Modeling major lung resection outcomes using classification trees and multiple imputation techniques

A New Functional Threshold for Minimally Invasive Lobectomy

OBJECTIVE

To assess the performance of a lower predicted postoperative (ppo) forced expiratory volume in 1 second (FEV 1 ) or diffusion capacity of the lung for carbon monoxide (DLCO) (ppoFEV 1 /ppoDLCO) threshold to predict cardiopulmonary complications after minimally invasive surgery (MIS) lobectomy.

BACKGROUND

Although MIS is associated with better postoperative outcomes than open surgery, MIS uses risk-assessment algorithms developed for open surgery. Moreover, several different definitions of cardiopulmonary complications are used for assessment.

METHODS

All patients who underwent MIS lobectomy for clinical stage I to II lung cancer from 2018 to 2022 at our institution were considered. The performance of a ppoFEV 1 /ppoDLCO threshold of <45% was compared against that of the current guideline threshold of <60%. Three different definitions of cardiopulmonary complications were compared: Society of Thoracic Surgeons (STS), European Society of Thoracic Surgeons (ESTS), and Berry and colleagues' study.

RESULTS

In 946 patients, the ppoFEV 1 /ppoDLCO threshold of <45% was associated with a higher proportion correctly classified [79% (95% CI, 76%-81%) vs 65% (95% CI, 62%-68%); P <0.001]. The complication with the biggest difference in incidence between ppoFEV 1 /ppoDLCO of 45% to 60% and >60% was prolonged air leak [33 (13%) vs 34 (6%); P <0.001]. The predicted probability curves for cardiopulmonary complications were higher for the STS definition than for the ESTS or Berry definitions across ppoFEV 1 and ppoDLCO values.

CONCLUSIONS

The ppoFEV 1 /ppoDLCO threshold of <45% more accurately classified patients for cardiopulmonary complications after MIS lobectomy, emphasizing the need for updated risk-assessment guidelines for MIS lobectomy to optimize additional cardiopulmonary function evaluation.

Association between recovery from desaturation after stair climbing and postoperative complications in lung resection

OBJECTIVE

The stair-climbing test (SCT) is used as a surrogate for cardiopulmonary exercise testing, which measures maximal oxygen uptake, and considered a useful method for assessing exercise capacity in thoracic surgery. This study aims to investigate whether the recovery time of percutaneous oxygen saturation (SpO2) after stair climbing is a predictor of postoperative complications after lobectomy.

METHODS

We retrospectively identified 54 patients who performed SCT and underwent lobectomy between January 2015 and February 2023 at Shizuoka Cancer Center. The SpO2 recovery time was defined as the time required to recover from the minimum to resting value after stair climbing. The association between SpO2 recovery time and early postoperative pulmonary complications within 30 days after surgery was analyzed.

RESULTS

Eleven patients (20.4%) had postoperative pulmonary complications (≥ Clavien-Dindo Classification Grade 2). The cutoff value of SpO2 recovery time obtained from the receiver operating characteristic curve analysis was 90 s [sensitivity, 81.8%; specificity, 72.1%; AUC, 0.77 (95% confidence interval, 0.64-0.90)]. The occurrence of postoperative pulmonary complications was 42.9% in the delayed recovery time (DRT; SpO2 recovery time ≥ 90 s) group and 6.1% in the non-DRT (SpO2 recovery time < 90 s) group (p = 0.002). DRT was a predictor of postoperative pulmonary complications (odds ratio, 11.60; 95% CI 2.19-61.80).

CONCLUSIONS

DRT of SpO2 after stair climbing is a predictor of postoperative pulmonary complications following lobectomy in borderline patients who require exercise capacity assessment. SpO2 monitoring after stair climbing may be useful as one of the preoperative assessments in patients undergoing lobectomy.

Value of preoperative evaluation of FEV1 in patients with destroyed lung undergoing pneumonectomy - a 20-year real-world study

BACKGROUND

Clinical guidelines recommend a preoperative forced expiratory volume in one second (FEV1) of > 2 L as an indication for left or right pneumonectomy. This study compares the safety and long-term prognosis of pneumonectomy for destroyed lung (DL) patients with FEV1 ≤ 2 L or > 2 L.

