Operative Risk for Major Lung Resection Increases at Extremes of Body Mass Index

Differences in outcomes by race/ethnicity after thoracic surgery in a large integrated health system

Background

Disparities exist throughout surgery. We aimed to assess for racial/ethnic disparities among outcomes in a large thoracic surgery patient population.

Methods

We reviewed all thoracic surgery patients treated at our integrated health system from January 1, 2016-December 31, 2020. Post-operative outcomes including length of stay (LOS), 30-day return to the emergency department (30d-ED), 30-day readmission, 30- and 90-day outpatient appointments, and 30- and 90-day mortality were compared by race/ethnicity. Bivariate analyses and multivariable logistic regression were performed. Our multivariable models adjusted for age, sex, body mass index, Charlson Comorbidity Index, surgery type, neighborhood deprivation index, insurance, and home region.

Results

Of 2730 included patients, 59.4 % were non-Hispanic White, 15.0 % were Asian, 11.9 % were Hispanic, 9.6 % were Black, and 4.1 % were Other. Median (Q1-Q3) LOS (in hours) was shortest among non-Hispanic White (37.3 (29.2-76.1)) and Other (36.5 (29.3-75.4)) patients followed by Hispanic (46.8 (29.9-78.1)) patients with Asian (51.3 (30.7-81.9)) and Black (53.7 (30.6-101.6)) patients experiencing the longest LOS (p < 0.01). 30d-ED rates were highest among Hispanic patients (21.3 %), followed by Black (19.2 %), non-Hispanic White (18.1 %), Asian (13.4 %), and Other (8.0 %) patients (p < 0.01). On multivariable analysis, Hispanic ethnicity (Odds Ratio (OR) 1.43 (95 % CI 1.03-1.97)) and Medicaid insurance (OR 2.37 (95 % CI 1.48-3.81)) were associated with higher 30d-ED rates. No racial/ethnic disparities were found among other outcomes.

Conclusions

Despite parity across multiple surgical outcomes, disparities remain related to patient encounters within our system. Health systems must track such disparities in addition to standard clinical outcomes.

Key message

While our large integrated health system has been able to demonstrate parity across many major surgical outcomes among our thoracic surgery patients, race/ethnicity disparities persist including in the number of post-operative return trips to the emergency department. Tracking outcome disparities to a granular level such as return visits to the emergency department and number of follow up appointments is critical as health systems strive to achieve equitable care.

Nomogram for predicting postoperative pulmonary complications in spinal tumor patients

OBJECTIVES

Although several independent risk factors for postoperative pulmonary complications (PPCs) after spinal tumor surgery have been studied, a simple and valid predictive model for PPC occurrence after spinal tumor surgery has not been developed.

PATIENTS AND METHODS

We collected data from patients who underwent elective spine surgery for a spinal tumor between 2013 and 2020 at a tertiary hospital in China. Data on patient characteristics, comorbidities, preoperative examinations, intraoperative variables, and clinical outcomes were collected. We used univariable and multivariable logistic regression models to assess predictors of PPCs and developed and validated a nomogram for PPCs. We evaluated the performance of the nomogram using the area under the receiver operating characteristic curve (ROC), calibration curves, the Brier Score, and the Hosmer-Lemeshow (H-L) goodness-of-fit test. For clinical use, decision curve analysis (DCA) was conducted to identify the model's performance as a tool for supporting decision-making.

RESULTS

Among the participants, 61 (12.4%) individuals developed PPCs. Clinically significant variables associated with PPCs after spinal tumor surgery included BMI, tumor location, blood transfusion, and the amount of blood lost. The nomogram incorporating these factors showed a concordance index (C-index) of 0.755 (95% CI: 0.688-0.822). On internal validation, bootstrapping with 1000 resamples yielded a bias-corrected area under the receiver operating characteristic curve of 0.733, indicating the satisfactory performance of the nomogram in predicting PPCs. The calibration curve demonstrated accurate predictions of observed values. The decision curve analysis (DCA) indicated a positive net benefit for the nomogram across most predicted threshold probabilities.

