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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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.

American Board of Thoracic Surgery 10-Year Maintenance of Certification Exam Improves and Validates Knowledge Acquisition

BACKGROUND

Previous "high-stakes" examinations by the American Board of Thoracic Surgery (ABTS) required remote testing, were noneducational, and were not tailored to individual practices. Given the ABTS mission of public safety and diplomate education, the ABTS Maintenance of Certification (MOC) examination was revised in 2015 to improve the educational experience and validate knowledge acquired.

METHODS

The ABTS-MOC Committee developed a web-based, secure examination tailored to the specialty-specific practice profile (cardiac, general thoracic, cardiothoracic, congenital) of the individual surgeon. After an initial answer to each question, an educational critique was reviewed before returning to the initial question and logging a second (final) response. Intraexam learning was assessed by comparing scores before and after reading the critique. Diplomate feedback was obtained.

RESULTS

A total of 988 diplomates completed the 10-year MOC examination between 2015 and 2017. Substantive learning was demonstrated with an 18%, 17%, 20%, and 9% improvement in cardiac, general thoracic, cardiothoracic, and congenital final scores, respectively. This improvement was most notable among diplomates with the lowest initial scores. Fewer diplomates failed the new exam (<1% vs 2.3%). Diplomate postexam survey highlighted marked improvements in clinical relevance (35% vs 78%), convenience (37% vs 78%), and learning (15% vs 45%). Over 80% acknowledged educational value, and 97% preferred the new format.

CONCLUSIONS

The new MOC process demonstrates increased knowledge acquisition through a convenient, secure, web-based practice-focused examination. This approach provides feedback, identifies baseline knowledge gaps for individual diplomates, and validates new knowledge attained.

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.

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.

Impact of Sublobar Resection on Pulmonary Function: Long-Term Results from American College of Surgeons Oncology Group Z4032 (Alliance)

BACKGROUND

Sublobar resection (SR) in high-risk operable patients may result in a long-term decrease in pulmonary function. We previously reported 3-month pulmonary function outcomes from a randomized phase III study of SR alone compared with SR with brachytherapy in patients with non-small cell lung cancer. We now report long-term pulmonary function after SR.

METHODS

Pulmonary function was measured at baseline and at 3, 12, and 24 months. A decline of 10% or more from baseline in the percentage predicted forced expiratory volume of 1 percentage or in the diffusion capacity of the lung for carbon monoxide was considered clinically meaningful. The effect of study arm, tumor location, size, approach (video-assisted thoracoscopic surgery vs thoracotomy), and SR type (wedge vs segmentectomy) on pulmonary function was assessed using a Wilcoxon rank sum test. A generalized estimating equation model was used to assess the effect of each factor on longitudinal data, including all four time points.

RESULTS

Complete pulmonary function data at all time points was available in 69 patients. No significant differences were observed in pulmonary function between SR and SR with brachytherapy, thus the study arms were combined for all analyses. A decline of 10% or more (p = 0.02) in the percentage predicted forced expiratory volume in 1 second was demonstrated for lower-lobe resections at 3 months but was not at 12 or 24 months. A decline of 10% or more (p = 0.05) in the percentage predicted diffusion capacity of the lung for carbon monoxide was seen for thoracotomy at 3 months but was not at 12 or 24 months.

CONCLUSIONS

Clinically meaningful declines in pulmonary function occurred after lower lobe resection and after thoracotomy at 3 months but subsequently recovered. This study suggests that SR does not result in sustained decreased pulmonary function in high-risk operable patients.

Predicting lung cancer prior to surgical resection in patients with lung nodules

BACKGROUND

Existing predictive models for lung cancer focus on improving screening or referral for biopsy in general medical populations. A predictive model calibrated for use during preoperative evaluation of suspicious lung lesions is needed to reduce unnecessary operations for a benign disease. A clinical prediction model (Thoracic Research Evaluation And Treatment [TREAT]) is proposed for this purpose.

METHODS

We developed and internally validated a clinical prediction model for lung cancer in a prospective cohort evaluated at our institution. Best statistical practices were used to construct, evaluate, and validate the logistic regression model in the presence of missing covariate data using bootstrap and optimism corrected techniques. The TREAT model was externally validated in a retrospectively collected Veteran Affairs population. The discrimination and calibration of the model was estimated and compared with the Mayo Clinic model in both the populations.

RESULTS

The TREAT model was developed in 492 patients from Vanderbilt whose lung cancer prevalence was 72% and validated among 226 Veteran Affairs patients with a lung cancer prevalence of 93%. In the development cohort, the area under the receiver operating curve (AUC) and Brier score were 0.87 (95% confidence interval [CI], 0.83-0.92) and 0.12, respectively compared with the AUC 0.89 (95% CI, 0.79-0.98) and Brier score 0.13 in the validation dataset. The TREAT model had significantly higher accuracy (p < 0.001) and better calibration than the Mayo Clinic model (AUC = 0.80; 95% CI, 75-85; Brier score = 0.17).

CONCLUSION

The validated TREAT model had better diagnostic accuracy than the Mayo Clinic model in preoperative assessment of suspicious lung lesions in a population being evaluated for lung resection.

Radiofrequency ablation of stage IA non-small cell lung cancer in medically inoperable patients: Results from the American College of Surgeons Oncology Group Z4033 (Alliance) trial

BACKGROUND

This study evaluated the 2-year overall survival rate, adverse event rate, local control rate, and impact on pulmonary function tests for medically inoperable patients with stage IA non-small cell lung cancer (NSCLC) undergoing computed tomography (CT)-guided radiofrequency ablation (RFA) in a prospective, multicenter trial.

METHODS

Fifty-four patients (25 men and 29 women) with a median age of 76 years (range, 60-89 years) were enrolled from 16 US centers; 51 patients were eligible for evaluation (they had biopsy-proven stage IA NSCLC and were deemed medically inoperable by a board-certified thoracic surgeon). Pulmonary function tests were performed within the 60 days before RFA and 3 and 24 months after RFA. Adverse events were recorded and categorized. Patients were followed with CT and fludeoxyglucose positron emission tomography. Local control rate and recurrence patterns were analyzed.

RESULTS

The overall survival rate was 86.3% at 1 year and 69.8% at 2 years. The local tumor recurrence-free rate was 68.9% at 1 year and 59.8% at 2 years and was worse for tumors > 2 cm. In the 19 patients with local recurrence, 11 were re-treated with RFA, 9 underwent radiation, and 3 underwent chemotherapy. There were 21 grade 3 adverse events, 2 grade 4 adverse events, and 1 grade 5 adverse event in 12 patients within the first 90 days after RFA. None of the grade 4 or 5 adverse events were attributable to RFA. There was no significant change in the forced expiratory volume in the first second of expiration or the diffusing capacity of lung for carbon monoxide after RFA. A tumor size less than 2.0 cm and a performance status of 0 or 1 were associated with statistically significant improved survival of 83% and 78%, respectively, at 2 years.

CONCLUSIONS

RFA is a single, minimally invasive procedure that is well tolerated in medically inoperable patients, does not adversely affect pulmonary function tests, and provides a 2-year overall survival rate that is comparable to the rate reported after stereotactic body radiotherapy in similar patients.

Audit of lymphadenectomy in lung cancer resections using a specimen collection kit and checklist

BACKGROUND

Audits of operative summaries and pathology reports reveal wide discordance in identifying the extent of lymphadenectomy performed (the communication gap). We tested the ability of a prelabeled lymph node specimen collection kit and checklist to narrow the communication gap between operating surgeons, pathologists, and auditors of surgeons' operation notes.

