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

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.

Visceral obesity and anastomotic leakage rates in colorectal cancer: a systematic review and meta-analysis

Background

Numberous studies have heatedly discussed whether obesity is a risk factor for anastomotic leakage (AL) because of the increasing number of colorectal cancer (CRC) cases and high incidence of CRC in patients with obesity.

Objective

We aimed to explore the relationship between visceral obesity(VO) and AL after CRC surgery. The databases of Pubmed, Embase, and the Cochrane Library were searched for relevant data and articles published until November 1, 2022. We identified the difference in the incidence of AL after CRC surgery between patients with and without VO. The quality of included studies was evaluated using the Newcastle- Ottawa Scale, and odds ratio (OR) and 95% CI were used to assess the association between VO and AL.

Results

This meta-analysis included 7 studies with 2,136 patients. The OR of patients with VO versus those without VO was 2.15 (95%CIs = 1.46-3.15, test for heterogeneity: P = 0.29, I2 = 18%) based on the fixed-effect model in seven studies. Notably, the difference between the two groups was statistically significant (Z = 3.91 P < 0.0001). Patients with VO in the colon cancer group exhibited a higher incidence of AL (OR = 2.88, 95% CIs = 1.38-5.99, test for heterogeneity: P = 0.27, I2 = 20%) than those in the rectal cancer group (OR = 2.74, 95% CIs = 1.13-6.65, test for heterogeneity: P = 0.20, I2 = 38%). In the studies in the relevant literature, heterogeneity was low. Regarding patients with VO, four Asian studies reported increased morbidity due to AL (OR = 2.79, 95% CIs = 1.35-5.78, test for heterogeneity: P = 0.35, I2 = 9%) compared with three non-Asian studies.

Conclusions

Our findings confirmed the significant relationship between VO and AL. Thus, VO could be considered a reliable risk factor of surgery for colon cancer.

Predictive value of the Naples prognostic score on postoperative outcomes in patients with rectal cancer

PURPOSE

The Naples prognostic score (NPS) is a prognostic index based on the nutritional and inflammatory status. However, its utility in predicting postoperative complications (POCs) has not been examined in rectal cancer (RC). We evaluated the predictive value of the preoperative NPS for POCs in RC.

METHODS

We retrospectively analyzed 235 patients who underwent surgery for RC. The NPS was calculated based on serum albumin, serum total cholesterol, the neutrophil-to-lymphocyte ratio (NLR) and the lymphocyte-to-monocyte ratio (LMR). Severe POCs were defined as Clavien-Dindo classification grade ≥ III. The optimal cut-off value of the NPS was determined by a receiver operator characteristic (ROC) curve analysis. The NPS, NLR, LMR, platelet-to-lymphocyte ratio (PLR), C-reactive protein (CRP)-to-albumin ratio (CAR), Glasgow prognostic score (GPS), Onodera prognostic nutritional index (PNI) and controlling nutritional status score (CONUT) were investigated as inflammation-based and/or nutritional markers. Predictors of severe POCs were analyzed by logistic regression modeling.

RESULTS

Severe POCs were observed in 64 patients (27.2%). Male sex, operation time (> 257 min), blood loss (≥ 30 mL), albumin (< 4.0 g/dL), CRP (≥ 1.0 mg/dL), total cholesterol (≤ 180 mg/dL), NPS (≥ 2), LMR (≥ 3.48), PLR (≥ 103.6), CAR (> 0.025), GPS (≥ 1), PNI (< 48.1) and CONUT (≥ 2) were significantly associated with severe POCs. The multivariate analysis revealed that male sex, operation time (> 257 min), and a high NPS (≥ 2) were independent predictors of severe POCs. The ROC curve analysis revealed that the NPS had the greatest predictive value among the inflammation-based and/or nutritional markers.

CONCLUSION

The NPS is a valuable predictor of severe POCs in RC.

The safety and prognosis of radical surgery in colorectal cancer patients over 80 years old

OBJECTIVE

The purpose of this study was to assess the safety and feasibility of radical surgery and to investigate prognostic factors influencing in colorectal cancer (CRC) patients over the age of 80.