CONCLUSIONS

We have developed a new nomogram for predicting PPCs in patients who undergo spinal tumor surgery.

Association between metabolically healthy obesity and metastasis in lung cancer patients - a systematic review and meta-analysis

Background

Many clinical trials have looked at the relationship between obesity and lung cancer (LC), however, there is scarcity of literature specifically addressing the association between metabolically healthy obesity and metastasis in LC patients. To address this gap in the body of evidence, the study was conducted to observe the association between metabolically healthy obesity and metastasis in LC patients.

Methods

We conducted a pre-registered systematic review by searching six major online databases to identify studies relevant related to our investigation, in adherence with the PRISMA guidelines. A proper data extraction protocol was further established to synthesize the findings from the selected papers through a meta-analysis.

Results

Eleven (11) studies met the requisite selection criterion and were included in the study. A random-effect model was used. Obesity was found to have a significant impact on readmission in LC patients. The combined analysis showed a significant effect size of 0.08 (95% CI 0.07 to 0.08), indicating a noticeable impact of obesity. It was also assessed that obese individuals had a 34% reduced risk of LC compared to normal weight individuals. Obesity was associated with a lower risk of surgical complications with a pooled risk ratio of 0.13 (95% CI 0.12 to 0.14). A statistically significant decreased risk of LC (pooled RR = 0.72, 95% CI: 0.68 to 0.77) was also observed in the obese individuals.

Conclusion

The analysis reveals that obesity is associated with a noticeable increase in readmissions, although the impact on LC risk itself is negligible. Moreover, obesity appears to have a beneficial effect by reducing the risk of surgical complications. These results highlight the complex relationship between the two aforementioned factors, emphasizing the importance of considering obesity as a significant factor in patient management and healthcare decision-making.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023427612.

Association of body mass index with morbidity following elective ventral hernia repair

Background

Prior work has linked body mass index (BMI) with postoperative outcomes of ventral hernia repair (VHR), though recent data characterizing this association are limited. This study used a contemporary national cohort to investigate the association between BMI and VHR outcomes.

Methods

Adults ≥ 18 years undergoing isolated, elective, primary VHR were identified using the 2016-2020 American College of Surgeons National Surgical Quality Improvement Program database. Patients were stratified by BMI. Restricted cubic splines were utilized to ascertain the BMI threshold for significantly increased morbidity. Multivariable models were developed to evaluate the association of BMI with outcomes of interest.

Results

Of ~89,924 patients, 0.5 % were considered Underweight, 12.9 % Normal Weight, 29.5 % Overweight, 29.1 % Class I, 16.6 % Class II, 9.7 % Class III, and 1.7 % Superobese. After risk adjustment, class I (Adjusted Odds Ratio [AOR] 1.22, 95 % Confidence Interval [95%CI]: 1.06-1.41), class II (AOR 1.42, 95%CI: 1.21-1.66), class III obesity (AOR 1.76, 95%CI: 1.49-2.09) and superobesity (AOR 2.25, 95 % CI: 1.71-2.95) remained associated with increased odds of overall morbidity relative to normal BMI following open, but not laparoscopic, VHR. A BMI of 32 was identified as the threshold for the most significant increase in predicted rate of morbidity. Increasing BMI was linked to a stepwise rise in operative time and postoperative length of stay.

Conclusion

BMI ≥ 32 is associated with greater morbidity following open, but not laparoscopic VHR. The relevance of BMI may be more pronounced in open VHR and must be considered for stratifying risk, improving outcomes, and optimizing care.

Key message

Body mass index (BMI) continues to be a relevant factor in morbidity and resource use for elective open ventral hernia repair (VHR). A BMI of 32 serves as the threshold for significant increase in overall complications following open VHR, though this association is not observed in operations performed laparoscopically.

Impact of body mass index on perioperative outcomes of laparoscopic major hepatectomies

BACKGROUND

Data on the effect of body mass index on laparoscopic liver resections are conflicting. We performed this study to investigate the association between body mass index and postoperative outcomes after laparoscopic major hepatectomies.