METHODS

We conducted a prospective single cohort study of lung cancer resections performed with a lymph node collection kit from November 2010 to January 2013. We used the kappa statistic to compare surgeon claims on a checklist of lymph node stations harvested intraoperatively with pathology reports and an independent audit of surgeons' operative summaries. Lymph node collection procedures were classified into four groups based on the anatomic origin of resected lymph nodes: mediastinal lymph node dissection, systematic sampling, random sampling, and no sampling.

RESULTS

From the pathology reports, 73% of 160 resections had a mediastinal lymph node dissection or systematic sampling procedure, 27% had random sampling. The concordance with surgeon claims was 80% (kappa statistic 0.69, 95% confidence interval: 0.60 to 0.79). Concordance between independent audits of the operation notes and either the pathology report (kappa 0.14, 95% confidence interval: 0.04 to 0.23) or surgeon claims (kappa 0.09, 95% confidence interval: 0.03 to 0.22) was poor.

CONCLUSIONS

A prelabeled specimen collection kit and checklist significantly narrowed the communication gap between surgeons and pathologists in identifying the extent of lymphadenectomy. Audit of surgeons' operation notes did not accurately reflect the procedure performed, bringing its value for quality improvement work into question.

Analysis of longitudinal quality-of-life data in high-risk operable patients with lung cancer: results from the ACOSOG Z4032 (Alliance) multicenter randomized trial

BACKGROUND

Prior studies have suggested that low baseline quality-of-life (QOL) scores predict worse survival in patients undergoing lung cancer surgery. However, these studies involved average-risk patients undergoing lobectomy. We report QOL results from a multicenter trial, American College of Surgeons Oncology Group Z4032, which randomized high-risk operable patients to sublobar resection (SR), or SR with brachytherapy, and included longitudinal QOL assessments.

METHODS

Global QOL, using the 36-item Short-Form Health Survey (SF36), and the dyspnea score from the University of California, San Diego Shortness of Breath Questionnaire (SOBQ) scale, was measured at baseline, 3, 12, and 24 months. SF36 physical component summary (PCS) and mental component summary (MCS) scores were standardized and adjusted for age and gender normals, with scores <50 indicating below-average health status. SOBQ scores were transformed to a 0-100 (poor-excellent) scale. Aims were to: (1) determine the impact of baseline scores on recurrence-free survival, overall survival, and 30-day adverse events (AEs); and (2) identify subgroups (surgical approach, resection type. tumor location, tumor size, respiratory function) with a ≥ 10-point decline or improvement in QOL after SR.

RESULTS

Two hundred twelve eligible patients were included. There were no significant differences in baseline QOL scores between arms. Median baseline PCS, MCS, and SOBQ scores were 42.7, 51.1, and 70.8, respectively. There were no differences in grade-3+ AEs, overall survival, or recurrence-free survival in patients with baseline scores ≤ median versus > median values, except for a significantly worse overall survival for patients with baseline SOBQ scores ≤ median value. There were no significant differences between the study arms in percentage change of QOL scores from baseline to 3, 12, or 24 months. Further comparison combining the 2 arms demonstrated a higher percentage of patients with a ≥ 10-point decline in SOBQ scores with segmentectomy compared with wedge resection (40.5% vs 21.9%, P = .03) at 12 months, with thoracotomy versus video-assisted thoracic surgery (VATS) (38.8% vs 20.4%, P = .03) at 12 months, and T1b versus T1a tumors (46.9% vs 23.5%, P = .020) at 24 months. A ≥ 10-point improvement in PCS score was seen at 3 months with VATS versus thoracotomy (16.5% vs 3.6%, P = .02).

CONCLUSIONS

In high-risk operable patients, poor baseline QOL scores were not predictive for worse overall or recurrence-free survival, or for higher risk for AEs following SR. VATS was associated with improvement in physical function at 3 months, and improved dyspnea scores at 12 months, lending support for the preferential use of VATS when SR is undertaken.

Ninety-day mortality after resection for lung cancer is nearly double 30-day mortality

OBJECTIVE

To evaluate 30-day and 90-day mortality after major pulmonary resection for lung cancer including the relationship to hospital volume.

METHODS

Major lung resections from 2007 to 2011 were identified in the National Cancer Data Base. Mortality was compared according to annual volume and demographic and clinical covariates using univariate and multivariable analyses, and included information on comorbidity. Statistical significance (P<.05) and 95% confidence intervals were assessed.

RESULTS

There were 124,418 major pulmonary resections identified in 1233 facilities. The 30-day mortality rate was 2.8%. The 90-day mortality rate was 5.4%. Hospital volume was significantly associated with 30-day mortality, with a mortality rate of 3.7% for volumes less than 10, and 1.7% for volumes of 90 or more. Other variables significantly associated with 30-day mortality include older age, male sex, higher stage, pneumonectomy, a previous primary cancer, and multiple comorbidities. Similar results were found for 90-day mortality rates. In the multivariate analysis, hospital volume remained significant with adjusted odds ratios of 2.1 (95% confidence interval [CI], 1.7-2.6) for 30-day mortality and 1.3 (95% CI, 1.1-1.6) for conditional 90-day mortality for the hospitals with the lowest volume (<10) compared with those with the highest volume (>90). Hospitals with a volume less than 30 had an adjusted odds ratio for 30-day mortality of 1.3 (95% CI, 1.2-1.5) compared with those with a volume greater than 30.

CONCLUSIONS

Mortality at 30 and 90 days and hospital volume should be monitored by institutions performing major pulmonary resection and benchmarked against hospitals performing at least 30 resections per year.

Impact of brachytherapy on local recurrence rates after sublobar resection: results from ACOSOG Z4032 (Alliance), a phase III randomized trial for high-risk operable non-small-cell lung cancer

PURPOSE

A major concern with sublobar resection (SR) for non-small-cell lung cancer (NSCLC) is high local recurrence (LR). Adjuvant brachytherapy may reduce LR This multicenter randomized trial compares SR to SR with brachytherapy (SRB).

PATIENTS AND METHODS

High-risk operable patients with NSCLC ≤ 3 cm were randomly assigned to SR or SRB. The primary end point was time to LR, where LR included recurrence at the staple line (local progression), in the primary tumor lobe away from the staple line, and in ipsilateral hilar nodes. The trial was designed to have a 90% power to detect a hazard ratio (HR) of 0.315 in favor of SRB, using a one-sided type I error rate of 0.05 with a sample size of 100 eligible patients in each arm.

RESULTS

Two hundred twenty-four patients were randomly assigned; 222 patients were evaluable for intent-to-treat analysis. Median age was 71 years (range, 49 to 87 years). No differences were found in baseline characteristics. Median follow-up time was 4.38 years (range, 0.04 to 5.59 years). There was no difference in time to LR (HR, 1.01; 95% CI, 0.51 to 1.98; log-rank P = .98) or in the types of LR. Local progression occurred in only 17 (7.7%) of 222 patients. In patients with potentially compromised margins (margin < 1 cm, margin-to-tumor ratio < 1, positive staple line cytology, wedge resection, nodule size > 2.0 cm), SRB did not reduce LR, although trends favored the SRB arm. This was most marked in 14 patients with positive staple line cytology (HR, 0.22; P = .24). Three-year overall survival rates were similar for patients in the SR (71%) and SRB (71%) arms (P = .97).

