compromise oncologic outcomes.

Benign emptying of the postpneumonectomy space

A drop in the air-fluid level in the postpneumonectomy space on a chest radiogram is an early sign of bronchopleural fistula (BPF). Any suspicion of BPF points to the need for urgent evaluation and appropriate management. Very rarely may this drop occur without the existence of a fistula, but such a condition is defined as benign emptying of the postpneumonectomy space. We share our successful conservative management in a case of postpneumonectomy space emptying with a suspicion of BPF.

Adding radiation to induction chemotherapy does not improve survival of patients with operable clinical N2 non-small cell lung cancer

OBJECTIVE

Radiotherapy is commonly used in induction regimens for patients with non-small cell lung cancer with operable mediastinal nodal disease, although evidence has not shown a benefit over induction chemotherapy alone. We compared outcomes between induction chemotherapy and induction chemoradiation using the National Cancer Data Base.

METHODS

Induction radiation use and survival of patients who underwent lobectomy or pneumonectomy after induction chemotherapy for clinical T1-3N2M0 non-small cell lung cancer in the National Cancer Data Base from 2003 to 2006 were assessed using logistic regression, general linear regression, Kaplan-Meier, and Cox proportional hazard analysis.

RESULTS

Of 1362 patients who met study criteria, 834 (61%) underwent induction chemoradiation and 528 (39%) underwent induction chemotherapy. Lobectomy was performed in 82% of patients (n = 1111), and pneumonectomy was performed in 18% of patients (n = 251). Pneumonectomy was performed more often after induction chemoradiation than after induction chemotherapy (20% vs 16%, P = .04). Downstaging from N2 to N0/N1 was more common with induction chemoradiation compared with induction chemotherapy (58% vs 46%, P < .01), but 5-year survival of patients receiving induction chemoradiation and patients receiving induction chemotherapy was similar in unadjusted analysis (41% vs 41%, P = .41). In multivariable analysis, the addition of radiation to induction chemotherapy also was not associated with a survival benefit (hazard ratio, 1.03; 95% confidence interval, 0.89-1.18; P = .73).

CONCLUSIONS

Induction chemoradiation is used in the majority of patients with non-small cell lung cancer with N2 disease who undergo induction therapy before surgical resection, but it is not associated with improved survival compared with induction chemotherapy.

Impact of Pulmonary Function Measurements on Long-Term Survival After Lobectomy for Stage I Non-Small Cell Lung Cancer

BACKGROUND

Pulmonary function tests predict respiratory complications after lobectomy. We evaluated the impact of pulmonary function measurements on long-term survival after lobectomy for stage I non-small cell lung cancer.

METHODS

The relationship between percent predicted forced expiratory volume in 1 second (FEV1) and percent predicted diffusing capacity of the lung for carbon monoxide (Dlco) and overall survival for patients who underwent lobectomy without induction therapy for stage I (T1-2N0M0) non-small cell lung cancer from 1996 to 2012 was evaluated using the Kaplan-Meier approach and a multivariable Cox proportional hazard model.

RESULTS

During the study period, 972 patients (mean Dlco 76 ± 21, mean FEV1 73 ± 21) met inclusion criteria. Perioperative mortality was 2.6% (n = 25). The 5-year survival of the entire cohort was 60.1%, with a median follow-up of 43 months. The 5-year survival for patients with percent predicted FEV1 stratified by more than 80%, 61% to 80%, 41% to 60%, and 40% or less was 70.1%, 59.3%, 52.5%, and 53.4%, respectively. The 5-year survival for patients with percent predicted Dlco stratified by more than 80%, 61% to 80%, 41% to 60%, and 40% or less was 70.2%, 63.4%, 44.2%, and 33.1%, respectively. In multivariable survival analysis, both larger tumor size (hazard ratio 1.15, p = 0.01) and lower Dlco (hazard ratio 0.986, p < 0.0001) were significant predictors of worse survival. The association of FEV1 and survival was not statistically significant (p = 0.18).