METHODS

This is a retrospective review of 4,348 laparoscopic major hepatectomies at 58 centers between 2005 and 2021, of which 3,383 met the study inclusion criteria. Concomitant major operations, vascular resections, and previous liver resections were excluded. Associations between body mass index and perioperative outcomes were analyzed using restricted cubic splines. Modeled effect sizes were visually rendered and summarized.

RESULTS

A total of 1,810 patients (53.5%) had normal weight, whereas 1,057 (31.2%) were overweight and 392 (11.6%) were obese. One hundred and twenty-four patients (3.6%) were underweight. Most perioperative outcomes showed a linear worsening trend with increasing body mass index. There was a statistically significant increase in open conversion rate (16.3%, 10.8%, 9.2%, and 5.6%, P < .001), longer operation time (320 vs 305 vs 300 and 266 minutes, P < .001), increasing blood loss (300 vs 300 vs 295 vs 250 mL, P = .022), and higher postoperative morbidity (33.4% vs 26.3% vs 25.0% vs 25.0%, P = .009) in obese, overweight, normal weight, and underweight patients, respectively (P < .001). However, postoperative major morbidity demonstrated a "U"-shaped association with body mass index, whereby the highest major morbidity rates were observed in underweight and obese patients.

CONCLUSION

Laparoscopic major hepatectomy was associated with poorer outcomes with increasing body mass index for most perioperative outcome measures.

The Influence of Preoperative Nutritional and Systemic Inflammatory Status on Perioperative Outcomes following Da Vinci Robot-Assisted Thoracic Lung Cancer Surgery

Background: Nutrition is an important factor in the outcome of any disease process. We evaluated the relationship of nutritional status and inflammatory status of non-small cell lung cancer (NSCLC) patients undergoing robotic-assisted thoracic surgery (RATS) with postoperative complications. Methods: This prospective cohort study included 107 NSCLC patients undergoing surgical treatment, between 2019 and 2021. Nutritional status and inflammatory status were assessed before pulmonary resection using anthropometric assessment, blood tests, and body mass index (BMI). Results: The BMI was 27.5 ± 4.4. Based on BMI, 29% (n = 31) were classified as normal weight, 43% (n = 46) as overweight, and 28% (n = 30) as obese. The mean neutrophil/lymphocyte ratio (NLR) was 2.16 ± 0.85, the platelet/lymphocyte ratio (PLR) was 121.59 ± 44.21, and the lymphocyte/monocyte ratio (LMR) was 3.52 ± 1.17. There was no increase in the number of intraoperative complications or bleeding (p = 0.696), postoperative complications (p = 0.569), mean hospital stay (p = 0.258) or duration of chest drain (p = 0.369). Higher inflammatory status, with an NLR > 1.84, was associated with more overall postoperative complications (p = 0.028), only in univariate analysis, but this significance was not maintained on multivariate analysis. Conclusions: BMI was not a predictor of increased postoperative risk in this cohort; therefore, weight should not deter surgeons from using RATS for pulmonary resection.

One-lung ventilation in obese patients undergoing thoracoscopic lobectomy for lung cancer

BACKGROUND

We evaluated the safety and feasibility of one-lung ventilation in obese patients undergoing thoracoscopic lobectomy and whether obesity affected peri- and postoperative outcomes.

METHODS

This was a retrospective single center study including consecutive patients undergoing thoracoscopic lobectomy between October 2019 and February 2022. Obese patients were statistically compared to a control group to evaluate any differences in relation to one-lung ventilation and peri- and postoperative outcomes.

