Oncologic evaluation of obesity as a factor in patients with rectal cancer undergoing laparoscopic surgery: a propensity-matched analysis using body mass index

Impact of obesity on postoperative complications in colorectal cancer surgery: A systematic review and meta-analysis

BACKGROUND

Obesity has been increasingly recognized as a factor that influences postoperative outcomes in colorectal cancer surgery. However, its impact on surgical complications, mortality, and oncological outcomes remains controversial. This systematic review and meta-analysis aimed to evaluate the association between obesity and postoperative complications in colorectal cancer surgery.

METHODS

A comprehensive search was conducted in MEDLINE/PubMed, Scopus, and Embase, including studies evaluating body mass index (BMI) in relation to postoperative complications such as infections, anastomotic leakage, postoperative ileus, bleeding, reoperation, and mortality. Data synthesis involved a qualitative analysis of all eligible studies and a meta-analysis when applicable. The quality of the studies included was assessed using the Newcastle-Ottawa Scale, while the certainty of evidence was evaluated through the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.

RESULTS

Twenty-nine studies were included in the qualitative analysis and 17 were eligible for the meta-analysis. Compared to BMI < 30 kg/m², patients with BMI ≥ 30 kg/m² showed significantly higher risk of any type of surgical site infection (OR=1.49; 95 % CI: 1.37-1.70; low certainty). No significant differences were found in mortality (OR=1.23; 95 % CI: 0.72-2.11; very low certainty), hemorrhage (OR=1.05; 95 % CI: 0.97-1.14; very low certainty), or gastrointestinal complications (OR=1.10; 95 % CI: 0.96-1.26; very low certainty).

CONCLUSION

Obesity significantly increases the risk of surgical site infections in colorectal cancer surgery. Although its impact on mortality and gastrointestinal complications remains unclear, implementing preoperative optimization protocols specifically aimed at obesity management could mitigate these surgical risks. The certainty of evidence ranges from low to very low, highlighting the need for high-quality prospective studies with standardized BMI criteria and surgical protocols.

Underweight as a Risk Factor for Major Intra-abdominal Malignancy Surgeries

Purpose The relationship between body mass index (BMI) and postoperative outcomes for oncology surgeries among the Asian population remains controversial. A prevailing perception suggests that excess adiposity is associated with reduced cancer survival. However, several reports have shown that overweight or early obese states confer better survival outcomes. It is hypothesized that patients with better nutrition and surplus calories grant survival advantages to radical cancer treatment. The purpose of this study is to examine the relationship between BMI and postoperative 30-day and one-year mortality in the Asian population. Methods This retrospective review investigates the postoperative mortality, intensive care unit (ICU) admission, and length of hospital stay following major abdominal cancer surgeries within the Asian population. Patients were stratified into three groups based on their BMI: underweight (BMI < 18.5 kg/m2), normal weight (BMI 18.5-27.5 kg/m2), and obese (BMI > 27.5 kg/m2). Results A total of 646 patients were included in this study. At 30 days, the underweight group presents an 8% mortality compared to 1% and 3% mortality in the normal BMI and obese groups, respectively. At one year, the low BMI group presents a significant increase in mortality of 53% as opposed to the normal BMI and obese group with mortality rates of 14% and 12%, respectively (p < 0.001). There is a significant increase in the ICU admission rate in the underweight group (n = 13, 25%) compared to the normal BMI and obese groups (n = 26, 6%; n = 8, 6% p < 0.001). Similarly, the group with lower BMI was observed to require a longer hospital stay postoperatively (median (IQR) 11.0 (4.0-24.0)) compared to the normal (median (IQR) 4.0 (3.0-9.0)) and obese (median (IQR) 4.5 (3.0-8.0)) patients. Conclusion Concordant results were observed in the underweight patient group with increased one-year mortality, ICU admission rate, and hospital stay postoperatively. Low BMI presents as an independent risk factor for major radical surgeries.

Comparison of partial and total cystectomy for colorectal cancer with histologically confirmed bladder invasion

BACKGROUND

Although organs are preserved and quality of life is improved, insufficient evidence is available for the oncologic safety of partial cystectomy in patients with colorectal cancer with suspected bladder invasion. Therefore, we aimed to compare partial and total cystectomy outcomes in patients with pathologically confirmed or clinically suspected bladder invasion.