CONCLUSION

Brachytherapy did not reduce LR after SR. This finding may have been related to closer attention to parenchymal margins by surgeons participating in this study.

Accuracy of fluorodeoxyglucose-positron emission tomography within the clinical practice of the American College of Surgeons Oncology Group Z4031 trial to diagnose clinical stage I non-small cell lung cancer

BACKGROUND

Fluorodeoxyglucose-positron emission tomography (FDG-PET) is recommended for diagnosis and staging of non-small cell lung cancer (NSCLC). Meta-analyses of FDG-PET diagnostic accuracy demonstrated sensitivity of 96% and specificity of 78% but were performed in select centers, introducing potential bias. This study evaluates the accuracy of FDG-PET to diagnose NSCLC and examines differences across enrolling sites in the national American College of Surgeons Oncology Group (ACOSOG) Z4031 trial.

METHODS

Between 2004 and 2006, 959 eligible patients with clinical stage I (cT1-2 N0 M0) known or suspected NSCLC were enrolled in the Z4031 trial, and with a baseline FDG-PET available for 682. Final diagnosis was determined by pathologic examination. FDG-PET avidity was categorized into avid or not avid by radiologist description or reported maximum standard uptake value. FDG-PET diagnostic accuracy was calculated for the entire cohort. Accuracy differences based on preoperative size and by enrolling site were examined.

RESULTS

Preoperative FDG-PET results were available for 682 participants enrolled at 51 sites in 39 cities. Lung cancer prevalence was 83%. FDG-PET sensitivity was 82% (95% confidence interval, 79 to 85) and specificity was 31% (95% confidence interval, 23% to 40%). Positive and negative predictive values were 85% and 26%, respectively. Accuracy improved with lesion size. Of 80 false-positive scans, 69% were granulomas. False-negative scans occurred in 101 patients, with adenocarcinoma being the most frequent (64%), and 11 were 10 mm or less. The sensitivity varied from 68% to 91% (p=0.03), and the specificity ranged from 15% to 44% (p=0.72) across cities with more than 25 participants.

CONCLUSIONS

In a national surgical population with clinical stage I NSCLC, FDG-PET to diagnose lung cancer performed poorly compared with published studies.

Impact of brachytherapy on local recurrence after sublobar resection: Results from ACOSOG Z4032 (Alliance), a phase III randomized trial for high-risk operable non-small cell lung cancer (NSCLC)

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Background: Prior studies suggest that adjuvant brachytherapy reduces local recurrence (LR) after sublobar resection (SR) for NSCLC. A multicenter randomized study was undertaken in patients (pts) with stage I NSCLC ≤3cm comparing SR to SR with brachytherapy (SRB). Methods: High-risk operable patients with NSCLC were randomized to SR or SRB. Brachytherapy involved placement of I125 seeds incorporated into Vicryl sutures or into Vicryl mesh placed over the staple line. Wedge or segmental resection was allowed. The primary endpoint was time to local recurrence (LR) defined as recurrence within the primary tumor lobe at the staple line (local progression), away from the staple line or within hilar nodes. The trial was designed to have 90% power to detect a hazard ratio (HR) of 0.315 in favor of the SRB arm using a one-sided α of 0.05 with a sample size of 100 eligible pts per arm. Follow-up CT scans were obtained serially for 36 months. Results: 224 pts were randomized; 213 (109 SR,104 SRB) were eligible. Median (range) age was 71 (49-87) yrs; 94 (44%) were male. No differences were found in baseline characteristics. Adverse events, previously reported, were not different between arms. Median (range) follow-up was 4.06 (0.04, 5.0) yrs. There was no difference between arms in time to LR (HR = 0.87; 5% CI: 0.41, 1.86, p=0.72) or to LR or death (LRD) (HR = 0.81, 95% CI: 0.50, 1.32, p=0.40). There was no difference between arms in pattern of LR (table). In subgroups of pts with potentially compromised surgical margin (margin < 1cm; margin:tumor ratio <1; positive staple line cytology) SRB did not reduce LR or LRD at 3-yrs. Overall 3-yr survival was similar for SR (71%) and SRB (72%) (p=0.81). Conclusions: LR remains a concern after sublobar resection. However, local progression at the staple line was low. This trial demonstrated that adjuvant brachytherapy does not impact oncologic outcomes. Clinical trial information: NCT00107172. [Table: see text]

Factors impacting oncologic outcomes after sublobar pulmonary resection: Results from ACOSOG Z4032 (Alliance), a randomized trial for high-risk operable non-small cell lung cancer (NSCLC)

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Background: A multicenter study (Z4032) compared sublobar resection (SR) to sublobar resection with brachytherapy (SRB) for stage I NSCLC. Local recurrence (LR) and overall survival (OS) rates at 3-years (3-yr) were similar between arms (see abstract 113613). This analysis combines arms, and evaluates the effect of factors previously reported to impact oncological outcomes after SR. Methods: 213 patients (pts) were evaluable for analysis. LR was defined as recurrence at the staple line (local progression), same lobe away from the staple line, or within hilar nodes. Factors assessed for impact on 3-yr outcomes were: resection type (wedge/segmentectomy), margin size (<1cm /≥1cm), margin:tumor ratio (<1/ ≥1), tumor size (≤2cm/>2cm) and staple line cytology (+/-). Results: LR occurred in 27/213 (12.6%) pts and included local progression in 12/213 (5.6%). OS rate at 3-yr was 152/213 (71.4%). Trends favored the use of segmentectomy, margin:tumor ratio≥1, tumor size ≤2cm and negative staple line cytology; no factor reached statistical significance at 3-yr. The only factor significantly (p=0.02) associated with decreased 3-yr LR was margin size ≥1cm (8.3%) compared to margin<1cm (19.3%). Conclusions: SR is a good option for high-risk pts with NSCLC. The 3-yr OS rate of 71.4% and local progression rate of 5.6% are useful benchmarks to compare to other therapies. A resection margin of at least 1 cm is desirable. Clinical trial information: NCT00107172. [Table: see text]

Abstract LB-296: FDG-PET avidity negatively impacts survival in pStage I NSCLC in the ACOSOG Z4031 trial

Background: Fluoro-deoxyglucose positron emission tomography (FDG-PET) scans are used for diagnosis and staging of known or suspected non-small cell lung cancer (NSCLC). Single institution studies examining the impact of avidity on survival have reported mixed results. The purpose of this study is to evaluate the association between FDG-PET avidity and survival in the national prospective ACOSOG Z4031 trial in patients with pathological Stage I NSCLC.

Methods: Between 2004 and 2006, 1074 patients with known or suspected clinical stage I (cT1-2N0M0) NSCLC were enrolled in the ACOSOG Z4031 trial and underwent surgical resection. FDG-PET results were abstracted from radiology interpretations included in the case report forms. FDG-PET avidity was categorized based on either radiologist description or reported maximum standard uptake value (SUV). The four categories were: 1) not avid and not cancerous (SUV=0), 2) low avidity and likely not cancerous (SUV&gt;0 and &lt;2.5), 3) avid and probably cancerous (SUV≥2.5 and &lt;5) and 4) highly avid and likely cancerous (SUV≥5). The lesion was classified as avid if in categories 3 or 4. The final diagnosis was determined by pathological examination and all cause mortality was reported. Cox proportional hazard regression was used to assess the impact of FDG-PET avidity on survival. The covariates used in the model included pStage, gender, age, race, and preoperative lesion size. Kaplan-Meier survival curves were calculated and the log-rank test was used to determine differences in survival based on FDG-PET avidity.