RESULTS

Our study population included 111 patients; of these, 26 (23%) were included in the obese group, while 85 (77%) were included within the nonobese group. To obtain one-lung ventilation in nonobese patients, a double-lumen tube was more frequently used than a single-lumen tube with bronchial blocker (61% vs. 39%; p = 0.02), while in obese patients a single-lumen tube with bronchial blocker was used more than a double-lumen tube (81% vs. 19%, p = 0.001). Intergroup comparison showed that a double-lumen tube was the preferred method in nonobese patients, while a single-lumen tube with bronchial blockers was the strategy of choice in obese patients (p = 0.0002). Intubation time was longer in the obese group than in the nonobese group (94.0 ± 6.1 vs. 85.0 ± 7.0 s; p = 0.0004) and failure rate of first attempt at intubation was higher in the obese group (23% vs. 5%; p = 0.01). Obesity was not associated with increased intra-, peri- and postoperative complications and/or mortality.

CONCLUSIONS

One-lung ventilation is a feasible and safe procedure also in obese patients and obesity did not negatively affect peri- and postoperative outcomes after lung resection.

Obesity Does Not Increase Perioperative Outcomes in Older Patients Undergoing Thoracoscopic Anatomic Lung Cancer Surgery

Objectives

To investigate the relationship between obesity status and perioperative outcomes in elderly patients undergoing thoracoscopic anatomic lung cancer surgery.

Methods

From January 2016 to December 2018, we performed a monocentric retrospective cohort study among 4164 consecutive patients aged 65 years or older who underwent thoracoscopic anatomic lung cancer surgery at Shanghai Chest Hospital. Two groups were stratified by body mass index (BMI): nonobese (BMI<28kg/m²) and obese status (BMI≥28kg/m²). Using a 1:1 propensity score matching (PSM) analysis to compare perioperative outcomes between two groups.

Results

4035 older patients were eventually enrolled, with a mean age of 69.8 years (range: 65-87), and 305 patients were eligible for obese status, with a mean BMI of 29.8 ± 1.7kg/m². Compared with nonobese patients, obese patients were more likely to have higher rates of intraoperative hypoxemia (1.2% vs 3.9%, P=0.001) and new-onset arrhythmia (2.3% vs 4.3%, P=0.034). The difference in intraoperative transfusion and conversion rates and postoperative outcomes regarding pulmonary complications, new-onset arrhythmia, transfusion, length of hospital stay, 30-day readmission and hospitalization costs between two groups were not significant (P>0.05). After a 1:1 PSM analysis, the difference in both intraoperative and postoperative complications among two groups were not significant (P>0.05). In subgroup analysis, patients with BMI≥30kg/m² had a similar incidence of perioperative complications compared to patients with BMI between 28 and 30 kg/m² (P>0.05).

Conclusions

Our research data support evidence for “obesity paradox” and also contribute the growing body of evidence that obesity in older patients should not exclude candidates for thoracoscopic anatomic lung cancer surgery.

"Obesity paradox" has not an impact on minimally invasive anatomical lung resection

INTRODUCTION

The paradoxical benefit of obesity, the 'obesity paradox', has been analyzed in lung surgical populations with contradictory results. Our goal was assessing the relationship of body mass index (BMI) to acute outcomes after minimally invasive major pulmonary resections.

METHODS

Retrospective review of consecutive patients who underwent pulmonary anatomical resection through a minimally invasive approach for the period 2014-2019. Patients were grouped as underweight, normal, overweight and obese type I, II and III. Adjusted odds ratios regarding postoperative complications (overall, respiratory, cardiovascular and surgical morbidity) were produced with their exact 95% confidence intervals. All tests were considered statistically significant at p<0.05.

RESULTS

Among 722 patients included in the study, 37.7% had a normal BMI and 61.8% were overweight or obese patients. When compared with that of normal BMI patients, adjusted pulmonary complications were significantly higher in obese type I patients (2.6% vs 10.6%, OR: 4.53 [95%CI: 1.86-12.11]) and obese type II-III (2.6% vs 10%, OR: 6.09 [95%CI: 1.38-26.89]). No significant differences were found regarding overall, cardiovascular or surgical complications among groups.

CONCLUSIONS

Obesity has not favourable effects on early outcomes in patients undergoing minimally invasive anatomical lung resections, since the risk of respiratory complications in patients with BMI≥30kg/m² and BMI≥35kg/m² is 4.5 and 6 times higher than that of patients with normal BMI.

