Outcome of rectal cancer surgery in obese and nonobese patients: a meta-analysis

Nutrition-related predictors of complications and length of hospital stay following total pelvic exenteration surgery

BACKGROUND & AIMS

Pelvic exenteration (PE) surgery is now a widely accepted procedure that is increasingly being performed worldwide but has significant morbidity. Although nutrition status, body mass index (BMI) and postoperative nutrition support practices are modifiable risk factors, few studies have examined the relationship of these with clinical outcomes following PE. The aim of this study was therefore to investigate the impact of these factors on postoperative complications and length of hospital stay (LOHS) following PE.

METHODS

This was a retrospective cohort study of all patients having total PE surgery at a tertiary teaching hospital from 2012 to 2021 (n = 69). Multivariable analyses were undertaken to confirm univariate associations and adjust for confounding variables. Binary logistic regression was undertaken to explore predictors of infectious and Grade III or above Clavien-Dindo complications, and negative binomial regression to identify predictors of LOHS.

RESULTS

Patients who were malnourished according to the Subjective Global Assessment were 5.66 (OR 5.66, 95% CI 1.07-29.74, p = 0.041) times more likely to develop an infectious complication. Increasing BMI was independently associated with development of Grade III or above Clavien-Dindo complications (p = 0.040). For each additional day until full diet commencement, there was a 19% (OR: 1.19, 95% CI 1.05-1.34, p = 0.005) increased incidence of significant complications and a 5.6% (IRR: 1.056, 95% CI: 1.02-1.09, p = 0.002) longer LOHS on multivariable analysis. There was a high rate of prolonged postoperative ileus (78%). The implementation of a nutrition support pathway with routine postoperative parenteral nutrition (PN) resulted in patients achieving adequate nutrition 7 days faster (p < 0.001) with minimal line-related complications (1.4% line-related thrombus). Routine PN did not impact ileus rates (p = 0.33) or time to diet commencement (p = 0.6).

CONCLUSIONS

Preoperative malnutrition and higher BMI were associated with complications following PE. Delay to full diet commencement was associated with increased complications and longer LOHS. Routine postoperative PN appears safe and resulted in patients achieving adequate nutrition faster.

Association between body mass index and short-term outcomes of laparoscopic right hemicolectomy for colon cancer

BACKGROUND

Laparoscopic right hemicolectomy can be technically challenging in patients with increased body mass index, reportedly associated with higher surgical site infection (SSI) and incisional hernia rates. We aimed to assess the association between increased body mass index and short-term outcomes of laparoscopic right hemicolectomy.

METHODS

This retrospective cohort study included patients with colon cancer who underwent laparoscopic right hemicolectomy between 2011 and 2021. Patients were managed with a standardized care protocol that comprised preoperative, intraoperative, and postoperative measures and were divided according to body mass index-normal body mass index (18-24.9 kg/m2), overweight (25-29.9 kg/m2), and obesity (≥30 kg/m2). Body mass index groups were compared for baseline characteristics and outcomes. The main outcome measures were operative time, hospital stay, 30-day complications, reoperation, number of harvested lymph nodes, and resection status.

RESULTS

A total of 270 patients (50% male sex; mean age: 68.7 ± 13.5 years) were included-28.5% had normal body mass index, 47% were overweight, and 24.5% had obesity. Mean operative times in obese and overweight patients were significantly longer than patients with normal body mass index (172.1 and 168.8 versus 143.3 minutes, P = .01). Compared to normal body mass index, obesity was associated with significantly higher odds of incisional SSI (odds ratio: 9.29, P = .039). Body mass index had a significant positive correlation with operation time (r = 0.205, P = .004) and incisional SSI (r = 0.126, P = .04). Body mass index groups had similar hospital stays, 30-day complications and mortality, anastomotic leak, ileus, and reoperation.

CONCLUSION

Patients with increased body mass index had longer operative times and higher SSI rates, yet similar hospital stays and comparable 30-day complication rates, mortality, and reoperation to patients with normal body mass index.

Comparing short-term outcomes of robot-assisted and conventional laparoscopic total mesorectal excision surgery for rectal cancer in elderly patients

BACKGROUND

Da Vinci Robotics-assisted total mesorectal excision (TME) surgery for rectal cancer is becoming more widely used. There is no strong evidence that robotic-assisted surgery and laparoscopic surgery have similar outcomes in elderly patients with TME for rectal cancer.

AIM

To determine the improved oncological outcomes and short-term efficacy of robot-assisted surgery in elderly patients undergoing TME surgery.

METHODS

A retrospective study of the clinical pathology and follow-up of elderly patients who underwent TME surgery at the Department of Gastrointestinal Oncology at the Affiliated Hospital of Nanjing University of Chinese Medicine was conducted from March 2020 through September 2023. The patients were divided into a robot-assisted group (the R-TME group) and a laparoscopic group (the L-TME group), and the short-term efficacy of the two groups was compared.

RESULTS

There were 45 elderly patients (≥ 60 years) in the R-TME group and 50 elderly patients (≥ 60 years) in the L-TME group. There were no differences in demographics, conversion rates, or postoperative complication rates. The L-TME group had a longer surgical time than the R-TME group [145 (125, 187.5) vs 180 (148.75, 206.25) min, P = 0.005), and the first postoperative meal time in the L-TME group was longer than that in the R-TME (4 vs 3 d, P = 0.048). Among the sex and body mass index (BMI) subgroups, the R-TME group had better outcomes than did the L-TME group in terms of operation time (P = 0.042) and intraoperative assessment of bleeding (P = 0.042). In the high BMI group, catheter removal occurred earlier in the R-TME group than in the L-TME group (3 vs 4 d, P = 0.001), and autonomous voiding function was restored.

CONCLUSION

The curative effect and short-term efficacy of robot-assisted TME surgery for elderly patients with rectal cancer are similar to those of laparoscopic TME surgery; however, robotic-assisted surgery has better short-term outcomes for individuals with risk factors such as obesity and pelvic stenosis. Optimizing the learning curve can shorten the operation time, reduce the recovery time of gastrointestinal function, and improve the prognosis.

Interpretable machine learning model to predict surgical difficulty in laparoscopic resection for rectal cancer

Background

Laparoscopic total mesorectal excision (LaTME) is standard surgical methods for rectal cancer, and LaTME operation is a challenging procedure. This study is intended to use machine learning to develop and validate prediction models for surgical difficulty of LaTME in patients with rectal cancer and compare these models' performance.

