Association of body mass index and outcomes after major lung resection

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.

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.

Effect of Pre-Transplant Recipient Underweight on the Postoperative Outcome and Graft Survival in Primary Kidney Transplantation

BACKGROUND

The objective of this study was to evaluate the influence of recipient underweight on the short- and long-term outcomes of patients undergoing primary kidney transplantation (KT).

PATIENTS AND METHODS

Three hundred thirty-three patients receiving primary KT in our department between 1993 and 2017 were included in the study. Patients were divided according to their body mass index (BMI) into underweight (BMI <18.5 kg/m2; N = 29) and normal weight (BMI 18.5-24.9 kg/m2; N = 304) groups. Clinicopathological characteristics, postoperative outcomes, and graft and patient survival were analyzed retrospectively.

RESULTS

The postoperative rate of surgical complications and renal function were comparable between the groups. One year and 3 years after KT, 70% and 92.9%, respectively, of the pre-transplant underweight patients reached a normal BMI (≥18.5 kg/m2). The mean death-censored graft survival was significantly lower in pre-transplant underweight patients than in pre-transplant normal-weight patients (11.5 ± 1.6 years vs 16.3 ± 0.6 years, respectively; P = .045). Especially KT recipients with a moderate or severe pre-transplant underweight (BMI <17 kg/m2; N = 8) showed an increased rate of graft loss (5- and 10-year graft survival: 21.4% each). No statistical difference could be observed between the 2 groups regarding causes of graft loss. In multivariate analysis, recipient underweight (P = .024) remained an independent prognostic factor for graft survival.

CONCLUSION

Being underweight did not affect the early postoperative outcome after primary KT. However, underweight, and especially moderate and severe thinness, is associated with reduced long-term kidney graft survival, and therefore this group of patients should be monitored with special attention.

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.

The Overweight Paradox: Impact of Body Mass Index on Patients Undergoing VATS Lobectomy or Segmentectomy

The aim of this study was to assess the impact of BMI on perioperative outcomes in patients undergoing VATS lobectomy or segmentectomy. Data from 5088 patients undergoing VATS lobectomy or segmentectomy, included in the VATS Group Italian Registry, were collected. BMI (kg/m²) was categorized according to the WHO classes: underweight, normal, overweight, obese. The effects of BMI on outcomes (complications, 30-days mortality, DFS and OS) were evaluated with a linear regression model, and with a logistic regression model for binary endpoints. In overweight and obese patients, operative time increased with BMI value. Operating room time increased by 5.54 minutes (S.E. = 1.57) in overweight patients, and 33.12 minutes (S.E. = 10.26) in obese patients (P < 0.001). Compared to the other BMI classes, overweight patients were at the lowest risk of pulmonary, acute cardiac, surgical, major, and overall postoperative complications. In the overweight range, a BMI increase from 25 to 29.9 did not significantly affect the length of stay, nor the risk of any complications, except for renal complications (OR: 1.55; 95% CI: 1.07-2.24; P = 0.03), and it reduced the risk of prolonged air leak (OR: 0.8; 95% CI: 0.71-0.90; P < 0.001). 30-days mortality is higher in the underweight group compared to the others. We did not find any significant difference in DFS and OS. According to our results, obesity increases operating room time for VATS major lung resection. Overweight patients are at the lowest risk of pulmonary, acute cardiac, surgical, major, and overall postoperative complications following VATS resections. The risk of most postoperative complications progressively increases as the BMI deviates from the point at the lowest risk, towards both extremes of BMI values. Thirty days mortality is higher in the underweight group, with no differences in DFS and OS.

Feasibility of double sleeve lobectomy after neoadjuvant chemotherapy in patients with non-small-cell lung cancer

OBJECTIVES

This study intends to appraise the feasibility of double sleeve lobectomy after neoadjuvant chemotherapy in central non-small-cell lung cancer with bronchovascular aggression.

METHODS

This retrospective study included non-small-cell lung cancer patients who received double sleeve lobectomy from January 2014 to June 2020. Patients were divided into 2 groups: the neoadjuvant chemotherapy group and the non-neoadjuvant chemotherapy group. Demographic data and perioperative outcomes were compared between these 2 groups.

RESULTS

Of the 110 patients who received double sleeve lobectomy during this period, 35 patients (31.8%) received neoadjuvant chemotherapy. Compared with the non-neoadjuvant chemotherapy group, patients who received neoadjuvant chemotherapy were associated with younger age (P = 0.026), smaller pathologic tumour size (P = 0.005), higher forced expiratory volume in 1 s (P = 0.007), higher forced expiratory volume in 1 s of predicted value (P = 0.005) and higher clinical stage (P < 0.001). In the neoadjuvant chemotherapy group, 18 patients (51.4%) attained a partial response and 17 patients (48.6%) achieved stable disease. The postoperative hospital stays (P = 0.042) and chest tube drainage duration (P = 0.030) were longer in the neoadjuvant chemotherapy group and other perioperative performances were similar between these 2 groups. No statistically significant difference was reported in postoperative complications and mortality between these 2 groups.

