Impact of Body Mass Index on Surgical and Oncological Outcomes in Laparoscopic Total Mesorectal Excision for Locally Advanced Rectal Cancer after Neoadjuvant 5-Fluorouracil-Based Chemoradiotherapy

Pathologic Outcomes and Survival in Patients with Rectal Cancer and Increased Body Mass Index

INTRODUCTION

We assessed the association between increased body mass index (BMI) and rectal cancer outcomes.

METHODS

We included patients who underwent surgery for stage I-III rectal adenocarcinoma who were divided according to BMI at diagnosis: ideal BMI (18.5-24.9 kg/m2) and increased BMI (≥25 kg/m2). Groups were compared using univariate association analyses relative to baseline characteristics, pathologic outcomes, overall survival (OS), and disease-free survival (DFS). Main outcome measures involved circumferential resection margin (CRM), pathologic TNM stage, total mesorectal incision (TME) grade, OS, and DFS.

RESULTS

243 patients (64.6% male; median age 59 years) with a median BMI of 26.3 kg/m2 were included. 62.1% had BMI ≥25 kg/m2. Increased BMI patients had similar proportions of males (66.9% vs. 60.9%; p = 0.407) and comorbidities (ASA III: 47% vs. 37.4%; p = 0.24) to ideal BMI patients. There were no significant differences in cN1-2 stage (p = 0.279) or positive CRM (p = 0.062) rates. The groups had similar complete/near-complete TME, pathologic TN stage, and survival rates. Pathologic and survival outcomes were also similar with a BMI cutoff of 30.

CONCLUSIONS

There was a trend toward more nodal involvement in preoperative assessment and less CRM involvement in the final pathology of patients with increased BMI. Complete/near-complete TME and survival rates were comparable between the groups.

Post-diagnosis adiposity and colorectal cancer prognosis: A Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis

The adiposity influence on colorectal cancer prognosis remains poorly characterised. We performed a systematic review and meta-analysis on post-diagnosis adiposity measures (body mass index [BMI], waist circumference, waist-to-hip ratio, weight) or their changes and colorectal cancer outcomes. PubMed and Embase were searched through 28 February 2022. Random-effects meta-analyses were conducted when at least three studies had sufficient information. The quality of evidence was interpreted and graded by the Global Cancer Update Programme (CUP Global) independent Expert Committee on Cancer Survivorship and Expert Panel. We reviewed 124 observational studies (85 publications). Meta-analyses were possible for BMI and all-cause mortality, colorectal cancer-specific mortality, and cancer recurrence/disease-free survival. Non-linear meta-analysis indicated a reverse J-shaped association between BMI and colorectal cancer outcomes (nadir at BMI 28 kg/m2). The highest risk, relative to the nadir, was observed at both ends of the BMI distribution (18 and 38 kg/m2), namely 60% and 23% higher risk for all-cause mortality; 95% and 26% for colorectal cancer-specific mortality; and 37% and 24% for cancer recurrence/disease-free survival, respectively. The higher risk with low BMI was attenuated in secondary analyses of RCTs (compared to cohort studies), among studies with longer follow-up, and in women suggesting potential methodological limitations and/or altered physiological state. Descriptively synthesised studies on other adiposity-outcome associations of interest were limited in number and methodological quality. All the associations were graded as limited (likelihood of causality: no conclusion) due to potential methodological limitations (reverse causation, confounding, selection bias). Additional well-designed observational studies and interventional trials are needed to provide further clarification.

Prognostic value of mesorectal package area in patients with locally advanced rectal cancer following neoadjuvant chemoradiotherapy: A retrospective cohort study

Background

The aim of this study is to explore the most effective inflammation, magnetic resonance imaging (MRI), and nutrition markers for survival and pathology complete response (pCR) in patients with locally advanced rectal cancer (LARC).

Methods

A total of 278 patients with LARC undergoing neoadjuvant chemoradiotherapy (NCRT) and radical surgery from 2016 to 2019 were included. The X-tile method was used to select the optimal cutoff points for the mesorectal package area (MPA), advanced lung cancer inflammation index (ALI), prognostic nutritional index (PNI), systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) scores. Cox regression analysis was used to identify risk factors of disease-free survival (DFS). To discover pCR risk factors, logistic regression analysis was employed. A predictive nomogram for DFS was constructed.