Exploring the Impact of the Obesity Paradox on Lung Cancer and Other Malignancies

Simple Summary

Studies have shown that obesity is associated with many adverse health effects, including worse cancer outcomes. Many studies paradoxically suggest a survival benefit for obesity in treatment outcomes of cancers such as non-small-cell lung cancer. This relationship is not seen in animal models. We hypothesize that this relationship is secondary to suboptimal quantification of adiposity, enhanced immunotherapy response, and variables such as sex, medications, and smoking status. There are many ways to measure and classify adiposity, but the ability to distinguish abdominal obesity is likely key in predicting accurate prognosis. There are many ways obesity impacts cancer treatment course from diagnosis to survivorship. In this paper, we aim to analyze the factors contributing to the obesity paradox and its effect on lung cancer. This can aid the treatment and prognosis of lung cancer and may support further research into obesity-specific impacts on this malignancy.

Abstract

There is a paradoxical relationship between obesity, as measured by BMI, and many types of cancer, including non-small-cell lung cancer. Obese non-small-cell lung cancer patients have been shown to fare better than their non-obese counterparts. To analyze the multifaceted effects of obesity on oncologic outcomes, we reviewed the literature on the obesity paradox, methods to measure adiposity, the obesity-related derangements in immunology and metabolism, and the oncologic impact of confounding variables such as gender, smoking, and concomitant medications such as statins and metformin. We analyzed how these aspects may contribute to the obesity paradox and cancer outcomes with a focus on lung cancer. We concluded that the use of BMI to measure adiposity is limited and should be replaced by a method that can differentiate abdominal obesity. We also concluded that the concomitant metabolic and immunologic derangements caused by obesity contribute to the obesity paradox. Medications, gender, and smoking are additional variables that impact oncologic outcomes, and further research needs to be performed to solidify the mechanisms.

Nontuberculous Mycobacteria

Nontuberculous mycobacteria (NTM) are ubiquitous in the environment and 193 species of NTM have been discovered thus far. NTM species vary in virulence from benign environmental organisms to difficult-to-treat human pathogens. Pulmonary infections remain the most common manifestation of NTM disease in humans and bronchiectasis continues to be a major risk factor for NTM pulmonary disease (NTM PD). This article will provide a useful introduction and framework for clinicians involved in the management of bronchiectasis and NTM. It includes an overview of the epidemiology, pathogenesis, diagnosis, and management of NTM PD. We will address the challenges faced in the diagnosis of NTM PD and the importance of subspeciation in guiding treatment and follow-up, especially in Mycobacterium abscessus infections. The treatment of both Mycobacterium avium complex and M. abscessus, the two most common NTM species known to cause disease, will be discussed in detail. Elements of the recent ATS/ERS/ESCMID/IDSA NTM guidelines published in 2020 will also be reviewed.

"Obesity paradox" has not an impact on minimally invasive anatomical lung resection

INTRODUCTION

The paradoxical benefit of obesity, the 'obesity paradox', has been analyzed in lung surgical populations with contradictory results. Our goal was assessing the relationship of body mass index (BMI) to acute outcomes after minimally invasive major pulmonary resections.

METHODS

Retrospective review of consecutive patients who underwent pulmonary anatomical resection through a minimally invasive approach for the period 2014-2019. Patients were grouped as underweight, normal, overweight and obese type I, II and III. Adjusted odds ratios regarding postoperative complications (overall, respiratory, cardiovascular and surgical morbidity) were produced with their exact 95% confidence intervals. All tests were considered statistically significant at p<0.05.

RESULTS

Among 722 patients included in the study, 37.7% had a normal BMI and 61.8% were overweight or obese patients. When compared with that of normal BMI patients, adjusted pulmonary complications were significantly higher in obese type I patients (2.6% vs 10.6%, OR: 4.53 [95%CI: 1.86-12.11]) and obese type II-III (2.6% vs 10%, OR: 6.09 [95%CI: 1.38-26.89]). No significant differences were found regarding overall, cardiovascular or surgical complications among groups.