CONCLUSIONS

The intraoperative performance and postoperative outcomes of double sleeve lobectomy following neoadjuvant chemotherapy were similar to direct surgery, indicating that double sleeve lobectomy after neoadjuvant chemotherapy is feasible and safe in central lung cancer involving both the pulmonary artery and bronchus.

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.

Expected and paradoxical effects of obesity on cancer treatment response

Obesity, whose prevalence is pandemic and continuing to increase, is a major preventable and modifiable risk factor for diabetes and cardiovascular diseases, as well as for cancer. Furthermore, epidemiological studies have shown that obesity is a negative independent prognostic factor for several oncological outcomes, including overall and cancer-specific survival, for several site-specific cancers as well as for all cancers combined. Yet, a recently growing body of evidence suggests that sometimes overweight and obesity may associate with better outcomes, and that immunotherapy may show improved response among obese patients compared with patients with a normal weight. The so-called 'obesity paradox' has been reported in several advanced cancer as well as in other diseases, albeit the mechanisms behind this unexpected relationship are still not clear. Aim of this review is to explore the expected as well as the paradoxical relationship between obesity and cancer prognosis, with a particular emphasis on the effects of cancer therapies in obese people.

Association of Adipopenia at Preoperative PET/CT with Mortality in Stage I Non-Small Cell Lung Cancer

Background Body mass index (BMI) and sarcopenia status are well-established prognostic factors in patients with lung cancer. However, the relationship between the amount of adipose tissue and survival remains unclear. Purpose To investigate the association between baseline adipopenia and outcomes in patients with early-stage non-small cell lung cancer (NSCLC). Materials and Methods Consecutive patients who underwent surgical resection for stage I NSCLC between 2011 and 2015 at a single tertiary care center were retrospectively identified. The primary outcome was the 5-year overall survival (OS) rate, and secondary outcomes were the 5-year disease-free survival (DFS) rate and the major postoperative complication rate. The abdominal total fat volume at the waist and the skeletal muscle area at the L3 level were obtained from preoperative PET/CT data and were normalized by the height squared to calculate the fat volume index (FVI) and skeletal muscle index. Adipopenia was defined as the sex-specific lowest quartile of the FVI for the study sample, and sarcopenia was determined using the skeletal muscle index reference value (men, <55 cm²/m²; women, <39 cm²/m²). The association between body composition and outcomes was evaluated using Cox regression analysis. Results A total of 440 patients (median age, 65 years [interquartile range, 58-72 years]; 243 men) were evaluated. Most underweight patients (<20 kg/m²) had adipopenia (97%, 36 of 37 patients), but overweight patients (25-30 kg/m², n = 138) and obese patients (>30 kg/m², n = 14) did not have adipopenia (3%, four of 152 patients). In the group with a normal BMI (20-25 kg/m²), 28% (70 of 251 patients) had adipopenia and 67% (168 of 251 patients) had sarcopenia. After adjusting for age, sex, smoking history, surgical procedure, stage, histologic type, BMI, and sarcopenia, adipopenia was associated with reduced 5-year OS (hazard ratio [HR] = 2.2; 95% CI: 1.1, 3.8; P = .02) and 5-year non-cancer-specific OS rates (HR = 3.2; 95% CI: 1.2, 8.7; P = .02). There was no association between adipopenia and postoperative complications (P = .45) or between adipopenia and the 5-year DFS rate (P = .18). Conclusion Baseline adipopenia was associated with a reduced 5-year overall survival rate in patients with early-stage non-small cell lung cancer and may indicate risk for non-cancer-related death. © RSNA, 2021 Online supplemental material is available for this article.

Impact of preoperative comorbidities on postoperative complication rate and outcome in surgically resected non-small cell lung cancer patients

Objective

This study aimed to analyze whether comorbidities impact postoperative complication rate or survival after anatomical lung resection for non-small cell lung cancer (NSCLC).

Methods

A retrospective analysis of 1219 patients who underwent NSCLC resection between 2000 and 2015 was performed. Analyzed comorbidities included chronic obstructive lung disease (COPD), hypertension, coronary artery disease (CAD), peripheral artery disease, myocardial infarction history, diabetes mellitus, renal insufficiency and other malignancies.

