Impact of FDG PET Standardized Uptake Value in Resected Clinical Stage IA Non-Small Cell Lung Cancer

BACKGROUND

A significant proportion of patients with clinical stage IA non-small cell lung cancer (NSCLC) experience will recurrence and decreased survival after surgery. This study examined the impact of preoperative primary tumor positron emission tomography (PET) scan maximum standardized uptake value (SUVmax) on oncologic outcomes after surgery.

METHODS

This was a retrospective review of 251 patients who underwent surgical treatment of clinical stage IA NSCLC at an academic medical center (2005-2014). Patients were classified according to PET SUVmax level (low vs high) for analysis of upstaging, tumor recurrence, and overall survival.

RESULTS

Median SUVmax values were higher in squamous cell carcinoma than in adenocarcinoma (median 3.3 vs 7.2; P < .0001). There were 109 (43.4%) patients in the SUVmax low group and 142 (56.6%) in the SUVmax high group. Patients with SUVmax high had larger tumors. SUVmax high was associated with higher rates of nodal upstaging (16.2% vs 4.6% in SUVmax low; P = .004), particularly in N1 nodes. SUVmax high was independently associated with nodal upstaging (adjusted odds ratio, 3.95; 95% CI, 1.36-11.46; P = .011). SUVmax high was associated with time to recurrence (hazard ratio, 1.62; 95% CI, 1.03-2.54; P = .036), but this association was lost on multivariable analysis (hazard ratio, 1.52; 95% CI, 0.91-2.54; P = .106). SUVmax was not associated with overall survival.

CONCLUSIONS

Preoperative PET SUVmax level is strongly associated with nodal upstaging, particularly in N1 nodes, in patients with clinical stage IA NSCLC who undergo resection. PET SUVmax should be regarded as a risk factor when considering candidacy for sublobar resections and in future trials involving patients with stage I NSCLC.

Esophagectomy Enhanced Recovery After Surgery Initiative Results in Improved Outcomes

BACKGROUND

Esophagectomy for esophageal cancer is a procedure with high morbidity and mortality. This study developed a Multidisciplinary Esophagectomy Enhanced Recovery Initiative (MERIT) pathway and analyzed implementation outcomes in a single institution.

METHODS

The MERIT pathway was developed as a practice optimization and quality improvement initiative. Patients were studied from November 1, 2021 to June 20, 2022 and were compared with historical control subjects. The Wilcoxon rank sum test and the Fisher exact test were used for statistical analysis.

RESULTS

The study compared 238 historical patients (January 17, 2017 to December 30, 2020) with 58 consecutive MERIT patients. There were no significant differences between patient characteristics in the 2 groups. In the MERIT group, 49 (85%) of the patients were male, and their mean age was 65 years (range, 59-71 years). Most cases were performed for esophageal cancer after neoadjuvant therapy. Length of stay improved by 27% from 11 to 8 days (P = .27). There was a 12% (P = .05) atrial arrhythmia rate reduction, as well as a 9% (P = .01) decrease in postoperative ileus. Overall complications were reduced from 54% to 35% (-19%; P = .01).

CONCLUSIONS

This study successfully developed and implemented an enhanced recovery after surgery pathway for esophagectomy. In the first year, study investigators were able to reduce overall complications, specifically atrial arrhythmias, and postoperative ileus.

An in-silico analysis reveals further evidence of an aggressive subset of lung carcinoids sharing molecular features of high-grade neuroendocrine neoplasms

Little is known as to whether there may be any pathogenetic link between pulmonary carcinoids and neuroendocrine carcinomas (NECs). A gene signature we previously found to cluster pulmonary carcinoids, large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC), and which encompassed MEN1, MYC, MYCL1, RICTOR, RB1, SDHA, SRC and TP53 mutations or copy number variations (CNVs), was used to reclassify an independent cohort of 54 neuroendocrine neoplasms (NENs) [31 typical carcinoids (TC), 11 atypical carcinoids (AC) and 12 SCLC], by means of transcriptome and mutation data. Unsupervised clustering analysis identified two histology-independent clusters, namely CL1 and CL2, where 17/42 (40.5%) carcinoids and all the SCLC samples fell into the latter. CL2 carcinoids affected survival adversely, were enriched in T to G transversions or T > C/C > T transitions in the context of specific mutational signatures, presented with at least 1.5-fold change (FC) increase of gene mutations including TSC2, SMARCA2, SMARCA4, ERBB4 and PTPRZ1, differed for gene expression and showed epigenetic changes in charge of MYC and MTORC1 pathways, cellular senescence, inflammation, high-plasticity cell state and immune system exhaustion. Similar results were also found in two other independent validation sets comprising 101 lung NENs (24 carcinoids, 21 SCLC and 56 LCNEC) and 30 carcinoids, respectively. We herein confirmed an unexpected sharing of molecular traits along the spectrum of lung NENs, with a subset of genomically distinct aggressive carcinoids sharing molecular features of high-grade neuroendocrine neoplasms.

Determinants of Long-term Survival Decades After Esophagectomy for Esophageal Cancer

BACKGROUND

Long-term survival in esophagectomy patients with esophageal cancer is low due to tumor-related characteristics, with few reports of modifiable variables influencing outcome. We identified determinants of overall survival, time to recurrence, and disease-free survival in this patient cohort.

METHODS

Adult patients who underwent esophagectomy for primary esophageal cancer from January 5, 2000, through December 30, 2010, at our institution were identified. Univariate Cox models and multivariable logistic regression analyses were used to identify associations between modifiable and unmodifiable patient and clinical variables and outcome of survival for the total cohort and a subgroup with locally advanced disease.

RESULTS

We identified 870 patients with esophageal cancer who underwent esophagectomy. The median follow-up time was 15 years, and the 15-year overall survival rate was 25.2%, survival free of recurrence was 57.96%, and disease-free survival was 24.21%. Decreased overall survival was associated with the following unmodifiable variables: older age, male sex, active smoking status, history of coronary artery disease, advanced clinical stage, and tumor location. Decreased overall survival was associated with the following modifiable variables: use of neoadjuvant therapy, advanced pathologic stage, resection margin positivity, surgical reintervention, and blood transfusion requirement. The overall survival probability 6 years after esophagectomy was 0.920 (95% CI, 0.895-0.947), and time-to-recurrence probability was 0.988 (95% CI, 0.976-1.000), with a total of 17 recurrences and 201 deaths.

CONCLUSIONS

Once patients survive 5 years, recurrence is rare. Long-term survival can be achieved in high-volume centers adhering to National Comprehensive Cancer Network guidelines using multidisciplinary care teams that is double what has been previously reported in the literature from national databases.

The diagnostic utility of inspiratory-expiratory radiography for the assessment of phrenic nerve palsy associated with brachial plexus injury

BACKGROUND

The phrenic nerve is commonly injured with trauma to the brachial plexus. Hemi-diaphragmatic paralysis may be well-compensated in healthy individuals at rest but can be associated with persistent exercise intolerance in some patients. This study aims to determine the diagnostic value of inspiratory-expiratory chest radiography compared to intraoperative stimulation of the phrenic nerve for assessing phrenic nerve injury associated with brachial plexus injury.

METHODS

Over a 21-year period, the diagnostic utility of three-view inspiratory-expiratory chest radiography for identification of phrenic nerve injury was determined by comparison to intraoperative phrenic nerve stimulation. Multivariate regression analysis was used to identify independent predictors of phrenic nerve injury and having an incorrect radiographic diagnosis.

RESULTS

A total of 237 patients with inspiratory-expiratory chest radiography underwent intraoperative testing of phrenic nerve function. Phrenic nerve injury was present in approximately one-fourth of cases. Preoperative chest radiography had a sensitivity of 56%, specificity of 93%, positive predictive negative of 75%, and negative predictive value of 86% for identification of a phrenic nerve palsy. Only C5 avulsion was found to be a predictor of having an incorrect diagnosis of phrenic nerve injury on radiography.

CONCLUSION

While inspiratory-expiratory chest radiography has good specificity for detecting phrenic nerve injuries, a high number of false negatives suggest that it should not be relied upon for routine screening of dysfunction after traumatic brachial plexus injury. This is likely multifactorial and relates to variation in diaphragm shape and position, as well as limitations regarding static image interpretation of a dynamic process.

Progress in genome-inspired treatment decisions for multifocal lung adenocarcinoma

INTRODUCTION

Multifocal lung adenocarcinoma (MFLA) is becoming increasingly recognized as a distinct subset of lung cancer, with unique biology, disease course, and treatment outcomes. While definitions remain controversial, MFLA is characterized by the development and concurrent presence of multiple independent (non-metastatic) lesions on the lung adenocarcinoma spectrum. Disease progression typically follows an indolent course measured in years, with a lower propensity for nodal and distant metastases than other more common forms of non-small cell lung cancer.

