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.

Costs Associated With Lobectomy for Lung Cancer: An Analysis Merging STS and Medicare Data.

BACKGROUND: Costs related to care of patients who undergo lobectomy for lung cancer may vary depending on patient, disease, and treating facility characteristics. We aimed to identify underlying case mix factors that contribute to variability of 90-day costs of lobectomy for early-stage lung cancer. METHODS: The Society of Thoracic Surgeons General Thoracic Surgery Database was queried for lobectomy for clinical stage I lung cancer (2008-2013). Demographics, clinical outcomes, and 90-day episode-of-care costs across all care settings were analyzed for patients successfully linked to Medicare data. Hospital costs were estimated from charges using cost-to-charge ratios. Comprehensive regression models were created to identify impact of preoperative patient factors and hospital characteristics on costs, and to delineate additive costs due to perioperative outcomes and complications. RESULTS: The mean 90-day cost for lobectomy was $45,080 ± $38,239. Variables associated with significant additive costs were age greater than or equal to 75 years, American Society of Anesthesiologists classification III or IV, forced expiratory volume in 1 second less than 80% predicted, body mass index less than 18.5 or greater than 35, current or past smoker, cerebrovascular disease, chronic kidney disease, impaired functional status, open thoracotomy, prolonged operative time, government hospitals, metropolitan setting, and geographic location. Patients with 1 or more postoperative complication resulted in an overall mean added cost of $27,259. Added costs increased with the number of complications; isolated recurrent laryngeal nerve paresis ($3,911) and respiratory failure ($35,011) were associated with the least and most additive cost, respectively. CONCLUSIONS: Lobectomy is associated with substantial variability of episode-of-care costs. Variability is driven by patient demographic and clinical factors, hospital characteristics, and the occurrence and severity of complications.

Consensus for Thoracoscopic Left Upper Lobectomy-Essential Components and Targets for Simulation.

BACKGROUND: Simulation-based training is a valuable component of cardiothoracic surgical education. Effective curriculum development requires consensus on procedural components and focused attention on specific learning objectives. Through use of a Delphi process, we established consensus on the steps of video-assisted thoracoscopic surgery (VATS) left upper lobectomy and identified targets for simulation. METHODS: Experienced thoracic surgeons were randomly selected for participation. Surgeons voted and commented on the necessity of individual steps comprising VATS left upper lobectomy. Steps with greater than 80% of participants in agreement of their necessity were determined to have established "consensus." Participants voted on the physical or cognitive complexity of each, or both, and chose steps most amenable to focused simulation. RESULTS: Thirty thoracic surgeons responded and joined in the voting process. Twenty operative steps were identified, with surgeons reaching consensus on the necessity of 19. Components deemed most difficult and amenable to simulation included those related to dissection and division of the bronchus, artery, and vein. CONCLUSIONS: Through a Delphi process, surgeons with a variety of practice patterns can achieve consensus on the operative steps of left upper lobectomy and agreement on those most appropriate for simulation. This information can be implemented in the development of targeted simulation for VATS lobectomy.

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.

Lack of correlation between short- and long-term performance after lung cancer surgery.

OBJECTIVE: Outcomes for lung cancer surgery are currently measured according to perioperative morbidity and mortality. However, the oncologic efficacy of the surgery is reflected by long-term survival. We examined correlation between measures of short-term and long-term performance for lung cancer surgery. METHODS: The Society of Thoracic Surgeons General Thoracic Surgery Database linked to Medicare survival data was queried for pathologic stage I lung cancer resected between 2009 and 2013. Two separate multivariable models were created: (1) short-term: avoidance of perioperative major morbidity and mortality; and (2) long-term: 3-year survival. Standardized incidence ratios were calculated for the Society of Thoracic Surgeons programs (participants) to determine risk-adjusted participant performance measures for the short- and long-term time points. Correlation of participant standardized incidence ratios for short- and long-term performance was assessed using the Pearson correlation coefficient. RESULTS: The study population included 12,596 patients from 229 participating programs. One hundred fifty-one participants met minimum volume and follow-up requirements for analysis. Overall, performance for the short-term measure was uniform with only 2 (1.3%) participants performing better than expected and 2 (1.3%) worse than expected. For the long-term measure, 9 (6%) participants achieved better than expected and 5 (3.3%) worse than expected survival. No participant was an above or below average performer for the short- and long-term measures. Further, no correlation was observed between participant short- and long-term performance (Pearson correlation coefficient, 0.12; 95% confidence interval, -0.04 to 0.28; P = .14). CONCLUSIONS: Avoidance of perioperative morbidity and mortality is an incomplete measure of performance in lung cancer surgery. Lung cancer surgery performance metrics should assess the safety of surgery and long-term survival.