Results

Most patients (78.9%) had comorbidities, most commonly hypertension (34.1%) followed by COPD (26.4%) and other malignancies (19%). The overall complication rate was 38.6% (26.4% pulmonary; 14.8% cardiac; and 3.0% gastrointestinal). Hypertension (odds ratio (OR) = 1.492, p = 0.031) was associated with more cardiac complications. Heavy smoking (OR = 1.008, p = 0.003) and low body mass index (BMI) (OR = 0.932, p < 0.001) affected the pulmonary complication rate significantly. None of the included comorbidities affected the overall complication rate or the survival negatively. However, the patient characteristics of advanced age (p < 0.001), low BMI (p = 0.008), and low FEV1 (p = 0.008) affected the overall complication rate as well as survival (each p < 0.001).

Conclusion

Advanced age, low BMI, and low FEV1 were predictive of greater complication risk and shorter long-term survival in patients who underwent NSCLC resection. Cardiac complications were associated with hypertension and CAD, whereas pulmonary complications were associated with a high pack year count.

Obese Patients Undergoing Tracheobronchoplasty Have Excellent Outcomes

BACKGROUND

Tracheobronchoplasty (TBP) is the gold-standard treatment for severe symptomatic excessive central airway collapse (ECAC), however outcomes among obese patients are unknown.

METHODS

A retrospective, single-center analysis was conducted on consecutive patients undergoing TBP for severe symptomatic ECAC from 2003 to 2020. Demographics, comorbidities, functional status, and peri-operative complications were collected. Functional status was assessed with a six-minute walk test (6MWT). Health-related quality of life (HRQOL) was assessed with the St. George's Respiratory Questionnaire (SGRQ), Cough-Specific Quality of Life Questionnaire (CSQL), and modified Medical Research Council dyspnea scale (mMRC) at baseline and post-operatively. Wilcoxon rank-sum and chi-squared tests were used to compare outcomes between groups. A mixed-effects regression model compared 6MWT and HRQOL over time.

RESULTS

One-hundred and three patients underwent TBP with complete follow-up data. Thirty-four patients (33%) were obese (BMI ≥ 35 kg/m²). Baseline demographics were similar between obese and non-obese groups, however obese patients had worse pre-operative SGRQ and mMRC. Overall complication rates were similar (52.9% vs. 43.5%, p=0.36). At 3-months, there was no significant difference in SGRQ, CSQL, or 6MWT, however, mMRC was higher in obese patients (p=0.04). At 12 months, there was no significant difference in SGRQ, CSQL, mMRC, or 6MWT. Correcting for age, sex, and Charlson Comorbidity Index, a mixed-effects regression model demonstrated obesity was not an independent predictor for lower 6MWT or HRQOL.

CONCLUSIONS

Obese patients achieve similar improvement in HRQOL and functional capacity with comparable morbidity following TBP as non-obese patients. Obesity should not preclude patients with severe symptomatic ECAC from TBP.

Analytic Morphomics Are Related to Outcomes After Lung Volume Reduction Surgery

:Lung volume reduction surgery continues to have a high morbidity despite National Emphysema Treatment Trial selection criteria. This study evaluated the association between analytic morphomics on chest computed tomography scans and outcomes after lung volume reduction surgery. In a retrospective review of 85 lung volume reduction surgery patients from 1998-2013, dorsal muscle group area, subcutaneous and visceral fat area, and bone mineral density were assessed using analytic morphomics. Lung density was divided into five levels of increasing density (Lung density 1, emphysema; 2, normal lung; 4-5, scarring). Outcomes including survival, hospital length of stay, readmission at 30 days, and pulmonary complications were analyzed using univariate and multivariable techniques. Pulmonary complications developed in 27.1% (23/85). Mortality at 90 days was 9.4% (8/85). On multivariable analysis, lower bone mineral density (Odds ratio 0.61; 95% confidence interval 0.39-0.95) was associated with decreased survival, longer length of stay (0.83; 0.77-0.89), and readmissions (0.39; 0.15-1.00). Higher lung density 5:lung density 2 volume (1.84; 1.05-3.23), possibly due to scarring, was associated with pulmonary complications and longer length of stay (1.32; 1.23-1.41) while lower subcutaneous fat area:height was associated with readmissions which may reflect decreased metabolic reserve (0.35; 0.13-0.93). Patients with signs of frailty including lower bone mineral density may be at increased risk of adverse outcomes including decreased survival after lung volume reduction surgery. The results of this hypothesis-generating study will need to be confirmed in larger, multicenter trials to determine whether analytic morphomics can improve risk stratification and patient selection.

"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.

