Obesity is associated with improved postoperative overall survival, independent of skeletal muscle mass in lung adenocarcinoma

Influence of abdominal fat distribution and inflammatory status on post-operative prognosis in non-small cell lung cancer patients: a retrospective cohort study

PURPOSE

To evaluate the influence of visceral fat area (VFA), subcutaneous fat area (SFA), the systemic immune-inflammation index (SII) and total inflammation-based systemic index (AISI) on the postoperative prognosis of non-small cell lung cancers (NSCLC) patients.

METHODS

266 NSCLC patients received surgery from two academic medical centers were included. To assess the effect of abdominal fat measured by computed tomography (CT) imaging and inflammatory indicators on patients' overall survival (OS) and progression-free survival (PFS), Kaplan-Meier survival analysis and Cox proportional hazards models were used.

RESULTS

Kaplan-Meier analysis showed the OS and PFS of patients in high-VFA group was better than low-VFA group (p < 0.05). AISI and SII were shown to be risk factors for OS and PFS (p < 0.05) after additional adjustment for BMI (Cox regression model II). After further adjustment for VFA (Cox regression model III), low-SFA group had longer OS (p < 0.05). Among the four subgroups based on VFA (high/low) and SFA (high/low) (p < 0.05), the high-VFA & low-SFA group had the longest median OS (108 months; 95% CI 74-117 months) and PFS (85 months; 95% CI 65-117 months), as well as the lowest SII and AISI (p < 0.05). Low-SFA was a protective factor for OS with different VFA stratification (p < 0.05).

CONCLUSION

VFA, SFA, SII and AISI may be employed as significant prognostic markers of postoperative survival in NSCLC patients. Moreover, excessive SFA levels may encourage systemic inflammation decreasing the protective impact of VFA, which may help to provide targeted nutritional support and interventions for postoperative NSCLC patients with poor prognosis.

Obesity worsens mitochondrial quality control and does not protect against skeletal muscle wasting in murine cancer cachexia

BACKGROUND

More than 650 million people are obese (BMI > 30) worldwide, which increases their risk for several metabolic diseases and cancer. While cachexia and obesity are at opposite ends of the weight spectrum, leading many to suggest a protective effect of obesity against cachexia, mechanistic support for obesity's benefit is lacking. Given that obesity and cachexia are both accompanied by metabolic dysregulation, we sought to investigate the impact of obesity on skeletal muscle mass loss and mitochondrial dysfunction in murine cancer cachexia.

METHODS

Male C57BL/6 mice were given a purified high fat or standard diet for 16 weeks before being implanted with 106 Lewis lung carcinoma (LLC) cells. Mice were monitored for 25 days, and hindlimb muscles were collected for cachexia indices and mitochondrial assessment via western blotting, high-resolution respirometry and transmission electron microscopy (TEM).

RESULTS

Obese LLC mice experienced significant tumour-free body weight loss similar to lean (-12.8% vs. -11.8%, P = 0.0001) but had reduced survival (33.3% vs. 6.67%, χ2  = 10.04, P = 0.0182). Obese LLC mice had reduced muscle weights (-24%, P < 0.0354) and mCSA (-16%, P = 0.0004) with similar activation of muscle p65 (P = 0.0337), and p38 (P = 0.0008). ADP-dependent coupled respiration was reduced in both Obese and Obese LLC muscle (-30%, P = 0.0072) consistent with reductions in volitional cage activity (-39%, P < 0.0001) and grip strength (-41%, P < 0.0001). TEM revealed stepwise reductions in intermyofibrillar and subsarcolemmal mitochondrial size with Obese (IMF: -37%, P = 0.0009; SS: -21%, P = 0.0101) and LLC (IMF: -40%, P = 0.0019; SS: -27%, P = 0.0383) mice. Obese LLC mice had increased pAMPK (T172; P = 0.0103) and reduced FIS1 (P = 0.0029) and DRP1 (P < 0.0001) mitochondrial fission proteins, which were each unchanged in Lean LLC. Further, mitochondrial TEM analysis revealed that Obese LLC mice had an accumulation of damaged and dysfunctional mitochondria (IMF: 357%, P = 0.0395; SS: 138%, P = 0.0174) in concert with an accumulation of p62 (P = 0.0328) suggesting impaired autophagy and clearance of damaged mitochondria. Moreover, we observed increases in electron lucent vacuoles only in Obese LLC muscle (IMF: 421%, P = 0.0260; SS: 392%, P = 0.0192), further supporting an accumulation of damaged materials that cannot be properly cleared in the obese cachectic muscle.