CONCLUSIONS

Survival after lobectomy for patients with stage I non-small cell lung cancer is impacted by lower Dlco, which can be used in the risk and benefit assessment when choosing therapy.

Adjuvant chemotherapy after resection of N1 non-small cell lung cancer: differential impact of new evidence on physician and patient decisions

BACKGROUND

Adjuvant cisplatin-based chemotherapy (ACT) after resection of stages II-IIIA non-small cell lung cancer (NSCLC) modestly increased survival in several clinical trials. This study evaluated the subsequent impact of those trials on ACT use in clinical practice.

METHODS

Patients who underwent lobectomy or more extensive lung resection without induction chemotherapy for pathologically confirmed N1 positive NSCLC between 2000 and 2012 were reviewed. Referrals to medical oncology, oncologist recommendations for ACT, and initiation of ACT were evaluated. Because major trials supporting ACT were published in 2004 and 2005, analysis was stratified into two eras: 2000-2005 and 2006-2012.

RESULTS

During the study period, 272 patients met inclusion criteria (110 in the 2000-2005 cohort, 162 in the 2006-2012 cohort). Referrals to medical oncology increased from 74.5% (n=82) in the 2000-2005 cohort to 90.1% (n=146) in the 2006-2012 cohort (P=0.002). Due to lack of referral or missed appointments, 35.5% (n=39) of the 2000-2005 patients and 17.9% (n=32) of the 2006-2012 patients did not have a documented conversation with an oncologist regarding ACT. The proportion of patients recommended for ACT increased from 61% (n=50) to 81.5% (n=119) between the eras (P<0.001). Of patients recommended for chemotherapy, 14% (7/50) in 2000-2005 and 13.4% (16/119) in 2006-2012 declined ACT (P=0.666).

CONCLUSIONS

Publication of supporting evidence increased recommendations for ACT but did not change the percentage of patients who ultimately agreed to receive ACT. Additional research is needed to better understand patient decision-making in this situation.

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

K-Ras activation with a CC10(Scgb1a1)-CreER driver leads to lung adenocarcinoma in a subset of alveolar type II cells and hyperplasia in the bronchioalveolar duct region. Xu et al. find that Notch inhibition 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. Sox2 binds to NOTCH1 and NOTCH2 regulatory regions and reduces Notch1 and Notch2 transcripts. This study shows that the cell of origin of K-Ras-induced tumors depends on levels of Sox2 expression affecting Notch signaling.

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.

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.

Outcomes after pneumonectomy for benign disease: the impact of urgent resection

BACKGROUND

Pneumonectomy for benign disease is often complicated by inflammatory processes that obscure operative planes. We reviewed our experience to evaluate the impact of requiring urgent or emergent pneumonectomy on outcomes.

STUDY DESIGN

All pneumonectomies for benign conditions from 1997 to 2012 at a single institution were retrospectively reviewed. Mortality was assessed using multivariable logistic regression that included laterality, age, and surgery status, which was emergent if performed within 24 hours of initial evaluation, urgent if performed after 24 hours but within the same hospital stay, and otherwise elective.

RESULTS

Among 42 pneumonectomies, completion pneumonectomy after previous ipsilateral lung resection was performed in 14 patients (33%). Resection was elective in 22 patients (52%), urgent in 12 (28%), and emergent in 8 (19%). The most common indication was for necrotic lung (n = 12; 29%). Muscle flaps were used in 26 patients (62%). Perioperative mortality for the entire cohort was 29% (n = 12) and was significantly higher when surgery was urgent (5 of 12; 42%) or emergent (5 of 8; 62.5%) compared with elective (2 of 22; 9.1%) (p = 0.03). Requiring urgent or emergent surgery remained a significant predictor of mortality in multivariable analysis (odds ratio 10.4, p = 0.01).

CONCLUSIONS

Pneumonectomy for benign disease has significant risk for mortality, particularly when not performed electively. Although surgery cannot be planned in the setting of trauma or some situations of acute infection, patients known to have conditions that are likely to require pneumonectomy should be considered for surgery earlier in their disease course, before developing an acute problem that requires urgent or emergent resection.