METHODS

Between January 2010 and December 2020, 372 elderly CRC patients who underwent curative resection at the National Cancer Center were enrolled in the study. Preoperative clinical characteristics, perioperative outcomes, and postoperative pathological features were all collected.

RESULTS

A total of 372 elderly patients with colorectal cancer were included in the study, including 226 (60.8%) men and 146 (39.2%) women. A total of 219 (58.9%) patients had a BMI < 24 kg/m², and 153 (41.1%) patients had a BMI ≥ 24 kg/m². The mean operation time and intraoperative blood loss were 152.3 ± 58.1 min and 67.6 ± 35.4 ml, respectively. The incidence of overall postoperative complications was 28.2% (105/372), and the incidence of grade 3-4 complications was 14.7% (55/372). In the multivariable Cox regression analysis, BMI ≥ 24 kg/m² (HR, 2.30, 95% CI, 1.27-4.17; P = 0.006) and N1-N2 stage (HR: 2.97; 95% CI, 1.48-5.97; P = 0.002) correlated with worse CSS.

CONCLUSION

The findings of this study showed that radical resection for CRC is safe and feasible for patients over the age of 80. After radical resection, BMI and N stage were independent prognostic factors for elderly CRC patients.

Body mass index-based predictions and personalized clinical strategies for colorectal cancer in the context of PPPM

Currently colorectal cancer (CRC) is the third most prevalent cancer worldwide. Body mass index (BMI) is frequently used in CRC screening and risk assessment to quantitatively evaluate weight. However, the impact of BMI on clinical strategies for CRC has received little attention. Within the framework of the predictive, preventive, and personalized medicine (3PM/PPPM), we hypothesized that BMI stratification would affect the primary, secondary, and tertiary care options for CRC and we conducted a critical evidence-based review. BMI dynamically influences CRC outcomes, which helps avoiding adverse treatment effects. The outcome of surgical and radiation treatment is adversely affected by overweight (BMI ≥ 30) or underweight (BMI < 20). A number of interventions, such as enhanced recovery after surgery and robotic surgery, can be applied to CRC at all levels of BMI. BMI-controlling modalities such as exercise, diet control, nutritional therapy, and medications may be potentially beneficial for patients with CRC. Patients with overweight are advised to lose weight through diet, medication, and physical activity while patients suffering of underweight require more focus on nutrition. BMI assists patients with CRC in better managing their weight, which decreases the incidence of adverse prognostic events during treatment. BMI is accessible, noninvasive, and highly predictive of clinical outcomes in CRC. The cost-benefit of the PPPM paradigm in developing countries can be advanced, and the clinical benefit for patients can be improved with the promotion of BMI-based clinical strategy models for CRC.

Left colic artery diameter is an important factor affecting anastomotic blood supply in sigmoid colon cancer or rectal cancer surgery: a pilot study

BACKGROUND

Anastomotic blood supply is vital to anastomotic healing. The aim of this study was to demonstrate the effect of the left colic artery (LCA) on blood supply in the anastomotic area, explore the relationship between individual differences in the LCA and blood supply in the anastomotic area, and elucidate the relevant indications for LCA retention during radical resection for sigmoid or rectal cancer.

METHOD

Radical sigmoid or rectal cancer resection with LCA retention was performed in 40 patients with colorectal cancer who participated in this study. Systemic pressure, LCA diameter, and the distance from the root of the LCA to the root of the inferior mesenteric artery were measured and recorded. The marginal artery stump pressure in the anastomotic colon before and after the LCA clamping was measured, respectively.

RESULTS

There is a significant difference between the marginal artery stump pressure before LCA ligation and after ligation (53.1 ± 12.38 vs 42.76 ± 12.71, p < 0.001). The anastomotic blood supply positively and linearly correlated with body mass index and systemic pressure. Receiver-operating curve analysis revealed that LCA diameter (area under the curve 0.971, cutoff 1.95 mm) was an effective predictor of LCA improving anastomosis blood supply. No relationship was found between the LCA root location and anastomotic blood supply.