METHODS

A total of 123 DL patients who underwent pneumonectomy between November 2002 and February 2023 at the Department of Thoracic Surgery, Beijing Chest Hospital were included. Patients were sorted into two groups: the FEV1 > 2 L group (n = 30) or the FEV1 ≤ 2 L group (n = 96). Clinical characteristics and rates of mortality, complications within 30 days after surgery, long-term mortality, occurrence of residual lung infection/tuberculosis (TB), bronchopleural fistula/empyema, readmission by last follow-up visit, and modified Medical Research Council (mMRC) dyspnea scores were compared between groups.

RESULTS

A total of 96.7% (119/123) of patients were successfully discharged, with 75.6% (93/123) in the FEV1 ≤ 2 L group. As compared to the FEV1 > 2 L group, the FEV1 ≤ 2 L group exhibited significantly lower proportions of males, patients with smoking histories, patients with lung cavities as revealed by chest imaging findings, and patients with lower forced vital capacity as a percentage of predicted values (FVC%pred) (P values of 0.001, 0.027, and 0.023, 0.003, respectively). No significant intergroup differences were observed in rates of mortality within 30 days after surgery, incidence of postoperative complications, long-term mortality, occurrence of residual lung infection/TB, bronchopleural fistula/empyema, mMRC ≥ 1 at the last follow-up visit, and postoperative readmission (P > 0.05).

CONCLUSIONS

As most DL patients planning to undergo left/right pneumonectomy have a preoperative FEV1 ≤ 2 L, the procedure is generally safe with favourable short- and long-term prognoses for these patients. Consequently, the results of this study suggest that DL patient preoperative FEV1 > 2 L should not be utilised as an exclusion criterion for pneumonectomy.

Prediction of postoperative cardiopulmonary complications after lung resection in a Chinese population: A machine learning-based study

Background

Approximately 20% of patients with lung cancer would experience postoperative cardiopulmonary complications after anatomic lung resection. Current prediction models for postoperative complications were not suitable for Chinese patients. This study aimed to develop and validate novel prediction models based on machine learning algorithms in a Chinese population.

Methods

Patients with lung cancer receiving anatomic lung resection and no neoadjuvant therapies from September 1, 2018 to August 31, 2019 were enrolled. The dataset was split into two cohorts at a 7:3 ratio. The logistic regression, random forest, and extreme gradient boosting were applied to construct models in the derivation cohort with 5-fold cross validation. The validation cohort accessed the model performance. The area under the curves measured the model discrimination, while the Spiegelhalter z test evaluated the model calibration.

Results

A total of 1085 patients were included, and 760 were assigned to the derivation cohort. 8.4% and 8.0% of patients experienced postoperative cardiopulmonary complications in the two cohorts. All baseline characteristics were balanced. The values of the area under the curve were 0.728, 0.721, and 0.767 for the logistic, random forest and extreme gradient boosting models, respectively. No significant differences existed among them. They all showed good calibration (p > 0.05). The logistic model consisted of male, arrhythmia, cerebrovascular disease, the percentage of predicted postoperative forced expiratory volume in one second, and the ratio of forced expiratory volume in one second to forced vital capacity. The last two variables, the percentage of forced vital capacity and age ranked in the top five important variables for novel machine learning models. A nomogram was plotted for the logistic model.

Conclusion

Three models were developed and validated for predicting postoperative cardiopulmonary complications among Chinese patients with lung cancer. They all exerted good discrimination and calibration. The percentage of predicted postoperative forced expiratory volume in one second and the ratio of forced expiratory volume in one second to forced vital capacity might be the most important variables. Further validation in different scenarios is still warranted.

Role of stereotactic body radiotherapy for early-stage non-small-cell lung cancer in patients borderline for surgery due to impaired pulmonary function

AIM

Stereotactic body radiotherapy (SBRT) is recommended only for inoperable patients with early-stage (e-stage) non-small-cell lung cancer (NSCLC). We compared outcomes between surgery and SBRT in patients borderline for surgery due to impaired pulmonary function (PF).