Penetration, Completeness, and Representativeness of The Society of Thoracic Surgeons General Thoracic Surgery Database for Lobectomy.

BACKGROUND: Not all surgeons performing lobectomy in the United States report outcomes to The Society of Thoracic Surgeons General Thoracic Surgery Database (STS GTSD). We examined penetration, completeness, and representativeness of the STS GTSD for lobectomy in the Centers for Medicare and Medicaid Services (CMS) patient population. METHODS: The STS GTSD lobectomies from 2002 to 2013 were linked and matched to CMS data using a deterministic matching algorithm. Penetration at center- and patient-level were determined by the number of CMS lobectomy sites and patients, matched to STS GTSD data, divided by the total number of CMS lobectomy sites and patients, respectively. Completeness was defined as the ratio of lobectomies linked to STS GTSD data to the total number of lobectomies. Representativeness was determined by comparing outcomes for patients undergoing lobectomy at matched and unmatched STS GTSD sites. RESULTS: A total of 9,569 centers were included in the study. Center level penetration steadily increased from 1.2% (10 of 859 sites) in 2002 to 25% (169 of 675 sites) in 2013. Patient-level penetration was highest, 38% (4,177 of 11,018), in 2013. Completeness at GTSD sites varied from 59% to 78% over the study period. Postoperative length of stay was longer for nonparticipants than for STS GTSD surgeons (median 6 versus 5 days, p < 0.001); 30-day mortality was higher for nonparticipants than for STS GTSD participants (3.3% versus 1.6%, p < 0.001). CONCLUSIONS: Participation in the STS GTSD has increased over time, but penetration lags behind that of the other STS National Databases. The STS GTSD participants have superior observed perioperative outcomes for lobectomy compared with nonparticipants. Database participation may reflect high quality care, and ongoing efforts to increase surgeon participation in the STS GTSD should be continued.

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.

Differential effects of operative complications on survival after surgery for primary lung cancer.

OBJECTIVE: Complications adversely affect survival after lung cancer surgery. We tested the hypothesis that effects of complications after lung cancer surgery on survival vary substantially across the spectrum of postoperative complications. METHODS: The Society of Thoracic Surgeons General Thoracic Surgery Database was linked to Medicare data for lung cancer resections from 2002 through 2013. Linkage was achieved for 29,899 patients. A survival model was created that included operative complications as explanatory variables and adjusted for relevant baseline covariates. Because of violation of the proportional hazard assumption, we used time-varying coefficient Cox modeling for the complication variables. RESULTS: Median patient age was 73 years, and 48% were male. Procedures performed were lobectomy in 69%, wedge in 17%, segmentectomy in 7%, bilobectomy in 3%, pneumonectomy in 3%, and sleeve lobectomy in 1%. Most frequent complications were atrial arrhythmia (14%), pneumonia (4.3%), reintubation (3.8%), delirium (2%), and acute kidney injury (1.4%). In the early period (0-90 days), 12 complications are associated with worse survival. From 3 to 18 months after surgery, only 4 complications are associated with survival: delirium, blood transfusion, reintubation, and pneumonia. After 18 months, only sepsis and blood transfusion are associated with a significant late hazard. CONCLUSIONS: Our analysis confirmed the presence of differential magnitude and time-varying effects on survival of individual complications after lung cancer surgery. We conclude that the derived time-dependent hazard ratios can serve as objective weights in future models that enhance performance measurement and focus attention on prevention and management of complications with greatest effects.

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.

Rationale for a Minimum Number of Lymph Nodes Removed with Non-Small Cell Lung Cancer Resection: Correlating the Number of Nodes Removed with Survival in 98,970 Patients.