AREAS COVERED

Traditional imaging and histopathological analyses of tumor biopsies are frequently unable to fully characterize the disease, prompting interest in molecular diagnosis. We highlight some of the key questions in the field, including accurate definitions to identify and stage MLFA, molecular tests to stratify patients and treatment decisions, and the lack of clinical trial data to delineate best management for this poorly understood subset of lung cancer patients. We review the existing literature and progress toward a genomic diagnosis for this unique disease entity.

EXPERT OPINION

Multifocal lung adenocarcinoma behaves differently than other forms of non-small cell lung cancer. Progress in molecular diagnosis may enhance potential for accurate definition, diagnosis, and optimizing treatment approach.

Pulmonary Open, Robotic, and Thoracoscopic Lobectomy (PORTaL) Study: Survival Analysis of 6646 Cases

OBJECTIVE

The aim of this study was to analyze overall survival (OS) of robotic-assisted lobectomy (RL), video-assisted thoracoscopic lobectomy (VATS), and open lobectomy (OL) performed by experienced thoracic surgeons across multiple institutions.

SUMMARY BACKGROUND DATA

Surgeons have increasingly adopted RL for resection of early-stage lung cancer. Comparative survival data following these approaches is largely from single-institution case series or administrative data sets.

METHODS

Retrospective data was collected from 21 institutions from 2013 to 2019. Consecutive cases performed for clinical stage IA-IIIA lung cancer were included. Induction therapy patients were excluded. The propensity-score method of inverse-probability of treatment weighting was used to balance baseline characteristics. OS was estimated using the Kaplan-Meier method. Multivariable Cox proportional hazard models were used to evaluate association among OS and relevant risk factors.

RESULTS

A total of 2789 RL, 2661 VATS, and 1196 OL cases were included. The unadjusted 5-year OS rate was highest for OL (84%) followed by RL (81%) and VATS (74%); P =0.008. Similar trends were also observed after inverse-probability of treatment weighting adjustment (RL 81%; VATS 73%, OL 85%, P =0.001). Multivariable Cox regression analyses revealed that OL and RL were associated with significantly higher OS compared with VATS (OL vs. VATS: hazard ratio=0.64, P <0.001 and RL vs. VATS: hazard ratio=0.79; P =0.007).

CONCLUSIONS

Our finding from this large multicenter study suggests that patients undergoing RL and OL have statistically similar OS, while the VATS group was associated with shorter OS. Further studies with longer follow-up are necessary to help evaluate these observations.

Multifocal bronchial neuroendocrine tumor (bNET): A new clinical entity

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Background: Bronchial carcinoid (BC) is often categorized into multifocal (MBC) or solitary (SBC). MBC, excluding tumorlet and diffuse idiopathic pulmonary neuroendocrine cell hyperplasia, is considered a relatively uncommon subgroup of BC, with much of the MBC literature stemming from case reports/small series. Our study analyzes MBC among a large cohort of 569 patients with BC and argues for change to the current clinical understanding of MBC. We suggest using the term bronchial neuroendocrine tumor (bNET) to more accurately represent its cells of origin and move away from “carcinoid” (historically meaning “carcinoma-like”) and the outdated associated connotation that carcinoids all have a similar, benign clinical and biological behavior. Methods: Using the Mayo Clinic Epidemiology and Genetics of Lung Cancer Database with Institutional Review Board approval, we retrospectively reviewed 569 patients with bNET (204 males, 365 females) presenting to Mayo Clinic Rochester between 1/1997-12/2012. We used univariate and multivariate Cox regression analyses to evaluate factors affecting overall survival. Results: 80 patients (of 569, 14.1%) were diagnosed with multifocal (MbNET) and 489 with solitary (SbNET). Two-sided Fisher’s exact tests found that older age, female gender, never having smoked cigarettes, and tumorlets were associated with MbNET diagnosis. Family lung cancer history, histopathologic grading (pathology: typical vs. atypical), Ki67, and presence of syndromes (carcinoid, Cushing, and MEN1 syndromes) were similar between MbNET and SbNET groups. Most MbNET cases were stage III-IV at the time of diagnosis, while the majority of SbNET cases were stage I. 5-year OS (83%) and 5-year PFS (75%) of MbNET patients were higher than those of their SbNET counterparts (74% and 68%, respectively). Metastasis status was an independent prognostic factor of poor OS in SbNET (P<0.001) but not in MbNET (P=0.71)(Table). Conclusions: Clinical, radiologic, and histopathologic characteristics and prognostic factors differed between SbNET and MbNET. MbNET arose as a new entity often with advanced stage disease, but good prognosis, which does not follow the NSCLC TNM staging system as in the 2009 NCCN guidelines (used during this study) or the updated 2021 NCCN guidelines which continue to stage lung carcinoid similarly to NSCLC. It may be beneficial to consider multifocal lung carcinoid instead as multifocal bNET, a new clinical entity, warranting a novel staging approach that more accurately reflects prognosis.[Table: see text]

First-in-Human Segmental Esophageal Reconstruction Using a Bioengineered Mesenchymal Stromal Cell-Seeded Implant

Introduction

Resection and reconstruction of the esophagus remains fraught with morbidity and mortality. Recently, data from a porcine reconstruction model revealed that segmental esophageal reconstruction using an autologous mesenchymal stromal cell-seeded polyurethane graft (Cellspan esophageal implant [CEI]) can facilitate esophageal regrowth and regeneration. To this end, a patient requiring a full circumferential esophageal segmental reconstruction after a complex multiorgan tumor resection was approved for an investigational treatment under the Food and Drug Administration Expanded Access Use (Investigational New Drug 17402).

Methods

Autologous adipose-derived mesenchymal stromal cells (Ad-MSCs) were isolated from the Emergency Investigational New Drug patient approximately 4 weeks before surgery from an adipose tissue biopsy specimen. The Ad-MSCs were grown and expanded under current Good Manufacturing Practice manufacturing conditions. The cells were then seeded onto a polyurethane fiber mesh scaffold (Cellspan scaffold) and cultured in a custom bioreactor to manufacture the final CEI graft. The cell-seeded scaffold was then shipped to the surgical site for surgical implantation. After removal of a tumor mass and a full circumferential 4 cm segment of the esophagus that was invaded by the tumor, the CEI was implanted by suturing the tubular CEI graft to both ends of the remaining native esophagus using end-to-end anastomosis.

Results

In this case report, we found that a clinical-grade, tissue-engineered esophageal graft can be used for segmental esophageal reconstruction in a human patient. This report reveals that the graft supports regeneration of the esophageal conduit. Histologic analysis of the tissue postmortem, 7.5 months after the implantation procedure, revealed complete luminal epithelialization and partial esophageal tissue regeneration.

Conclusions

Autologous Ad-MSC seeded onto a tubular CEI tissue-engineered graft stimulates tissue regeneration following implantation after a full circumferential esophageal resection.

Induction versus no induction chemotherapy before neoadjuvant chemoradiotherapy and surgery in oesophageal adenocarcinoma: a multicentre randomised phase II trial (NCCTG N0849 [Alliance])

AIM

report primary results from the first multicentre randomised trial evaluating induction chemotherapy prior to trimodality therapy in patients with oesophageal or gastro-oesophageal junction adenocarcinoma. Notably, recent data from a single-institution randomised trial reported that induction chemotherapy prolonged overall survival (OS) in patients with well/moderately differentiated tumours.

METHODS

In this phase 2 trial (28 centres in the U.S. NCI-sponsored North Central Cancer Treatment Group [Alliance]), trimodality-eligible patients (T3-4N0, TanyN+) were randomised to receive induction (docetaxel, oxaliplatin, capecitabine; Arm A) or no induction chemotherapy (Arm B) followed by oxaliplatin/5-fluorouracil/radiation and subsequent surgery. The primary endpoint was the rate of pathologic complete response (pathCR). Secondary/exploratory endpoints were OS and disease-free survival (DFS).

RESULTS

Of 55 patients evaluable for the primary endpoint, the pathCR rate was 28.6% (8/28) in A versus 40.7% (11/27) in B (P = .34). Given interim results indicating futility, accrual was terminated, but patients were followed. After a median follow-up of 60.4 months, a longer median OS in Arm A versus B was unexpectedly observed (3-year rates 57.1% versus 41.7%, respectively) driven by longer DFS after margin-free surgery. In posthoc analysis, induction (versus no induction) chemotherapy was associated with significantly longer OS and DFS among patients with well/moderately differentiated tumours, but not among patients with poorly/undifferentiated tumours (Pinteraction = 0.037).

CONCLUSIONS

Adding induction chemotherapy prior to trimodality therapy did not improve the primary endpoint, pathCR. However, induction chemotherapy was associated with longer median OS, particularly among patients with well/moderately differentiated tumours. These findings may inform further development of curative-intent trials in this disease.