CONCLUSIONS

Taken together, these results demonstrate that obesity is not protective against cachexia and suggest exacerbated impairments to mitochondrial function and quality control with a particular disruption in the removal of damaged mitochondria. Our findings highlight the need for consideration of the severity of obesity and pre-existing metabolic conditions when determining the impact of weight status on cancer-induced cachexia and functional mitochondrial deficits.

Increased adipose tissue is associated with improved overall survival, independent of skeletal muscle mass in non-small cell lung cancer

BACKGROUND

The prognostic significance of non-cancer-related prognostic factors, such as body composition, has gained extensive attention in oncological research. Compared with sarcopenia, the prognostic significance of adipose tissue for overall survival in non-small cell lung cancer remains unclear. We investigated the prognostic value of skeletal muscle and adipose tissue in patients with non-small cell lung cancer.

METHODS

This retrospective study included 4434 patients diagnosed with non-small cell lung cancer between January 2014 and December 2016. Cross-sectional areas of skeletal muscle and subcutaneous fat were measured, and the pericardial fat volume was automatically calculated. The skeletal muscle index and subcutaneous fat index were calculated as skeletal muscle area and subcutaneous fat area divided by height squared, respectively, and the pericardial fat index was calculated as pericardial fat volume divided by body surface area. The association between body composition and outcomes was evaluated using Cox proportional hazards model.

RESULTS

A total of 750 patients (501 males [66.8%] and 249 females [33.2%]; mean age, 60.9 ± 9.8 years) were included. Sarcopenia (60.8% vs. 52.7%; P < 0.001), decreased subcutaneous fat index (51.4% vs. 25.2%; P < 0.001) and decreased pericardial fat index (55.4% vs. 16.5%; P < 0.001) were more commonly found in the deceased group than survived group. In multivariable Cox regression analysis, after adjusting for clinical variables, increased subcutaneous fat index (hazard ratio [HR] = 0.56, 95% confidence interval [CI]: 0.47-0.66, P < 0.001) and increased pericardial fat index (HR = 0.47, 95% CI: 0.40-0.56, P < 0.001) were associated with longer overall survival. For stage I-III patients, increased subcutaneous fat index (HR = 0.62, 95% CI: 0.48-0.76, P < 0.001) and increased pericardial fat index (HR = 0.43, 95% CI: 0.34-0.54, P < 0.001) were associated with better 5-year overall survival rate. Similar results were recorded in stage IV patients. For patients with surgery, the prognostic value of increased subcutaneous fat index (HR = 0.60, 95% CI: 0.44-0.80, P = 0.001) and increased pericardial fat index (HR = 0.51, 95% CI: 0.38-0.68, P < 0.001) remained and predicted favourable overall survival. Non-surgical patients showed similar results as surgical patients. No association was noted between sarcopenia and overall survival (P > 0.05).

CONCLUSIONS

Increased subcutaneous fat index and pericardial fat index were associated with a higher 5-year overall survival rate, independent of sarcopenia, in non-small cell lung cancer and may indicate a reduced risk of non-cancer-related death.

Obesity paradox in patients with non-small cell lung cancer undergoing immune checkpoint inhibitor therapy

BACKGROUND

The obesity paradox in patients with advanced non-small cell lung cancer receiving immune checkpoint inhibitor therapy has been observed, but its underlying mechanism is not fully understood. We aimed to investigate whether body composition affects the prognostic impact of obesity, as determined by body mass index (BMI), on survival.