CONCLUSIONS

Obesity has not favourable effects on early outcomes in patients undergoing minimally invasive anatomical lung resections, since the risk of respiratory complications in patients with BMI≥30kg/m2 and BMI≥35kg/m2 is 4.5 and 6 times higher than that of patients with normal BMI.

Impact of postoperative complications on outcomes of second surgery for second primary lung cancer

PURPOSE

The best surgical approach for second primary lung cancer remains a subject of debate. The purpose of this study was to review the postoperative complications after second surgery for second primary lung cancer and to investigate the outcomes based on these complications.

METHODS

The clinical data of 105 consecutive patients who underwent pulmonary resection for multiple primary lung cancers between January, 1996 and December, 2017, were reviewed according to the Martini-Melamed criteria.

RESULTS

After the second surgery, low body mass index (BMI) (< 18.5 kg/m²) (P = 0.004) and high Charlson comorbidity index (CCI) (P = 0.002) were independent predictors of postoperative complications. Survival analysis revealed the 5-year overall survival rates of 74.5% and 61.4% for patients without postoperative complications and those with postoperative complications (P = 0.044), respectively, but the 5-year cancer-specific survival rates of 82.5% and 80.0% (P = 0.926), respectively. During this period, there were significantly more respiratory-related deaths of patients with complications than of those without complications (P = 0.011).

CONCLUSION

Surgical intervention is feasible and potentially effective for second primary lung cancer but may not achieve positive perioperative and long-term outcomes for patients with a low BMI or a high CCI. Treatment options should be considered carefully for these patients.

Assessing Malnutrition Before Major Oncologic Surgery: One Size Does Not Fit All

BACKGROUND

There are multiple definitions for malnutrition, without evidence of superiority of any one definition to assess preoperative risk. Therefore, to aid in identification of patients that might warrant prehabilitation, we aimed to determine the optimal definition of malnutrition before major oncologic resection for 6 cancer types.

METHODS

The American College of Surgeons NSQIP database was queried for patients undergoing elective major oncologic operations from 2005 to 2017. Nutritional status was evaluated using the European Society for Parenteral and Enteral Nutrition definitions, NSQIP's variable for >10% weight loss during the previous 6 months, and the WHO BMI classification system. Multivariable logistic regression was performed to evaluate the adjusted effect of nutritional status on mortality and major morbidity.

RESULTS

We identified 205,840 operations (74% colorectal, 10% pancreatic, 9% lung, 3% gastric, 3% esophageal, and 2% liver). A minority (16%) of patients met criteria for malnutrition (0.6% severe malnutrition, 1% European Society for Parenteral and Enteral Nutrition 1, 2% European Society for Parenteral and Enteral Nutrition 2, 6% NSQIP, and 6% mild malnutrition), 31% were obese, and the remaining 54% had a normal nutrition status. Both mortality and major morbidity varied significantly between the nutrition groups (both p < 0.0001). An interaction between nutritional status and cancer type was observed in the models for mortality and major morbidity (interaction term p < 0.0001 for both), indicating the optimal definition of malnutrition varied by cancer type.

CONCLUSIONS

The definition of malnutrition used to assess postoperative risk is specific to the type of cancer being treated. These findings can be used to enhance nutritional preparedness in the preoperative setting.

Performance in 6-min walk test in prediction of post-operative pulmonary complication in major oncosurgeries: A prospective observational study

Background and Aims

Post-operative pulmonary complications (PPC) contribute to increased morbidity and mortality, necessitating pre-operative functional assessment. Six-minute walk test (6MWT) is a simple option for functional assessment.