Obesity, Sarcopenia, and Outcomes in Non-Small Cell Lung Cancer Patients Treated With Immune Checkpoint Inhibitors and Tyrosine Kinase Inhibitors

Body composition refers to the proportional content of body fat mass and lean body mass that can lead to a continuum of different phenotypes ranging from cachectic/sarcopenic state to obesity. The heterogenetic phenotypes of body composition can contribute to formation of some cancer types and can sometimes lead to disparate outcomes. Both of these extremes of the spectrum exist in patients with non-small cell lung carcinoma (NSCLC). The discovery of new pathways that drive tumorigenesis contributing to cancer progression and resistance have expanded our understanding of cancer biology leading to development of new targeted therapies including tyrosine kinase inhibitors (TKI) and immune checkpoint inhibitors (ICI) that have changed the landscape of NSCLC treatment. However, in the new era of precision medicine, the impact of body composition phenotypes on treatment outcomes and survival is now being elucidated. In this review, we will discuss the emerging evidence of a link between body composition and outcomes in patients with NSCLC treated with TKI and ICI. We will also discuss suggested mechanisms by which body composition can impact tumor behavior and anti-tumor immunological response.

What is the prevalence of inspiratory muscle weakness in preoperative cardiac surgery patients? An observational study

BACKGROUND

In patients undergoing elective cardiac surgery, the prevalence of inspiratory muscle weakness is not well-understood. This information could guide pre-operative therapy.

OBJECTIVES

To determine the prevalence of inspiratory muscle weakness in preoperative cardiac surgery patients, and describe relationships between pre-operative factors (including maximal inspiratory pressure, MIP) and post-operative pulmonary complications (PPCs).

METHODS

Prospective study of elective cardiac surgery patients. Pre-operative MIP was measured (cmH₂O) and PPC data were extracted from medical records (Melbourne Group Score) while age, height, weight, frailty and physical activity levels were captured via questionnaire. Backwards-stepwise logistic regression was used to describe associations.

RESULTS

24 participants were recruited (79% male, age 70 ± 10.7, BMI 26.8 ± 4.14). The prevalence of inspiratory muscle weakness (MIP < 60% predicted) was 25% (n = 6). PPCs were associated with body mass index (BMI) (r = 0.464, p = 0.022).

CONCLUSION

The prevalence of pre-operative inspiratory muscle weakness was 25%. BMI may be an important determinant of PPCs in elective cardiac surgery patients.

Pre-Disease and Pre-Surgery BMI, Weight Loss and Sarcopenia Impact Survival of Resected Lung Cancer Independently of Tumor Stage

Lower pre-surgery Body Mass Index (BMI) and low muscle mass impact negatively long-term survival of non-small cell lung cancer (NSCLC). We investigated their influence on survival after major lung resection for NSCLC.

METHODS

A retrospective analysis of a prospectively collected database was made on 304 consecutive patients.

RESULTS

Underweight, normal, overweight and obese patients represented 7.6%, 51.6%, 28.6%, and 12.6% of the pre-disease population. Weight loss and gain were recorded in 5% and 44.4% of patients, respectively. Low muscle mass was more frequently associated with BMI < 25 kg/m² (p < 0.000001). Overall survival was positively affected by pre-disease (p = 0.036) and pre-surgery (p = 0.017) BMI > 25 kg/m², and, even more, in case of BMI > 25 kg/m² and increasing weight (p = 0.012). Long-term outcome was negatively influenced by low muscle mass (p = 0.042) and weight loss (p = 0.0052) as well as age (p = 0.017), ASA categories (p = 0.025), extent of resection (p = 0.0001), pleural invasion (p = 0.0012) and higher pathologic stage (p < 0.0001). Three stepwise multivariable models confirmed the independent favorable prognostic value of higher pre-disease (RR 0.66[0.49-0.89], p = 0.006) and pre-surgery BMI (RR 0.72[0.54-0.98], p = 0.034), and the absence of low muscle mass (RR 0.56[0.37-0.87], p = 0.0091).

CONCLUSIONS

Body reserves assessed by simple clinical markers impact survival of surgically treated NSCLC. Strategies improving body fat and muscular mass before surgery should be considered.

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.

Prevalence of and risk factors for pulmonary complications after curative resection in otherwise healthy elderly patients with early stage lung cancer

BACKGROUND AND OBJECTIVE

The prevalence of lung cancer has been increasing in healthy elderly patients with preserved pulmonary function and without underlying lung diseases. We aimed to determine the prevalence of and risk factors for postoperative pulmonary complications (PPCs) in healthy elderly patients with non-small cell lung cancer (NSCLC) to select optimal candidates for surgical resection in this subpopulation.

METHODS

We included 488 patients older than 70 years with normal spirometry results who underwent curative resection for NSCLC (stage IA-IIB) between 2012 and 2016.