Methods

We retrospectively collected the preoperative clinical and MRI pelvimetry parameter of rectal cancer patients who underwent laparoscopic total mesorectal resection from 2017 to 2022. The difficulty of LaTME was defined according to the scoring criteria reported by Escal. Patients were randomly divided into training group (80%) and test group (20%). We selected independent influencing features using the least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression method. Adopt synthetic minority oversampling technique (SMOTE) to alleviate the class imbalance problem. Six machine learning model were developed: light gradient boosting machine (LGBM); categorical boosting (CatBoost); extreme gradient boost (XGBoost), logistic regression (LR); random forests (RF); multilayer perceptron (MLP). The area under receiver operating characteristic curve (AUROC), accuracy, sensitivity, specificity and F1 score were used to evaluate the performance of the model. The Shapley Additive Explanations (SHAP) analysis provided interpretation for the best machine learning model. Further decision curve analysis (DCA) was used to evaluate the clinical manifestations of the model.

Results

A total of 626 patients were included. LASSO regression analysis shows that tumor height, prognostic nutrition index (PNI), pelvic inlet, pelvic outlet, sacrococcygeal distance, mesorectal fat area and angle 5 (the angle between the apex of the sacral angle and the lower edge of the pubic bone) are the predictor variables of the machine learning model. In addition, the correlation heatmap shows that there is no significant correlation between these seven variables. When predicting the difficulty of LaTME surgery, the XGBoost model performed best among the six machine learning models (AUROC=0.855). Based on the decision curve analysis (DCA) results, the XGBoost model is also superior, and feature importance analysis shows that tumor height is the most important variable among the seven factors.

Conclusions

This study developed an XGBoost model to predict the difficulty of LaTME surgery. This model can help clinicians quickly and accurately predict the difficulty of surgery and adopt individualized surgical methods.

Outcomes of transanal total mesorectal excision compared to laparoscopic total mesorectal excision: A meta-analysis of randomized controlled trials

BACKGROUND

Transanal dissection is increasingly used in laparoscopic surgery for total mesorectal excision of lower rectal cancers. Several studies compared outcomes of laparoscopic total mesorectal excision with and without transanal dissection, yet there is a paucity of high-quality evidence. This meta-analysis aimed to provide a pooled comparative analysis of outcomes of laparoscopic total mesorectal excision with and without transanal dissection based on evidence from randomized controlled trials.

METHODS

This Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2022-compliant systematic review of randomized controlled trials compared laparoscopic total mesorectal excision with and without transanal dissection. PubMed, Scopus, and Web of Science were searched through March 2023. The Medical Subject Headings terms used in the search were Rectal neoplasms, Proctectomy, Laparoscopy, and Transanal. The main outcomes included operative and pathologic outcomes. The risk of bias was assessed using the Risk of Bias version 2 tool, and certainty of the evidence was graded using the Grading of Recommendations Assessment, Development, and Evaluation approach. The primary study outcome was conversion to open surgery.

RESULTS

Four randomized controlled trials (1,339 patients; median age 61.2 years) were included; 671 patients underwent laparoscopic total mesorectal excision with transanal dissection, and 668 underwent laparoscopic total mesorectal excision without transanal dissection. Both groups were similar in age, body mass index, and disease stage, but the laparoscopic total mesorectal excision with transanal dissection group had a higher male-to-female ratio, received neoadjuvant therapy and had a hand-sewn anastomosis more often. Patients who underwent laparoscopic total mesorectal excision with transanal dissection had lower conversion rates (odds ratio = 0.179; P = .001), a higher likelihood of achieving complete total mesorectal excision (odds ratio = 1.435; P = .025), and fewer harvested lymph nodes (weighted mean difference = -1.926; P = .035). The groups had similar operative times (weighted mean difference = -3.476; P = .398), total complications (odds ratio = 0.94; P = .665), major complications (odds ratio = 1.112; P = .66), anastomotic leak (odds ratio = 0.67; P = .432), positive circumferential resection margin (odds ratio = 0.549; P = .155), and positive distal margins (odds ratio = 0.559; P = .171).

CONCLUSION

Laparoscopic total mesorectal excision with transanal dissection was associated with lower odds of conversion to open surgery, greater likelihood of achieving complete total mesorectal excision, and fewer harvested lymph nodes than laparoscopic total mesorectal excision without transanal dissection.

The impact of obesity on thyroidectomy outcomes: a case-matched study

Obesity is a well-known public health concern in Western World. Accordingly, an elevated number of obese patients undergo thyroidectomy every year. We aim to assess the impact of obesity on intraoperative and postoperative outcomes of patients who undergo thyroidectomy. 1228 patients underwent thyroidectomy at our department between January 2021 and September 2021. We divided patients into two groups according to body mass index (BMI): non-obese (BMI < 30 kg/m2) and obese (BMI ≥ 30 kg/m2). A propensity score approach was performed to create 1:1 matched pairs (matching according to age, gender, diagnosis, nodule size and type of operation). After matching, the final population included 522 patients, equally divided between each group: non-obese group (Group A; n = 261) and obese group (Group B; n = 261). The primary endpoint of the study was the overall rate of postoperative complications; secondary endpoints of the study were operative time, use of energy device and length of hospital stay. The duration of hospital stay resulted longer in Group B (p = 0.002). No statistically significant differences were documented in terms of operative time (p = 0.206), use of energy devices (p = 0.855) and surgical complications (p = 0.429). Moreover, no statistically significant differences were documented considering each specific complication: transient and permanent hypocalcemia (p = 0.336; p = 0.813, respectively), transient and permanent recurrent laryngeal nerve palsy (p = 0.483; p = 0.523, respectively), hematoma (p = 0.779), bleeding (p = 0.178), wound infection (p = 0.313) and cheloid formation (p = 0.412). Thyroidectomy can safely be performed in obese patients. Outcomes resulted comparable; nonetheless, obesity correlates to longer hospital stay.

Endoscopic management of anastomotic leakage after colorectal cancer surgery in a Moroccan center: A case series and literature review

Endoscopic management has become an alternate treatment to a revision surgery for colorectal fistulas. Eight patients who were treated by endoscopy for postoperative anastomotic leakage to colorectal cancer were included. A univariate analysis was carried out to determine the predictive factors of success. All our patients were treated using metallic clips. The primary efficiency of this technique was 50%. In a univariate analysis, the size of the fistula and its distance from the anal margin had an influence on the efficiency of the endoscopic treatment, which was not the case for either the surgical technique or the use of neoadjuvant radiotherapy. This endoscopic treatment is effective and represents a more secure alternative than revision surgery. In our study, the use of metallic clips showed a 50% success rate, going up to 100% for the group of patients with a fistula ostium of a size ⩽1 cm, proving the necessity of using this technique.

A history of bariatric surgery before surgery for colorectal cancer may improve short-term postoperative outcomes: Analysis of the national inpatient sample 2015-2019

BACKGROUND

Bariatric surgery is the most effective and sustainable form of weight loss. Bariatric surgery before elective operations for colorectal pathology may improve postoperative outcomes. To compare patients with and without prior bariatric surgery undergoing surgery for colorectal cancer in terms of postoperative morbidity and health care use.