BACKGROUND: The benefit of thoracic lymphadenectomy in the treatment of resectable non-small cell lung cancer (NSCLC) continues to be debated. We hypothesized that the number of lymph nodes (LNs) removed for patients with pathologic node-negative NSCLC would correlate with survival. METHODS: The National Cancer Data Base (NCDB) was queried for resected, node-negative, NSCLC patients treated between 2004 and 2014. Patients were grouped according to the number of LNs removed (1-4, 5-8, 9-12, 13-16, and ≥17). Patients with <10 LNs removed were also compared with those with ≥10 LNs removed. A Cox regression analysis was performed and hazard ratios (HRs) calculated, with 95 % confidence intervals (CIs). RESULTS: Of 1,089,880 patients with NSCLC reported to the NCDB during the study period, 98,970 (9.0 %) underwent resection without evidence of pathologic nodal involvement. Lobectomy was performed in 83.9 %, sublobar resection was performed in 12.7 % and pneumonectomy was performed in 2.8 % of patients. The number of LNs removed correlated with increasing tumor size and extent of resection. On multivariate analysis, increasing age, male sex, white ethnicity, high tumor grade, larger tumor size, pneumonectomy, and positive surgical margins were all negatively correlated with overall survival. The number of LNs removed and lobectomy/bi-lobectomy correlated with improved survival. The removal of <10 LNs was associated with a 12 % increased risk of death (HR: 1.12, 95 % CI 1.09-1.14; p < 0.001). CONCLUSION: Survival of early-stage NSCLC patients is associated with the number of LNs removed. The surgical management of early-stage NSCLC should include thoracic lymphadenectomy of at least 10 nodes.

Longitudinal Follow-up of Lung Cancer Resection From the Society of Thoracic Surgeons General Thoracic Surgery Database in Patients 65 Years and Older.

BACKGROUND: The Society of Thoracic Surgeons (STS) General Thoracic Surgery Database (GTSD) does not capture long-term survival after lung cancer surgery. Our objective was to provide longitudinal follow-up to the STS GTSD through linkage to Centers for Medicare and Medicaid Services (CMS) data for patients 65 years of age or older. METHODS: Lung cancer operations reported in the STS GTSD from 2002 through 2012 were linked to CMS data for patients 65 years of age or older using variables common to both databases with a deterministic matching algorithm. Mortality data were abstracted for each linked patient from the CMS data. The Kaplan-Meier method was used to estimate long-term survival for lung cancer surgery patients based on tumor stage. RESULTS: From 2002 through 2012, 60,089 lung cancer resections were identified in the GTSD, and 37,009 (61.7%) were in patients 65 years or older. Of these, 26,055 of 37,099 lung cancer resections (70%) in patients 65 years or older were successfully linked to CMS data. Failure to link was most commonly related to having a health maintenance organization or commercial insurance as the primary payer: 40.5% (5,290 of 13,065) of such patients were not linked from 2009 to 2012 (years payer data available). Median survival after lung cancer resection was 6.7 years for pathologic stage I, 3.5 years for stage II, 2.4 years for stage III, and 2.2 years for stage IV. CONCLUSIONS: The CMS data complement the STS GTSD data by enabling examination of long-term survival and resource utilization in patients 65 years or older. Linked data from the STS GTSD and the CMS will allow for longitudinal analyses of comparative effectiveness among different surgical approaches for the treatment of lung cancer.

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.

A Nomogram to Predict Recurrence and Survival of High-Risk Patients Undergoing Sublobar Resection for Lung Cancer: An Analysis of a Multicenter Prospective Study (ACOSOG Z4032).

BACKGROUND: Individualized prediction of outcomes may help with therapy decisions for patients with non-small cell lung cancer. We developed a nomogram by analyzing 17 clinical factors and outcomes from a randomized study of sublobar resection for non-small cell lung cancer in high-risk operable patients. The study compared sublobar resection alone with sublobar resection with brachytherapy. There were no differences in primary and secondary outcomes between the study arms, and they were therefore combined for this analysis. METHODS: The clinical factors of interest (considered as continuous variables) were assessed in a univariate Cox proportional hazards model for significance at the 0.10 level for their impact on overall survival (OS), local recurrence-free survival (LRFS), and any recurrence-free survival (RFS). The final multivariable model was developed using a stepwise model selection. RESULTS: Of 212 patients, 173 had complete data on all 17 risk factors. Median follow-up was 4.94 years (range, 0.04 to 6.22). The 5-year OS, LRFS, and RFS were 58.4%, 53.2%, and 47.4%, respectively. Age, baseline percent diffusing capacity of lung for carbon monoxide, and maximum tumor diameter were significant predictors for OS, LRFS, and RFS in the multivariable model. Nomograms were subsequently developed for predicting 5-year OS, LRFS, and RFS. CONCLUSIONS: Age, baseline percent diffusing capacity of lung for carbon monoxide, and maximum tumor diameter significantly predicted outcomes after sublobar resection. Such nomograms may be helpful for treatment planning in early stage non-small cell lung cancer and to guide future studies.