RESULTS

The median (interquartile range) age of our cohort was 73 (71-76) years. Fifty-two patients (10.7%) had PPCs. Severe PPCs like acute respiratory distress syndrome, pneumonia, and respiratory failure had prevalences of 3.7, 3.7, and 1.4%, respectively. Compared to patients without PPCs, those with PPCs were more likely to be male and current smokers; have a lower body mass index (BMI), higher American Society of Anesthesiologists (ASA) classification, more interstitial lung abnormalities (ILAs), and higher emphysema index on computed tomography (CT); and have undergone pneumonectomy or bilobectomy (all p < 0.05). On multivariate analysis, ASA classification ≥3, lower BMI, ILA, and extent of resection were independently associated with PPC risk. The short-term all-cause mortality was significantly higher in patients with PPCs.

CONCLUSIONS

Curative resection for NSCLC in healthy elderly patients appeared feasible with 10% PPCs. ASA classification ≥3, lower BMI, presence of ILA on CT, and larger extent of resection are predictors of PPC development, which guide treatment decision-making in these patients.

Risk factors of postoperative pulmonary complications after minimally invasive anatomic resection for lung cancer

Purpose

This study investigated the perioperative risk factors of postoperative pulmonary complications (PPCs) after minimally invasive anatomic resection for lung cancer.

Patients and methods

We retrospectively reviewed the data from medical records of 729 lung cancer patients undergoing minimally invasive anatomic lung resections between January 2017 and December 2017. Univariate and binary logistic regression analyses were performed to select the independent risk factors for PPCs during the patient’s postoperative hospitalization after surgery.

Results

The incidence of PPCs was 24.8% (n=181/729). No patient died during the period of hospitalization. Logistic regression analysis revealed that body mass index (BMI) ≥24.0 kg/m² (vs <24.0 kg/m²: OR 1.514, 95% CI 1.057–2.167, P=0.024), single segmentectomy (vs single lobectomy: OR 2.115, 95% CI 1.150–3.891, P=0.016), bilobectomy or combined lobectomy and segmentectomy (vs single lobectomy: OR 2.731, 95% CI 1.013–7.361, P=0.047), and right lung lobe surgery (vs left lung lobe surgery: OR 1.519, 95% CI 1.046–2.205, P=0.028) were independent risk factors for PPCs in lung cancer patients who received minimally invasive anatomic lung resections.

Conclusion

Individual factors such as BMI ≥24.0 kg/m², single segmentectomy, bilobectomy or combined lobectomy and segmentectomy, and right lung lobe surgery were independent risk factors of PPCs, which should be helpful for risk stratification, patient counseling, and perioperative care for lung cancer patients.

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.

Association of body mass index and outcomes following lobectomy for non-small-cell lung cancer

Background

Obesity and overweight have become increasingly prevalent, but no consensus has been reached regarding the effect of body mass index (BMI) on surgical outcomes. In this study, we sought to examine the influence of BMI on perioperative outcomes in a large cohort of patients with non-small-cell lung cancer (NSCLC) who underwent lobectomy.

Methods

A retrospective study was conducted in 1198 patients who underwent lobectomy for primary NSCLC at Shandong Provincial Hospital between November 2006 and January 2017. BMI was calculated using measured height and weight on admission and categorized as obese (≥ 30 kg/m²), overweight (25 to 29.9 kg/m²), normal (18.5 to 24.9 kg/m²), or underweight (< 18.5 kg/m²). Patients’ baseline characteristics and outcomes were abstracted from medical records following institutional review board approval. Endpoints included operative mortality, perioperative complications, and length of stay (LOS). Complications were divided into four groups as respiratory, cardiovascular, other, and overall. Logistic regression models were constructed to assess the association between BMI and adverse outcomes.

Results

When compared with normal BMI, obesity and overweight did not increase the risk of complications in any category, operative mortality, or prolonged LOS. In fact, the incidence of operative mortality and respiratory complications tended to be lower in overweight patients than in normal weight patients (P = 0.047 and P = 0.041, respectively). Conversely, underweight patients experienced significantly more operative mortality, respiratory complications, and prolonged LOS (P = 0.004, P = 0.011, and P = 0.003, respectively).

Conclusions

Obesity and overweight did not confer adverse surgical outcomes. Underweight patients presented increased risk of respiratory complications, perioperative death, and prolonged LOS. Thus, overweight and obesity should not be a relative contraindication for lobectomy. Meanwhile, nurses and surgeons should focus on perioperative management of underweight patients.

Gender differences in the correlation between prognosis and postoperative weight loss in patients with non-small cell lung cancer

OBJECTIVES

The aim of this study was to investigate gender differences in the relationship between preoperative body mass index (BMI), postoperative body weight change and prognosis in patients with non-small cell lung cancer (NSCLC).