METHODS

Adult patients undergoing resection for colorectal cancer from 2015 to 2019 were identified from the National Inpatient Sample. Patients were stratified according to their history of bariatric surgery. Propensity score matching with 4:1 nearest-neighbor matching was performed according to demographic, operative, and hospital characteristics. The primary outcome was postoperative morbidity. Secondary outcomes included system-specific postoperative complications, postoperative mortality, postoperative length of stay, total admission health care cost, and post-discharge disposition. McNemar's test and Wilcoxon matched-pairs signed-rank test were performed.

RESULTS

After propensity score matching, 1,197 patients without prior bariatric surgery and 376 patients with prior bariatric surgery were included. Patients with prior bariatric surgery had an absolute reduction of 6.5% in overall in-hospital postoperative morbidity (19.1% vs 25.6%, P < .0001), a $5,256 decrease in hospitalization cost ($70,344 vs $75,600, P = .034), and were more likely to be discharged home after their index operation (72.9% vs 63.9%, P < .0001).

CONCLUSION

Bariatric surgery before surgery for colorectal cancer may be associated with decreased postoperative morbidity and health care use. Bariatric surgery and other forms of rapid and effective weight loss, such as very low-energy diets, should be evaluated further for the optimization of obese patients before nonbariatric abdominal surgery.

[Obesity and Colorectal Cancer]

The prevalence of obesity has increased significantly worldwide, and this trend is likely to continue in the coming years. There is substantial evidence that obesity plays a crucial role in the development of colorectal cancer. Epidemiological data have consistently demonstrated a correlation between obesity and colorectal cancer. Insulin resistance, hyperinsulinemia, chronic inflammation, altered levels of growth factors, adipocytokines, and various hormones are plausible biological mechanisms. In addition, obesity has been shown to have an impact on recurrence, treatment success, and overall survival. There are some reports, although the evidence is not conclusive, that weight loss and lifestyle changes such as dietary modification and physical activity can reduce the risk of colorectal cancer. The understanding that obesity is a potentially modifiable risk factor that can affect the incidence and prognosis of colorectal cancer is crucial knowledge that can have an impact on the prevention and treatment of the condition.

Effect of obesity on perioperative outcomes following gastrointestinal surgery: meta-analysis

BACKGROUND

Obesity can pose perioperative challenges related to obesity-associated co-morbidities and technical factors. However, the true impact of obesity on postoperative outcomes is not well established and reports are conflicting. The aim was to perform a systematic review and meta-analysis to explore the effect of obesity on perioperative outcomes for general surgery procedures in distinct obesity subtypes.

METHODS

A systematic review was performed for studies reporting postoperative outcomes in relation to BMI in upper gastrointestinal, hepatobiliary and colorectal based on an electronic search using the Cochrane Library, Science Direct, PubMed and Embase up to January 2022. The primary outcome was the incidence of 30-day postoperative mortality among patients with obesity undergoing general surgical procedures in comparison to patients with normal range BMI.

RESULTS

Sixty-two studies, including 1 886 326 patients, were eligible for inclusion. Overall, patients with obesity (including class I/II/II) had lower 30-day mortality rates in comparison to patients with a normal BMI (odds ratio (OR) 0.75, 95 per cent c.i. 0.66 to 0.86, P < 0.0001, I2 = 71 per cent); this was also observed specifically in emergency general surgery (OR 0.83, 95 per cent c.i. 0.79 to 0.87, P < 0.0000001, I2 = 7 per cent). Compared with normal BMI, obesity was positively associated with an increased risk of 30-day postoperative morbidity (OR 1.11, 95 per cent c.i. 1.04 to 1.19, P = 0.002, I2 = 85 per cent). However, there was no significant difference in postoperative morbidity rates between the cohorts of patients with a normal BMI and class I/II obesity (OR 0.98, 95 per cent c.i. 0.92 to 1.04, P = 0.542, I2 = 92 per cent). Overall, the cohort with obesity had a higher rate of postoperative wound infections compared with the non-obese group (OR 1.40, 95 per cent c.i. 1.24 to 1.59, P < 0.0001, I2 = 82 per cent).

CONCLUSION

These data suggest a possible 'obesity paradox' and challenge the assumption that patients with obesity have higher postoperative mortality compared with patients with normal range BMI. Increased BMI alone is not associated with increased perioperative mortality in general surgery, highlighting the importance of more accurate body composition assessment, such as computed tomography anthropometrics, to support perioperative risk stratification and decision-making.

REGISTRATION NUMBER

CRD42022337442 (PROSPERO https://www.crd.york.ac.uk/prospero/).

[Obesity from the Perspective of Surgical Oncology]

Up to 40% of all adults worldwide are overweight or obese. Besides the established obesity-related comorbidities, such as type 2 diabetes mellitus, hypertension or NAFLD (non-alcoholic fatty liver disease), the focus of interest is shifting towards the influence of increased body weight as a risk factor for the development of malignant diseases. For more than 20 different types of malignancies, interactions between increased body weight and cancer risk have been established. Pathophysiological influences of obesity on carcinogenesis are diverse, including factors such as chronic inflammation, hyperinsulinaemia and insulin resistance, various changes in growth factor and changes in sex hormones. In cohorts of visceral oncology patients, malignancies such as colorectal carcinomas, hepatocellular carcinomas, adenocarcinomas of the pancreas, oesophageal and gastric carcinomas are also linked to an increased disease risk with increasing body weight. Since obesity must be considered a preventable or at least treatable cause of cancer, this review examines the influence of obesity in the field of visceral oncology, examining the effects of obesity on tumour prevalence, prevention and diagnostic testing, as well as its influence on treatment and prognosis. Furthermore, this review explores the current evidence on the influence of bariatric surgery on the prevalence of these obesity associated tumours. For example, in the case of colorectal carcinomas, the evidence base following bariatric surgery is mixed, painting an inhomogeneous picture. On the other hand, significantly lower prevalence of pancreatic adenocarcinoma and hepatocellular carcinomas is to be noted. The latter effect can be explained by the decrease in non-alcoholic fatty liver disease (NAFLD) associated with weight loss. Despite the justified concern that bariatric procedures (especially gastric sleeve resection) lead to increased prevalence of malignancies of the oesophageal junction, the currently available epidemiological data does not seem to identify a relevant increase in the incidence of these malignancies.

Impact of obesity on morbidity and oncologic outcomes after total mesorectal excision for mid and low rectal cancer

BACKGROUND

A recent meta-analysis showed that obesity increased the conversion rate and postoperative morbidity of rectal cancer surgery, but did not influence pathological results. However, this meta-analysis included patients with cancer of the upper rectum and had many biases. The aim of the present retrospective study was to investigate the impact of obesity, defined as a body mass index (BMI) ≥ 30 kg/m², on postoperative morbidity and short- and long-term oncologic outcomes of total mesorectal excision for mid and low rectal cancer in consecutive patients.