METHODS

Patients with colorectal cancer with suspected bladder invasion who underwent R0 resection from 2000 to 2020 were evaluated. Long-term outcomes were determined in patients with histologically confirmed bladder invasion.

RESULTS

Of the 151 consecutive patients, 96 (64.6%) had histologically confirmed bladder involvement, and 105 (69.5%) underwent partial cystectomy. Operative time, estimated blood loss, and reoperation rate in ≤30 days were significantly worse in the total cystectomy group than in the partial cystectomy group. The overall recurrence rate was significantly higher in the total cystectomy group than in the partial cystectomy group (39.1% vs 21.9%; P = .046). Five-year overall survival (75.8% vs 53.2%; P = .006) rates were higher in the partial cystectomy group than in the total cystectomy group; however, disease-free survival (60.8% vs 41.6%; P = .088) rates were similar in patients with suspected bladder invasion. In patients with histologically confirmed bladder invasion, 5-year overall survival rates (78.1% vs 52.1%; P = .017) were higher in the partial cystectomy group than in the total cystectomy group; however, disease-free survival rates (53.4% vs 41.2%; P = .220) did not differ significantly.

CONCLUSION

R0 resection is associated with favorable long-term outcomes in patients with locally advanced colorectal cancer. If R0 resection is possible, partial cystectomy is considered safe.

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.

Comparison of robotic versus laparoscopic surgery for visceral obesity in mid-low rectal cancer: a propensity-matched analysis

Obesity is becoming more and more common, and measuring visceral fat area (VFA) is a useful diagnostic technique for visceral obesity (VO). The purpose of this research is to compare the surgical results of robotic versus laparoscopic rectal surgery, with a focus on assessing the benefits of the latter method for treating both VO and mid-low rectal cancer. Patients receiving laparoscopic or robotic anterior rectal excision at Northern Jiangsu People's Hospital's general surgery department were included in the retrospective analysis. 242 people in all took part in the study; 121 cases were assigned to the robotic surgery (RS) group and another 121 cases to the laparoscopic surgery (LS) group. In comparison to LS, our results show that RS led to a shorter period for the recovery of bowel function (p = 0.03), a shorter hospital stay (p < 0.001), a smaller intraoperative blood loss (p < 0.001), and a shorter time until the commencement of oral intake (p = 0.041). However, there were no statistically significant differences between the two groups in terms of the indices of histopathologic specimens, the proportion of temporary loop ileostomy, and the incidence of early postoperative problems (p > 0.05). When patients with VO undergo surgery for rectal cancer, RS has the added benefit of accelerating patient recovery while producing results that are similar to LS in the near run.

Does the visceral fat area impact the histopathology specimen metrics after total mesorectal excision for distal rectal cancer?

BACKGROUND

The aim of this study was to evaluate whether the visceral fat area (VFA) has an impact on the histopathology specimen metrics of male patients undergoing robotic total mesorectal resection (rTME) for distal rectal cancer.

METHODS

Prospectively collected data of patients undergoing rTME for resectable rectal cancer by five surgeons during a period of three years were extracted from the REgistry of Robotic SURgery for RECTal cancer (RESURRECT). VFA was measured in all patients at preoperative computed tomography. Distal rectal cancer was defined as <6cm from the anal verge. The histopathology metrics included circumferential resection margin (CRM) (in mm) and its involvement rate (if <1mm), distal resection margin (DRM), and quality of TME (complete, nearly-complete, incomplete).

RESULTS

Of 839 patients who underwent rTME, 500 with distal rectal cancer were included. One hundred and six (21.2%) males with VFA>100cm2 were compared to 394 (78.8%) males or females with VFA≤100cm2. The mean CRM of males with VFA>100cm2 was not significantly different from its counterpart (6.6 ± 4.8 mm versus 7.1 ± 9.5mm; p=0.752). CRM involvement rates were 7.6% in both groups (p=1.000). The DRM was not significantly different: 1.8±1.9cm versus 1.8±2.6cm; p=0.996. The quality of TME did not significantly differ: complete TME 87.3% vs. 83.7%; nearly complete TME 8.9% vs. 12.8%; incomplete TME 3.8% vs. 3.6%. Complications and clinical outcomes did not significantly differ.

CONCLUSION

This study did not find evidence to support that increased VFA would result in suboptimal histopathology specimen metrics when performing rTME in males with distal rectal cancer.