METHODS

Two hundred and sixty-three patients with NSCLC were enrolled in this study. Preoperative BMI was categorized based on WHO definition as follows: underweight (BMI <18.5): 21 patients (8.0%), normal (18.5 ≦ BMI <25): 179 patients (68%), overweight and obese (BMI ≧25): 63 patients (24%). Several factors such as age, sex, cancer stage, body weight change and BMI were recorded and correlated to the postoperative overall survival (OS).

RESULTS

For male patients, those in the low-BMI group had the worst prognosis (P < 0.05) whereas female patients with low BMI did not. Male patients with low BMI had statistically significant poorer prognosis compared to corresponding female patients (P < 0.05). Male patients with more than 5% body weight loss within 1 year after operation when compared to preoperative body weight had poorer prognosis than those with less than 5% body weight loss (P < 0.001). Furthermore, these male patients had statistically significant worse prognosis than the corresponding female patients (P < 0.05). In multivariable analysis, gender, more than 5% of body weight loss compared to preoperative body weight, and pathological stage were independent prognostic factors in NSCLC.

CONCLUSIONS

This study illustrates significant gender differences in the relationship between prognosis and BMI or body weight change in patients with postoperative NSCLC.

Analytic Morphomics Predict Outcomes After Lung Transplantation

BACKGROUND

The purpose of this study was to identify morphomic factors on standard, pretransplantation computed tomography (CT) scans associated with outcomes after lung transplantation.

METHODS

A retrospective review of 200 patients undergoing lung transplantation at a single institution from 2003 to 2014 was performed. CT scans obtained within 1 year before transplantation underwent morphomic analysis. Morphomic characteristics included lung, dorsal muscle group, bone, and subcutaneous and visceral fat area and density. Patient data were gathered from institutional and United Network for Organ Sharing databases. Outcomes, including initial ventilator support greater than 48 hours, length of stay, and survival, were evaluated using univariate and multivariable analyses.

RESULTS

On multivariable Cox regression, subcutaneous fat/total body area (hazard ratio [HR] 0.60, p = 0.001), lung density 3 volume (HR 0.67, p = 0.013), and creatinine (HR 4.37, p = 0.010) were independent predictors of survival. Initial ventilator support more than 48 hours was associated with decreased vertebral body to linea alba distance (odds ratio [OR] 0.49, p = 0.002) and Zubrod score 4 (OR 14.0, p < 0.001). Increased bone mineral density (p < 0.001) and increased cross-sectional body area (p < 0.001) were associated with decreased length of stay, whereas supplemental oxygen (p < 0.001), bilateral transplantation (p = 0.002), cardiopulmonary bypass (p < 0.001), and Zubrod score 3 (p < 0.001) or 4 (p = 0.040) were associated with increased length of stay.

CONCLUSIONS

Morphomic factors associated with lower metabolic reserve and frailty, including decreased subcutaneous fat, bone density, and body dimensions were independent predictors of survival, prolonged ventilation, and increased length of stay. Analytic morphomics using pretransplantation CT scans may improve recipient selection and risk stratification.

Prognostic value of combined preoperative prognostic nutritional index and body mass index in HCC after hepatectomy

BACKGROUND

Malnutrition and immunological status are associated with survival in many cancers. Prognostic nutritional index (PNI) and body mass index (BMI) are recognized immune-nutritional indices and associated with postoperative outcome in hepatocellular carcinoma (HCC) patients. However, this association is still controversial. Our aim was to determine whether the combination of PNI and BMI is better than either alone in HCC patients' prognosis.

MATERIAL AND METHODS

Preoperative PNI and BMI, patient demographics, clinical and pathological data from 322 HCC patients were collected and analyzed.

RESULTS

Low PNI was correlated with age, cirrhosis, total bilirubin (TBIL) ≥34.2 μmol/L, and recurrence. Likewise, low BMI was associated with TBIL ≥34.2 μmol/L, portal vein tumor thrombi (PVTT), tumor size, tumor differentiation, TNM stage, and recurrence. Multivariate analysis identified TNM stage, PVTT, tumor size, PNI, and BMI as independent predictors of outcome in HCC patients. Low PNI combined with BMI (PNI + BMI) accurately predicted poorer outcome, particularly in patients with TNM stage I HCC. The predictive range of PNI + BMI was more sensitive than that of either alone.

CONCLUSIONS

preoperative PNI/BMI is an independent predictor of outcome for HCC patients, especially in patients with early stage HCC. Intriguingly, the PNI + BMI combination can enhance the accuracy of prognosis.

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.

The Influence of Body Mass Index on Overall Survival Following Surgical Resection of Non-Small Cell Lung Cancer

BACKGROUND

Population studies suggest that high body mass index (BMI) correlates with a reduced risk for death from lung cancer. The aim of our study was to evaluate definitively the influence of BMI on long-term overall survival (OS) in surgical patients with NSCLC.