METHODS

This study included all eligible patients who were operated on for mid and lower rectal cancer between 1999 and 2018 in our hospital. We compared 90-day postoperative morbidity and mortality, and short- and long-term oncologic outcomes between obese and non-obese patients.

RESULTS

Three hundred and ninety patients [280 males, mean age 65.7 ± 11.3 years, 59 obese individuals (15.1%)] were included. There was no difference in the 90-day mortality rate between obese and non-obese groups (p = 0.068). There was a difference in the overall 90-day morbidity rate between the obese and non-obese groups that disappeared after propensity score matching of the patients. There was no difference in short-term oncological parameters, with a median follow-up of 43 (20-84) months, and there were no significant differences in disease-free and overall survival between obese and non-obese patients (p = 0.42 and p = 0.11, respectively).

CONCLUSIONS

Obesity does not affect the 90-day morbidity rate, or short- and long-term oncologic results in patients operated on for mid and lower rectal cancer.

Impact of preoperative body mass index and weight loss on morbidity and mortality following colorectal cancer-a retrospective cohort study

PURPOSE

Body weight and preoperative weight loss (WL) are controversially discussed as risk factors for postoperative morbidity and mortality in colorectal cancer surgery. The objective of this study is to determine whether body mass index (BMI) or WL is associated with a higher postoperative complication rate.

METHODS

In this retrospective cohort study, data analysis of 1241 consecutive patients undergoing colorectal cancer surgery in an 11-year period was performed. The main outcome measures were wound infections (WI), anastomotic leakages (AL), and in-house mortality.

RESULTS

A total of 697 (56%) patients with colon and 544 (44%) with rectum carcinoma underwent surgery. The rate of WI for each location increased with rising BMI. The threshold value was 28.8 kg/m2. Obese patients developed significantly more WI than normal-weight patients did following rectal resection (18.0% vs. 8.2%, p = 0.018). Patients with preoperative WL developed significantly more AL following colon resections than did patients without preoperative WL (6.2% vs. 2.5%, p = 0.046). In-house mortality was significantly higher in obese patients following colon resections than in overweight patients (4.3% vs. 0.4%, p = 0.012). Regression analysis with reference to postoperative in-house mortality revealed neither increased BMI nor WL as an independent risk factor.

CONCLUSIONS

Increased preoperative BMI is associated with a higher WI rate. AL rate after colon resection was significantly higher in patients showing preoperative WL. Preoperative BMI and WL are therefore risk factors for postoperative morbidity in this study. Nevertheless, this has to be further clarified by means of prospective studies. Trial registration DRKS00025359, 21.05.2021, retrospectively registered.

Review article: obesity and colorectal cancer

BACKGROUND

Obesity is a growing global public health problem. More than half the European and North American population is overweight or obese. Colon and rectum cancers are still the second leading cause of cancer death worldwide, and epidemiological data support an association between obesity and colorectal cancers (CRCs).

AIM

To review the literature on CRC epidemiology in obese subjects, assessing the effects of obesity, including childhood or maternal obesity, on CRC, diagnosis, management, and prognosis, and discussing targeted prophylactic measures.

METHOD

We searched PubMed for obesity/overweight/metabolic syndrome and CRC. Other key words included 'staging', 'screening', 'treatment', 'weight loss', 'bariatric surgery' and 'chemotherapy'.

RESULTS

In Europe, about 11% of CRCs are attributed to overweight and obesity. Epidemiological data suggest that obesity is associated with a 30%-70% increased risk of colon cancer in men, the association being less consistent in women. Visceral fat or abdominal obesity seems to be of greater concern than subcutaneous fat obesity, and any 1 kg/m² increase in body mass index confers more risk (hazard ratio 1.03). Obesity might increase the likelihood of recurrence or mortality of the primary cancer and may affect initial management, including accurate staging. The risk maybe confounded by different factors, including lower adherence to organised CRC screening programmes. It is unclear whether bariatric surgery helps reduce rectal cancer risk.

CONCLUSIONS

Despite a growing body of evidence linking obesity to CRC, many questions remain unanswered, including whether we should screen patients with obesity earlier or propose prophylactic bariatric surgery for certain patients with obesity.

Laparoscopic versus open resection for stage II/III rectal cancer in obese patients: A multicenter propensity score-based analysis of short- and long-term outcomes

Aim

Whether a laparoscopic procedure can contribute to the improvement of clinical outcomes in obese patients with stage II/III rectal cancer compared to an open procedure remains unclear.

Objective

This study evaluated the technical and oncological safety of laparoscopic surgery versus open surgery in obese patients (body mass index [BMI] ≥25 kg/m²) with rectal cancer.

Patients and Methods

Data were collected from patients with pathological stage II/III rectal cancer and analyzed. Operations were performed via laparoscopic or open surgery from 2009 to 2013. A comparative analysis was performed after applying propensity score matching to the two cohorts (laparoscopic group and open group). The primary endpoint was 3-y relapse-free survival (RFS).

Results

Overall, 524 eligible cases were collected from 51 institutions. Equal numbers of propensity score-matched patients were included in the laparoscopic (n = 193) group and open (n = 193) group. Although the rate of D3 lymph node dissection did not differ between the laparoscopic group (87.0%) and the open group (88.6%), the median number of harvested lymph nodes was significantly lower in the laparoscopic group versus open group (17.5 vs 21, P = 0.0047). The median postoperative hospital stay was also significantly shorter in the laparoscopic group (14 d) vs the open group (17 d) (P = 0.0014). Three-y RFS was not significantly different between the two groups (hazard ratio 1.2454, 95% confidence interval 0.9201-1.6884, P = 0.4689).

Conclusion

The short- and long-term results of this large cohort study (UMIN ID: UMIN000033529) indicated that laparoscopic surgery in obese rectal cancer patients has advantageous short-term outcomes and no disadvantageous long-term outcomes.

Effect of body mass index on surgical site wound infection, mortality, and postoperative hospital stay in subjects undergoing possibly curative surgery for colorectal cancer: A meta-analysis

We performed a meta-analysis to evaluate the effect of body mass index on surgical site wound infection, mortality, and postoperative hospital stay in subjects undergoing possibly curative surgery for colorectal cancer. A systematic literature search up to March 2022 was performed and 2247 subjects with possibly curative surgery for colorectal cancer at the baseline of the studies; 2889 of them were obese, and 9358 were non-obese. Odds ratio (OR) and mean difference (MD) with 95% confidence intervals (CIs) were calculated to assess the effect of body mass index on surgical site wound infection, mortality, and postoperative hospital stay in subjects undergoing possibly curative surgery for colorectal cancer using the dichotomous or contentious methods with a random or fixed-effect model. The obese subjects had a significantly higher surgical site wound infection after colorectal surgery (OR, 1.87; 95% CI, 1.62-2.15, P < .001), and higher mortality (OR, 1.58; 95% CI, 1.07-2.32, P = .02) in subjects with possibly curative surgery for colorectal cancer compared with non-obese. However, obese did not show any significant difference in postoperative hospital stay (MD, 0.81; 95% CI, -0.030 to 1.92, P = .15) compared with non-obese in subjects with possibly curative surgery for colorectal cancer. The obese subjects had a significantly higher surgical site wound infection after colorectal surgery, higher mortality, and no significant difference in postoperative hospital stay compared with non-obese in subjects with possibly curative surgery for colorectal cancer. The analysis of outcomes should be with caution because of the low number of studies in certain comparisons.