METHODS

We reviewed single-institution retrospective data of 578 patients with clinically T1-2N0M0 NSCLC treated by surgery or SBRT between 2004 and 2014, and extracted a cohort with borderline impaired PF for surgery, which was defined as predicted postoperative (PPO) forced expiratory volume in 1 s (FEV₁ ) of <50% and ≥30%. Overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS) were compared between surgery and SBRT using propensity score-matching (PSM) to avoid bias.

RESULTS

Among a total of 116 eligible patients with a median PPO FEV₁ of 45%, PSM identified 25 patients from each group with similar characteristics. The median age, pretreatment FEV₁ , and follow-up durations for the surgery and SBRT groups were 75 and 74 years, 58% and 56%, and 56 and 60 months, respectively. The 5-year OS, CSS, and DFS rates of the surgery versus SBRT groups were 60% versus 63%, 76% versus 81%, and 52% versus 48%, respectively (p = 0.97, 0.81, and 0.99). The surgical mortality was 4.0%, but no treatment-related death was observed after SBRT. The incidence of ≥ grade 2 adverse events after surgery was double that after SBRT (40% versus 20%, p = .22).

CONCLUSION

Our study suggests that SBRT is a reasonable option for patients with e-stage NSCLC and impaired PF who are considered borderline candidates for surgery.

SPECT/CT versus planar imaging to determine treatment strategy for non-small-cell lung cancer: a cost-effectiveness analysis

Aim: SPECT/CT has been found to improve predicted postoperative forced expiratory volume in one second (ppoFEV₁) assessments in patients with non-small-cell lung cancer (NSCLC). Methods: An economic simulation was developed comparing the cost-effectiveness of SPECT/CT versus planar scintigraphy for a US payer. Clinical outcomes and cost data were obtained through review of the published literature. Results: SPECT/CT increased the accuracy ppoFEV₁ assessment, changing the therapeutic decision for 1.3% of nonsurgical patients to a surgical option, while 3.3% of surgical patients shifted to more aggressive procedures. SPECT/CT led to an expected cost of $4694 per life year gained, well below typical thresholds. Conclusion: SPECT/CT resulted in substantially improved health outcomes and was found to be highly cost-effective.

A systematic review of risk prediction models for perioperative mortality after thoracic surgery

OBJECTIVES

Guidelines advocate that patients being considered for thoracic surgery should undergo a comprehensive preoperative risk assessment. Multiple risk prediction models to estimate the risk of mortality after thoracic surgery have been developed, but their quality and performance has not been reviewed in a systematic way. The objective was to systematically review these models and critically appraise their performance.

METHODS

The Cochrane Library and the MEDLINE database were searched for articles published between 1990 and 2019. Studies that developed or validated a model predicting perioperative mortality after thoracic surgery were included. Data were extracted based on the checklist for critical appraisal and data extraction for systematic reviews of prediction modelling studies.

RESULTS

A total of 31 studies describing 22 different risk prediction models were identified. There were 20 models developed specifically for thoracic surgery with two developed in other surgical specialties. A total of 57 different predictors were included across the identified models. Age, sex and pneumonectomy were the most frequently included predictors in 19, 13 and 11 models, respectively. Model performance based on either discrimination or calibration was inadequate for all externally validated models. The most recent data included in validation studies were from 2018. Risk of bias (assessed using Prediction model Risk Of Bias ASsessment Tool) was high for all except two models.

CONCLUSIONS

Despite multiple risk prediction models being developed to predict perioperative mortality after thoracic surgery, none could be described as appropriate for contemporary thoracic surgery. Contemporary validation of available models or new model development is required to ensure that appropriate estimates of operative risk are available for contemporary thoracic surgical practice.

Risk factors for the development of complications after surgical treatment for bronchopulmonary carcinoma

INTRODUCTION

The most suitable treatment in most early-stage lung cancer patients is surgical resection. Despite previously assessing each patient's status being relevant to detect possible complications inherent to surgery, no consensus has been reached on which factors are "high risk" in such patients. Our study aimed to analyse the morbidity and the mortality incidence associated with this surgery in our setting with a multicentre study and to detect risk parameters.