Perirenal fat thickness as a risk factor for postoperative complications in elective colorectal cancer surgery

Visceral obesity is an important factor that increases the risk of complications after colorectal cancer surgery. As calculating visceral fat is difficult and time-consuming, more practical fat measurements that are not time-consuming have been introduced. This study aimed to investigate the effects of perirenal fat thickness on postoperative complications and prognosis in patients undergoing surgery for colorectal cancer. Perirenal fat thickness was measured from the dorsal aspect of the left kidney on preoperative computerized tomography of patients who underwent surgery for colorectal cancer. The effects of perirenal fat thickness on postoperative complications were investigated. Diagnostic test performance was examined using the Roc Curve test to determine the cutoff value for the perirenal fat thickness values according to the complication findings of the patients. The cutoff value of perirenal fat thickness was found to be above 25.1, according to the presence of complications in the patients. Those with a perirenal fat thickness greater than 25.1 mm were considered to have high perirenal fat thickness values, and those with a low perirenal fat thickness value were considered low. Multivariate analysis revealed that increased perirenal fat thickness is an independent risk factor for postoperative complications. We believe that perirenal fat thickness measurement, as an indicator of visceral fat volume, can be used to identify patients at high risk of developing complications after colorectal cancer surgery. This may change the disease management and affect the patient information process.

Impact of obesity on patients undergoing surgery for rectal cancer in Australia and New Zealand

PURPOSE

Patients with obesity undergoing rectal cancer surgery may have an increased risk of developing complications, though evidence is inconclusive. The aim of this study was to determine the direct impact of obesity on postoperative outcomes using data from a large clinical registry.

METHOD

The Binational Colorectal Cancer Audit registry was used to identify patients who underwent rectal cancer surgery in Australia and New Zealand from 2007-2021. Primary outcomes were inpatient surgical and medical complications. Logistic regression models were developed to describe the association between body-mass index (BMI) and outcomes.

RESULTS

Among 3,708 patients (median age 66 years [IQR 56.75-75], 65.0% male), 2.0% had a BMI < 18.5 kg/m2, 35.4% had a BMI of 18.5-24.9 kg/m2, 37.6% had a BMI of 25.0-29.9 kg/m2, 16.7% had a BMI of 30.0-34.9 kg/m2, and 8.2% had a BMI ≥ 35.0 kg/m2. Surgical complications occurred in 27.7% of patients with a BMI of 18.5-24.9 kg/m2, 26.6% of patients with a BMI of 25.0-29.9 kg/m2 (OR 0.91, 95% CI 0.76-1.10), 28.5% with a BMI of 30.0-34.9 kg/m2 (OR 0.96, 95% CI 0.76-1.21), and 33.2% with a BMI ≥ 35.0 kg/m2 (OR 1.27, 95% CI 0.94-1.71). Modelling BMI as a continuous variable confirmed a J-shaped relationship. The association between BMI and medical complications was more linear.

CONCLUSION

Risk of postoperative complications is increased in patients with obesity undergoing rectal cancer surgery.

Does the mesorectal fat area impact the histopathology metrics of the specimen in males undergoing TME for distal rectal cancer?

The aim of this study was to evaluate whether the mesorectal fat area (MFA) has an impact on the histopathology metrics of the specimen in male patients undergoing robotic total mesorectal excision (rTME) for cancer in the distal third of the rectum. Prospectively collected data of patients undergoing rTME for resectable rectal cancer by five surgeons during 3 years were extracted from the REgistry of Robotic SURgery for RECTal cancer (RESURRECT). MFA was measured at preoperative MRI. Distal rectal cancer was defined as within 6 cm from the anal verge. Specimen metrics included circumferential resection margin (CRM) measured by pathologists as involved if < 1 mm, distal resection margin (DRM) and TME quality. Of 890 patients who underwent rTME for rectal cancer, a subgroup analysis compared 116/581 (33.4%) with MFA > 20 cm2 to 231/581 (66.6%) with MFA ≤ 20 cm2. The mean CRM in patients with MFA > 20 cm2 was neither statistically nor clinically significantly different from patients with MFA ≤ 20 m2 (6.8 ± 5.6 mm vs. 6.0 ± 7.5 mm; p = 0.544). The quality of TME did not significantly differ: complete TME 84.3% vs. 80.3%; nearly complete TME 12.9% vs. 10.1%; incomplete TME 6.8% vs. 5.6%. The DRM was not significantly different: 1.9 ± 1.9 cm vs. 1.9 ± 2.5 cm; p = 0.847. In addition, the intraoperative complication rate was not significantly different: 4.3% (n = 5) vs. 2.2% (n = 5) (p = 0.314). This prospective multicenter study did not find any evidence to support that larger MFA would result in poorer histopathology metrics of the specimen when performing rTME in male patients with distal rectal cancer.