METHODS

This retrospective study evaluated the data collected from Asian patients who were treated with immune checkpoint inhibitors for advanced non-small cell lung cancer between October 2015 and October 2021. We used abdominal cross-sectional imaging to calculate the skeletal muscle and visceral fat indices (cm2 /m2 ) by dividing the cross-sectional areas of the skeletal muscle and visceral fat by the height squared. Cox proportional-hazards regression was performed to determine the correlation between BMI according to the Asia-Pacific classification, body composition metrics and overall survival.

RESULTS

We analysed the data of 820 patients (630 men and 190 women, with a mean age of 64.3 years [standard deviation: 10.4 years]) and observed 572 (69.8%) deaths with the 1-year mortality rate of 0.58 (95% confidence interval, 0.55-0.62). Obese BMI was associated with longer overall survival, independent of clinical covariates (hazard ratio, 0.64; 95% confidence interval: 0.52-0.80). The prognostic value of obese BMI remained after additional adjustments for skeletal muscle index (hazard ratio, 0.68; 95% confidence interval, 0.53-0.87) or visceral fat index (hazard ratio, 0.54; 95% confidence interval: 0.41-0.70). No association was observed between sex and the impact of BMI on overall survival (P-value for interaction >0.05).

CONCLUSIONS

In Asian patients with advanced non-small cell lung cancer who received immune checkpoint inhibitors, obese BMI was associated with favourable overall survival independent of skeletal muscle or visceral fat mass.

Prognostic significance of body mass index in small-cell lung cancer: Exploring the relationship with skeletal muscle status

BACKGROUND

We investigated the prognostic significance of body mass index in small-cell lung cancer and explored whether skeletal muscle status affects the body mass index-survival relationship.

METHODS

This retrospective study evaluated data from patients who underwent platinum-etoposide chemotherapy for small-cell lung cancer between March 2010 and December 2021. Skeletal muscle status was assessed using non-contrast computed tomography images of baseline positron-emission tomography-computed tomography, with the skeletal muscle index defined as the cross-sectional area of skeletal muscle divided by height squared, and the average attenuation values of skeletal muscle. Cox proportional hazards regression analysis was used to determine the correlations of body mass index, skeletal muscle metrics, and overall survival.

RESULTS

We analysed the data of 1146 Asian patients (1006 men and 140 women, with a median age of 67 years [interquartile range: 61-72 years]), including 507 and 639 patients with limited and extensive disease, respectively. Being underweight, defined as a body mass index <18.5 kg/m2 , was associated with shorter overall survival, independent of clinical covariates in both the limited-disease (hazard ratio, 1.77; 95% confidence interval, 1.01-3.09) and extensive-disease (hazard ratio, 1.71; 95% confidence interval, 1.18-2.48) groups. The prognostic value of being underweight remained significant after additional adjustment for skeletal muscle index and attenuation in both limited-disease (hazard ratio, 1.96; 95% confidence interval, 1.09-3.51) and extensive-disease (hazard ratio, 1.75; 95% confidence interval, 1.17-2.61) groups.

CONCLUSIONS

Being underweight is an independent poor prognostic factor for shorter overall survival in Asian patients with small-cell lung cancer, regardless of skeletal muscle status.

The MAPS-CRAFITY score: a novel efficacy predictive tool for unresectable hepatocellular carcinoma treated with targeted therapy plus immunotherapy

BACKGROUND

Body composition parameters (BCPs) are associated with mortality in patients with hepatocellular carcinoma (HCC). Our purpose was to develop a practical scoring model by BCP and the CRAFITY score to predict the overall survival (OS) and tumor response of patients with HCC who received targeted therapy plus immunotherapy.

METHODS

This retrospective study included 265 patients with HCC who received targeted therapy plus immunotherapy at 2 centers in China from August 2018 to February 2022. Univariate and multivariate Cox regression analyses were applied to analyze clinical factors and BCP. A scoring model based on independent risk factors was developed to predict OS and tumor response. Moreover, the model's prediction was further validated by an external cohort.