METHODS

A prospective analysis study with 3,307 patients operated for bronchopulmonary carcinoma in 24 hospitals. Study variables were age, TNM, gender, stage, smoking habit, surgery approach, surgical resection, ECOG, neoadjuvant therapy, comorbidity, spirometric values, and intraoperative and postoperative morbidity and mortality. A multivariate logistic regression analysis of the morbidity and mortality predictor factors was done.

RESULTS

We recorded 34.2% postoperative morbidity and 2.1% postoperative mortality. Gender, myocardial infarction, angina, ECOG ≥1, COPD, DLCO <60%, clinical pathological status, surgical resection and surgery approach were shown as morbidity and mortality predictor factors in lung cancer surgery in our series.

CONCLUSIONS

The main variables to consider when assessing the lung cancer patients to undergo surgery are gender, myocardial infarction, angina, ECOG, COPD, DLCO, clinical pathological status, surgical resection and surgery approach.

Cardiopulmonary Testing Before Lung Resection: What Are Thoracic Surgeons Doing?

BACKGROUND

Cardiopulmonary assessment for lung resection is important for risk stratification, and the American College of Chest Physicians (ACCP) guidelines provide decision support. We ascertained the cardiopulmonary assessment practices of thoracic surgeons and determined whether they are guideline concordant.

METHODS

An anonymous survey was emailed to 846 thoracic surgeons who participate in The Society of Thoracic Surgeons General Thoracic Surgery Database. We analyzed survey responses by practice type (general thoracic [GT] versus cardiothoracic [CT]) and years in practice (0-9, 10-19, and ≥20) with the use of contingency tables. We compared adherence of survey responses with the guidelines.

RESULTS

The response rate was 24.0% (n = 203). Most surgeons (n = 121, 59.6%) cited a predicted postoperative forced expiratory volume in 1 second or diffusing capacity of lung for carbon monoxide threshold of 40% for further evaluation. Experienced surgeons (≥20 years) were more likely to have a threshold that varies by surgical approach (31.3% versus 23.5% with 10-19 years of experience and 15.9% for 0-9 years of experience, P = .007). Overall, 52.2% refer patients with cardiovascular risk factors to cardiology and 42.9% refer patients with abnormal stress testing. CT surgeons were more likely to refer all patients to cardiology than GT surgeons (17.6% versus 2.4%, P < .001). Only one respondent (0.5%) was 100% adherent to the ACCP guidelines, and 4.4% and 45.8% were 75% and 50% adherent, respectively.

CONCLUSIONS

Among thoracic surgeons, there is variation in preoperative cardiopulmonary assessment practices, with differences by practice type and years in practice, and marked discordance with the ACCP guidelines. Further study of guideline adherence linked to postoperative morbidity and mortality is warranted to determine whether adherence affects outcomes.

Office-Based Spirometry: A New Model of Care in Preoperative Assessment for Low-Risk Lung Resections

BACKGROUND

Formal pulmonary function testing with laboratory spirometry (LS) is the standard of care for risk stratification before lung resection. LS and handheld office spirometry (OS) are clinically comparable for forced expiratory volume in 1 second and forced vital capacity. We investigated the safety of preoperative risk stratification based solely on OS.

METHODS

Patients at low-risk for cardiopulmonary complications were enrolled in a single-center prospective study and underwent preoperative OS. Formal LS was not performed when forced expiratory volume in 1 second was more than 60% by OS. Propensity score matching was used to compare patients in the OS group to low-risk institutional database patients (2008 to 2015) who underwent LS and lung resection. Standardized mean differences determined model covariate balance. The McNemar test and log-rank test were performed, respectively, for categorical and continuous paired outcome data.