METHODS

The study population consisted of 1935 patients who underwent surgical resection for lung cancer at M. D. Anderson Cancer Center (2000-2014). Study variables included both patient- and treatment-related characteristics. Univariate and multivariate Cox regression analyses were performed to identify variables associated with OS.

RESULTS

On univariate analysis, significant predictors of improved survival were higher BMI, pathologic tumor stage (stage I versus stage II, III, or IV), type of surgical procedure (lobectomy/pneumonectomy versus wedge resection/segmentectomy), younger age, female sex, and adenocarcinoma histologic subtype (versus squamous) (all p < 0.05). Morbidly obese patients (BMI ≥ 35) demonstrated a trend toward better outcomes than those classified as obese (BMI ≥30 and <35 kg/m²) (p = 0.05), overweight (BMI ≥ 25 and <30 kg/m²) (p = 0.13), or healthy weight (BMI <25 kg/m²) (p = 0.37) (hazard ratio = 0.727, 0.848, 0.926, and 1, respectively). On multivariate analysis, BMI remained an independent predictor of survival (p = 0.02). Propensity matching analysis demonstrated significantly better OS (p = 0.003) in patients with a BMI of 30 kg/m² or higher as compared with a BMI of 25 kg/m².

CONCLUSIONS

In this large, retrospective, single-center series, after control for disease stage and other variables, higher BMI was associated with improved OS after surgical resection of NSCLC. Further studies are necessary to elucidate the precise relationship between BMI and treatment outcomes.

Bronchial colonization and complications after lung cancer surgery

PURPOSE

Infectious complications occur following pulmonary resections preceded or not by induction chemoradiotherapy. We aimed to investigate whether bacterial colonization of the bronchial tree at the time of surgery was associated with postoperative complications.

PATIENTS AND METHODS

A retrospective analysis of all patients who underwent open anatomical pulmonary resections for malignancies at a single center was performed. Demographical data of the included patients, intraoperative data, and data on the postoperative course of patients were collected. Outcome of patients with a positive intraoperative bronchial culture was compared to patients with a negative bronchial culture. Relations between the presence of potential bacterial pathogens in the bronchial tree and other possible risk factors for the development of postoperative infectious and non-infectious complications, were analyzed using uni- and multivariate analysis.

RESULTS

Between January 2010 and January 2012, a total of 121 consecutive patients underwent open anatomical pulmonary resections for malignancy, of whom 45 were preceded by induction chemoradiotherapy and 5 by induction chemotherapy. Intraoperative bronchial cultures were taken from 58 patients (48 %). Patients with a positive bronchial culture developed significantly more infectious (88 % vs. 20 %, p < 0.001) and non-infectious complications (63 % vs. 12 %, p = 0.001). Positive intraoperative bronchial cultures showed the strongest association with the development of infectious and non-infectious postoperative complications (OR 24.8 and 12.2, respectively). After multivariate analysis, only BMI less than 20 kg/m(2) and the presence of a positive intraoperative bronchial culture were found to be independent risk factors for the development of infectious complications. Chemoradiotherapy was not associated with postoperative complications in the present study.

CONCLUSIONS

Bacterial colonization of the bronchial tree assessed intraoperatively, appears to be associated with higher rates of infectious and non-infectious complications after pulmonary resection. Whether early starting of appropriate antibiotics based on intraoperative-taken culture findings will reduce the infectious complication rate in a subcategory of patients needs to be investigated.

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

BACKGROUND

Although body mass index (BMI) has been used in risk stratification for lung resection, many models only take obesity into account. Recent studies have demonstrated that underweight patients also experience increased postoperative complications. We explored the relationship of extremes of BMI to outcomes after lung resection for non-small cell cancer.

METHODS

Patients in the Society of Thoracic Surgeons General Thoracic Surgery Database (2009 to 2014) undergoing elective lung resection for cancer were evaluated. Multivariable logistic regression was used to adjust for potential confounders including functional status and spirometry.

RESULTS

We evaluated 41,446 patients (median 68 years of age; 53% female) grouped by BMI: underweight (<18.5 kg/m²; 3.0%), normal (18.5 to 24.9 kg/m²; 33.5%), overweight (25 to 29.9 kg/m²; 35.4%), obese I (30 to 34.9 kg/m²; 18.1%), obese II (35 to 39.9 kg/m²; 6.4%), and obese III (≥40 kg/m²; 3.6%). Pulmonary complication rates were higher in underweight and obese III patients compared to normal BMI patients (p < 0.001). On multivariable analysis, compared to patients with normal BMI, being underweight was associated with an increased risk of pulmonary complications (adjusted odds ratio [OR]: 1.41, 95% confidence interval [CI]: 1.16 to 1.70) and any postoperative event (adjusted OR: 1.44, 95% CI: 1.26 to 1.64). Obese III patients had an increased risk of any major postoperative complication (adjusted OR: 1.18, 95% CI: 1.02 to 1.36). Overweight and obese class I to II patients had a lower risk of pulmonary complications and any postoperative event.