Autologous blood patch pleurodesis for prolonged postoperative air leaks

Background

A prolonged air leak (PAL) is the most frequent complication after pulmonary resection. This study aimed to assess the safety and efficacy of autologous blood patch pleurodesis (ABPP) to treat PAL.

Methods

A prospectively maintained database identified patients with a PAL after pulmonary resection for lung cancer between 2015–2019. In this observational cohort study, clinical data were collected to retrospectively compare patients undergoing ABPP to no ABPP in a propensity-matched analysis. Kaplan Meier estimates and Cox models accounting for inverse probability weighting (IPTW) were used to assess the association of ABPP with each outcome.

Results

Of the 740 patients undergoing lung resection, 110 (15%) were identified as having a PAL at postoperative day (POD) 5. There was no difference between baseline characteristics among those undergoing ABPP (n=34) versus no ABPP (n=76). Propensity-weighted analysis did not reveal a significant association of ABPP treatment with in-hospital complication (P=0.18), hospital length of stay (LOS) (P=0.13), or post-discharge complication (P=0.13). However, ABPP treatment was associated with a lower risk of hospital readmission [P=0.02, hazard ratio (HR) 0.16] and reoperation for air leak or empyema (P=0.05, HR 0.11). Although not statistically significant, the mean chest tube (CT) removal of 11 days for the ABPP group was less than the no ABPP group (16 days) (P=0.14, HR 1.5–2). Those treated with ABPP were less likely to be discharged with a CT (ABPP 7/34, 21% vs. no ABPP 40/76, 53%). There was no statistical difference in empyema development between groups (ABPP 0/34, 0% vs. no ABPP 4/76, 5%, P=0.39, HR 0.24).

Conclusions

ABPP administration is safe compared to traditional PAL management. In a retrospective propensity-matched analysis, postoperative patients treated with ABPP required less readmission and reoperation for PAL. Larger powered randomized trials may demonstrate the magnitude of benefit from treatment with ABPP.

Integration of immunotherapy into adjuvant therapy for resected non-small-cell lung cancer: ALCHEMIST chemo-IO (ACCIO)

Non-small-cell lung cancer (NSCLC) causes significant mortality each year. After successful resection of disease stage IB (>4 cm) to IIIA (per AJCC 7), adjuvant platinum-based chemotherapy improves median overall survival and is the standard of care, but many patients still experience recurrence of disease. An adjuvant regimen with greater efficacy could substantially improve outcomes. Pembrolizumab, a programmed cell death-1 inhibitor, has become an important option in the treatment of metastatic NSCLC. ALCHEMIST is a clinical trial platform of the National Cancer Institute that includes biomarker analysis for resected NSCLC and supports therapeutic trials including A081801 (ACCIO), a three-arm study that will evaluate both concurrent chemotherapy plus pembrolizumab and sequential chemotherapy followed by pembrolizumab to standard of care adjuvant platinum-based chemotherapy.

Clinical trial registration: NCT04267848 (ClinicalTrials.gov)

Non-small-cell lung cancer adjuvant platinum-based therapy is standard of care (SOC). Including pembrolizumab may improve efficacy. A081801 (ACCIO) is a three-arm study: SOC versus sequential chemotherapy–pembrolizumab versus concurrent chemotherapy + pembrolizumab.

Perioperative outcomes of pulmonary resection after neoadjuvant pembrolizumab in patients with non-small cell lung cancer

OBJECTIVES

Pembrolizumab is a programmed death receptor-1 masking antibody approved for metastatic non-small cell lung cancer. This Phase 2 study (NCT02818920) of neoadjuvant pembrolizumab in non-small cell lung cancer had a primary end point of safety and secondary end points of efficacy and correlative science.

METHODS

Patients with untreated clinical stage IB to IIIA non-small cell lung cancer were enrolled. Two cycles of pembrolizumab (200 mg) were administered before surgery. Standard adjuvant chemotherapy and radiation were encouraged but not required. Four cycles of adjuvant pembrolizumab were provided.

RESULTS

Of 35 patients enrolled, 30 received neoadjuvant pembrolizumab and 25 underwent lung resection. Only 1 patient had a delay before surgery attributed to pembrolizumab; this was due to thyroiditis. All patients underwent anatomic resection and mediastinal lymph node dissection; the majority (18/25%, 72%) of patients underwent lobectomy. Of the 25 patients, 23 had an initial minimally invasive approach (92%); 5 of these were converted to thoracotomy (21.7%). R0 resection was achieved in 22 patients (88%), and major pathologic response was observed in 7 of 25 patients (28%). The most common postoperative adverse event was atrial fibrillation, affecting 6 of 25 patients (24%). Median chest tube duration and length of stay were 3 and 4 days, respectively. One patient required readmission to the hospital within 30 days. There was no mortality within 90 days of surgery.

CONCLUSIONS

In this study, pembrolizumab was safe and well tolerated in the neoadjuvant setting, and its use was not associated with excess surgical morbidity or mortality. Minimally invasive approaches are feasible in this patient population, but may be more challenging than in cases without neoadjuvant immunotherapy. Pathologic response was higher than typically observed with standard neoadjuvant chemotherapy.

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'.

HER2-overexpression/amplification and survival in patients with resectable esophageal/gastroesophageal junction adenocarcinoma (E/GEJ-AC) treated with neoadjuvant carboplatin/paclitaxel-based chemoradiation

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Background: After trastuzumab (T) approval for advanced HER2-positive E/GEJ-AC, HER2 testing has increased in patients (pts) with resectable disease. Neoadjuvant carboplatin/paclitaxel chemoradiation (nCP-CRT) is a common therapy approach. We performed the largest evaluation, to our knowledge, of the prognostic impact of HER2 in E/GEJ-AC pts treated with nCP-CRT. Methods: We retrospectively reviewed medical records of all trimodality-eligible (T2+ or N+) pts with E/GEJ-AC who started nCP-CRT (usually 50.4 Gy) with planned surgery at Mayo Clinic (2014-2019). HER2 was tested using standard criteria for HER2 positivity (ie, immunohistochemistry 3+ or amplification by in situ hybridization). Clinicopathologic data and time to recurrence (TTR), disease free survival (DFS), overall survival (OS), survival after recurrence (SAR), and pathologic complete response (pCR – ie, no residual tumor in primary or nodes) were collected. Kaplan Meier and multivariate Cox analysis were used. Results: Of 161 consecutive eligible pts, HER2 status was available in 107 pts (HER2-positive n=26, HER2-negative n=81) of whom n=82 had surgery and n=19 had pCR. Most tumors were clinical T3 (80%) or N+ (81%), histologic grade 3 of 3 (62%). HER2 positivity was significantly associated with lower grade, but not with age, clinical T or N, or ECOG performance status (PS). A similar proportion of HER2-positive ( vs negative) pts had surgery. Among pts who had surgery, pCR rates were lower in HER2-positive ( vs negative) pts (11% [2/19] vs 27% [17/63]). After a median follow up of 23 mo, DFS and TTR were significantly shorter in HER2 positive ( vs negative) pts, independent of other pretreatment covariables (Table). Yet OS was comparable. Lung recurrence was enriched in HER2 positive ( vs negative) pts. Among pts with recurrence, SAR was longer in HER2-positive vs -negative pts. A total of 53% (10/19) of previously HER2-positive pts received T-based therapy after recurrence, and these pts were the drivers of favorable SAR (median 22 mo in n=10 HER2-positive pts who received T vs 11 mo in n=9 HER2-positive pts who did not receive T vs 11 mo in n=40 HER2-negative pts; P log-rank=.01). Conclusions: HER2 positivity ( vs negativity) is independently associated with shorter TTR and DFS, but more comparable OS. The adverse association of HER2 on tumor response and TTR may have been largely overcome through enhanced survival after recurrence, although OS data are maturing. These data may have implications for the design of endpoints in future curative-intent anti-HER2 trials. [Table: see text]

Serial evaluation of segmental esophageal reconstruction using a polyurethane scaffold in a pig model

Background

Many esophageal pathologies are clinically treated by resection and reconstruction of the esophagus. Surgical esophagectomy remains a morbid procedure and despite minimally invasive advances, has changed little in decades. Novel approaches to esophageal segmental resection and reconstruction are an unmet need.

Methods

Circumferential thoracic esophageal transection was performed in both male and female pigs and the defects reconstructed using 5 or 10 cm polyurethane (PU) tubular grafts and stented. A subset were treated with stent only. Animals were survived to 14, 30, 60, and 399 days. Tissues were evaluated histologically, and via non-invasive serial endoscopy and contrast swallowing studies in long-term animals.

Results

Luminal patency was achieved in all animals with no clinical evidence of leak. In short-term animals, there was healing noted in all cases with a variably sized region of ulceration remaining at the most central part of the repaired tube (between the proximal and distal anastomosis). In four long-term animals following stent removal, two resumed normal diet and thrived, while two animals were euthanized prior to the proposed endpoint because of stricture formation and inability to tolerate a normal diet. Re-epithelialization was observed in all groups, and more complete over time.