Methods

This is a prospective observational study conducted in 75 patients who underwent elective abdominal or thoracic oncosurgery under general anaesthesia with either age above 60 years or with cardiopulmonary diseases or obstructive sleep apnoea or low serum albumin or smoking. Patients with history of acute coronary syndrome in past 6 months, dyspnoea at rest, severe pain, inability to walk or interpret instructions and haemodynamic instability were excluded. Preoperatively 6MWT was conducted according to the American Thoracic Society guidelines and patients were observed for PPC. Patients were divided into two groups: group 1-no PPC and group 2-developed PPC. Statistical analysis was done using SPSS software (version 11.0.1). Categorical variables were assessed using Chi-square/Fisher's exact test and continuous variables using student's t-test/Mann-Whitney U test. Association was tested using logistic regression.

Results

Out of the 75 patients, 40 patients had no PPC (group 1) and 35 patients had PPC (group 2) including a death. The 6MWD of group with PPCs was significantly less (344 ± 61.927 m) compared to the group without PPCs (442.28 ± 83.194 m, P value = 0.001). The cut-off 6MWD obtained was 390 m, which correlated with longer duration of hospital stay and ICU stay (P = 0.001).

Conclusion

Six-minute walk test is a reliable predictor of post-operative pulmonary complications with a cut-off 6MWD of 390 m in the studied oncosurgery patients.

A Morphomic Index Is an Independent Predictor of Survival After Lung Cancer Resection

BACKGROUND

Sarcopenia, visceral fat volume, and bone density have been associated with lung cancer survival. We developed a morphomic index based on computed tomographic measurements of these components, and assessed its relationship to survival after lung cancer resection.

METHODS

Patients who underwent lung cancer resection from 1995 to 2014 were evaluated. A morphomic index (range of 0 to 3) was developed as the sum of the scores for three body components-dorsal muscle area, vertebral trabecular bone density, and visceral fat area-measured at vertebral levels T10 to T12, with a point assigned to each component when in the lowest tercile. The relationship of the morphomic index to overall survival was assessed by the log rank test. Overall survival was assessed using Cox proportional hazards models adjusted for relevant covariates.

RESULTS

We included 944 patients (451 women; 48%). The mean age was 66.4 ± 10.3 years. Median follow-up was 4.5 years. Median survival was associated with the morphomic index scores on univariate analysis (P < .001). Morphomic index scores of 2 (P = .026) and 3 (P = .004) referenced to score 0 or 1 were independent predictors of survival on Cox regression analysis.

CONCLUSIONS

A morphomic index is an independent predictor of survival after lung cancer resection. The index may help in calibrating patient expectations and in shared decision making regarding lung cancer surgery.

Postoperative outcomes of robotic-assisted lobectomy in obese patients with non-small-cell lung cancer

OBJECTIVES

The aim of this study was to assess the postoperative outcomes of robotic-assisted lobectomy in obese patients to determine the impact of the robotic approach on a high-risk population who were candidates for major pulmonary resection for non-small-cell lung cancer (NSCLC).

METHODS

Between January 2007 and August 2018, we retrospectively reviewed the medical records of 224 obese patients (body mass index ≥ 30) who underwent pulmonary lobectomy at our institution via robotic-assisted thoracic surgery (RATS, n = 51) or lateral muscle-sparing thoracotomy (n = 173).

RESULTS

Forty-two patients were individually matched with those who had the same pathological tumour stage and similar comorbidities and presurgical treatment. The median operative time was significantly longer in the RATS group compared to that in the thoracotomy group (200 vs 158 min; P = 0.003), whereas the length of stay was significantly better for the RATS group (5 vs 6 days; P = 0.047). Postoperative complications were significantly more frequent after open lobectomy than in the RATS group (42.9% vs 16.7%; P = 0.027). After a median follow-up of 4.4 years, the 5-year overall survival rate was 67.6% [95% confidence interval (CI) 45.7–82.2] for the RATS group, and 66.1% (95% CI 46.8–79.9) for the open surgery group (log-rank P = 0.54). The 5-year cumulative incidence of cancer-related deaths was 24.8% (95% CI 9.7–43.5) for the RATS group and 23.6% (95% CI 10.8–39.2) for the open surgery group (Gray’s test, P = 0.69).