Results: There were 51 enrolling sites in 39 cities with 969 eligible participants. Preoperative FDG-PET results were available for 540 participants with NSCLC and 81% had FDG-PET avid or highly avid lesions. 400 patients had pStage I NSCLC and the 5 year survival was 70% with 95%CI (65%, 75%). FDG-PET avidity, male gender, age, and lesion size negatively impacted survival. FDG-PET avidity in pStage I disease still negatively impacted survival (p=0.03) when controlling for lesion size. The 5 year survival for Stage I disease was 80% with 95%CI (68%, 88%) in FDG-PET negative patients and 67% with 95% CI (61%, 72%) in FDG-PET positive patients (p=0.02).

Conclusions: In a national surgical population with pathological stage I NSCLC, FDG-PET avidity negatively impacted five year survival, independently of lesion size. Further work should be done to determine if chemotherapy would be beneficial in patients with PET avid lesions and pStage I NSCLC.

Citation Format: Eric L. Grogan, Stephen A. Deppen, Heidi Chen, Karla V. Ballman, Francys C. Verdial, Melinda C. Aldrich, Paul A. Decker, David H. Harpole, Robert J. Cerfolio, Robert J. Keenan, David R. Jones, Thomas A. D'Amico, Joseph B. Shrager, Bryan F. Meyers, Joe B. Putnam. FDG-PET avidity negatively impacts survival in pStage I NSCLC in the ACOSOG Z4031 trial. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-296. doi:10.1158/1538-7445.AM2013-LB-296

Obesity increases operating room time for lobectomy in the society of thoracic surgeons database

BACKGROUND

Obesity has become a major epidemic in the United States. Although research suggests obesity does not increase major morbidity or mortality after thoracic operations, it likely results in greater use of health care resources.

METHODS

We examined all patients in The Society of Thoracic Surgeons General Thoracic Surgery database with primary lung cancer who underwent lobectomy from 2006 to 2010. We investigated the impact of body mass index (BMI) on total operating room time using a linear mixed-effects regression model and multiple imputations to account for missing data. Secondary outcomes included postoperative length of stay and 30-day mortality. Covariates included age, sex, race, forced expiratory volume, smoking status, Zubrod score, prior chemotherapy or radiation, steroid use, number of comorbidities, surgical approach, hospital lobectomy volume, hospital percent obesity, and the addition of mediastinoscopy or wedge resection.

RESULTS

A total of 19,337 patients were included. The mean BMI was 27.3 kg/m2, with 4,898 patients (25.3%) having a BMI of 30 kg/m2 or greater. The mean total operating room time, length of stay, and 30-day mortality were 240 minutes, 6.7 days, and 1.8%, respectively. For every 10-unit increase in BMI, mean operating room time increased by 7.2 minutes (range, 4.8 to 8.4 minutes; p<0.0001). Higher hospital lobectomy volume and hospital percentage of obese patients did not affect the association between BMI and operative time. Body mass index was not associated with 30-day mortality or increased length of stay.

CONCLUSIONS

Increased BMI is associated with increased total operating room time, regardless of institutional experience with obese patients.

Validation of the lung cancer staging system revisions using a large prospective clinical trial database (ACOSOG Z0030)

OBJECTIVES

A new revision of the international lung cancer staging system has been recently introduced. The revisions are largely focussed on the T descriptor. We sought to test the validity of this new system on a separate prospectively collected cohort of patients from a recent multicentre trial of early-stage lung cancer.

METHODS

We reviewed the prospectively collected data from 1012 patients undergoing pulmonary resection for early-stage lung cancer in the ACOSOG Z0030 trial. TNM descriptors and overall staging were assessed using both the sixth and seventh editions of the American Joint Committee on Cancer and the Union Internationale Contre le Cancer (AJCC/UICC) lung cancer staging system. Survival results were analysed according to both staging allocations.

RESULTS

Using the proposed criteria, the number of patients by stage in the sixth and seventh edition allocations, respectively, were as follows: IA (432, 431); IB (402, 303); IIA (39, 167); IIB (94, 70); IIIA (26, 40); IIIB (19,0); there were no stage IV patients by either version. Overall, 180 (18%) patients had a change in the stage group from the sixth to seventh edition versions with 76 (8%) being downstaged and 104 (10%) being upstaged. In the sixth edition staging system based on pathological stages, median survivals in years were as follows: IA, NA; IB, 7.7; IIA, 4.0; IIB, 3.6; IIIA, 2.6 and IIIB, 2.4. Five-year survivals were: IA, 76.4%; IB, 62.0%; IIA, 47.8%; IIB, 40.4%; IIIA, 31.3% and IIIB, 44.4%. In the new system, median survivals in years were as follows: IA, NA; IB, 8.2; IIA, 4.4; IIB, 3.6 and IIIA, 1.8. Five-year survivals were: IA, 76.9%; IB, 65.0%; IIA, 48.5%; IIB, 42.9% and IIIA, 30.6%. Survival analysis and Kaplan-Meier survival curves showed more monotonic progression, distinction and homogeneity within groups in the seventh edition.

CONCLUSIONS

This study provides an external validation of the recently revised lung cancer staging system using a large multicentre database. The seventh edition of the AJCC/UICC lung cancer staging system appears to be an improvement over the preceding system.

Poor survival for veterans with pathologic stage I non-small-cell lung cancer

BACKGROUND

Pathologic stage (pStage) IA and IB non-small-cell lung cancer (NSCLC) has a median survival time of 119 and 81 months, respectively. We describe the outcomes of veterans with pStage I NSCLC.

METHODS

A retrospective review of 78 patients with pStage I NSCLC who underwent cancer resection was performed at the Tennessee Valley Veterans Affairs Hospital between 2005 and 2010. All-cause 30-day, 90-day, and overall mortality were determined. Survival was assessed with the Kaplan-Meier and Cox proportional hazards methods.

RESULTS

There were 55 (71%) pStage IA and 23 (29%) IB patients. Thirty- and 90-day mortality was 3.8% (3 of 78) and 6.4% (5 of 78), respectively. Median survival was 59 and 28 months for pStage 1A and 1B, respectively. Postoperative events were associated with impaired survival on multivariable analysis (hazard ratio, 1.26, P = .03).

CONCLUSIONS

Veterans with pStage I NSCLC at our institution have poorer survival than the general population. More research is needed to determine the etiology of this disparity.