RESULTS

There were 66 prospectively enrolled patients who received OS and underwent pulmonary resection, and 1,290 patients received preoperative LS, resulting in 52 propensity score-matched pairs (83%). There were no deaths and two 30-day readmissions per group. The major morbidity risk was similar in each group (7.7%). All analyses of discordant pair morbidity had p exceeding 0.56. There was no association between length of stay and exposure to OS vs LS (p = 0.31). The estimated annual institutional cost savings from performing OS only and avoiding LS was $38,000.

CONCLUSIONS

Low-risk patients undergoing lung resection can be adequately and safely assessed using OS without formal LS, with significant cost savings. With upcoming bundled care reimbursement paradigms, such safe and effective strategies are likely to be more widely used.

Risk Stratification in Lung Resection

PURPOSE OF REVIEW

Surgery is considered the best treatment option for patients with early stage lung cancer. Nevertheless, lung resection may cause a variable functional impairment that could influence the whole cardio-respiratory system with potential life-threatening complications. The aim of the present study is to review the most relevant evidences about the evaluation of surgical risk before lung resection, in order to define a practical approach for the preoperative functional assessment in lung cancer patients.

RECENT FINDINGS

The first step in the preoperative functional evaluation of a lung resection candidate is a cardiac risk assessment. The predicted postoperative values of forced expiratory volume in one second and carbon monoxide lung diffusion capacity should be estimated next. If both values are greater than 60 % of the predicted values, the patients are regarded to be at low surgical risk. If either or both of them result in values lower than 60 %, then a cardiopulmonary exercise test is recommended. Patients with VO2max >20 mL/kg/min are regarded to be at low risk, while those with VO2max <10 mL/kg/min at high risk. Values of VO2max between 10 and 20 mL/kg/min require further risk stratification by the VE/VCO2 slope. A VE/VCO2 <35 indicates an intermediate-low risk, while values above 35 an intermediate-high risk.

SUMMARY

The recent scientific evidence confirms that the cardiologic evaluation, the pulmonary function test with DLCO measurement, and the cardiopulmonary exercise test are the cornerstones of the preoperative functional evaluation before lung resection. We present a simplified functional algorithm for the surgical risk stratification in lung resection candidates.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Innate immune responses after resection for lung cancer via video-assisted thoracoscopic surgery and thoracotomy

OBJECTIVE

Innate immune responses to pulmonary resection may be critical in the pathogenesis of important postoperative pulmonary complications and potentially longer-term survival. We sought to compare innate immunity of patients undergoing major pulmonary resection for bronchogenic carcinoma via video-assisted thoracoscopic surgery (VATS) and thoracotomy.

METHODS

Bronchoalveolar lavage was conducted in the contralateral lung before staging bronchoscopy and mediastinoscopy and immediately after lung resection. Blood and exhaled nitric oxide were sampled preoperatively and at 6, 24, and 48 hours postoperatively.

RESULTS

Forty patients were included (26 VATS and 14 thoracotomy). There was a lower systemic cytokine response from lung resection undertaken by VATS compared with thoracotomy [interleukin 6 (IL-6), analysis of variance (ANOVA) P = 0.026; IL-8, ANOVA P = 0.018; and IL-10, ANOVA P = 0.047]. The VATS patients had higher perioperative serum albumin levels (ANOVA P = 0.001). Lower levels of IL-10 were produced by lipopolysaccharide-stimulated blood monocytes from the VATS patients compared with the thoracotomy patients at 6 hours postoperatively (geometric mean ratio, 1.16; 95% confidence interval, 1.08-1.33; P = 0.011). No statistically significant differences in the neutrophil phagocytic capacity, overall leukocyte count, or differential leukocyte count were found between the surgical groups (ANOVA P > 0.05). No statistically significant differences in bronchoalveolar lavage fluid parameters were found. Exhaled nitric oxide levels fell postoperatively, which reached statistical significance at 48 hours (geometric mean ratio, 1.2; 95% confidence interval, 1.02-1.46; P = 0.029). There were no significant differences found between the surgical groups (ANOVA P = 0.331).

CONCLUSIONS

Overall, a trend toward greater proinflammatory and anti-inflammatory responses is seen with lung resection performed via thoracotomy compared with VATS.