CONCLUSION

Preserving the LCA is effective in improving blood supply in the anastomotic area, and larger LCA diameters result in a better blood supply to the anastomotic area.

The obesity paradox in patients with colorectal cancer: a systematic review and meta-analysis

CONTEXT

Obesity is widely regarded as an established risk factor for colorectal cancer (CRC). However, recent studies have shown that lower mortality and better cancer-specific survival were observed in CRC patients with elevated body mass index (BMI), an example of the obesity paradox, which is the inverse correlation between obesity and mortality in some populations.

OBJECTIVE

The aim of this systematic review and meta-analysis was to investigate the association between BMI and CRC outcomes.

DATA SOURCES

PubMed, Web of Science, MEDLINE, the Cochrane Library, and Embase databases were searched for relevant articles published from inception to December 31, 2020.

STUDY SELECTION

Studies comparing the prognosis of CRC patients with obesity or overweight with that of normal-weight CRC patients were eligible.

DATA EXTRACTION

Data were extracted by 2 reviewers independently; differences were resolved by a third reviewer. BMI was classified according to WHO categories.

DATA ANALYSIS

To assess the prognostic effects of different BMI categories in CRC patients, hazard ratios and 95%CIs of overall survival, disease-free survival, and cancer-specific survival were extracted from included articles.

RESULTS

Sixteen studies (55 391 patients in total) were included. Higher BMI was significantly associated with more favorable CRC outcomes. Compared with normal-weight patients, underweight patients had worse overall survival (HR = 1.26; 95%CI, 1.15-1.37) and disease-free survival (HR = 1.19; 95%CI, 1.11-1.27, while patients with overweight had better overall survival (HR = 0.92; 95%CI, 0.86-0.99), disease-free survival (HR = 0.96; 95%CI, 0.93-1.00), and cancer-specific survival (HR = 0.86; 95%CI, 0.76-0.98). Patients with morbid obesity had worse overall survival (HR = 1.12; 95%CI, 1.02-1.22) and disease-free survival (HR = 1.15; 95%CI, 1.07-1.24) than normal-weight patients. There was no significant difference in cancer-specific survival between patients with obesity (HR = 0.94; 95%CI, 0.76-1.16) and patients with normal weight, nor between patients with underweight and patients with normal weight (HR = 1.14; 95%CI, 0.82-1.58).

CONCLUSIONS

CRC patients with a higher BMI appear to have reduced mortality compared with normal-weight CRC patients, even though higher BMI/obesity is an established determinant for the development of CRC.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020202320.

The impact of obesity on postoperative outcomes in colorectal cancer patients: a retrospective database study

PURPOSE

Obesity is an independent risk factor for worse outcomes in various surgical settings. Whether obesity is a prognostic factor for postoperative morbidity and mortality of colorectal cancer (CRC) is inconclusive. This study aimed to determine the impact of obesity on short-term postoperative outcomes in CRC patients undergoing laparoscopic surgery.

METHODS

Data of a total of 23,898 CRC patients aged ≥ 20 years and undergoing laparoscopic resection were extracted from the US National Inpatient Sample (NIS) database and analyzed. The study endpoints were in-hospital mortality, any postoperative complications, infection/sepsis, acute kidney injury (AKI), deep vein thrombosis (DVT)/pulmonary embolisms (PE), and extended hospital stay. Univariate and multivariate logistic regression analyses were performed to examine the associations between patients' obesity status (morbid obese: BMI >  = 40 kg/m²; obese: BMI 30-39.9 kg/m²) and the study outcomes.