CONCLUSIONS

RATS is feasible and safe for obese patients with NSCLC with advantages compared to open surgery in terms of early postoperative outcomes. In addition, the long-term survival rate was comparable to that of the open approach.

Body Mass Index (BMI), BMI Change, and Overall Survival in Patients With SCLC and NSCLC: A Pooled Analysis of the International Lung Cancer Consortium

INTRODUCTION

The relationships between morbid obesity, changes in body mass index (BMI) before cancer diagnosis, and lung cancer outcomes by histology (SCLC and NSCLC) have not been well studied.

METHODS

Individual level data analysis was performed on 25,430 patients with NSCLC and 2787 patients with SCLC from 16 studies of the International Lung Cancer Consortium evaluating the association between various BMI variables and lung cancer overall survival, reported as adjusted hazard ratios (aHRs) from Cox proportional hazards models and adjusted penalized smoothing spline plots.

RESULTS

Overall survival of NSCLC had putative U-shaped hazard ratio relationships with BMI based on spline plots: being underweight (BMI < 18.5 kg/m2; aHR = 1.56; 95% confidence interval [CI]:1.43-1.70) or morbidly overweight (BMI > 40 kg/m2; aHR = 1.09; 95% CI: 0.95-1.26) at the time of diagnosis was associated with worse stage-specific prognosis, whereas being overweight (25 kg/m2 ≤ BMI < 30 kg/m2; aHR = 0.89; 95% CI: 0.85-0.95) or obese (30 kg/m2 ≤ BMI ≤ 40 kg/m2; aHR = 0.86; 95% CI: 0.82-0.91) was associated with improved survival. Although not significant, a similar pattern was seen with SCLC. Compared with an increased or stable BMI from the period between young adulthood until date of diagnosis, a decreased BMI was associated with worse outcomes in NSCLC (aHR = 1.24; 95% CI: 1.2-1.3) and SCLC patients (aHR=1.26 (95% CI: 1.0-1.6). Decreased BMI was consistently associated with worse outcome, across clinicodemographic subsets.

CONCLUSIONS

Both being underweight or morbidly obese at time of diagnosis is associated with lower stage-specific survival in independent assessments of NSCLC and SCLC patients. In addition, a decrease in BMI at lung cancer diagnosis relative to early adulthood is a consistent marker of poor survival.

Thoracic Surgery Considerations in Obese Patients

The obesity epidemic in the United States has increased greatly over the past several decades, and thoracic surgeons are likely to see obese patients routinely in their practices. Obesity has direct deleterious health effects such as metabolic disorder and cardiovascular disease, and is associated with many cancers. Obese patients who need thoracic surgery pose practical challenges to many of the routine elements in perioperative management. Preoperative assessment of obesity-related comorbid conditions and risk stratification for surgery, thorough intraoperative planning for anesthesia and surgery, and postoperative strategies to optimize pulmonary hygiene and mobility minimize the risk of adverse outcomes.

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.

Obesity Paradox in Lung Cancer Prognosis: Evolving Biological Insights and Clinical Implications

The survival rate of lung cancer remains low despite the progress of surgery and chemotherapy. With the increasing comorbidity of obesity in patients with lung cancer, new challenges are emerging in the management of this patient population. A key issue of interest is the prognostic effect of obesity on surgical and chemotherapeutic outcomes in patients with lung cancer, which is fueled by the growing observation of survival benefits in overweight or obese patients. This unexpected inverse relationship between obesity and lung cancer mortality, called the obesity paradox, remains poorly understood. The evolving insights into the heterogeneity of obesity phenotypes and associated biological connections with lung cancer progression in recent years may help explain some of the seemingly paradoxical relationship, and well-designed clinical studies looking at the causal role of obesity-associated molecules are expected. Here, we examine potential biological mechanisms behind the protective effects of obesity in lung cancer. We highlight the need to clarify the clinical implications of this relationship toward an updated intervention strategy in the clinical care of patients with lung cancer and obesity.