Does surgeon experience affect outcomes in pathologic stage I lung cancer?

OBJECTIVE

The study objective was to evaluate the influence of surgeon experience on outcomes in early-stage non-small cell lung cancer.

METHODS

In an institutional database, patients undergoing operations for pathologic stage I non-small cell lung cancer were categorized by surgeon experience: within 5 years of completion of training, the low experience group; with 5 to 15 years of experience, the moderate experience group; and with more than 15 years, the high experience group.

RESULTS

From 2000 to 2012, 800 operations (638 lobectomies, 162 sublobar resection) were performed with the following distribution: low experience 178 (22.2%), moderate experience 224 (28.0%), and high experience 398 (49.8%). Patients in the groups were similar in age and comorbidities. The use of video-assisted thoracoscopic surgery was higher in the moderate experience group (low experience: 62/178 [34.8%], moderate experience: 151/224 [67.4%], and high experience: 133/398 [33.4%], P < .001), as was the mean number of mediastinal (N2) lymph node stations sampled (low experience: 2.8 ± 1.6, moderate experience: 3.5 ± 1.7, high experience: 2.3 ± 1.4, P < .001). The risk of perioperative morbidity was similar across all groups (low experience: 54/178 [30.3%], moderate experience: 51/224 [22.8%], and high experience: 115/398 [28.9%], P = .163). Five-year overall survival in the moderate experience group was 76.9% compared with 67.5% in the low experience group (P < .001) and 71.4% in the high experience group (P = .006). In a Cox proportional hazard model, increasing age, male gender, prior cancer, and R1 resection were associated with an elevated risk of mortality, whereas being operated on by surgeons with moderate experience and having a greater number of mediastinal (N2) lymph node stations sampled were protective.

CONCLUSIONS

The experience of the surgeon does not affect perioperative outcomes after resection for pathologic stage I non-small cell lung cancer. At least moderate experience after fellowship is associated with improved long-term survival.

Preoperative evaluation for lung cancer resection

During the last decades lung cancer is the leading cause of death worldwide for both sexes. Even though cigarette smoking has been proved to be the main causative factor, many other agents (e.g., occupational exposure to asbestos or heavy metals, indoor exposure to radon gas radiation, particulate air pollution) have been associated with its development. Recently screening programs proved to reduce mortality among heavy-smokers although establishment of such strategies in everyday clinical practice is much more difficult and unknown if it is cost effective compared to other neoplasms (e.g., breast or prostate cancer). Adding severe comorbidities (coronary heart disease, COPD) to the above reasons as cigarette smoking is a common causative factor, we could explain the low surgical resection rates (approximately 20-30%) for lung cancer patients. Three clinical guidelines reports of different associations have been published (American College of Chest Physisians, British Thoracic Society and European Respiratory Society/European Society of Thoracic Surgery) providing detailed algorithms for preoperative assessment. In the current mini review, we will comment on the preoperative evaluation of lung cancer patients.

National cooperative group trials of "high-risk" patients with lung cancer: are they truly "high-risk"?

BACKGROUND

The American College of Surgery Oncology Group (ACOSOG) trials z4032 and z4033 prospectively characterized lung cancer patients as "high-risk" for surgical intervention, and these results have appeared frequently in the literature. We hypothesized that many patients who meet the objective enrollment criteria for these trials ("high-risk") have similar perioperative outcomes as "normal-risk" patients.

METHODS

We reviewed a prospective institutional database and classified patients undergoing resection for clinical stage I lung cancer as "high-risk" and "normal-risk" by ACOSOG major criteria.