RESULTS

A total of 150 patients (55.5 ± 10.8 years) and 115 patients (55.0 ± 8.9 years) treated with lenvatinib or bevacizumab biosimilar plus anti-programmed death-1 (PD-1) antibody were included in training and validation cohorts, respectively. In the training cohort, independent predictive factors for OS included macrovascular invasion (p = 0.016), Child‒Pugh class (A vs. B, p = 0.001; A vs. C, p < 0.001), sarcopenia (p = 0.034), and the CRAFITY score (p = 0.011). Based on independent risk factors (MAcrovascular invasion, Child‒Pugh class, Sarcopenia, and the CRAFITY score) identified by multivariate analysis, a novel efficacy predictive tool named the MAPS-CRAFITY score was developed to predict OS. In all the training and validation cohorts, the OS differed significantly across the three groups based on the MAPS-CRAFITY score (< 2.1, 2.1-2.3, ≥ 2.4; p < 0.001). Moreover, the C-index of the MAPS-CRAFITY score was 0.720 and 0.761 in the training and validation cohorts, respectively. In both the validation and training cohorts, the MAPS-CRAFITY score was predictive of tumor response and disease control (p < 0.001). The AUCs of the MAPS-CRAFITY score for predicting disease control were 0.752 in the training cohort and 0.836 in the validation cohort.

CONCLUSIONS

The MAPS-CRAFITY score based on sarcopenia and the CRAFITY score is a reliable and practical tool for predicting the efficacy of targeted therapy plus immunotherapy in patients with unresectable HCC, and may help hepatologists and oncologists in clinical decision-making.

Ectopic and visceral fat deposition in aging, obesity, and idiopathic pulmonary fibrosis: an interconnected role

Idiopathic pulmonary fibrosis (IPF) is considered an age-related disease. Age-related changes, along with other factors such as obesity, hormonal imbalances, and various metabolic disorders, lead to ectopic fat deposition (EFD). This accumulation of fat outside of its normal storage sites is associated with detrimental effects such as lipotoxicity, oxidative stress, inflammation, and insulin resistance. This narrative review provides an overview of the connection between ectopic and visceral fat deposition in aging, obesity, and IPF. It also elucidates the mechanism by which ectopic fat deposition in the airways and lungs, pericardium, skeletal muscles, and pancreas contributes to lung injury and fibrosis in patients with IPF, directly or indirectly. Moreover, the review discusses the impact of EFD on the severity of the disease, quality of life, presence of comorbidities, and overall prognosis in IPF patients. The review provides detailed information on recent research regarding representative lipid-lowering drugs, hypoglycemic drugs, and lipid-targeting drugs in animal experiments and clinical studies. This may offer new therapeutic directions for patients with IPF.

Obesity Paradox in Lung Diseases: What Explains It?

BACKGROUND

Obesity is a globally increasing health problem that impacts multiple organ systems and a potentially modifiable risk factor for many diseases. Obesity has a significant impact on lung function and is strongly linked to the pathophysiology that contributes to lung diseases. On the other hand, reports have emerged that obesity is associated with a better prognosis than for normal weight individuals in some lung diseases, including pneumonia, acute lung injury/acute respiratory distress syndrome, chronic obstructive pulmonary disease, and lung cancer. The lesser mortality and better prognosis in patients with obesity is known as obesity paradox. While obesity paradox is both recognized and disputed in epidemiological studies, recent research has suggested possible mechanisms.

SUMMARY

In this review, we attempted to explain and summarize these factors and mechanisms, including immune response, pulmonary fibrosis, lung function, microbiota, fat and muscle reserves, which are significantly altered by obesity and may contribute to the obesity paradox in lung diseases. We also discuss contrary literature that attributes the "obesity paradox" to confounding.