Conclusions

The PU scaffold provides a matrix across which formation of new tissue can occur. The mechanisms through which this happens remain unclear, but likely a combination of fibrosis and tissue contraction, in conjunction with new tissue formation.

Optimizing clinical cytology touch preparations for next generation sequencing

Intraoperative diagnosis is routinely performed on cytology touch preparations (TPs) from core needle biopsies (CNBs). Current interest promotes their utility as an important source of patient tissue for clinical genomic testing. Herein we present whole genome structural variant analysis (SVA) from mate-pair sequencing (MPseq) and whole exome sequencing (WES) mutation calling in DNA directly whole genome amplified (WGA) from TPs. Chromosomal copy changes and somatic DNA junction detection from MPseq of TPs were highly consistent with associated CNBs and bulk resected tissues in all cases. While increased frequency coverage noise from limitations of amplification of limited sample input was significant, this was effectively compensated by natural tumor enrichment during the TP process, which also enhanced variant detection and loss of heterozygosity evaluations from WES. This novel TP methodology enables expanded utility of frequently limited CNB for both clinical and research genomic testing.

Management of Epiphrenic Diverticula and Short-term Outcomes

Epiphrenic diverticulum is a rare and benign condition with significant surgical morbidity and evolving surgical management. The objective of this study was to analyze short-term clinical outcomes after surgery for epiphrenic diverticula. We conducted a retrospective cohort study in a single tertiary care center of all patients who underwent treatment for epiphrenic esophageal diverticula from June 1990 to December 2016. Data collection included demographics, operative details and short-term outcomes (esophageal leak, other complications, 30-day mortality). In addition, all preoperative imaging was reviewed by an esophageal radiologist in order to describe epiphrenic diverticula characteristics in a uniform and blinded manner. Of the 94 patients in the study, 84 patients were managed with an open surgical approach and 10 with minimally invasive techniques. Median size of diverticula was 5.5 cm and mean height above gastroesophageal junction was 4 cm. A myotomy was completed in 95% of patients and a fundoplication in 58%. The MIS group had a shorter length of stay (4 vs 6 days). Overall complication rate was 27% with an esophageal leak rate of 7% with 60% grade I leaks that sealed with conservative management. Complete resection of the diverticulum, closure of the muscle over the resection, contralateral myotomy, and consideration for partial fundoplication are common strategies utilized to surgically treat patients with epiphrenic diverticulum. Minimally invasive approaches are increasingly utilized.

Predictors of Patient-Reported Reflux After Esophagectomy

BACKGROUND

Patient-reported reflux is among the most common symptoms after esophagectomy. This study aimed to determine predictors of patient-reported reflux and to ascertain whether a preserved pylorus would protect patients from symptomatic reflux.

METHODS

A prospective clinical study recorded patient-reported reflux after esophagectomy from August 2015 to July 2018. Eligible patients were at least 6 months from creation of a traditional posterior mediastinal gastric conduit, had completed at least 1 reflux questionnaire, and had the pylorus treated either temporarily (≥100 IU Botox [onabotulinumtoxinA]) or permanently (pyloromyotomy or pyloroplasty).

RESULTS

Of the 110 patients meeting inclusion criteria, the median age was 65 years, and 88 of the 110 (80%) were male. Botox was used in 15 (14%) patients, pyloromyotomy in 88 (80%), and pyloroplasty in 7 (6%). A thoracic anastomosis was performed in 78 (71%) patients, and a cervical anastomosis was performed in 32 (29%). Esophagectomy was performed for malignant disease in 105 of 110 (95%), and 78 of 110 (71%) patients were treated with perioperative chemoradiation. Multivariable linear regression analysis revealed that patient-reported reflux was significantly worse in patients with shorter gastric conduit lengths (P = .02) and in patients who did not undergo perioperative chemoradiation (P = .01). No significant difference was found between patients treated with pyloric drainage and those treated with Botox.

CONCLUSIONS

The absence of perioperative chemoradiation therapy and a shorter gastric conduit were predictors of patient-reported reflux after esophagectomy. Although few patients had Botox, preservation of the pylorus did not appear to affect patient-reported reflux. Further objective studies are needed to confirm these findings.

Trastuzumab with trimodality treatment for esophageal adenocarcinoma with HER2 overexpression: NRG Oncology/RTOG 1010

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Background: Trastuzumab is a monoclonal antibody against human epidermal growth factor receptor 2 (HER2). The primary objective of RTOG 1010 was to determine if trastuzumab increases disease-free survival (DFS) when combined with trimodality treatment for patients with HER2 overexpressing esophageal adenocarcinoma. Methods: This open label, randomized phase III trial included patients with newly diagnosed stage T1N1-2, T2-3N0-2 adenocarcinoma of the esophagus involving the mid, distal, or esophagogastric junction and up to 5cm of the stomach. All patients received chemotherapy (C) of paclitaxel, 50mg/m2 and carboplatin AUC = 2, weekly for 6 weeks, with radiation (XRT: 3D-CRT or IMRT, 50.4 Gy in 28 fractions) followed by surgery. Patients were randomized 1:1 to receive weekly trastuzumab 4mg/kg week 1 then 2mg/kg/weekly x 5 during CXRT then 6 mg/kg for 1 dose prior to surgery and 6mg/kg every 3 weeks for 13 treatments after surgery. HER2 status was determined by IHC and gene amplification by FISH. With a 2-sided alpha of 0.05, 162 DFS events provide 90% power to detect a signal for an increase in median DFS from 15 to 25 months. DFS and overall survival (OS) were estimated by the Kaplan-Meier method. and arms were compared using the log rank test. The Cox proportional hazards model was used to analyze treatment effect. Results: 571 patients were entered for assessment of HER2 expression, 203 HER2+ patients randomized. The median follow-up for alive patients is 5.0 years. The estimated 2, 3, and 4-year DFS (95% CI) for the CXRT +trastuzumab arm were 41.8% (31.8%, 51.7%), 34.3% (24.7%, 43.9%), and 33.1% (23.6%, 42.7%), respectively, and for the CXRT arm were 40.0% (30.0%, 49.9%), 33.4% (23.8%, 43.0%), and 30.1% (20.7%, 39.4%), respectively; log-rank p = 0.85. The median DFS time is 19.6 months (13.5-26.2) for the CXRT +trastuzumab arm compared to 14.2 months (10.5-23.0) for the CXRT arm. The hazard ratio (95% CI) comparing the DFS of CXRT+trastuzumab arm to the CXRT arm was 0.97 (0.69, 1.36). The median OS time was 38.5 months (26.2-70.4) for the CXRT+trastuzumab arm compared to 38.9 months (29.0-64.5) for the CXRT arm, hazard ratio (95% CI): 1.01 (0.69, 1.47). There was no statistically significant increase in treatment-related toxicities with the addition of trastuzumab including no increase in cardiac events. Conclusions: The addition of trastuzumab to trimodality treatment did not improve DFS for patients with HER2 overexpressing esophageal adenocarcinoma. Supported by NCI grants U10CA180868, UG1CA189867, U10CA180822 and Genentech. Clinical trial information: NCT01196390 .

Management of bronchopulmonary carcinoid: NCDB database analysis

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Background: There is a lack of data to guide the management of resectable bronchopulmonary carcinoid tumors (BCTs). Methods: The NCDB database was retrospectively reviewed to analyze the roles of surgery, chemotherapy and radiation. Patients with a diagnosis of clinically staged T1-2/N0-1 typical carcinoid (TC) and atypical carcinoid (AC) between 2004-2012 were included. Kaplan-Meier methods and multivariable analysis were performed. Results: A total of 2148 patients (TC 1874 & AC 274; T1/1648 & T2/500) were identified. The median age was 59 (range 18-89). There was a female (69.7%) and right lung (56.9%) predominance. Fifty-three patients received pneumonectomy, 68 chemotherapy, and 84 radiation therapy. The impact of age, histology (TC vs. AC), medical comorbidities (Charlson/Deyo score 0 vs. ≥1) and type of surgery [sublobar resection (SR) vs. lobectomy vs. lobectomy with mediastinal lymph node dissection (L/MLND)] were subsequently examined. AC, older age, and comorbidities were associated with shorter overall survival (OS) by both univariate and multivariable analysis. Patients who underwent lobectomy had longer OS (119 months) than those with SR (109 months) or L/MLND (115 months). However, this association was not significant by multivariable analysis with age incorporated as either a categorical ( < 60 vs. ≥60) or a continuous variable (Table). In the subgroup analysis of patients with T1, T2, TC and AC respectively, type of surgical resection was not significantly associated with OS by multivariable analysis. Conclusions: Patients with resectable BCTs have excellent OS. Atypical histology, older age, and comorbidities predicted inferior OS. There were insufficient data to support the use of perioperative chemotherapy or radiation therapy. Lobectomy was associated with prolonged OS by univariate analysis but this was not significant in the multivariable model, suggesting that SR is a reasonable approach for patients who cannot tolerate lobectomy. MLND did not seem to provide additional survival benefits. [Table: see text]