Posterior mesorectal thickness as a predictor of increased operative time in rectal cancer surgery: a retrospective cohort study

BACKGROUND

In rectal cancer surgery, larger mesorectal fat area has been shown to correlate with increased intraoperative difficulty. Prior studies were mostly in Asian populations with average body mass indices (BMIs) less than 25 kg/m². This study aimed to define the relationship between radiological variables on pelvic magnetic resonance imaging (MRI) and intraoperative difficulty in a North American population.

METHODS

This is a single-center retrospective cohort study analyzing all patients who underwent low anterior resection (LAR) or transanal total mesorectal excision (TaTME) for stage I-III rectal adenocarcinoma from January 2015 until December 2019. Eleven pelvic magnetic resonance imaging measures were defined a priori according to previous literature and measured in each of the included patients. Operative time in minutes and intraoperative blood loss in milliliters were utilized as the primary indicators of intraoperative difficulty.

RESULTS

Eighty-three patients (39.8% female, mean age: 62.4 ± 11.6 years) met inclusion criteria. The mean BMI of included patients was 29.4 ± 6.2 kg/m². Mean operative times were 227.2 ± 65.1 min and 340.6 ± 78.7 min for LARs and TaTMEs, respectively. On multivariable analysis including patient, tumor, and MRI factors, increasing posterior mesorectal thickness was significantly associated with increased operative time (p = 0.04). Every 1 cm increase in posterior mesorectal thickness correlated with a 26 min and 6 s increase in operative time. None of the MRI measurements correlated strongly with BMI.

CONCLUSION

As the number of obese rectal cancer patients continues to expand, strategies aimed at optimizing their surgical management are paramount. While increasing BMI is an important preoperative risk factor, the present study identifies posterior mesorectal thickness on MRI as a reliable and easily measurable parameter to help predict operative difficulty. Ultimately, this may in turn serve as an indicator of which patients would benefit most from pre-operative resources aimed at optimizing operative conditions and postoperative recovery.

Impact of BMI on Adverse Events After Laparoscopic and Open Surgery for Rectal Cancer

PURPOSE

The impact of body mass index (BMI) on outcomes after open or laparoscopic surgery for rectal cancer remains unclear. The objective of this retrospective cohort study was to examine the interaction of body mass index and surgical modality (i.e., laparoscopy versus open) with respect to short-term clinical outcomes in patients with rectal cancer.

METHODS

The ACS-NSQIP database (2012-2016) was reviewed for patients undergoing open or laparoscopic surgery for rectal cancer. The primary outcome was 30-day all-cause morbidity. Logistic regression and Cox proportional hazard models were used for analysis.

RESULTS

A total of 16,145 patients were grouped into open (N = 6759, 42%) and laparoscopic (N  = 9386, 58%) cohorts. Patients with higher BMI (p < 0.001) and those undergoing open surgery (p < 0.001) were at increased risk of all-cause morbidity. There was no significant change in the odds ratio of experiencing all-cause morbidity between open and laparoscopic surgery with increasing BMI (p = 0.572). Median length of stay was significantly shorter in the laparoscopy group (4 days vs. 6 days; p < 0.001), at the cost of increased operative time (239 min vs. 210 min, p < 0.001). The difference in operative time between laparoscopy and open surgery did not increase with rising BMI (i.e., ∆37 min vs. ∆39 min at BMI 25 kg/m² vs 50 kg/m², respectively, p = 0.491).

CONCLUSION

BMI may not be a strong modifier for surgical approach with respect to short-term clinical outcomes in patients with obesity and rectal cancer. Laparoscopic surgery was associated with improved short-term clinical outcomes, without much change in the absolute difference in operative time compared with open surgery, even at higher BMIs.

Safety of subxiphoid uniportal video-assisted thoracoscopic surgery for anterior mediastinal tumour in obese patients

Introduction

Subxiphoid uniportal video-assisted thoracoscopic surgery (VATS) has been gradually applied for the treatment of anterior mediastinal tumour (AMT). However, whether obesity is a risk factor for subxiphoid uniportal VATS for AMT is still unknown.

Aim

To explore the safety and short-term outcome of subxiphoid uniportal VATS for AMT in obese patients.

Material and methods

The clinical data of 142 patients who received VATS via subxiphoid approach for AMT were analysed. According to body mass index (BMI), the patients were divided into an obese group (BMI ≥ 28 kg/m²) and a non-obese group (BMI < 28 kg/m²). Then, the clinical and surgical characteristics between the obese group and the non-obese group were analysed to explore the effect of obesity on VATS for AMT. The pain scores were evaluated by the Numeric Rating Scale.

Results

The operative time and tracheal intubation time using subxiphoid uniportal VATS for AMT in the obese group were longer than that in the non-obese group (p < 0.05). However, there was no obvious difference in intraoperative blood loss, chest tube drainage time, chest tube drainage volume, and length of hospital stay between the obese group and the non-obese group (p > 0.05). Moreover, there was also no significant difference in postoperative complications, including pulmonary complications, wound infection, arrhythmia, and pulmonary leak, between the obese group and the non-obese group. In addition, the pain scores in the obese group were similar to those in the non-obese group.

Conclusions

Although obesity might prolong operative time of subxiphoid uniportal VAST for AMT, it does not increase the rate of postoperative complications. An experienced centre can properly conduct VAST via subxiphoid approach when treating AMT in obese patients.

Prophylactic negative-pressure wound therapy after ileostomy reversal for the prevention of wound healing complications in colorectal cancer patients: a randomized controlled trial

Background

The aim of this study was to assess the usefulness of protective negative-pressure wound therapy (NPWT) in the reduction of wound healing complications (WHC) and surgical site infections (SSI) after diverting ileostomy closure in patients who underwent surgery for colorectal cancer.

Methods

In this prospective randomized clinical trial in a tertiary academic surgical center, patients who had colorectal cancer surgery with protective loop ileostomy and were scheduled to undergo ileostomy closure with primary wound closure from January 2016 to December 2018 were randomized to be treated with or without NPWT. The primary endpoint was the incidence of WHC. Secondary endpoints were incidence of SSI, length of postoperative hospital stay (LOS), and length of complete wound healing (CWH) time.