RESULTS

In 23,898 CRC patients undergoing laparoscopic resection, the prevalence of obesity prevalence was 11.8%. After adjustment, the results revealed that morbid obesity was significantly associated with increased risk for in-hospital mortality (aOR = 2.06, 95%CI: 1.11-3.83), AKI (aOR = 1.78, 95%CI = 1.34-2.36), DVT/PE (aOR = 2.88, 95%CI = 1.70-4.88), and extended LOS (aOR = 1.21, 95%CI = 1.02-1.43), while non-morbid obesity was significantly associated with more DVT/PE (aOR = 2.12, 95%CI = 1.32-3.41) as compared with non-obesity.

CONCLUSION

In patients with CRC undergoing laparoscopic surgery, morbid obesity is strongly associated with worse postoperative outcomes, including increased in-hospital mortality, postoperative AKI and DVT/PE, and extended LOS. The findings of the present study highlight the importance of obesity status in risk stratification for laparoscopic CRC surgery.

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.

Obesity and anastomotic leak rates in colorectal cancer: a meta-analysis

PURPOSE

Anastomotic leak (AL) following colorectal cancer resection is associated with considerable morbidity and mortality with an impact on recurrence rates and survival. The impact of obesity on AL rates is debated. This meta-analysis aims to investigate the relationship between obesity and AL.

METHODS

A search was conducted of the PubMed/MEDLINE, and Web of Science databases and included studies were split into Western and Asian groups based on population-specific body mass index (BMI) ranges for obesity. A meta-analysis was performed to assess the impact of obesity on AL rate following colorectal cancer resection.

RESULTS

Two thousand three hundred and four articles were initially screened. Thirty-one studies totaling 32,953 patients were included. Patients with obesity had a statistically significant increase in AL rate in all Western and Asian study groups. However, this increase was only clinically significant in the rectal anastomotic subgroups-Western: 10.8% vs 8.4%, OR 1.57 (1.01-2.44) and Asian: 9.4% vs 7.4%, OR 1.58 (1.07-2.32).

CONCLUSIONS

The findings of this analysis confirm that obesity is a significant risk factor for anastomotic leak, particularly in rectal anastomoses. This effect is thought to be primarily mediated via technical difficulties of surgery although metabolic and immunological factors may also play a role. Obesity in patients undergoing restorative CRC resection should be discussed and considered as part of the pre-operative counselling.

The impact of anthropometric parameters on colorectal cancer prognosis: A systematic review and meta-analysis

BACKGROUND & AIMS

Our study aims to clarify the relationship between weight parameters and colorectal cancer outcomes.

METHODS

NCBI, Embase, Cochrane, and Web of Science were searched from inception to December 2019. Studies reporting colorectal cancer (CRC) mortality, recurrence, disease-free survival, overall survival, overall mortality stratified by pre-diagnosis BMI or post-diagnosis weight change, were included in the analysis. Random effects analysis was performed for all outcomes, with heterogeneity assessed by the I² statistic.

RESULTS

Our meta-analysis included 45 studies encompassing 607,266 patients. Obesity was associated with increased odds of overall mortality and CRC-specific mortality compared to normal weight (p < 0.001). Patients with underweight BMI had increased odds of CRC-specific mortality compared to normal BMI but were not significantly different from obese BMI.

CONCLUSIONS

Obese and underweight BMI are associated with increased CRC-specific and overall mortality compared to normal BMI. Long term prognosis was similar for patients with obese and underweight BMI.

BMI May Be a Prognostic Factor for Local Advanced Rectal Cancer Patients Treated with Long-Term Neoadjuvant Chemoradiotherapy

OBJECTIVE

This study aims to develop feasible nomograms to predict the overall survival (OS) and cancer-specific survival (CSS) of the local advanced rectal cancer (LARC) patients who were treated with neoadjuvant chemoradiotherapy (nCRT) and operation.

METHODS

A total of 243 LARC patients undergoing nCRT followed by total mesorectal excision (TME) were enrolled. Preoperative clinical features and postoperative pathological characteristics were collected. A Cox regression analysis was performed, and Cox-based nomograms were developed to predict the OS and CSS. We assessed the predictive performance of the nomogram with concordance index and calibration plots.