Surgery for Mesothelioma After Radiation Therapy (SMART); A Single Institution Experience

Background: The optimal treatment sequence for localized malignant pleural mesothelioma (MPM) is controversial. We aimed to assess outcomes and toxicities of treating localized MPM with neoadjuvant radiation therapy (RT) followed by extrapleural pneumonectomy (EPP). Methods: Patients were enrolled on an institutional protocol of surgery for mesothelioma after radiation therapy (SMART) between June 2016 and May 2017. Eligible patients were adults with MPM localized to the ipsilateral pleura. Patients underwent staging with PET/CT, pleuroscopy, bronchoscopy/EBUS, mediastinoscopy, and laparoscopy. Five fractions of RT were delivered using intensity modulated radiation therapy (IMRT), with 30 Gy delivered to gross disease and 25 Gy to the entire pleura. EPP was performed 4-10 days following completion of RT. Results: Five patients were treated on protocol. Median age was 62 years (range 36-66). Histology was epithelioid on initial biopsy in all patients, but one was found to have biphasic histology after surgery. Three patients had surgeon-assessed gross total resection, and two had gross residual disease. While all patients were clinically node negative by pretreatment staging, three had positive nodal disease at surgery. Patients were hospitalized for a median 24 days (range 5-69) following surgery. Two patients developed empyema, one of whom developed respiratory failure and subsequently renal failure requiring dialysis, while the other required multiple surgical debridements. Two patients developed atrial fibrillation with rapid ventricular response after surgery, one of whom developed acute respiratory distress requiring intubation and tracheostomy. At last follow-up, one patient died at 1.4 years after local and distant progression, two were alive with local and distant progression, and the remaining two were alive without evidence of disease at 0.1 and 2.7 years. Median time to progression was 9 months. Three patients received salvage chemotherapy. Conclusions: SMART provided promising oncologic outcomes at the cost of significant treatment related morbidity. Due to the significant treatment associated morbidity and favorable treatment alternatives, we have not broadly adopted SMART at our institution.

Postoperative Opioid Consumption in Thoracic Surgery Patients: How Much Is Actually Used?

BACKGROUND

The objective of this initiative was to perform a prospective, multicenter survey of patients after lung resection to assess the amount of opioid medication consumed and the disposition of unused opioids to inform the development of evidence-based prescribing guidelines.

METHODS

Adults undergoing lung resection with either minimally invasive surgery (MIS; n = 108) or thoracotomy (n = 45) were identified prospectively from 3 academic centers (from March 2017 to January 2018) to complete a 28-question telephone survey 21 to 35 days after discharge. Discharge opioids were converted into morphine milligram equivalents (MME) and were compared across patient and surgical details.

RESULTS

Of the 153 patients who completed the survey, 89.5% (137) received opioids at discharge with a median prescription of 320 MME (interquartile range [IQR], 225, 450 MME) after MIS and 450 MME (IQR, 300, 600 MME) after thoracotomy (P = .001). Median opioid consumption varied by surgical approach: 90 MME (IQR, 0, 262.5) after MIS and 300 MME (IQR, 50, 382.5 MME) after thoracotomy (P < .001). The majority of patients (73.7%; 101) had residual opioid medication at the time of the survey, and patients after MIS had a relative increase in amount of remaining opioid medication: 58.3% vs 33.3% (P = .05) of the original prescription. Only 5.9% of patients with opioids remaining had properly disposed of them.

CONCLUSIONS

Although patients undergoing MIS lung resection used significantly less opioid medication over a shorter duration of time than did patients after thoracotomy, they had relatively more excess opioid prescription. Evidence-based, procedure-specific guidelines with tailored pain regimens should be developed and implemented to reduce the amount of postoperative opioid medication remaining in the community.

Abstract 728: Genomic alterations in lung adenocarcinoma precursor lesions

Background: Adenocarcinoma of the lung is the most common type of non-small cell lung cancer and is the subtype found in approximately 50% of all lung cancer cases. Adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) are thought to be precursor lesions of invasive disease. It has been hypothesized that there is a step-wise progression to lung adenocarcinoma, but little is known about genomic alterations in these precursor lesions.

Methods: Genomic analysis including whole genome and exome sequencing, and SNP array analysis were performed on 9 AIS and 18 MIA pathologically confirmed samples to identify single nucleotide variants (SNVs), structural variations and copy number variations. Mutation significance and signature analysis were determined by MutSig and NMF analyses. Altered pathways were determined by Ingenuity variant effect pathway analysis.

Results: The tumor mutation burden (TMB) for AIS and MIA ranged from 0.8 to 23.1 mut/Mb with a median of 3.0mut/Mb and a mean of 5.1mut/Mb. Highly mutated genes identified in AIS and MIA were RPL10, NBPF1, KRAS, GPR52, CAMK2A, ATOX1, STK11, TP53, MET and EGFR. Genes with recurrent mutations included SPTA1, USH2A, CACNA1E, EGFR, KRAS, MUC16, MUC17, OTOG, RYR2, COL20A1, CSMD3, RFX6 and XIRP2, which implicated pathways involving the EGFR-KRAS-TP53-MAPK axis. Somatic mutations were characterized by a C&gt;T, T&gt;C transitions and C&gt;A transversion signature. There were comparable structural variations in the AIS cases compared to MIA.

Conclusion: In contrast to hypothesized models of tumor progression, AIS and MIA can harbor significant genomic alterations and tumor mutation burden, which suggests an intriguing concept of immunotherapeutic options for either treatment or chemoprevention. Deregulation of EGFR-KRAS-TP53-MAPK pathway indicates a role in early events of carcinogenesis.

Citation Format: Michael K. Asiedu, Nanette R. Reed, Marie Christine Aubry, Anja C. Roden, Dennis A. Wigle. Genomic alterations in lung adenocarcinoma precursor lesions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 728.

Using Genomics to Differentiate Multiple Primaries From Metastatic Lung Cancer

INTRODUCTION

Genomic technologies present a promising mechanism of resolving the clinical dilemma of distinguishing independent primary tumors from intrapulmonary metastases in NSCLC. We evaluated the utility of discordant mapping somatic junctions from chromosomal rearrangements in diagnosing metastatic disease compared to the current standard histologic review.

MATERIAL AND METHODS

Mate-pair sequencing was performed on DNA extracted from 76 distinct tumors from 37 cases of multiple lung cancers. Discordant mapping junctions and chromosomal copy levels were assessed for each tumor. Blood-derived DNA was available on 22 of these cases for germline assessments. A lung cancer next-generation sequencing panel was additionally performed on tumor pairs from 17 patients.

RESULTS

Whereas mate-pair sequencing was able to classify lineage in all tumor pairs, histologic review appeared to misclassify lineage in 9 of 33 (27%) same-histology tumor pair comparisons. Based on disagreement between the reviewing pathologists, histopathologic lineage was classified as indeterminate in seven cases. In two cases where pathologists agreed on a metastatic call, no shared junctions were found suggesting independent primaries. Although germline junctions passing algorithmic filters were common, on average less than three were present and all had predictable structures of small focal rearrangements or transposons. Evaluation of shared chromosomal copy changes and driver mutations through a lung cancer next-generation sequencing panel, while informative, were nondefinitive in calling lineage in all cases.

CONCLUSIONS

The highly unique nature and prevalence of chromosomal rearrangement in lung cancers provide a useful and definitive technique for calling lineage in multifocal lung cancer.

Immune Cell Infiltration May Be a Key Determinant of Long-Term Survival in Small Cell Lung Cancer

INTRODUCTION

Although most patients with SCLC die within a few months of diagnosis, a subgroup of patients survive for many years. Factors determining long-term survivorship remain largely unknown. We present the first comprehensive comparative genomic and tumor microenvironment analyses of SCLC between patients with long-term survivorship and patients with the expected survivorship.

METHODS

We compared surgically resected tumors of 23 long-term SCLC survivors (survival >4 years) and 18 SCLC survivors with the expected survival time (survival ≤2 years). There were no significant differences in clinical variables, including TNM staging and curative- versus non-curative-intent surgery between the groups. Gene expression profiling was performed by using microarrays, and tumor microenvironment analyses were performed by immunohistochemistry of prominent immune-related markers.

