Effects of a high body mass index on the short-term outcomes and prognosis after radical gastrectomy

Multiomics insights into BMI-related intratumoral microbiota in gastric cancer

Introduction

Body mass index (BMI) is considered an important factor in tumor prognosis, but its role in gastric cancer (GC) remains controversial. There is a lack of studies exploring the effect of BMI on gastric cancer from the perspective of intratumoral microbiota. This study aimed to compare and analyze the differences in and functions of intratumoral microbiota among GC patients with varying BMIs, aiming to ascertain whether specific microbial features are associated with prognosis in low-BMI (LBMI) gastric cancer patients.

Methods

A retrospective analysis of the clinicopathological features and prognosis of 5567 patients with different BMIs was performed between January 2010 and December 2019. Tumor tissues from 189 GC patients were collected for 16S rRNA sequencing, 64 samples were selected for transcriptome sequencing, and 57 samples were selected for untargeted metabolomic analysis.

Results

Clinical cohort analysis revealed that GC patients with a low BMI presented poorer clinical and pathological characteristics than those with a non-low-BMI (NLBMI). LBMI was identified as a significant independent risk factor for adverse prognosis, potentially exerting immunosuppressive effects on postoperative adjuvant chemotherapy. 16S rRNA sequencing revealed no significant differences in the alpha and beta diversity of the intratumoral microbiota between the two groups of GC patients. However, LEfSe analysis revealed 32 differential intratumoral microbiota between the LBMI and NLBMI groups. Notably, the genus Abiotrophia was significantly enriched in the LBMI group. Further in-depth analysis indicated that the genus Abiotrophia was inversely associated with eosinophils, P2RY12, and SCN4B genes, and positively linked with LGR6 in LBMI gastric cancer patients. Metabolomic assessments revealed that LBMI was positively associated with purine metabolites, specifically guanine and inosine diphosphate (IDP).

Discussion

In conclusion, LBMI is an independent risk factor for poor prognosis in gastric cancer patients and may have an inhibitory effect on postoperative adjuvant chemotherapy. Intratumor flora of gastric cancer patients with different BMI levels differed, with different immune cell infiltration and metabolic characteristics. The genus Abiotrophia may promote gastric cancer development and progression by regulating eosinophils and the purine metabolism pathway, which provides a new idea for the precise treatment of gastric cancer.

Association of preoperative body mass index with postoperative complications and survival for patients with gastric cancer: A systematic review and meta-analysis

OBJECTIVE

The relationship among body mass index (BMI), postoperative complications, and clinical outcomes in patients undergoing gastrectomy for gastric cancer remains unclear. This study aimed to evaluate this association using a meta-analysis.

METHOD

We conducted a systematic search of the PubMed, Embase, and Cochrane Library databases up to February 25, 2024. Patients were classified into underweight (<18.5 kg/m2), normal weight (18.5-25.0 kg/m2), and overweight (≥25.0 kg/m2) groups based on BMI categories. Meta-analysis was performed using a random-effects model. Additionally, exploratory sensitivity and subgroup analyses were performed.

RESULTS

Twenty-two studies involving 41,144 patients with gastric cancer were included for quantitative analysis. Preoperative underweight (odds ratio [OR]: 1.26; 95% confidence interval [CI]: 1.03-1.55; P = 0.024) and overweight (OR: 1.19; 95%CI: 1.09-1.30; P <0.001) were associated with an increased risk of postoperative complications. Furthermore, preoperative underweight was associated with poorer overall survival (hazard ratio [HR]: 1.40; 95%CI: 1.28-1.53; P <0.001), whereas preoperative overweight was associated with better over-survival (HR: 0.82; 95%CI: 0.73-0.91; P <0.001). Furthermore, preoperative underweight was not associated with disease-free survival (HR: 1.48; 95%CI: 0.97-2.26; P = 0.069), whereas preoperative overweight was associated with longer disease-free survival (HR: 0.80; 95%CI: 0.70-0.91; P = 0.001). In terms of specific postoperative complications, preoperative underweight was associated with an increased risk of septic shock (OR: 3.40; 95%CI: 1.26-9.17; P = 0.015) and a reduced risk of fever (OR: 0.39; 95%CI: 0.18-0.83; P = 0.014). Preoperative overweight was associated with an increased risk of wound infections (OR: 1.78; 95%CI: 1.08-2.93; P = 0.023), intestinal fistula (OR: 5.23; 95%CI: 1.93-14.21; P = 0.001), arrhythmia (OR: 6.38; 95%CI: 1.70-24.01; P = 0.006), and pancreatic fistula (OR: 3.37; 95%CI: 1.14-9.96; P = 0.028).

CONCLUSION

This study revealed that both preoperative underweight and overweight status were associated with an increased risk of postoperative complications. Moreover, the postoperative survival outcomes were significantly better in overweight compared to that of underweight patients.

TRIAL REGISTRATION

Registration: INPLASY202480004.