RESULTS

A total of 243 patients were included with a median follow-up period of 46 months (range from 9 to 86 months). Cox regression analysis showed that low BMI (BMI < 18.5, HR= 21.739, P < 0.05), high level of preoperative CA19-9 (HR = 3.369, P = 0.036), high ypStage (HR = 19.768, P < 0.001), positive neural invasion (HR = 4.218, P = 0.026) and no adjuvant chemotherapy (HR = 5.495, P < 0.001) were independent predictors of poor OS. Age ≥70 (HR = 2.284, P <0.001), low BMI (BMI < 18.5, HR = 3.906, P < 0.05), positive preoperative CA19-9 (HR = 1.920, P = 0.012), high ypStage (HR = 5.147, P <0.001) and positive neural invasion (HR = 2.873, P = 0.022) were independent predictors of poor CSS. The predictive nomograms were developed to predict the OS and CSS with a C-index of 0.837 and 0.760. Good statistical performance on internal validation was shown by calibration plots.

CONCLUSION

In conclusion, this study demonstrated that BMI was an independent prognostic factor for OS and CSS in LARC patients treated with nCRT followed TME. A nomogram incorporating BMI, neural invasion, pre-CA19-9, ypStage, age, and adjuvant chemotherapy could be helpful to predict the OS and CSS.

Which obesity-associated parameters can better reflect the risk of the occurrence of the anastomotic leakage?

Purpose: We investigated which obesity-associated parameters can better predict the risk of anastomotic leakage (AL) in rectal cancer patients that underwent anterior resection of the rectum.Method: Patients (n = 589) who underwent anterior resection of the rectum with a primary anastomosis were included in this study, including 44 patients with AL and 545 without AL. Univariate analysis was used to compare demographic characteristics and to select risk factors that were used in one-to-one propensity score matching (PSM). Obesity-associated parameters, including preoperative body mass index (BMI), visceral fat area (VFA), subcutaneous fat area (SFA), total fat area (TFA), VFA/TFA ratio, serum cholesterol, and triglycerides, were compared between the two groups after PSM.Results: Sex, neoadjuvant chemotherapy, operation time, and anastomosis level from the anal verge were risk factors for AL (p < .05). After the PSM, BMI, VFA, SFA, TFA, VFA/TFA, and serum cholesterol showed no significant difference between the two group (p > .05). However, the level of serum triglycerides was an independent risk factor for AL (p = .024, odds ratio = 2.95).Conclusions: Serum triglycerides have potential as a predictive indicator for AL, which may improve the treatment and outcomes of patients with AL.

Visceral obesity is a preoperative risk factor for postoperative ileus after surgery for colorectal cancer: Single-institution retrospective analysis

AIM

Visceral obesity (VO) reportedly has a stronger association with complications after colorectal surgery than does body mass index. Here, we retrospectively assessed VO as a risk factor for postoperative ileus (POI) after colorectal resection in patients with colorectal cancer.

METHODS

This study included 417 consecutive patients with colorectal cancer who underwent elective surgery at our institute from January 2010 to December 2012. Visceral fat area (VFA) was calculated by image analysis software. VO was defined as VFA ≥100 cm2. We assessed 49 factors, including VO, comorbidities, surgical procedure, and postoperative complications. Data were analyzed using a propensity score-matching strategy.

RESULTS

Postoperative ileus occurred in 18 patients (4.3%) from the entire cohort, and in 14 (5.5%) of the 256 matched patients. Multivariate analysis (n = 417 patients) showed that significant risk factors for POI included VO (OR 7.9, 95% confidence interval [CI] 1.9-32.1, P = .004), open surgery (OR 6.4, 95% CI 1.6-26.7, P = .010), and pelvic/intra-abdominal abscess (OR 11.0, 95% CI 1.1-110.2, P = .041). Propensity score matching showed two independent risk factors in the multivariate analysis: VO (OR 6.2, 95% CI 1.3-30.4, P = .025) and open surgery (OR 9.1, 95% CI 2.0-40.5, P = .004).

CONCLUSION

Visceral obesity may be an independent risk factor for POI in patients with colorectal cancer.