A phase II study of neoadjuvant therapy with cisplatin, docetaxel, panitumumab plus radiation therapy followed by surgery in patients with locally advanced adenocarcinoma of the distal esophagus (ACOSOG Z4051)

4062

Background: Multiple clinical trials have incorporated preoperative chemotherapy and radiation (RT) in an attempt to improve local tumor control, distant disease failure and overall survival rates for locally advanced but resectable adenocarcinoma of the distal esophagus and gastroesophageal junction (GEJ). This multicenter, cooperative group study combined active chemotherapy agents cisplatin (C), docetaxel (D) and the targeted EGFR agent panitumumab (P) in the induction phase followed by concurrent chemotherapy (CDP) and radiation. Pathologic complete response (pCR), a surrogate for improved survival, was the primary endpoint. Methods: From 01/15/09 to 07/22/11, 70 patients (pts) with Siewert I or II adenocarcinomas and clinical stages T3N0M0, T2-3N1M0 or T2-3N0-1M1a (celiac LN ≤ 2 cm) were accrued. Patients received cisplatin (40 mg/m2), docetaxel (40 mg/m2) and panitumumab (6 mg/kg) on weeks 1, 3, 5, 7, 9 with RT (5040 cGy, 180 cGy/day x 28d) beginning week 5. The decision rule had a 90% power with a 0.10 significance level to detect a pCR rate of at least 35%. Secondary objectives included near-pathologic complete response (near-pCR), toxicity, and overall and disease-free survival rates. Results: Five pts were ineligible. Of the remaining 65 pts (59 M, 6 F; median age 61), 12 pts did not undergo surgery (5 progressed, 4 refused, 3 other). Of the 58 evaluable pts, the pCR rate was 32.8% (90% CI: 22.6% -42.9%) and near-pCR 22.4% (90% CI: 13.4%-31.4%). Total doses of C, D, and P were achieved in 76%, 80%, and 73%, respectively (n = 70). 66 pts (94%) received the total RT dose. Sixteen pts (23%) had a grade 4+ non-heme adverse event possibly related to treatment. Venous thrombosis (5 pts) was most common. Conclusions: The CDP regimen in the neoadjuvant setting in patients with esophageal adenocarcinomas is active (pCR + near-pCR = 55.2%) and feasible. The toxicity though tolerable is substantial.

Accuracy of FDG-PET to diagnose lung cancer in the ACOSOG Z4031 trial

7008

Background: Fluoro-deoxyglucose positron emission tomography (FDG-PET) is recommended for diagnosis and staging of known or suspected NSCLC. Meta-analyses examining the accuracy of FDG-PET to diagnose lung cancer demonstrated high sensitivity 94% and specificity 83% but were performed in select centers. The purpose of this study is to evaluate the accuracy of FDG-PET to diagnose NSCLC and examine enrolling site differences in the national prospective ACOSOG Z4031 trial. Methods: 1,074 patients with clinical stage I (cT1-2N0M0) known or suspected NSCLC were enrolled between 2004 and 2006 in the Z4031 study and underwent surgical resection. The final diagnosis was determined by pathological examination. FDG-PET results were abstracted from radiology interpretations included in the case report forms. FDG-PET avidity was categorized based on either radiologist description or reported maximum standard uptake value (SUV). The four categories were: not avid and not cancerous (SUV=0), low avidity and likely not cancerous (SUV>0 and <2.5), avid and probably cancerous (SUV>2.5 and <5) and highly avid and likely cancerous (SUV>5). Sensitivity analysis of FDG-PET diagnostic accuracy was performed for varying levels of avidity and by preoperative lesion size. Differences in accuracy by enrolling site were examined. Results: There were 51 enrolling sites in 39 cities with 969 eligible participants. Preoperative FDG-PET results were available for 682 participants. Lung cancer prevalence was 83%. FDG-PET sensitivity was 82% (95% CI: 79-85), and specificity was 31% (95% CI: 23-40). Positive and negative predictive values were 85% and 26%, respectively and accuracy improved with lesion size. There were 80 false positive scans and 69% were granulomas. False negative scans occurred in 101 patients (11were ≤10mm) with adenocarcinoma, squamous, bronchoalveolar cell and neuroendocrine tumors responsible for 64%, 12%, 10% and 8% of false negative results, respectively. Specificity did not differ between the 8 sites with >25 patients (p=0.74). Conclusions: In a national surgical population with clinical stage I NSCLC, FDG-PET to diagnose lung cancer performed poorly compared to published studies. Reasons for poor test performance should be explored.

Added value of a serum proteomic signature in the diagnostic evaluation of lung nodules

BACKGROUND

Current management of lung nodules is complicated by nontherapeutic resections and missed chances for cure. We hypothesized that a serum proteomic signature may add diagnostic information beyond that provided by combined clinical and radiographic data.

METHODS

Cohort A included 265 and cohort B 114 patients. Using multivariable logistic regression analysis we calculated the area under the receiver operating characteristic curve (AUC) and quantified the added value of a previously described serum proteomic signature beyond clinical and radiographic risk factors for predicting lung cancer using the integration discrimination improvement (IDI) index.

RESULTS

The average computed tomography (CT) measured nodule size in cohorts A and B was 37.83 versus 23.15 mm among patients with lung cancer and 15.82 versus 17.18 mm among those without, respectively. In cohort A, the AUC increased from 0.68 to 0.86 after adding chest CT imaging variables to the clinical results, but the proteomic signature did not provide meaningful added value. In contrast, in cohort B, the AUC improved from 0.46 with clinical data alone to 0.61 when combined with chest CT imaging data and to 0.69 after adding the proteomic signature (IDI of 20% P = 0.0003). In addition, in a subgroup of 100 nodules between 5 and 20 mm in diameter, the proteomic signature added value with an IDI of 15% (P ≤ 0.0001).

CONCLUSIONS

The results show that this serum proteomic biomarker signature may add value to the clinical and chest CT evaluation of indeterminate lung nodules.

IMPACT

This study suggests a possible role of a blood biomarker in the evaluation of indeterminate lung nodules.

Occult metastases in lymph nodes predict survival in resectable non-small-cell lung cancer: report of the ACOSOG Z0040 trial

PURPOSE

The survival of patients with non-small-cell lung cancer (NSCLC), even when resectable, remains poor. Several small studies suggest that occult metastases (OMs) in pleura, bone marrow (BM), or lymph nodes (LNs) are present in early-stage NSCLC and are associated with a poor outcome. We investigated the prevalence of OMs in resectable NSCLC and their relationship with survival.

PATIENTS AND METHODS

Eligible patients had previously untreated, potentially resectable NSCLC. Saline lavage of the pleural space, performed before and after pulmonary resection, was examined cytologically. Rib BM and all histologically negative LNs (N0) were examined for OM, diagnosed by cytokeratin immunohistochemistry (IHC). Survival probabilities were estimated using the Kaplan-Meier method. The log-rank test and Cox proportional hazards regression model were used to compare survival of groups of patients. P < .05 was considered significant.

RESULTS

From July 1999 to March 2004, 1,047 eligible patients (538 men and 509 women; median age, 67.2 years) were entered onto the study, of whom 50% had adenocarcinoma and 66% had stage I NSCLC. Pleural lavage was cytologically positive in only 29 patients. OMs were identified in 66 (8.0%) of 821 BM specimens and 130 (22.4%) of 580 LN specimens. In univariate and multivariable analyses OMs in LN but not BM were associated with significantly worse disease-free survival (hazard ratio [HR], 1.50; P = .031) and overall survival (HR, 1.58; P = .009).

CONCLUSION

In early-stage NSCLC, LN OMs detected by IHC identify patients with a worse prognosis. Future clinical trials should test the role of IHC in identifying patients for adjuvant therapy.

Thirty- and ninety-day outcomes after sublobar resection with and without brachytherapy for non-small cell lung cancer: results from a multicenter phase III study

OBJECTIVE

Sublobar resection (SR) is commonly used for patients considered high risk for lobectomy. Nonoperative therapies are increasingly being reported for patients with similar risk because of perceived lower morbidity. We report 30- and 90-day adverse events (AEs) from American College of Surgeons Oncology Group Z4032, a multicenter phase III study for high-risk patients with stage I non-small cell lung cancer.