RESULTS

Immune-related genes and pathways represented the majority of the differentially overexpressed genes in long-term survivorship compared with in expected survivorship. The differences in the immunological tumor microenvironment were confirmed by quantitative immunostaining. Increased numbers of tumor-infiltrating and associated lymphocytes were present throughout tumors of long-term survivors of SCLC. Several differentiating patterns of enhanced antitumor immunity were identified. Although some areas of the tumors of long-term survivors of SCLC also harbored higher numbers of suppressive immune cells (monocytes, regulatory lymphocytes, and macrophages), the ratios of these suppressive cells to CD3-positive lymphocytes were generally lower in the tumors of long-term survivors of SCLC, indicating a less tumor-suppressive microenvironment.

CONCLUSIONS

Our data demonstrate that long-term survivorship of patients with SCLC is strongly influenced by the presence of the immune cells in the tumor microenvironment. Characterization of the antitumor immune responses may identify opportunities for individualized immunotherapies for SCLC.

Comparison of Laparoscopic Versus Open Surgical Management of Morgagni Hernia

BACKGROUND

Morgagni hernias are rare congenital diaphragmatic hernias that often do not become clinically significant until adulthood. The purpose of this study was to characterize the preoperative findings and describe surgical outcomes of Morgagni hernia repair based on operative approach.

METHODS

Charts of patients who underwent repair of a Morgagni hernia were retrospectively reviewed from 1987 to 2015. Medical records were reviewed for demographics, symptoms, comorbidities, surgical approach, hospital course, complications, and preoperative imaging.

RESULTS

Forty-three cases were identified, 23 male and 20 female. Median age was 50.4 years, and median body mass index was 33.1 kg/m². Most common presenting symptoms were respiratory (35.7%) and gastrointestinal (28.6%). Although 83.3% of cases were newly diagnosed, none required emergent repair. Preoperative imaging demonstrated an average hernia size of 8.2 cm. Surgical approaches included laparotomy (62.8%), laparoscopic (23.3%), and thoracotomy (14%). Primary hernia repair was most common (72%). Comparing laparotomy, thoracotomy, and laparoscopic approaches, mesh repair was more common with laparoscopy (p = 0.005), operative time was shortest with laparotomy (p = 0.029), and hospital length of stay was shortest with laparoscopy (p = 0.024). The most common complication was incisional/port site hernia, with no statistical significance between surgical approaches. There was one Morgagni hernia recurrence.

CONCLUSIONS

Morgagni hernias often present with respiratory and gastrointestinal symptoms and require repair. All cases in our series were repaired electively. Regardless of approach recurrence rate was low (2.3%) and complication rate was similar between laparoscopic, laparotomy, and thoracotomy. Given the shorter length of stay with similar recurrence rates, a laparoscopic approach is a viable option for repair of Morgagni hernia.

Long-term regeneration and remodeling of the pig esophagus after circumferential resection using a retrievable synthetic scaffold carrying autologous cells

Treatment of esophageal disease can necessitate resection and reconstruction of the esophagus. Current reconstruction approaches are limited to utilization of an autologous conduit such as stomach, small bowel, or colon. A tissue engineered construct providing an alternative for esophageal replacement in circumferential, full thickness resection would have significant clinical applications. In the current study, we demonstrate that regeneration of esophageal tissue is feasible and reproducible in a large animal model using synthetic polyurethane electro-spun grafts seeded with autologous adipose-derived mesenchymal stem cells (aMSCs) and a disposable bioreactor. The scaffolds were not incorporated into the regrown esophageal tissue and were retrieved endoscopically. Animals underwent adipose tissue biopsy to harvest and expand autologous aMSCs for seeding on electro-spun polyurethane conduits in a bioreactor. Anesthetized pigs underwent full thickness circumferential resection of the mid-lower thoracic esophagus followed by implantation of the cell seeded scaffold. Results from these animals showed gradual structural regrowth of endogenous esophageal tissue, including squamous esophageal mucosa, submucosa, and smooth muscle layers with blood vessel formation. Scaffolds carrying autologous adipose-derived mesenchymal stem cells may provide an alternative to the use of a gastro-intestinal conduit for some patients following resection of the esophagus.

Analysis of Patients Discharged From the Hospital With a Chest Tube in Place

BACKGROUND

Persistent air leak can complicate pulmonary resection, and one management option is dismissal with a chest tube in place. This study evaluated the rate of empyema and readmission after dismissal with a chest tube.

METHODS

A retrospective review of our prospective database from January 2004 to December 2013 identified 236 patients who were discharged from our institution with an indwelling chest tube and attached one-way valve for air leak. Empyema was defined by leukocytosis or fever and undrained effusion on chest roentgenogram or computed tomography. Readmission was defined as readmission for any reason. Logistic regression analyses were performed to identify risk factors for empyema or readmission.

RESULTS

Median age was 67 years (range, 18 to 91 years). Median chest tube duration was 18 days (range, 6 to 90 days). Empyema occurred in 40 patients (16.9%), and 62 patients (26.3%) were readmitted. Treatment required included antibiotics alone in 45% (18 of 40), further drainage in 30% (12 of 40), fibrinolytic therapy in 12.5% (5 of 40), and operative decortication in 12.5% (5 of 40). Predictors of empyema included male sex, coronary artery disease, and peripheral vascular disease. A secondary analysis grouping patients into an earlier era (2004 to 2008) vs a later era (2009 to 2013) revealed that the use of thoracoscopy increased from 34% to 48% of lung resections and dismissal with a chest tube increased from 3.4% to 4.5% (p = 0.03).

CONCLUSIONS

Dismissal with an indwelling chest tube is not without consequence, having significant risk for further complications and potential need for additional interventions.

Chylothorax as a Risk Factor for Thrombosis in Adults: A Proof-of-Concept Study

BACKGROUND

Postoperative chylothorax in children is associated with an increased risk of vascular thrombosis, hypothesized to be from loss of antithrombin into chylous fluid resulting in a hypercoagulable state. In adults, an increased thrombotic risk with chylothorax has not been described. Adults undergoing Ivor-Lewis esophagogastrectomy have two strong thrombotic risk factors-active malignancy and postoperative state-allowing for relative homogeneity in baseline thrombotic risk; therefore, we studied the association of chylothorax with thrombosis in this population.

METHODS

We performed a single-center retrospective cohort study at a tertiary care academic center. Patients included adults undergoing Ivor-Lewis esophagogastrectomy between January 1, 2006, and December 31, 2012. We collected demographics, pleural fluid characteristics, and relevant imaging within 30 days after the operation. Using nominal logistic regression, we studied the effects of chylothorax, age, sex, body mass index, American Society of Anesthesiologists Physical Status Classification, operative duration, and hospital length of stay on the incidence of postoperative thrombosis.

RESULTS

We identified 608 patients who underwent Ivor-Lewis esophagogastrectomy. Of these, 524 (86.2%) had no pleural fluid analysis, 48 (7.9%) had nonchylous effusions, and 36 (5.9%) had chylothoraces, with incident acute vascular thrombosis within 30 days postoperatively occurring in 22 of 524 (4.2%), 2 of 48 (4.2%), and 8 of 36 (22.2%), respectively (p = 0.001). In multivariate analyses, after adjusting for the above factors, chylothorax was associated with significantly higher odds of any vascular thrombosis (odds ratio, 5.46; p = 0.0013) and deep venous thrombosis/pulmonary embolism (odds ratio, 6.76; p = 0.0016).

CONCLUSIONS

Chylothorax is associated with a significantly higher incidence of vascular thrombosis in adults undergoing Ivor-Lewis esophagogastrectomy. Vascular thrombosis was associated with a significantly higher 90-day mortality rate.

Full-thickness oesophageal regeneration in pig using a polyurethane mucosal cell seeded graft

Malignant oesophageal pathology typically requires resection of a portion of oesophagus. The aim of this study was to investigate attachment and growth of swine oesophageal mucosal cells on electrospun synthetic nanofibre matrices of varying chemistries and to determine whether a mucosal-seeded graft, in a swine animal model, could induce regeneration. Swine mucosal oesophageal cells were isolated and seeded them onto five different matrix materials. Matrix samples were cultured for up to 14 days, after which matrices were analysed for cell attachment. Attachment varied for each of the matrix materials tested, with the most rigid showing the lowest levels of attachment. Importantly, sections of these matrices illustrated that multiple layers of mucosal cells formed, mimicking endogenous oesophageal structure. A tdTomato reporter line (mucosal^tdt cells) was created to enable cell tracking. As polyurethane matrix was found optimal through in vitro testing, a graft was prepared using mucosal^tdt cells, along with an unseeded control, and implanted into swine for determination of oesophageal regeneration. Mucosal seeded polyurethane grafts initiated full thickness regeneration of the oesophagus, including epithelial, submucosal, and skeletal muscle layers which were highly vascularized. Interestingly, an unseeded graft showed similar regeneration, indicating that the role of cells in the process of oesophageal regeneration is still unclear. The electrospun polyurethane matrix does appear suitable for multilayered cellular attachment and growth of oesophageal mucosal cells, and implantation of polyurethane grafts initiated full thickness regeneration of the oesophagus, indicating potential for oesophageal reconstruction in humans. Copyright © 2016 John Wiley & Sons, Ltd.