Results

We enrolled 35 patients NPWT (24 males [68.6%]; mean age 61.6 ± 11.3 years), with NPWT and 36 patients (20 males [55.6%]; mean age 62.4 ± 11.3 years) with only primary wound closure (control group). WHC was observed in 11 patients (30.6%) in the control group and 3 (8.57%) in the NPWT group (p = 0.020). Patients in the NPWT group had a significantly lower incidence of SSI (2 [5.71%] vs. 8 [22.2%] in the control group; p = 0.046) as well as significantly shorter median CWH (7 [7–7] days vs. 7 [7–15.5] days, p = 0.030). There was no difference in median LOS between groups (3 [2.5–5] days in the control group vs. 4 [2–4] days in the NPWT group; p = 0.072).

Conclusions

Prophylactic postoperative NPWT after diverting ileostomy closure in colorectal cancer patients reduces the incidence of WRC and SSI.

Clinical trial registration

clinicaltrials.gov (NCT04088162).

Circular RNA NOX4 promotes the development of colorectal cancer via the microRNA‑485‑5p/CKS1B axis

Colorectal cancer (CRC) is a common malignancy globally. The aim of the present study was to explore the role and the working mechanism of circular RNA NADPH oxidase 4 (circNOX4; circBase ID, hsa_circ_0023990) in CRC. Reverse transcription‑quantitative (RT‑q)PCR was used to examine the expression of circNOX4, NOX4 mRNA and microRNA (miR)‑485‑5p in CRC tissues and cell lines. 3‑(4,5‑Dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide and Transwell assays were performed to analyze CRC cell viability and motility. The glycolytic ability of CRC cells was assessed by measuring glucose consumption, lactate production, extracellular acidification and O2 consumption rates using commercial kits. The starBase database was used to predict the targets of circNOX4 and miR‑485‑5p, and the interaction was confirmed by dual‑luciferase reporter and RNA immunoprecipitation assays. A murine xenograft model was established to verify the role of circNOX4 in CRC in vivo. The results demonstrated that the expression of circNOX4 was upregulated in CRC tissues and cell lines compared with that in adjacent normal tissues and a normal colon epithelial cell line, respectively. The expression of circNOX4 was negatively associated with the prognosis of patients with CRC. CircNOX4 silencing suppressed the proliferation, migration, invasion and glycolysis of CRC cells. miR‑485‑5p was identified as a target of circNOX4. CircNOX4 promoted CRC progression by sponging miR‑485‑5p. miR‑485‑5p was demonstrated to bind to the 3' untranslated region (UTR) of CDC28 protein kinase regulatory subunit 1B (CKS1B). miR‑485‑5p overexpression‑mediated malignant properties of CRC cells were partly reversed by the transfection with the CKS1B overexpression plasmid. CircNOX4 silencing restrained the CRC xenograft growth in vivo. Collectively, the results of the present study demonstrated that circNOX4 may serve an oncogenic role in CRC by promoting the proliferation, migration, invasion and glycolysis of CRC cells via the miR‑485‑5p/CKS1B axis.

Obese patients and robotic colorectal surgery: systematic review and meta-analysis

BACKGROUND

Obesity is a major health problem, demonstrated to double the risk of colorectal cancer. The benefits of robotic colorectal surgery in obese patients remain largely unknown. This meta-analysis evaluated the clinical and pathological outcomes of robotic colorectal surgery in obese and non-obese patients.

METHODS

MEDLINE, Embase, Global Health, Healthcare Management Information Consortium (HMIC) and Midwives Information and Resources Service (MIDIRS) databases were searched on 1 August 2018 with no language restriction. Meta-analysis was performed according to PRISMA guidelines. Obese patients (BMI 30 kg/m2 or above) undergoing robotic colorectal cancer resections were compared with non-obese patients. Included outcome measures were: operative outcomes (duration of surgery, conversion to laparotomy, blood loss), postoperative complications, hospital length of stay and pathological outcomes (number of retrieved lymph nodes, positive circumferential resection margins and length of distal margin in rectal surgery).

RESULTS

A total of 131 full-text articles were reviewed, of which 12 met the inclusion criteria and were included in the final analysis. There were 3166 non-obese and 1420 obese patients. A longer duration of surgery was documented in obese compared with non-obese patients (weighted mean difference -21·99 (95 per cent c.i. -31·52 to -12·46) min; P < 0·001). Obese patients had a higher rate of conversion to laparotomy than non-obese patients (odds ratio 1·99, 95 per cent c.i. 1·54 to 2·56; P < 0·001). Blood loss, postoperative complications, length of hospital stay and pathological outcomes were not significantly different in obese and non-obese patients.

CONCLUSION

Robotic surgery in obese patients results in a significantly longer duration of surgery and higher conversion rates than in non-obese patients. Further studies should focus on better stratification of the obese population with colorectal disease as candidates for robotic procedures.

Skeletal muscle index is an independent predictor of early recurrence in non-obese colon cancer patients

Purpose

Progressive loss (sarcopenia) and fatty infiltration of muscle mass (myosteatosis) are well-established risk factors for an adverse clinical outcome in obese patients. Data concerning non-obese sarcopenic patients in oncologic surgery are scarce and heterogeneous. The aim of this study was to determine the impact of sarcopenia and myosteatosis in non-obese patients with cancer of the right colon on clinical outcome.

Methods

This study comprised 85 patients with a BMI < 30 kg/m², who underwent surgery for right colon cancer in a single center. Skeletal muscle area (SMA), visceral fat area (VFA), and myosteatosis were retrospectively assessed using preoperative abdominal CT images. Univariate und multivariate analysis was performed to evaluate the association between body composition, complications, and oncologic follow-up.

Results

Traditional risk factors such as visceral fat (p = 0.8653), BMI (p = 0.8033), myosteatosis (p = 0.7705), and sarcopenia (p = 0.3359) failed to show any impact on postoperative complications or early recurrence. In our cohort, the skeletal muscle index (SMI) was the only significant predictor for early cancer recurrence (p = 0.0467).

Conclusion

SMI is a significant prognostic factor for early cancer recurrence in non-obese colon cancer patients. Our study shows that conventional thresholds for sarcopenia and BMI do not seem to be reliable across various cohorts. Target prehabilitation programs could be useful to improve outcome after colorectal surgery.

Trial Registration

DRKS00014655, www.apps.who.int/trialsearch

Nutritional status and its effect on complications in patients with colorectal cancer

BACKGROUND

Nutritional status is an important factor for predicting the risk of developing complications after a surgical procedure. Many nutritional assessments are used in clinical practice, but their role in predicting postoperative outcomes is unknown. Therefore, the aim of this study was to assess the utility of nutritional risk factors at the diagnosis of colorectal cancer (CRC) for predicting early postsurgical complications.