METHODS

Data from 222 evaluable patients randomized to SR (n = 114) or SR with brachytherapy (n = 108) are reported. AEs were recorded using the Common Terminology Criteria for Adverse Events, Version 3.0, at 30 and 90 days after surgery. Risk factors (age, percent baseline carbon monoxide diffusion in the lung [DLCO%], percent forced expiratory volume in 1 second [FEV1%], upper lobe vs lower lobe resections, performance status, surgery approach, video-assisted thoracic surgery vs open and extent, and wedge vs segmentectomy) were analyzed using a multivariable logistic model for their impact on the incidence of grade 3 or higher (G3+) AEs. Respiratory AEs were also specifically analyzed.

RESULTS

Median age, FEV1%, and DLCO% were similar in the 2 treatment groups. There was no difference in the location of resection (upper vs lower lobe) or the use of segmental or wedge resections. There were no differences between the groups with respect to "respiratory" G3+ AEs (30 days: 14.9% vs 19.4%, P = .35; 0-90 days: 19.3% vs 25%, P = .31) and "any" G3+ AEs (30 days: 25.4% vs 30.6%, P = .37; 0-90 days: 29.8% vs 37%, P = .25). Further analysis combined the 2 groups. Mortality occurred in 3 patients (1.4%) by 30 days and in 6 patients (2.7%) by 90 days. Four of the 6 deaths were thought to be due to surgery. When considered as continuous variables, FEV1% was associated with "any" G3+ AE at days 0 to 30 (P = .03; odds ratio [OR] = 0.98) and days 0 to 90 (P = .05; OR = 0.98), and DLCO% was associated with "respiratory" G3+ AE at days 0 to 30 (P = .03; OR = 0.97) and days 0 to 90 (P = .05; OR = 0.98). Segmental resection was associated with a higher incidence of any G3+ AE compared with wedge resection at days 0 to 30 (40.3% vs 22.7%; OR = 2.56; P < .01) and days 0 to 90 (41.5% vs 29.7%; OR = 1.96; P = .04). The median FEV1% was 50%, and the median DLCO% was 46%. By using these median values as potential cutpoints, only a DLCO% of less than 46% was significantly associated with an increased risk of "respiratory" and "any" G3+ AE for days 0 to 30 and 0 to 90.

CONCLUSIONS

In a multicenter setting, SR with brachytherapy was not associated with increased morbidity compared with SR alone. SR/SR with brachytherapy can be performed safely in high-risk patients with non-small cell lung cancer with low 30- and 90-day mortality and acceptable morbidity. Segmental resection was associated with increased "any" G3+ AE, and DLCO% less than 46% was associated with "any" G3+ AE and "respiratory" G3+ AE at both 30 and 90 days.

Successful treatment of atrioesophageal fistula by cervical esophageal ligation and decompression

Atrioesophageal fistula is a rare yet devastating complication of transcatheter ablation for atrial fibrillation. This condition requires urgent intervention, but the optimal treatment strategy is yet to be defined. Reported therapies range from endoscopic stenting to direct atrial repair or reconstruction while on cardiopulmonary bypass. Here, we describe the successful management of an atrioesophageal fistula by cervical esophageal ligation and decompression, along with gastric drainage.

Accuracy of FDG-PET to diagnose lung cancer in a region of endemic granulomatous disease

BACKGROUND

The 18 F-fluorodeoxyglucose-positron emission tomography (FDG-PET) is used to evaluate suspicious pulmonary lesions due to its diagnostic accuracy. The southeastern United States has a high prevalence of infectious granulomatous lung disease, and the accuracy of FDG-PET may be reduced in this population. We examined the diagnostic accuracy of FDG-PET in patients with known or suspected non-small cell lung cancer treated at our institution.

METHODS

A total of 279 patients, identified through our prospective database, underwent an operation for known or suspected lung cancer. Preoperative FDG-PET in 211 eligible patients was defined by standardized uptake value greater than 2.5 or by description ("moderate" or "intense") as avid. Sensitivity, specificity, positive and negative predictive values, likelihood ratios, and decision diagrams were calculated for FDG-PET in all patients and in patients with indeterminate nodules.

RESULTS

In all eligible patients (n=211), sensitivity and specificity of FDG-PET were 92% and 40%, respectively. Positive and negative predictive values were 86% and 55%. Overall FDG-PET accuracy to diagnose lung cancer was 81%. Preoperative positive likelihood ratio for FDG-PET diagnosis of lung cancer in this population was 1.5 compared with previously published values of 7.1. In 113 indeterminate lesions, 65% had lung cancer and the sensitivity and specificity were 89% and 40%, respectively. Twenty-four benign nodules (60%) had false positive FDG-PET scans. Twenty-two of 43 benign nodules (51%) were granulomas.

CONCLUSIONS

In a region with endemic granulomatous diseases, the specificity of FDG-PET for diagnosis of lung cancer was 40%. Clinical decisions and future clinical predictive models for lung cancer must accommodate regional variation of FDG-PET scan results.

The impact of adjuvant brachytherapy with sublobar resection on pulmonary function and dyspnea in high-risk patients with operable disease: preliminary results from the American College of Surgeons Oncology Group Z4032 trial

BACKGROUND

Z4032 was a randomized study conducted by the American College of Surgeons Oncology Group comparing sublobar resection alone versus sublobar resection with brachytherapy for high-risk operable patients with non-small cell lung cancer (NSCLC). This evaluates early impact of adjuvant brachytherapy on pulmonary function tests, dyspnea, and perioperative (30-day) respiratory complications in this impaired patient population.

METHODS

Eligible patients with stage I NSCLC tumors 3 cm or smaller were randomly allocated to undergo sublobar resection with (SRB group) or without (SR group) brachytherapy. Outcomes measured included the percentage predicted forced expiratory volume in 1 second (FEV1%), percentage predicted carbon monoxide diffusion capacity (DLCO%), and dyspnea score per the University of California San Diego Shortness of Breath Questionnaire. Pulmonary morbidity was assessed per the Common Terminology Criteria for Adverse Events version 3.0. Outcomes were measured at baseline and 3 months. A 10% change in pulmonary function test or 10-point change in dyspnea score was deemed clinically meaningful.

RESULTS

Z4032 permanently closed to patient accrual in January 2010 at 224 patients. At 3-month follow-up, pulmonary function data are currently available for 148 (74 SR and 74 SRB) patients described in this report. There were no differences in baseline characteristics between arms. In the SR arm, 9 patients (12%) reported grade 3 respiratory adverse events, compared with 12 (16%) in the SRB arm (P = .49). There was no significant change in percentage change in DLCO% or dyspnea score from baseline to 3 months within either arm. In the case of FEV1%, percentage change from baseline to 3 months was significant within the SR arm (P = .03), with patients reporting improvement in FEV1% at month 3. Multivariable regression analysis (adjusted for baseline values) showed no significant impact of treatment arm, tumor location (upper vs other lobe), or surgical approach (video-assisted thoracoscopic surgery vs thoracotomy) on 3-month FEV1%, DLCO%, and dyspnea score. There was no significant difference in incidence of clinically meaningful (10% pulmonary function or 10-point dyspnea score change) change between arms. Twenty-two percent of patients with lower-lobe tumors and 9% with upper-lobe tumors demonstrated 10% decline in FEV1% (odds ratio, 2.79; 95 confidence interval, 1.07-7.25; P = .04).