Results

According to the least absolute shrinkage and selection operator analysis, the MPA was the only significant predictor for the DFS in patients with LARC. Kaplan-Meier (K-M) analysis demonstrated that groups with higher MPA, PNI, SII, NLR, MLR, and ALI score had improved DFS (all P < 0.05). Receiver operating characteristic (ROC) analysis revealed that the MPA and PNI could accurately predict the pCR in patients with LARC after NCRT. The MPA score and NLR score were found to be independent predictors of DFS after NCRT using Cox regression analysis. Logistical regression analysis demonstrated that the MPA score, PNI score, and pre-NCRT cN stage were all independent predictors of pCR in patients with LARC after NCRT. Recursive partitioning analysis and time-independent ROC curve analysis demonstrated that MPA score was the most important predictor of pCR and prognosis in patients with LARC after NCRT.

Conclusions

MPA was identified as the most effective marker for MRI, and the prognostic value was further confirmed by time–ROC analysis. More intense adjuvant treatment could be considered for lower–MPA score patients with LARC after NCRT. Obesity in the pelvis encourages the understanding of the prognosis prediction of patients with LARC after NCRT.

Assessment of mesorectal fascia status in MRI compared with circumferential resection margin after total mesorectal excision and predictors of involved margins

BACKGROUND

Circumferential resection margin is an important prognosticator for total mesorectal excision outcome. We investigated the status of mesorectal fascia on magnetic resonance imaging compared with circumferential resection margin on pathology and factors associated with status change.

METHODS

This was a retrospective analysis of a prospective database of rectal cancer patients who underwent surgery. Mesorectal fascia status on magnetic resonance imaging done before neoadjuvant therapy and circumferential resection margin status on pathology were compared. The study outcomes were factors associated with a margin status conversion between magnetic resonance imaging and pathology, and predictors of involved circumferential resection margin.

RESULTS

In total, 244 patients (average follow-up of 25.4 months) were included. Eighty-one (33.2%) patients had potentially involved mesorectal fascia in magnetic resonance imaging and 12 (4.9%) had involved circumferential resection margin in pathology. A total of 2.8% of patients had a conversion of clear mesorectal fascia in magnetic resonance imaging to involved circumferential resection margin. Abdominoperineal resection was significantly associated with this status change (odds ratio: 25, 95% confidence interval: 2.4-255.8, P = .007). In total, 7.4% of patients with potentially involved mesorectal fascia had persistently involved circumferential resection margin. Lack of total neoadjuvant therapy was associated with higher, yet statistically insignificant, odds of persistently involved circumferential resection margin (odds ratio: 12, 95% confidence interval: 0.65-220.8, P = .09). The significant independent predictors of involved circumferential resection margin were body mass index (odds ratio: 1.2, P = .016) and abdominoperineal resection (odds ratio: 4.22, P = .04).

CONCLUSION

Change of clear mesorectal fascia in magnetic resonance imaging to an involved circumferential resection margin in pathology was recorded in 2.8% of patients; abdominoperineal resection might be associated with this change. Approximately 7% of patients had persistent involvement of circumferential resection margin as determined by pathology. Omission of total neoadjuvant therapy might be associated with persistent margin involvement.

The effect of increased body mass index values on surgical outcomes after radical resection for low rectal cancer

PURPOSES

This study aimed to explore the effect of increased body mass index (BMI) values (overweight: BMI ≥ 25-30 kg/m²; obese: BMI ≥ 30 kg/m²) on surgical outcomes after radical resection for low rectal cancer (LRC).

METHODS

Patients with LRC who underwent radical surgery from January 2009 to December 2013 were included. The patients were divided into three groups according to their BMI values (control group: BMI < 25 kg/m²; overweight group: BMI 25 to < 30 kg/m²; obese group: BMI ≥ 30 kg/m²). The patients' clinicopathological characteristics and survival data were collected and analyzed.

RESULTS

A total of 792 patients were enrolled in this study finally (control, n = 624; overweight, n = 147; obese, n = 21). The baseline characteristics of the three groups were similar. We found that an increased BMI was associated with a longer operative time (P < 0.001) and length of postoperative hospital stay (P = 0.032). Patients with increased BMI values had a significantly higher incidence of postoperative complications, including pulmonary infection (P = 0.008), anastomotic leakage (P = 0.029), allergy (P = 0.017) and incisional hernia (P = 0.045). The limited data showed that the pathological outcomes of the three groups did not differ to a statistically significant extent. A multivariate analysis showed that increased BMI was not associated with poorer OS or DFS.

CONCLUSION

In LRC resection, an increased BMI was associated with a longer operative time, postoperative hospital stay, and an increased number of postoperative complications. However, it did not contribute to poorer pathological or survival outcomes.