Clinical impact of perirenal thickness on short- and long-term outcomes of gastric cancer after curative surgery

Background

A variety of factors for short- and long-term outcomes have been reported after radical resection for gastric cancer (GC). Obesity and emaciation had been reported to be a cause of poor short- and long-term outcomes with gastrointestinal cancer. However, the indicators are still controversial. The purpose of this study was to evaluate the relationship between perirenal thickness (PT) and short- and long-term outcomes after radical surgery for GC.

Methods

We analyzed the data of 364 patients with GC who underwent radical surgery. We evaluated the distance from the anterior margin of the quadratus lumborum muscle to the dorsal margin of the left renal pole using computed tomography (CT) as an indicator of PT. The association between PT and clinicopathological factors and short- and long-term outcomes was evaluated.

Results

The PT data were divided into low, normal, and high groups by gender using the tertile value. We found that the PT low group was 121 patients, normal group was 121 patients, and high group was 122 patients. Multivariate analyses showed that the high PT group was an independent risk factor for a short-outcome after curative surgery in GC patients (odds ratio 2.163; 95% confidence interval [CI] 1.156-4.046; P = .016). And the low PT group was an independent risk factor for overall survival (hazard ratio 2.488; 95% CI 1.400-4.421; P = .0019) and relapse-free survival (hazard ratio 2.342; 95% CI 1.349-4.064; P = .0025) after curative surgery in GC patients.

Conclusion

Perirenal thickness is a simple and useful factor for predicting short- and long-term outcomes after radical surgery for GC.

Body Mass Index and Prognosis of Patients With Stage II/III Gastric Cancer After Curative Gastrectomy: Completion of Perioperative Adjuvant Chemotherapy May Be a Confounding Factor

Objective

To investigate the association between body mass index (BMI) and overall survival (OS) of patients with stage II/III gastric cancer (GC) after radical gastrectomy, and evaluate the potential influence of perioperative adjuvant chemotherapy (PAC).

Methods

Medical records of 2,510 consecutive stage II/III GC patients who underwent curative resection between November 2010 and December 2020 were retrospectively reviewed. The optimal cutoff value of BMI for OS was determined by X-tile. The independent predictive factors for completeness of PAC were identified using univariate and multivariate logistic regression analyses. Cox regression analyses assessed the association among BMI, completeness of PAC, and OS.

Results

Of the 2,510 patients, 813 cases with BMI < 20.3 kg/m² were classified as belonging in the low BMI group. Further analyses confirmed that low BMI was an independent predictor for incomplete PAC (< 6 cycles, n = 920) and poorer OS (hazard ratio: 1.317, 95% confidence interval: 1.162-1.494, P < 0.001), but neo-adjuvant chemotherapy (NAC) was a protective factor. An additive effect was found in those with both low BMI and incomplete PAC, as they had even worse OS. However, in patients with low BMI, completion of PAC (≥ 6 cycles) significantly improved OS, which became comparable to that in the high BMI group (P = 0.143).

Conclusions

Low preoperative BMI independently affects completion of PAC and prognosis of patients with stage II/III GC, but completing PAC can compensate for the adverse influence of low BMI on OS. Thus, strategies designed to ensure the completion of PAC, such as NAC and nutritional support, should be further investigated.

Incidence of and Risk Factors for Gastroepiploic Lymph Node Involvement in Patients with Cancer of the Transverse Colon Including the Hepatic Flexure

BACKGROUND

To define the incidence of gastroepiploic lymph node (GLN) metastasis in patients with cancer of the transverse colon, including the hepatic flexure, and to identify the preoperative predictors of GLN involvement in a large-volume center in China.

METHODS

This retrospective monocentric cross-sectional study respected the STROBE statement. Of 3208 consecutive patients who underwent colon cancer resection, a total of 371 patients with cancer of the transverse colon including the hepatic flexure who underwent complete mesocolic excision and GLN resection in our center were retrospectively reviewed between November 2010 and November 2017. Logistic regression was performed to identify predictors of GLN metastasis. Endoscopic obstruction was defined as a luminal obstruction of the colon severe enough to prevent the colonoscope from passing beyond the tumor regardless of the presenting symptoms.

RESULTS

The GLN involvement rate was 4.0 (2.0-6.1)%. Patients who had GLN involvement had a significantly higher rate of endoscopic obstruction (P = 0.030), higher rate of signet ring adenocarcinoma or lymphovascular invasion (P < 0.05), higher preoperative CEA level (P = 0.037), more advanced pN stage (P < 0.001) and more advanced M stage (P = 0.003) than the patients without GLN involvement. ROC curve analyses showed that the cutoff value for CEA was 17.0 ng/ml (46.7% sensitivity, 84.3% specificity, P = 0.037) for the prediction of GLN metastasis. Multivariate analysis showed that endoscopic obstruction, signet ring adenocarcinoma, a CEA level ≥17 ng/ml and M1 stage were independently correlated with the GLN metastasis.

CONCLUSION

The incidence rate of GLN metastasis was low. To the best of our knowledge, the present study was the first to evaluate the preoperative predictors of GLN metastasis. Combinations of predictive factors may be useful for stratifying patients at high risk of GLN metastasis.