KEY MESSAGES

The review will illustrate the possible role of obesity in the prognosis or course of lung diseases, leading to a better understanding of the obesity paradox and provide hints for further basic and clinical research in lung diseases.

Protective effect of obesity on survival in cancers treated with immunotherapy vanishes when controlling for type of cancer, weight loss and reduced skeletal muscle

INTRODUCTION

Association of high body mass index (BMI) with longer survival has been reported in patients on immune checkpoint inhibitors (ICIs), but results are inconsistent. This 'obesity paradox' is potentially confounded by the effects of BMI change over time and of skeletal muscle depletion.

METHODS

We conducted a secondary analysis of a prospective cohort, including consecutive patients receiving ICI treatment for melanoma (n = 411) and non-small cell lung cancer (NSCLC) (n = 389) in routine care.

RESULTS

In the univariable analysis of the entire population, overweight/obesity (BMI ≥ 25 kg/m²) was associated with longer survival (p < 0.01); however, this effect was limited to NSCLC (p < 0.01) and was absent in melanoma. Weight loss (WL) and reduced skeletal muscle mass were observed in patients within all BMI categories. WL was associated with shorter survival in multivariable analysis in both tumour sites (p < 0.01), and for NSCLC, BMI lost significance when WL was included (p = 0.13). In models further adjusted for CT-defined skeletal muscle mass, WL retained significance for both tumour types (p < 0.01), and reduced skeletal muscle only for NSCLC (p = 0.02) was associated with shorter survival. WL retained significance when biomarkers (lactate dehydrogenase enzyme, albumin and derived neutrophil to lymphocyte ratio) were added to the multivariable model.

CONCLUSIONS

The so-called 'obesity paradox', counterintuitive association between high BMI and longer survival, vanished when controlling for confounders, such as type of cancer, and manifestations of depletion (WL and reduced skeletal muscle mass).

Early recurrence factors in patients with stage III non-small cell lung cancer treated with concurrent chemoradiotherapy

BACKGROUND

The clinical characteristics and risk factors for cancer recurrence have not been well evaluated regarding early recurrence in patients with unresectable locally advanced non-small cell lung cancer (LA-NSCLC) who receive concurrent chemoradiotherapy (CRT). The aim of this study was to determine the clinical characteristics and risk factors of patients with stage III unresectable LA-NSCLC treated with CRT who developed early recurrence.

METHODS

We retrospectively reviewed the clinical records of 46 patients diagnosed with stage III unresectable LA-NSCLC treated with CRT at our center between July 2012 and July 2021. A tumor proportion score (TPS) < 50% was defined as "low expression" and a TPS > 50% was defined as "high expression."

RESULTS

A total of 17 (37.0%) patients had a confirmed recurrence within 1 year of treatment. More patients had a lower body mass index in the early recurrence group than in the later recurrence group (p = 0.038). A higher number of patients in the late recurrence group underwent surgery after CRT (p = 0.036). Patients with a higher TPS were more likely to experience late recurrence than early recurrence (p = 0.001), whereas more patients with stage N3 disease were in the early recurrence group (p = 0.011). Multivariate analysis identified lower TPS expression as an independent risk factor for early recurrence after CRT. Overall survival was prolonged in the late recurrence group (p < 0.001).

CONCLUSIONS

A lower TPS may be a predictor of early recurrence after CRT in patients with LA-NSCLC. These patients should be closely monitored for post-treatment recurrence.

Visceral adiposity and systemic inflammation in the obesity paradox in patients with unresectable or metastatic melanoma undergoing immune checkpoint inhibitor therapy: a retrospective cohort study

BACKGROUND

The obesity paradox is a topic of increasing interest in oncology and epidemiology research. Although this phenomenon has been observed in melanoma patients receiving immune checkpoint inhibitors, little is known about its mechanism. We aim to investigate the prognostic value of obesity and its association with adiposity and systemic inflammation.