RESULTS

From 2000 to 2010, 1,066 patients underwent resection for clinical stage I lung cancer. Of these, 194 (18%) met ACOSOG major criteria for risk (preoperative forced expiratory volume in 1 second or diffusion capacity of the lung for carbon monoxide≤50% predicted). "High-risk" patients were older (66.4 vs 64.6 years, p=0.02) but similar to controls in sex, prevalence of hypertension, diabetes, and coronary artery disease. "High-risk" patients were less likely than "normal-risk" patients to undergo a lobectomy (117 of 194 [60%] vs 665 of 872 [76%], p<0.001). "High-risk" and control patients experienced similar morbidity (any complication: 55 of 194 [28%] vs 230 of 872 [26%], p=0.59) and 30-day mortality (2 of 194 [1%] vs 14 of 872 [ 2%], p=0.75). A regression analysis showed age (hazard risk, 1.04; 95% confidence interval, 1.02 to 1.06) and coronary artery disease (hazard risk, 1.58; 95% confidence interval, 1.05 to 2.40) were associated with an elevated risk of complications in those undergoing lobectomy, whereas female sex (hazard ratio, 0.63; 95% confidence interval, 0.44 to 0.91) was protective. ACOSOG "high-risk" status was not associated with perioperative morbidity.

CONCLUSIONS

There are no important differences in early postsurgical outcomes between lung cancer patients characterized as "high-risk" and "normal-risk" by ACOSOG trial enrollment criteria, despite a significant proportion of "high-risk" patients undergoing lobectomy.

Predicted postoperative lung function is associated with all-cause long-term mortality after major lung resection for cancer

OBJECTIVES

Preoperative lung function is an independent predictor of long-term survival after lung resection for non-small-cell lung cancer (NSCLC). The extent of resection has an impact on operative mortality, determines postoperative lung function and may influence both overall- and cancer-specific survival. We sought to determine the impact of predicted postoperative (ppo) lung function on long-term survival after lung cancer resection.

METHODS

We previously reported long-term survival analyses for patients who underwent major lung resection for NSCLC 1980-2006. For this study, we calculated ppo spirometry (forced expiratory volume in the first second, FEV1) and diffusing capacity of the lung for carbon monoxide (DLCO) in the same cohort using the functional segment technique or quantitative perfusion scans when available, and updated survival data; missing data were imputed. We assessed the relationship of ppoFEV1 and ppoDLCO to long-term survival using Cox regression.

RESULTS

Of 854 patients, 471 (55%) were men, the mean age was 63 years and median survival was 42 months. At the time of analysis, 70% of patients had died. On regression analysis, all-cause mortality was related to age, stage, performance status, renal function and prior myocardial infarction. Preoperative lung function was marginally associated with mortality [DLCO (10-percentage point decrease): HR (hazard ratio) 1.04, 95% confidence interval (95% CI) 1.00-1.08, P = 0.056; FEV1 (10-percentage point decrease): HR 1.04, 95% CI 1.00-1.09, P = 0.067]. In contrast, ppo lung function was strongly associated with mortality (ppoDLCO: HR 1.06, 95% CI 1.01-1.12, P = 0.024; ppoFEV1: HR 1.06, 95% CI 1.01-1.12, P = 0.031).

CONCLUSIONS

Ppo lung function is strongly associated with long-term survival after major lung resection and is more strongly related to survival than preoperative lung function. Surgeons struggle with challenging decisions about the appropriate extent of resection for early-stage cancer, balancing factors such as operative morbidity/mortality, local recurrence and postoperative quality of life. Ppo lung function and its relation to survival also should be taken into consideration during such deliberations.

American College of Chest Physicians and Society of Thoracic Surgeons consensus statement for evaluation and management for high-risk patients with stage I non-small cell lung cancer

BACKGROUND

The standard treatment of stage I non-small cell lung cancer (NSCLC) is lobectomy with systematic mediastinal lymph node evaluation. Unfortunately, up to 25% of patients with stage I NSCLC are not candidates for lobectomy because of severe medical comorbidity.

METHODS

A panel of experts was convened through the Thoracic Oncology Network of the American College of Chest Physicians and the Workforce on Evidence-Based Surgery of the Society of Thoracic Surgeons. Following a literature review, the panel developed 13 suggestions for evaluation and treatment through iterative discussion and debate until unanimous agreement was achieved.

RESULTS

Pretreatment evaluation should focus primarily on measures of cardiopulmonary physiology, as respiratory failure represents the greatest interventional risk. Alternative treatment options to lobectomy for high-risk patients include sublobar resection with or without brachytherapy, stereotactic body radiation therapy, and radiofrequency ablation. Each is associated with decreased procedural morbidity and mortality but increased risk for involved lobe and regional recurrence compared with lobectomy, but direct comparisons between modalities are lacking.