METHODS

This was a prospective observational study including 127 patients with CRC at diagnosis. Their preoperative nutritional status was analyzed by body mass index (BMI), triceps and subscapular skinfolds and two nutritional scales: the Patient-Generated Subjective Global Assessment (PG-SGA) and the Malnutrition Universal Screening Tool (MUST). The outcome variables, including postoperative complications, length of hospital stay and mortality, were analyzed.

RESULTS

Patients identified as malnourished by PG-SGA score had prolonged hospital stays (p = 0.01). The risk of infection was increased in older patients (hazard ratio, HR 1.12; 95% confidence interval, CI 1.04-1.21) but was not associated with nutritional status. Early wound dehiscence was increased in patients with higher BMI (HR 1.15; 95% CI 1.01-1.29), with higher subscapular skinfold thickness and increased age (HR 1.05; 95% CI 1.05-1.10). Postoperative mortality was not significantly associated with nutritional status.

CONCLUSION

Malnourished patients, as identified by the PG-SGA score, stayed longer in hospital than patients who were not malnourished, while increased BMI was recognized as a risk factor for wound dehiscence.

Assessing surgical difficulty in locally advanced mid-low rectal cancer: the accuracy of two MRI-based predictive scores

AIM

Predicting surgical difficulty is a critical factor in the management of locally advanced rectal cancer (LARC). This study evaluates the accuracy and external validity of a recently published morphometric score to predict surgical difficulty and additionally proposes a new score to identify preoperatively LARC patients with a high risk of having a difficult surgery.

METHODS

This is a retrospective study based on the European MRI and Rectal Cancer Surgery (EuMaRCS) database, including patients with mid/low LARC who were treated with neoadjuvant chemoradiation therapy and laparoscopic total mesorectal excision (L-TME) with primary anastomosis. For all patients, pretreatment and restaging MRI were available. Surgical difficulty was graded as high and low based upon a composite outcome, including operative (e.g. duration of surgery) and postoperative variables (e.g. hospital stay). Score accuracy was assessed by estimating sensitivity, specificity and area under the receiver operating characteristic curve (AROC).

RESULTS

In a total of 136 LARC patients, 17 (12.5%) were graded as high surgical difficulty. The previously published score (calculated on body mass index, intertuberous distance, mesorectal fat area, type of anastomosis) showed low predictive value (sensitivity 11.8%; specificity 92.4%; AROC 0.612). The new EuMaRCS score was developed using the following significant predictors of surgical difficulty: body mass index > 30, interspinous distance < 96.4 mm, ymrT stage ≥ T3b and male sex. It demonstrated high accuracy (AROC 0.802).

CONCLUSION

The EuMaRCS score was found to be more sensitive and specific than the previous score in predicting surgical difficulty in LARC patients who are candidates for L-TME. However, this score has yet to be externally validated.

Laparoscopic Mesorectal Excision in Obesity: Novel Insights and Technical Strategies

INTRODUCTION

Obesity is a burgeoning problem worldwide. Although beneficial in obese patients, conventional laparoscopic mesorectal excision for rectal cancer is technically challenging, with a higher conversion rate to open compared with nonobese patients. We describe novel strategies to circumvent these difficulties.

TECHNIQUE

The key steps are 1) lateral-to-medial colonic mobilization and left-sided mesorectal excision with the surgeon on the patient's right; 2) switching to the patient's left for right-sided mesorectal excision; 3) further rectal retraction with cotton tape and preperitoneal fat sling; and 4) caudal-to-cephalad mobilization of colon after distal transection, which facilitates extrapelvic mesenteric dissection and vessel ligation.

RESULTS

These techniques optimize gravity to negate the lack of exposure due to visceral obesity. Triangulation is improved by changing the surgeon's position during mesorectal dissection. This allows accurate identification of anatomical planes and avoids excessive pneumoperitoneum pressures and Trendelenburg tilt.

CONCLUSIONS

Adopting these strategies can facilitate laparoscopic mesorectal excision in the obese patient and may reduce conversion to open.

A Comparison of Pathologic Outcomes of Open, Laparoscopic, and Robotic Resections for Rectal Cancer Using the ACS-NSQIP Proctectomy-Targeted Database: a Propensity Score Analysis

BACKGROUND

There is ongoing debate regarding the benefits of minimally invasive techniques for rectal cancer surgery. The aim of this study was to compare pathologic outcomes of patients who underwent rectal cancer resection by open surgery, laparoscopy, and robotic surgery using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) proctectomy-targeted database.

METHODS

All patients from the 2016 ACS-NSQIP proctectomy-targeted database who underwent elective proctectomy for rectal cancer were identified. Patients were divided into three groups based on initial operative approach: open surgery, laparoscopy, and robotic surgery. Pathologic and 30-day clinical outcomes were then compared between the groups. A propensity score analysis was performed to control for confounders, and adjusted odds ratios for pathologic outcomes were reported.

RESULTS

A total of 578 patients were included-211 (36.5%) in the open group, 213 (36.9%) in the laparoscopic group, and 154 (26.6%) in the robotic group. Conversion to open surgery was more common among laparoscopic cases compared to robotic cases (15.0% vs. 6.5%, respectively; p = 0.011). Positive circumferential resection margin (CRM) was observed in 4.7%, 3.8%, and 5.2% (p = 0.79) of open, laparoscopic, and robotic resections, respectively. Propensity score adjusted odds ratios for positive CRM (open surgery as a reference group) were 0.70 (0.26-1.85, p = 0.47) for laparoscopy and 1.03 (0.39-2.70, p = 0.96) for robotic surgery.

CONCLUSIONS

The use of minimally invasive surgical techniques for rectal cancer surgery does not appear to confer worse pathologic outcomes.

Clinical Significance of Gender and Body Mass Index in Asian Patients with Colorectal Cancer

Objective: Colorectal cancer is a disease closely associated with anthropometric values. This study aimed to evaluate the clinical relevance of gender and body mass index (BMI) with colorectal cancer using a Korean nationwide cohort. Methods: Data of colorectal cancer cohorts between 2012 and 2013 were acquired from the Health Insurance Review and Assessment Service. All patients underwent surgery due to colorectal cancers. Stage IV patients were excluded due to possible clinical heterogeneity. BMI was classified with the World Health Organization criteria. Results: A total of 31,756 patients were analyzed. The underweight group had 33% higher risk of stage III disease (p<0.001). The overweight and obese groups had 20% and 19% lower risk of stage III (p<0.001 and p=0.002, respectively). The underweight and obese groups had higher risk of longest hospitalization period quartile (≥19 days), with odds ratio of 2.26 (p<0.001) and 1.33 (p<0.001), respectively. The overweight group had a 22% lower risk of the longest hospitalization period quartile (p=0.002). Females had 12% lower risk of distal cancer than males (p<0.001). There was no significant relationship between cancer stage and gender. The proportions of patients who were <50 years and ≥70 years old were higher in the females, and the proportions of patients in their 50s and 60s were higher in the males. Conclusions: Cancer stages and hospitalization period varied depending on BMI. Disease location and the age distribution were affected by gender.