CONCLUSIONS

Adjuvant intraoperative brachytherapy in conjunction with sublobar resection did not significantly worsen pulmonary function or dyspnea at 3 months in a high-risk population with NSCLC, nor was it associated with increased perioperative pulmonary adverse events. Lower-lobe resection was the only factor significantly associated with clinically meaningful decline in FEV1%.

Lung cancer diagnosis from proteomic analysis of preinvasive lesions

Early detection may help improve survival from lung cancer. In this study, our goal was to derive and validate a signature from the proteomic analysis of bronchial lesions that could predict the diagnosis of lung cancer. Using previously published studies of bronchial tissues, we selected a signature of nine matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) mass-to-charge ratio features to build a prediction model diagnostic of lung cancer. The model was based on MALDI MS signal intensity (MALDI score) from bronchial tissue specimens from our 2005 published cohort of 51 patients. The performance of the prediction model in identifying lung cancer was tested in an independent cohort of bronchial specimens from 60 patients. The probability of having lung cancer based on the proteomic analysis of the bronchial specimens was characterized by an area under the receiver operating characteristic curve of 0.77 (95% CI 0.66-0.88) in this validation cohort. Eight of the nine features were identified and validated by Western blotting and immunohistochemistry. These results show that proteomic analysis of endobronchial lesions may facilitate the diagnosis of lung cancer and the monitoring of high-risk individuals for lung cancer in surveillance and chemoprevention trials.

Randomized trial of mediastinal lymph node sampling versus complete lymphadenectomy during pulmonary resection in the patient with N0 or N1 (less than hilar) non-small cell carcinoma: results of the American College of Surgery Oncology Group Z0030 Trial

OBJECTIVE

To determine whether mediastinal lymph node dissection improves survival compared with mediastinal lymph node sampling in patients undergoing resection for N0 or nonhilar N1, T1, or T2 non-small cell lung cancer.

METHODS

Patients with non-small cell lung cancer underwent sampling of 2R, 4R, 7, and 10R for right-sided tumors and 5, 6, 7, and 10L for left-sided tumors. If all tumors were negative for malignancy, patients were randomized to no further lymph node sampling (mediastinal lymph node sampling) or complete mediastinal lymph node dissection.

RESULTS

Of 1111 patients randomized, 1023 (mediastinal lymph node sampling in 498, mediastinal lymph node dissection in 525) were eligible and evaluable. There were no significant differences between the 2 groups in terms of demographics, Eastern Cooperative Oncology Group status, histology, cancer location, type or extent of resection, and pathologic stage. Occult N2 disease was found in 21 patients in the mediastinal lymph node dissection group. At a median follow-up of 6.5 years, 435 patients (43%) have died: mediastinal lymph node sampling in 217 (44%) and mediastinal lymph node dissection in 218 (42%). The median survival is 8.1 years for mediastinal lymph node sampling and 8.5 years for mediastinal lymph node dissection (P = .25). The 5-year disease-free survival was 69% (95% confidence interval, 64-74) in the mediastinal lymph node sampling group and 68% (95% confidence interval, 64-73) years in the mediastinal lymph node dissection group (P = .92). There was no difference in local (P = .52), regional (P = .10), or distant (P = .76) recurrence between the 2 groups.

CONCLUSIONS

If systematic and thorough presection sampling of the mediastinal and hilar lymph nodes is negative, mediastinal lymph node dissection does not improve survival in patients with early stage non-small cell lung cancer, but these results are not generalizable to patients staged radiographically or those with higher stage tumors.

Existing general population models inaccurately predict lung cancer risk in patients referred for surgical evaluation

BACKGROUND

Patients undergoing resections for suspicious pulmonary lesions have a 9% to 55% benign rate. Validated prediction models exist to estimate the probability of malignancy in a general population and current practice guidelines recommend their use. We evaluated these models in a surgical population to determine the accuracy of existing models to predict benign or malignant disease.

METHODS

We conducted a retrospective review of our thoracic surgery quality improvement database (2005 to 2008) to identify patients who underwent resection of a pulmonary lesion. Patients were stratified into subgroups based on age, smoking status, and fluorodeoxyglucose positron emission tomography (PET) results. The probability of malignancy was calculated for each patient using the Mayo and solitary pulmonary nodules prediction models. Receiver operating characteristic and calibration curves were used to measure model performance.

RESULTS

A total of 189 patients met selection criteria; 73% were malignant. Patients with preoperative PET scans were divided into four subgroups based on age, smoking history, and nodule PET avidity. Older smokers with PET-avid lesions had a 90% malignancy rate. Patients with PET-nonavid lesions, PET-avid lesions with age less than 50 years, or never smokers of any age had a 62% malignancy rate. The area under the receiver operating characteristic curve for the Mayo and solitary pulmonary nodules models was 0.79 and 0.80, respectively; however, the models were poorly calibrated (p<0.001).

CONCLUSIONS

Despite improvements in diagnostic and imaging techniques, current general population models do not accurately predict lung cancer among patients referred for surgical evaluation. Prediction models with greater accuracy are needed to identify patients with benign disease to reduce nontherapeutic resections.

Automated symptom alerts reduce postoperative symptom severity after cancer surgery: a randomized controlled clinical trial

PURPOSE

Patients receiving cancer-related thoracotomy are highly symptomatic in the first weeks after surgery. This study examined whether at-home symptom monitoring plus feedback to clinicians about severe symptoms contributes to more effective postoperative symptom control.

PATIENTS AND METHODS

We enrolled 100 patients receiving thoracotomy for lung cancer or lung metastasis in a two-arm randomized controlled trial; 79 patients completed the study. After hospital discharge, patients rated symptoms twice weekly for 4 weeks via automated telephone calls. For intervention group patients, an e-mail alert was forwarded to the patient's clinical team for response if any of a subset of symptoms (pain, disturbed sleep, distress, shortness of breath, or constipation) reached a predetermined severity threshold. No alerts were generated for controls. Group differences in symptom threshold events were examined by generalized estimating equation modeling.

RESULTS

The intervention group experienced greater reduction in symptom threshold events than did controls (19% v 8%, respectively) and a more rapid decline in symptom threshold events. The difference in average reduction in symptom interference between groups was -0.36 (SE, 0.078; P = .02). Clinicians responded to 84% of e-mail alerts. Both groups reported equally high satisfaction with the automated system and with postoperative symptom control.

CONCLUSION

Frequent symptom monitoring with alerts to clinicians when symptoms became moderate or severe reduced symptom severity during the 4 weeks after thoracic surgery. Methods of automated symptom monitoring and triage may improve symptom control after major cancer surgery. These results should be confirmed in a larger study.

Number of lymph nodes harvested from a mediastinal lymphadenectomy: results of the randomized, prospective American College of Surgeons Oncology Group Z0030 trial

BACKGROUND

Lymph node status is a major determinant of stage and survival in patients with lung cancer; however, little information is available about the expected yield of a mediastinal lymphadenectomy.

METHODS

The American College of Surgeons Oncology Group Z0030 prospective, randomized trial of mediastinal lymph node sampling vs complete mediastinal lymphadenectomy during pulmonary resection enrolled 1,111 patients from July 1999 to February 2004. Data from 524 patients who underwent complete mediastinal lymph node dissection were analyzed to determine the number of lymph nodes obtained.