Treatment of Postsurgical Chylothorax

BACKGROUND

Postoperative chylothorax can be managed by any or all of observation, parenteral nutrition, surgical duct ligation, pleurodesis, or thoracic duct embolization. The objective of this study was to determine the efficacy of standard therapies, such as surgical duct ligation and observation, compared with newer treatment methods (thoracic duct embolization).

METHODS

A prospectively maintained database at a single institution was used to identify and review patients with postoperative chylothorax from 2008 to 2015.

RESULTS

Postoperative chylothorax occurred in 97 patients, including 54 men (56%). The median age was 61 years (range, 24 to 87 years). Thoracic duct leak followed esophagectomy in 46 patients (47%), pulmonary resection in 30 (31%), mediastinal mass resection in 7 (8%), and after other procedures in 15. Of 28 medically observed patients achieving resolution without intervention, the median peak chest tube output in 24 hours was 725 mL compared with 1,910 mL in the group that required intervention (p = 0.0001). Thoracic duct ligation was successful in 44 of 52 patients that proceeded to the operating room (85%). Of the 40 patients undergoing diagnostic lymphangiography, a leak was identified in 34 (85%), but the cisterna chyli could only be cannulated in 19 (48%) and was subsequently successful in 15 (38%).

CONCLUSIONS

Patients with chylous chest tube outputs of 1,100 mL or more in 24 hours postoperatively should be considered for intervention. Intention-to-treat analysis shows surgical duct ligation is more effective than thoracic duct embolization, with the ability to cannulate the cisterna chyli being the limiting factor. Lymphangiography may help determine which patients are better treated with ligation or embolization.

A novel strategy to initiate a peroral endoscopic myotomy program

OBJECTIVES

The standard of care for achalasia remains laparoscopic Heller myotomy with partial fundoplication. Peroral endoscopic myotomy (POEM) has been introduced as an alternative, but safety and long-term comparative efficacy are not yet established. We report our experience in developing a POEM program using a novel hybrid approach.

METHODS

We developed a hybrid approach to POEM with a POEM followed by laparoscopic evaluation, extension of the myotomy, if necessary, and partial fundoplication. We reviewed the results of the programme from April 2012 until May 2015. Starting in 2014, we began offering patients stand-alone POEM. Patient data were collected. Preoperative and postoperative Eckardt scores were compared.

RESULTS

A total of 28 patients underwent POEM or POEM plus laparoscopic evaluation with partial fundoplication. Patient characteristics and perioperative and postoperative data were recorded. The median preoperative Eckardt score was 6 (range 4-11). The mean follow-up period was 136 days (range 41-330) and the median postoperative Eckardt score was 0 (range 0-6) at 6 weeks. Of our initial 10 patients, 6 required laparoscopic extension of the myotomy; 7 subsequent patients did not require an additional myotomy. Three patients who underwent POEM without laparoscopy continued to have dysphagia postoperatively. One patient had an attempted POEM that was aborted secondary to bleeding, and a standard laparoscopic modified Heller myotomy with partial fundoplication was performed.

CONCLUSIONS

The excellent results of laparoscopic myotomy with partial fundoplication are challenging to duplicate during the initial adoption of a POEM approach. We present a program developed to steepen the learning curve and enhance patient safety while implementing this new procedure.

Patient- and Cell Type-Specific Heterogeneity of Metformin Response

Most FDA-approved drugs are not equally effective in all patients, suggesting that identification of biomarkers to predict responders to a chemoprevention agent will be needed to stratify patients and achieve maximum benefit. The goal of this study was to investigate both patient-specific and cell context-specific heterogeneity of metformin response, using fibroblast cell lines and induced pluripotent stem cells differentiated into lung epithelial lineages. We performed cell survival analysis, transcriptome and whole exome sequencing analysis on both patient-derived cell lines and cancer cell lines to assess differential metformin response and identify response genes. We found differences in response to metformin treatment across a variety of cell lines and cellular contexts, suggesting that heterogeneity may be patient- and cell type-specific. Gene expression profiling and analysis of metformin-sensitive and metformin-resistant cells identified differentially expressed genes that may be able to stratify patients into metformin responders and non-responders. Sequencing analysis found genomic alterations that correlated with metformin response. These results suggest that the identification of genomic biomarkers for patients who may respond to metformin treatment can provide an opportunity for individualizing metformin chemoprevention in the clinical setting.

Quantification of Etoposide Hypersensitivity: A Sensitive, Functional Method for Assessing Pluripotent Stem Cell Quality

Human induced pluripotent stem cells (hiPSC) hold great promise in diagnostic and therapeutic applications. However, translation of hiPSC technology depends upon a means of assessing hiPSC quality that is quantitative, high‐throughput, and can decipher malignant teratocarcinoma clones from normal cell lines. These attributes are lacking in current approaches such as detection of cell surface makers, RNA profiling, and/or teratoma formation assays. The latter remains the gold standard for assessing clone quality in hiPSCs, but is expensive, time‐consuming, and incompatible with high‐throughput platforms. Herein, we describe a novel method for determining hiPSC quality that exploits pluripotent cells’ documented hypersensitivity to the topoisomerase inhibitor etoposide (CAS No. 33419‐42‐0). Based on a study of 115 unique hiPSC clones, we established that a half maximal effective concentration (EC50) value of <300 nM following 24 hours of exposure to etoposide demonstrated a positive correlation with RNA profiles and colony morphology metrics associated with high quality hiPSC clones. Moreover, our etoposide sensitivity assay (ESA) detected differences associated with culture maintenance, and successfully distinguished malignant from normal pluripotent clones independent of cellular morphology. Overall, the ESA provides a simple, straightforward method to establish hiPSC quality in a quantitative and functional assay capable of being incorporated into a generalized method for establishing a quality control standard for all types of pluripotent stem cells. Stem Cells Translational Medicine2017;6:1829–1839

Predictors of relapse and evaluation of the role of postoperative radiation therapy in a modern series of patients with surgically resected stage III (N2) non-small cell lung cancer

PURPOSE

For patients with stage III (N2) non-small cell lung cancer (NSCLC) treated with surgical resection, postoperative chemotherapy improves overall survival (OS), but the role of postoperative radiation therapy (PORT) is controversial. The purpose of this study was to evaluate risk factors for local-regional recurrence and to evaluate the impact of PORT on local-regional control (LRC) and OS in a modern series of patients with surgically resected stage III (N2) NSCLC.

METHODS AND MATERIALS

A retrospective review was performed of patients with Stage III (N2) NSCLC who underwent curative intent resection at our institution between February 1999 and January 2012. OS, LRC, and metastasis-free survival were estimated from the date of surgery using the Kaplan Meier method.

RESULTS

A total of 71 patients were included in the study. Patient median age was 63 years. Histology was adenocarcinoma in 69% of patients. Pretreatment positron emission tomography/computed tomography staging was performed for 90% of patients, and preoperative chemotherapy was administered in 23%. The rate of R0 resection was 96%. Forty-one patients (58%) received PORT and the median PORT dose was 50 Gy (range, 41.4-60 Gy). The median follow-up time for living patients was 5.0 years. Five-year OS for all patients was 66%. OS at 5 years for patients who received PORT compared with patients who did not receive PORT was 71% versus 60%, respectively (hazard ratio [HR], 0.61; 95% CI, 0.30-1.44; P = .28). LRC at 5 years for patients who received PORT compared with patients who did not receive PORT was 89% versus 76%, respectively (HR, 0.44; 95% CI, 0.13-1.45; P = .17). Factors associated with decreased LRC were male sex (P = .011) and primary tumor (pT) stage (pT3/4 vs. pT1/2, P = .006). Metastasis-free survival at 5 years for patients who received PORT compared with those who did not receive PORT was 62% versus 63%, respectively (HR, 1.07; 95% CI, 0.51-2.40; P = .86).

CONCLUSIONS

In this modern series of patients with resected stage III (N2) NSCLC, patients who received PORT had higher rates of OS and LRC, but these differences were not statistically significant.

Safety of air travel in the immediate postoperative period after anatomic pulmonary resection

OBJECTIVE

The study objective was to determine whether air travel in the immediate postoperative period after anatomic pulmonary resection is associated with increased morbidity or mortality.

METHODS

All patients undergoing anatomic pulmonary resection at the Mayo Clinic (2005-2012) were identified and sent surveys querying their mode of transportation home after hospital dismissal and any complications encountered during or shortly after this travel. This included pneumonia, hospital readmission, deep venous thrombosis/pulmonary embolism, and specific pleural complications (pneumothorax, empyema, or chest tube placement). We compared the results of patients returning home by conventional ground travel with the results of patients using air travel.