Does Robot Overcome Obesity-related Limitations of Minimally Invasive Rectal Surgery for Cancer?

BACKGROUND

Adoption of laparoscopic surgery for cancers requiring partial or total proctectomy has been slow due to difficulty of achieving oncologically adequate resection. Obesity is a factor complicating use and outcomes of laparoscopic technique for rectal surgery. Impact of obesity on the outcomes of robotic rectal surgery for cancer is not well defined. This study is designed to assess whether if the robotic technique has potential to overcome the limitations of obesity and to improve outcomes of minimally invasive rectal surgery for cancer.

PATIENTS AND METHODS

Patients undergoing robotic sphincter-saving radical resection with da Vinci Xi System between December 2014 and December 2016 were included. Patients were divided into 2 groups as obese and nonobese. Patient demographics, perioperative outcomes and short-term results were compared between the groups.

RESULTS

The study included 101 patients (30 were obese). Sex (female: 35 vs. 37%, P=0.89), American Society of Anesthesiologists score (2 vs. 2, P=0.41), number of patients undergoing neoadjuvant chemoradiation (39% vs. 23%, P=0.12) and history of prior abdominal surgery (28% vs. 23%, P=0.62) were comparable between the groups. Operative time was longer in the obese group (311 vs. 332 min. P=0.01). Overall complication rates (27% vs. 23%, P=0.72), length of hospital stay (6 vs. 7, P=0.10) and pathologic outcomes were similar between the groups. Conversion to laparoscopy was not required in any operation. Two nonobese patients required conversion to open surgery.

CONCLUSION

Robotic rectal surgery for cancer in obese patients is equally safe and effective as in nonobese patients. The new robotic platform can facilitate to overcome obesity-related limitations of rectal surgery.

The relationship between body mass index and short term postoperative outcomes in patients undergoing potentially curative surgery for colorectal cancer: A systematic review and meta-analysis

BACKGROUND

The prevalence of obesity has increased worldwide over the last few decades, and is a well-recognized risk factor for colorectal cancer. Surgical site infection is the most frequent complication following surgery for colorectal cancer, and the main cause of postoperative morbidity. The aim of the present systematic review and meta-analysis was to examine the relationship between increasing BMI and postoperative surgical site infection following surgery for colorectal cancer.

METHODS

A systemic literature search was conducted using Medline, PubMed, Embase (Ovid) and Web of Science databases from inception to the end of August 2016. Studies examining the relationship between obesity and surgical site infection following surgery for colorectal cancer were included. Analysis of the data was performed using Review Manager version 5.3(The Nordic Cochrane Centre, The Cochrane Collaboration, Copen-hagen, Denmark,) RESULTS: In this meta-analysis, a total of 9535 patients from 16 studies were included. BMI <30 vs ≥30kg/m² was used to examine the association of obesity and surgical site infection in patients from Western countries. The estimated pooled OR demonstrated that obesity increased the risk of surgical site infection by approximately 100% (OR=2.13; 95% CI 1.66-2.72, p<0.001).BMI <25 vs ≥25kg/m² was used to examine the association of obesity and surgical site infection from Asian countries. The estimated pooled OR demonstrated that obesity increased the risk of surgical site infection by approximately 60% (OR=1.63; 95% CI 1.29-2.06, p<0.001). There was little evidence of publication bias in the meta-analysis.

CONCLUSION

From this systematic review and meta-analysis there was good evidence that obesity was associated with a significantly higher risk of developing surgical site infection following surgery for colorectal cancer in both ethnic groups. The magnitude of the effect warrants further investigation.

Is There Any Reason Not to Perform Standard Laparoscopic Total Mesorectal Excision?

The curative treatment of locally advanced rectal cancer is currently based on chemoradiotherapy and total mesorectal excision (TME). Laparoscopy has developed considerably because of obvious clinical benefits such as reduced pain and shorter hospital stay. Recently, several prospective randomized clinical trials with long-term follow-up have showed that laparoscopy is noninferior to laparotomy with the same oncologic outcomes in terms of survival and local control rate. However, laparoscopic TME remains a challenging procedure requiring a high level of expertise and a long learning curve to ensure an adequate and safe resection. The only relative contraindication of laparoscopic rectal surgery is T4 rectal cancer extended beyond the plane of TME. In this situation, it is reasonable to consider an open resection to avoid an uncomplete resection. In obese and elderly patients, laparoscopic TME also provides the same benefits as in nonobese and younger patients but may be more difficult to achieve. This review summarizes current knowledge on the place of laparoscopic TME in the treatment of rectal cancer.

Decrease of miR-622 expression suppresses migration and invasion by targeting regulation of DYRK2 in colorectal cancer cells

Background

More and more evidence indicates that microRNAs are present and involved in many tumor-related diseases. The function of microRNA-622 (miR-622) in colorectal cancer (CRC) remains controversial. Dual specificity tyrosine phosphorylation-regulated kinase 2 (DYRK2) has been reported as a tumor suppressor gene in different cancers. The detailed regulation mechanism of DYRK2 in CRC remains unclear.

Methods

miR-622 and DYRK2 expression levels were detected at tissue and cellular level respectively by using real time polymerase chain reaction (PCR), Western blot, and immunohistochemical staining. Pearson’s correlation analysis was used to evaluate the correlation between miR-622 and DYRK2. Transwell assay was applied to measure the effect of miR-622 on migration and invasion of SW1116 and SW480. We used dual luciferase reporter assay to confirm the targeted binding effect of miR-622 and DYRK2 3′-untranslated region (3′UTR). An antisense experiment was executed to further confirm the role miR-622 had played with regard to migration and invasion by targeting regulation of DYRK2 pathway in CRC cells.

Results

In our research, we found that the expression of miR-622 was elevated in CRC tissues and cell lines compared to that of nonCRC tissues and the normal human colon epithelial cell line NCM460. Correspondingly, the expression of DYRK2 in CRC tissues and cell lines showed a contrary tendency. The different expression level of DYRK2 was closely correlated with clinicopathological characteristics of CRC patients. We demonstrated that down-regulation of miR-622 could inhibit the ability of migration and invasion of CRC cell lines SW1116 and SW480. Also, we confirmed that DYRK2 was negatively regulated by miR-622 via a specific targeted binding site within the 3′UTR. We finally verified that the migration and invasion ability of CRC cells in the conducted DYRK2 3′UTR defect plasmid transfection group were lower compared to miR-622 and cotransfection group.

Conclusion

The findings of this study indicate that a decrease of miR-622 expression could suppress migration and invasion by targeting regulation of DYRK2 and miR-622/DYRK2 could be a potential molecular treating target of CRC.