RESULTS

The median number of additional lymph nodes harvested from a mediastinal lymphadenectomy following systematic sampling was 18 with a range of one to 72 for right-sided tumors, and 18 with a range of four to 69 for left-sided tumors. The median number of N2 nodes harvested was 11 on the right and 12 on the left. A median of at least six nodes was harvested from at least three stations in 99% of patients, and 90% of patients had at least 10 nodes harvested from three stations. Overall, 21 patients (4%) were found to have occult N2 disease.

CONCLUSIONS

Although high variability exists in the actual number of lymph nodes obtained from various nodal stations, complete mediastinal lymphadenectomy removes one or more lymph nodes from all mediastinal stations. Adequate mediastinal lymphadenectomy should include stations 2R, 4R, 7, 8, and 9 for right-sided cancers and stations 4L, 5, 6, 7, 8, and 9 for left-sided cancers. Six or more nodes were resected in 99% of patients in this study.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00003831; URL: clinicaltrials.gov.

Diagnostic characteristics of a serum biomarker in patients with positron emission tomography scans

BACKGROUND

Surgery for pulmonary nodules results in a benign diagnosis in 10% to 30% of cases. Computed tomography and fluorodeoxyglucose-positron emission tomography (FDG-PET) are highly sensitive but less specific. High-risk patients (age > 55 years and smoke > 15 pack-years) for lung cancer with negative FDG-PET scans, or low-risk patients (age < 55 years or smoke < 15 pack-years) with FDG-PET-avid lesions may have higher rates of benign nodules. We hypothesized that our serum biomarker improves diagnostic accuracy by providing greater specificity.

METHODS

Fifty-eight patients with pulmonary nodules (< or = 3 cm) were prospectively enrolled. We tested the accuracy of our proteomic biomarker in the serum by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Malignancy rates, contingency tables, sensitivity, and specificity analyses were calculated for the entire group and in a subset of patients at high risk for benign disease.

RESULTS

We identified 46 (79%) lung cancers and 12 (21%) benign lesions. Forty-five nodules were FDG-PET-avid. In 36 high-risk patients with FDG-PET-avid lesions, 32 (89%) had cancer. Of the remaining 22 lower-risk patients, 14 (64%) had cancer (p = 0.02). The serum biomarker sensitivity was 26.1%, specificity was 91.7%, positive predictive value was 92%, negative predictive value was 24%, and overall accuracy was 40%. The serum signature accurately predicted all eight benign nodules in this 22-patient subset.

CONCLUSIONS

The serum protein biomarker has a high specificity. This biomarker has a high positive predictive value but low negative predictive value and may improve noninvasive evaluation of lung nodules. Validation in a larger population is warranted.

Abstract 2727: Predicting lung cancer risk based on a novel proteomic signature of bronchial lesions

A biomarker signature to identify individuals at-risk for lung cancer would be of great clinical value. We hypothesized that the bronchial epithelium expresses a subset of proteins that once increased confer an elevated risk for lung cancer. We have therefore developed a proteomic approach to assess the risk for lung cancer. From our previous studies, we selected 11 matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) features to distinguish normal bronchial epithelium and low grade preinvasive lesions from high grade preinvasive lesions and invasive lung tumors. We tested this signature in an independent validation set consisting of bronchial specimens from 60 patients. The prediction accuracy was 78% with 73% sensitivity and 81% specificity. There was a 19-fold increased risk of having lung cancer for individuals with a signature intensity above the third quartile (95% CI, 5.65-64.81). We identified 10 of the 11 features corresponding to 7 proteins, thymosin ß4, ubiquitin, acyl-coA binding protein, cystatin A, S100A11, cytochrome c and macrophage migration inhibitory factor. The identity of these proteins was validated by immunohistochemistry, Western blotting and MALDI imaging mass spectrometry (IMS). MALDI IMS localized the candidate biomarker proteins specifically to high grade preinvasive lesions and invasive tumors. This novel proteomic signature may facilitate the selection and monitoring of high risk individuals for lung cancer early detection and chemoprevention strategies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2727.

Surgery with or without preoperative paclitaxel and carboplatin in early-stage non-small-cell lung cancer: Southwest Oncology Group Trial S9900, an intergroup, randomized, phase III trial

PURPOSE Patients with early-stage non-small-cell lung cancer (NSCLC) have a poor prognosis even after complete resection. Earlier studies of preoperative (induction) chemotherapy in resectable NSCLC demonstrated feasibility and encouraging survival data. This randomized phase III trial compared overall survival (OS) for preoperative paclitaxel and carboplatin followed by surgery with surgery alone in patients with early-stage NSCLC. PATIENTS AND METHODS Patients with clinical stage IB-IIIA NSCLC (excluding superior sulcus tumors and N2 disease) were eligible. Patients were randomly assigned to surgery alone or to three cycles of paclitaxel (225 mg/m(2)) and carboplatin (area under curve, 6) followed by surgical resection. The primary end point was OS; secondary end points were progression-free survival (PFS), chemotherapy response, and toxicity. RESULTS The trial closed early with 354 patients after reports of a survival benefit for postoperative chemotherapy in other studies. The median OS was 41 months in the surgery-only arm and 62 months in the preoperative chemotherapy arm (hazard ratio, 0.79; 95% CI, 0.60 to 1.06; P = .11.) The median PFS was 20 months for surgery alone and 33 months for preoperative chemotherapy (hazard ratio, 0.80; 95% CI, 0.61 to 1.04; P = .10.) Major response to chemotherapy was seen in 41% of patients; no unexpected toxicity was observed. CONCLUSION This trial closed prematurely after compelling evidence supporting postoperative chemotherapy emerged. Although OS and PFS were higher with preoperative chemotherapy, the differences did not reach statistical significance. At present, stronger evidence exists for postoperative chemotherapy in early-stage NSCLC.

Prognostic factors for resected non-small cell lung cancer with pN2 status: implications for use of postoperative radiotherapy

BACKGROUND

For non-small cell lung cancer (NSCLC) patients with pN2 status, the use of postoperative radiotherapy (PORT) remains controversial. Here, we investigated the association between different clinicopathological features and postoperative therapy and local control and survival in patients with resected pN2 NSCLC.

METHODS

We retrospectively analyzed 83 patients with pN2 NSCLC who underwent resection at Vanderbilt University Medical Center between 1994 and 2004. The relationship between 10 prognostic factors-gender, age at diagnosis, histology, tumor size, number of nodal stations involved, positive node number, surgical margin, extracapsular extension (ECE), and use of postoperative chemotherapy and PORT-and 2-year local recurrence-free survival (LRFS), distant recurrence-free survival (DRFS), recurrence-free survival (RFS), and overall survival (OS) rates was evaluated. Univariate and multivariate analyses were conducted using the Kaplan-Meier method and Cox proportional hazards ratios, respectively.

RESULTS

On univariate analysis, PORT was significantly associated with greater LRFS, RFS, and OS rates, whereas chemotherapy was associated with a trend toward a higher OS rate. Negative surgical margins were predictive of a higher OS rate, and negative ECE was associated with higher LRFS and RFS rates. On multivariate analysis, only PORT and negative ECE were associated with a higher LRFS rate. On subgroup analysis, in negative ECE patients, PORT was significantly associated with a higher OS rate.

CONCLUSIONS

PORT is associated with a higher OS rate for patients with resected pN2 NSCLC with negative ECE but not with positive ECE. The absence of ECE may serve as a useful prognostic variable in the selection of pN2 NSCLC patients for PORT and warrants further investigation in randomized clinical trials.