Does the mesorectal fat area impact the histopathology metrics of the specimen in males undergoing TME for distal rectal cancer?

The aim of this study was to evaluate whether the mesorectal fat area (MFA) has an impact on the histopathology metrics of the specimen in male patients undergoing robotic total mesorectal excision (rTME) for cancer in the distal third of the rectum. Prospectively collected data of patients undergoing rTME for resectable rectal cancer by five surgeons during 3 years were extracted from the REgistry of Robotic SURgery for RECTal cancer (RESURRECT). MFA was measured at preoperative MRI. Distal rectal cancer was defined as within 6 cm from the anal verge. Specimen metrics included circumferential resection margin (CRM) measured by pathologists as involved if < 1 mm, distal resection margin (DRM) and TME quality. Of 890 patients who underwent rTME for rectal cancer, a subgroup analysis compared 116/581 (33.4%) with MFA > 20 cm² to 231/581 (66.6%) with MFA ≤ 20 cm². The mean CRM in patients with MFA > 20 cm² was neither statistically nor clinically significantly different from patients with MFA ≤ 20 m² (6.8 ± 5.6 mm vs. 6.0 ± 7.5 mm; p = 0.544). The quality of TME did not significantly differ: complete TME 84.3% vs. 80.3%; nearly complete TME 12.9% vs. 10.1%; incomplete TME 6.8% vs. 5.6%. The DRM was not significantly different: 1.9 ± 1.9 cm vs. 1.9 ± 2.5 cm; p = 0.847. In addition, the intraoperative complication rate was not significantly different: 4.3% (n = 5) vs. 2.2% (n = 5) (p = 0.314). This prospective multicenter study did not find any evidence to support that larger MFA would result in poorer histopathology metrics of the specimen when performing rTME in male patients with distal rectal cancer.

Impact of body-mass index on treatment and outcome in locally advanced rectal cancer: A secondary, post-hoc analysis of the CAO/ARO/AIO-04 randomized phase III trial

BACKGROUND

A better understanding of the impact of body-mass index (BMI) on the course of multimodal therapy and oncologic outcome in locally advanced rectal cancer could provide new insights for optimization of treatment and supportive strategies.

PATIENTS AND METHODS

Correlations of BMI with pretreatment clinical, surgical, and pathological characteristics, toxicity and treatment adherence using the Pearson's Chi-squared test or logistic regression were analyzed in the CAO/ARO/AIO-04 III trial cohort (n = 1236). One-way ANOVA or Welch test were used to analyze correlations of baseline blood-parameters and BMI. The prognostic role of BMI was examined with log-rank test and multivariate cox regression.

RESULTS

Obese had a better ECOG performance status (P = 0.027) but were less likely to undergo sphincter preserving surgery (P = 0.01). Post-surgical complications did not differ significantly between BMI classes, whereas underweight was associated with increased neutrophil (P = 0.025) and platelet counts (P < 0.001), poorer TME quality (P = 0.007) and increased incidence of acute organ toxicity (P < 0.001). After a median follow-up of 50 months, underweight [HR 1.896, P = 0.014] and overweight [HR 1.392, P = 0.042] were associated with worse DFS. Obese patients had an increased risk of death [HR 1.653, P = 0.032]. Normalweight men showed superior OS compared to underweight [HR 4.070, P = 0.002], overweight [HR 2.077, P = 0.010], severe overweight [HR 1.886, P = 0.026] and obese [HR 2.046, P = 0.015] men. Adding oxaliplatin to standard CRT significantly improved DFS in obese patients (P = 0.034).

CONCLUSION

In our study, underweight and overweight correlated with inferior DFS, underweight experienced more organ toxicity and obesity was associated with an increased risk of abdominoperineal resection and poorer overall survival.