METHODS

This retrospective study evaluates the data of patients who received pembrolizumab or nivolumab for unresectable or metastatic melanoma between June 2015 and April 2021. The skeletal muscle index (SMI) and visceral fat index (VFI) (cm²/m²) were calculated by dividing the cross-sectional areas of skeletal muscle and visceral fat by height squared. The systemic immune-inflammation index (SII) was defined as the total peripheral platelet count×neutrophil/lymphocyte ratio. Cox proportional hazard regression analysis was conducted to determine the association with overall survival.

RESULTS

We analyzed 266 patients with a median age of 60 years (IQR 51-69 years; 135 men and 131 women). The protective effect of obesity was independent of covariates (HR 0.60; 95% CI 0.37 to 0.99; p=0.048), but disappeared after adjusting for VFI (HR 0.76; 95% CI 0.41 to 1.40; p=0.380) or SII (HR 0.71; 95% CI 0.42 to 1.18; p=0.186). An increase of 10 cm²/m² in VFI was associated with longer overall survival after adjusting for covariates (HR 0.88; 95% CI 0.79 to 0.99; p=0.029). The prognostic value of VFI remained and predicted favorable overall survival after additional adjustment for SMI (HR 0.86; 95% CI 0.76 to 0.98; p=0.025), but disappeared with adjustment for SII (HR 0.92; 95% CI 0.82 to 1.03; p=0.142). An increase of 100×10⁹/L in SII was associated with poor overall survival when adjusted for covariates (HR 1.08; 95% CI 1.05 to 1.11; p<0.001) or when additionally adjusted for VFI (HR 1.07; 95% CI 1.04 to 1.10; p<0.001).

CONCLUSIONS

Visceral adiposity and systemic inflammation are significant prognostic factors in patients with unresectable or metastatic melanoma receiving immune checkpoint inhibitors. The prognostic impact of visceral adiposity is dependent on systemic inflammation status.

Obesity is associated with improved postoperative overall survival, independent of skeletal muscle mass in lung adenocarcinoma

BACKGROUND

Although the obesity paradox is a topic of immense interest for oncologists and epidemiologists, the mechanism underlying this unexpected benefit of obesity is poorly understood. We explored the prognostic value of obesity and its association with skeletal muscle mass.

METHODS

This retrospective study evaluated the data of patients who underwent surgical excision for lung adenocarcinoma between January 2011 and December 2015. Body mass index was categorized according to the criteria of the Asia-Pacific classification. Cross-sectional areas of the skeletal muscle, subcutaneous fat, and visceral fat were measured. Skeletal muscle mass status was defined based on the cut-offs of skeletal muscle index (cm² /m² ), calculated as the area of skeletal muscle divided by height squared. Overall survival was estimated using the Kaplan-Meier method, and differences in survival probabilities were compared using the log-rank test. Cox proportional hazards regression analysis was conducted to determine the association with overall survival.

RESULTS

A total of 636 patients with a median age of 61 years (interquartile range, 54.0-68.5 years; 321 men and 315 women) were included. Obese patients (body mass index ≥ 25 kg/m² ) had longer overall survival than non-obese patients (mean, 110.2 months vs. 98.7 months; log-rank P = 0.015). Under multivariable Cox proportional hazard regression analysis, obesity was associated with longer overall survival after adjusting for covariates (hazard ratio, 0.59; 95% confidence interval, 0.40-0.86; P = 0.007). The prognostic value of obesity remained and predicted favourable overall survival after additional adjusting for skeletal muscle mass status (hazard ratio, 0.57; 95% confidence interval, 0.36-0.89; P = 0.014), skeletal muscle index (hazard ratio, 0.53; 95% confidence interval, 0.33-0.84; P = 0.008), or skeletal muscle area (hazard ratio, 0.61; 95% confidence interval, 0.38-0.98; P = 0.041). No association was observed between skeletal muscle mass status and the impact of body mass index on overall survival (P for interaction = 0.512).

CONCLUSIONS

Obesity was associated with favourable overall survival, independent of skeletal muscle mass, after surgical excision of lung adenocarcinoma.