RESULTS

Surveys were sent to 1833 patients, and 817 responded (44.6% response rate). A total of 96 responders (11.8%) used air travel (median distance, 1783 km; range, 486-9684 km) compared with 278 km (range, 1-2618 km) for the 721 responders (88.2%) using ground travel (P < .0001). Male patients used air travel more than female patients (14.4% vs 9.3%; P = .02). Otherwise, no significant differences were observed between the 2 groups. The median duration of hospitalization was 5 days in both groups using air travel (range, 1-25 days) and ground travel (range, 1-42 days) (P = .83). There was no mortality due to postdismissal travel. The rates of major complication after hospital dismissal for those using air and ground travel were 8.3% and 7.8%, respectively (P = .87).

CONCLUSIONS

Overall major complications are rare in the immediate posthospital dismissal period after lung resection. Air travel during this period was not associated with any significant increase in risk of complications when compared with conventional ground transportation and seems to be a safe option for patients after chest tube removal.

Use of Shear Wave Ultrasound Vibrometry for Detection of Simulated Esophageal Malignancy in Ex Vivo Porcine Esophagi

Esophageal cancer is a malignant neoplasm with poor outcomes. Determination of local disease progression is a major determining factor in treatment modality, radiation dose, radiation field and subsequent surgical therapy. Discrimination of true tumor extent is difficult given the similarity of soft tissues of the malignancy compared to non-malignant tissues using current imaging modalities. A possible method to discriminate between these tissues may be to exploit mechanical properties to diagnostic advantage, as malignant tissues tend to be stiffer relative to normal adjacent tissue. Shear waves propagate faster in stiffer tissues relative to softer tissues. This may be measured by using ultrasound based shear wave vibrometry. In this method, acoustic radiation force is used to create a shear wave in the tissue of interest and ultrafast ultrasound imaging is used to track the propagating wave to measure the wave velocity and estimate the shear moduli. In this study we created simulated malignant lesions (1.5 cm length) using radiofrequency ablation in ex vivo esophageal samples with varied progression (partial thickness n = 4, and full thickness n = 5) and used normal regions of the same esophageal specimen as controls. Shear wave vibrometry was used to measure shear wave group velocity and shear wave phase velocity in the ex vivo specimens. These values were used to estimate shear moduli using an elastic shear wave model and elastic and viscoelastic Lamb wave models. Our results show that the group and phase velocities increase due to both full and mucosal ablation, and that discrimination may be provided by higher order analysis using viscoelastic Lamb wave fitting. This technique may have application for determination of extent of early esophageal malignancy and warrants further investigation using in vivo approaches to determine performance compared to current imaging modalities.

Lymphadenectomy During Pulmonary Metastasectomy

Pulmonary metastasectomy continues to be an effective approach to prolong survival in appropriately selected patients. The incidence of lymphatic spread is more common than previously recognized, with an estimate of 20% to 25% across multiple tumor types. The presence of metastatically involved lymph nodes adversely affects survival. What remains unclear is whether N1 vs N2, or the number of stations involved affects survival differently. The role of surgery for pulmonary metastasectomy in the patient with nodal metastases will likely expand with ongoing improvements in targeted and immunotherapies.

Nondestructive measurement of esophageal biaxial mechanical properties utilizing sonometry

Malignant esophageal pathology typically requires resection of the esophagus and reconstruction to restore foregut continuity. Reconstruction options are limited and morbid. The esophagus represents a useful target for tissue engineering strategies based on relative simplicity in comparison to other organs. The ideal tissue engineered conduit would have sufficient and ideally matched mechanical tolerances to native esophageal tissue. Current methods for mechanical testing of esophageal tissues both in vivo and ex vivo are typically destructive, alter tissue conformation, ignore anisotropy, or are not able to be performed in fluid media. The aim of this study was to investigate biomechanical properties of swine esophageal tissues through nondestructive testing utilizing sonometry ex vivo. This method allows for biomechanical determination of tissue properties, particularly longitudinal and circumferential moduli and strain energy functions. The relative contribution of mucosal-submucosal layers and muscular layers are compared to composite esophagi. Swine thoracic esophageal tissues (n  =  15) were tested by pressure loading using a continuous pressure pump system to generate stress. Preconditioning of tissue was performed by pressure loading with the pump system and pre-straining the tissue to in vivo length before data was recorded. Sonometry using piezocrystals was utilized to determine longitudinal and circumferential strain on five composite esophagi. Similarly, five mucosa-submucosal and five muscular layers from thoracic esophagi were tested independently. This work on esophageal tissues is consistent with reported uniaxial and biaxial mechanical testing and reported results using strain energy theory and also provides high resolution displacements, preserves native architectural structure and allows assessment of biomechanical properties in fluid media. This method may be of use to characterize mechanical properties of tissue engineered esophageal constructs.

Tumor-Free Transplantation of Patient-Derived Induced Pluripotent Stem Cell Progeny for Customized Islet Regeneration

Human induced pluripotent stem cells (iPSCs) and derived progeny provide invaluable regenerative platforms, yet their clinical translation has been compromised by their biosafety concern. Here, we assessed the safety of transplanting patient-derived iPSC-generated pancreatic endoderm/progenitor cells. Transplantation of progenitors from iPSCs reprogrammed by lentiviral vectors (LV-iPSCs) led to the formation of invasive teratocarcinoma-like tumors in more than 90% of immunodeficient mice. Moreover, removal of primary tumors from LV-iPSC progeny-transplanted hosts generated secondary and metastatic tumors. Combined transgene-free (TGF) reprogramming and elimination of residual pluripotent cells by enzymatic dissociation ensured tumor-free transplantation, ultimately enabling regeneration of type 1 diabetes-specific human islet structures in vivo. The incidence of tumor formation in TGF-iPSCs was titratable, depending on the oncogenic load, with reintegration of the cMYC expressing vector abolishing tumor-free transplantation. Thus, transgene-free cMYC-independent reprogramming and elimination of residual pluripotent cells are mandatory steps in achieving transplantation of iPSC progeny for customized and safe islet regeneration in vivo.

SIGNIFICANCE

Pluripotent stem cell therapy for diabetes relies on the safety as well as the quality of derived insulin-producing cells. Data from this study highlight prominent tumorigenic risks of induced pluripotent stem cell (iPSC) products, especially when reprogrammed with integrating vectors. Two major underlying mechanisms in iPSC tumorigenicity are residual pluripotent cells and cMYC overload by vector integration. This study also demonstrated that combined transgene-free reprogramming and enzymatic dissociation allows teratoma-free transplantation of iPSC progeny in the mouse model in testing the tumorigenicity of iPSC products. Further safety assessment and improvement in iPSC specification into a mature β cell phenotype would lead to safe islet replacement therapy for diabetes.

Minimally invasive thymectomy: the Mayo Clinic experience

BACKGROUND

The prevalence of minimally invasive thymectomy (MIT) is increasing and may have significant benefit to patients in terms of morbidity and post-operative recovery. Our aim was to review the Mayo Clinic experience of MIT.

METHODS

We reviewed data from all MIT cases collected in a prospectively maintained database from January 1995 to February 2015. Data were collected regarding patient demographics, perioperative management and patient outcomes.

RESULTS

A total of 510 thymectomies were performed in 20 years. Fifty-six patients underwent MIT (45 video-assisted thoracoscopy, 11 robotic-assisted). The median age was 55 years (range, 23-87 years) with male to female ratio of 25:31. Thymoma was the main pathologic diagnosis in 27/56 patients (48%), with 11/27 (41%) associated with myasthenia gravis (MG), and 16/27 (59%) non-MG. Other pathologies included 1/56 (2%) of each teratoma, lymphoma, lymphangioma, carcinoma and thymolipoma. There were 3/56 (5%) atrophic glands, 4/56 (7%) cysts, 6/56 (11%) benign glands and 11/56 (20%) hyperplastic. Mean blood loss (mL) and operative time (min) were significantly lower in the video-assisted thoracoscopic surgery (VATS) group compared to robotic (65±41 vs. 160±205 mL, P=0.04 and 102±39 vs. 178±53 min, P=0.001, respectively). There was no 30-day mortality. Post-operative morbidity occurred in 7/45 (16%) VATS patients (phrenic nerve palsy 7%, pericarditis 4%, atrial fibrillation 2%, pleural effusion 2%) and 1/11 (9%) robotic (urinary retention requiring self-catheterization). Reoperation was required in 1/3 of VATS patients with phrenic nerve palsy. There was no significant difference in length of hospital stay [VATS 1.5 days (range, 1-4 days) and robotic 2 days (range, 1-5 days) VATS; P=0.05]. Mean follow-up was 18.4 months (range, 1-50.4 months) with no tumor recurrences.

CONCLUSIONS

MIT can be performed with low morbidity and mortality. VATS is associated with reduced blood loss, operative times and earlier hospital discharge compared to robotic MIT.