CONCLUSIONS

Therapeutic options for the treatment of high-risk patients are evolving quickly. Improved radiographic staging and the diagnosis of smaller and more indolent tumors push the risk-benefit decision toward parenchymal-sparing or nonoperative therapies in high-risk patients. Unbiased assessment of treatment options requires uniform reporting of treatment populations and outcomes in clinical series, which has been lacking to date.

Diffusing capacity predicts long-term survival after lung resection for cancer

OBJECTIVES

Predictors of long-term survival for patients with lung cancer assist in individualizing treatment recommendations. Diffusing capacity (DLCO) is a predictor of complications after resection for lung cancer. We sought to determine whether DLCO is also prognostic for long-term survival after lung resection for cancer.

METHODS

We assessed survival among patients in our prospective database who underwent lung resection for cancer between 1980-2006. Potential prognostic factors for all-cause mortality were evaluated by computing average annual hazard rates, and variables significantly associated with survival were included in multivariable Cox modelling. Multiple imputation was used to address missing values.

RESULTS

Among 854 unique patients, there were 587 deaths. The median follow-up time from surgery was 9.6 years. Predictors of survival included age, stage, performance status, body mass index, history of myocardial infarction, renal function and DLCO. On univariate analysis, the hazard ratio increased incrementally compared with those with a DLCO of ≥ 80% (70-79%, 1.12; 60-69%, 1.29; <60%, 1.35). On multivariable analysis, DLCO was an independent predictor of long-term survival for all patients (corrected for all other important covariates; HR 1.04 per 10-point decrement; 95% CI 1.00-1.08; P = 0.05). Its prognostic ability for long-term survival was above and beyond its influence on operative mortality.

CONCLUSIONS

DLCO is an independent and clinically important determinant of long-term survival after major lung resection for cancer, a finding that is not generally known. Knowledge of this may help improve selection of patients for lung resection and may help tailor the extent of resection, when possible, in order to appropriately balance operative risk with long-term outcomes.

Pulmonary function tests do not predict pulmonary complications after thoracoscopic lobectomy

BACKGROUND

Pulmonary function tests predict respiratory complications and mortality after lung resection through thoracotomy. We sought to determine the impact of pulmonary function tests upon complications after thoracoscopic lobectomy.

METHODS

A model for morbidity, including published preoperative risk factors and surgical approach, was developed by multivariable logistic regression. All patients who underwent lobectomy for primary lung cancer between December 1999 and October 2007 with preoperative forced expiratory volume in 1 second (FEV1) or diffusion capacity to carbon monoxide (Dlco) 60% or less predicted were reviewed. Preoperative, histopathologic, perioperative, and outcome variables were assessed using standard descriptive statistics. Pulmonary complications were defined as atelectasis requiring bronchoscopy, pneumonia, reintubation, and tracheostomy.

RESULTS

During the study period, 340 patients (median age 67) with Dlco or FEV1 60% or less (mean % predicted FEV1, 55+/-1; mean % predicted Dlco, 61+/-1) underwent lobectomy (173 thoracoscopy, 167 thoracotomy). Operative mortality was 5% (17 patients) and overall morbidity was 48% (164 patients). At least one pulmonary complication occurred in 57 patients (17%). Significant predictors of pulmonary complications by multivariable analysis for all patients included Dlco (odds ratio 1.03, p=0.003), FEV1 (odds ratio 1.04, p=0.003), and thoracotomy as surgical approach (odds ratio 3.46, p=0.0007). When patients were analyzed according to operative approach, Dlco and FEV1 remained significant predictors of pulmonary morbidity for patients undergoing thoracotomy but not thoracoscopy.

CONCLUSIONS

In patients with impaired pulmonary function, preoperative pulmonary function tests are predictors of pulmonary complications when lobectomy for lung cancer is performed through thoracotomy but not through thoracoscopy.