CONCLUSIONS

BMI is associated with postoperative complications after lung resection for cancer. Being underweight or severely overweight is associated with an increased risk of complications, whereas being overweight or moderately obese appears to have a protective effect.

Perioperative lung protective ventilation in obese patients

The perioperative use and relevance of protective ventilation in surgical patients is being increasingly recognized. Obesity poses particular challenges to adequate mechanical ventilation in addition to surgical constraints, primarily by restricted lung mechanics due to excessive adiposity, frequent respiratory comorbidities (i.e. sleep apnea, asthma), and concerns of postoperative respiratory depression and other pulmonary complications. The number of surgical patients with obesity is increasing, and facing these challenges is common in the operating rooms and critical care units worldwide. In this review we summarize the existing literature which supports the following recommendations for the perioperative ventilation in obese patients: (1) the use of protective ventilation with low tidal volumes (approximately 8 mL/kg, calculated based on predicted -not actual- body weight) to avoid volutrauma; (2) a focus on lung recruitment by utilizing PEEP (8–15 cmH₂O) in addition to recruitment maneuvers during the intraoperative period, as well as incentivized deep breathing and noninvasive ventilation early in the postoperative period, to avoid atelectasis, hypoxemia and atelectrauma; and (3) a judicious oxygen use (ideally less than 0.8) to avoid hypoxemia but also possible reabsorption atelectasis. Obesity poses an additional challenge for achieving adequate protective ventilation during one-lung ventilation, but different lung isolation techniques have been adequately performed in obese patients by experienced providers. Postoperative efforts should be directed to avoid hypoventilation, atelectasis and hypoxemia. Further studies are needed to better define optimum protective ventilation strategies and analyze their impact on the perioperative outcomes of surgical patients with obesity.

[Obesity and lung cancer: incidence and repercussions on epidemiology, pathology and treatments]

INTRODUCTION

Obesity and lung cancer are major public health problems. The purpose of this work is to review the data concerning this association.

METHOD

We report clinical and epidemiological data on obesity and discuss the impact on the incidence of lung cancer, as well as the safety and efficiency of anti-tumor treatments.

RESULTS

Obesity does not contribute to the occurrence of lung cancer, unlike other malignancies. Patients may be more likely to undergo treatment at lower risk. Regarding surgery, obesity makes anaesthesia more difficult, increases the operative duration but does not increase postoperative morbidity and mortality. Chemotherapy and radiotherapy seem to be administered according to the same criteria as patients with normal weight. Paradoxically, survival rates of lung cancer are better in obese patients as well after surgery than after non-surgical treatment.

CONCLUSION

Obesity is related to many neoplasms but not to lung cancer. Regarding long-term survival all treatments combined, it has a favorable effect: this is the "obesity paradox".

Impact of body mass index on perioperative outcomes and survival after resection for gastric cancer

BACKGROUND

Among patients undergoing resection for gastric cancer, the impact of body mass index (BMI) on outcomes is not well understood. We sought to define the impact of non-normal BMI on short- and long-term outcomes after gastric cancer resection.

METHODS

We identified 775 patients who underwent gastrectomy for adenocarcinoma between 2000 and 2012 from the multi-institutional US Gastric Cancer Collaborative. Clinicopathologic characteristics, operative details, and oncologic outcomes were collected, and patients were stratified according to BMI.

RESULTS

Most patients in the cohort were classified as having normal BMI (n = 338, 43.6%), followed by overweight (n = 229, 29.6%), obese (n = 153, 19.7%), and underweight (n = 55, 7.1%). After stratifying by BMI, there were no significant differences in the incidence of postoperative blood transfusions, perioperative morbidity, postoperative infectious complications, length of stay, perioperative 30-d in-hospital death, or readmission across groups (all P > 0.05). BMI did not impact overall or recurrence-free survival after stratifying by stage (all P > 0.05). However, underweight patients with low preoperative albumin levels had worse overall survival (OS) compared with that of patients of normal BMI.

CONCLUSIONS

BMI did not impact perioperative morbidity, recurrence-free, or OS in patients undergoing gastric resection for adenocarcinoma. Underweight patients with BMI <18.5 kg/m(2) and low preoperative albumin levels, however, had a significantly decreased OS after gastrectomy for cancer. These high-risk patients should have their nutritional status optimized both before and after gastrectomy in an attempt to modify this risk factor and, in turn, achieve better outcomes.