Obesity and colorectal cancer

Breaking Myths: Comparable Outcomes in Lymph Node Analysis Across Surgical Methods

BACKGROUND/OBJECTIVES

Colorectal cancer is the third most common cancer worldwide, making lymph node recovery critical for treatment decisions and prognosis. The relationship between body mass index (BMI) and the number of lymph nodes retrieved during laparoscopic and open surgeries remains controversial. This study aimed to evaluate whether surgical approach and BMI influence lymph node retrieval in colon cancer surgeries.

METHODS

A retrospective analysis was conducted on 560 patients who underwent colon cancer surgery at a single institution between 2018 and 2023. The average number of lymph nodes retrieved during laparoscopic and open procedures was compared. Distribution analysis using violin plots was performed to assess the pattern of lymph node yield between surgical approaches. Additionally, the impact of BMI on lymph node recovery was assessed. All surgeries were performed by a standardized surgical team using consistent fat clearance techniques.

RESULTS

The mean number of lymph nodes retrieved was 15.89 ± 0.84 for laparoscopic surgeries and 15.98 ± 0.50 for open surgeries, with no statistically significant difference (p = 0.9166). The violin plot analysis confirmed overlapping distributions between the two surgical approaches, with no significant difference (p = 0.6270). BMI also showed no significant effect on the number of lymph nodes removed during surgery. The consistency in outcomes was attributed to standardized surgical practices across all cases.

CONCLUSIONS

Laparoscopic and open surgical approaches yield comparable lymph node recovery in colon cancer surgeries, both in terms of mean values and overall distribution patterns, regardless of patient BMI. These findings emphasize the importance of standardized surgical techniques in ensuring reliable outcomes and suggest that both approaches are equally effective in meeting oncological standards for lymph node retrieval.

The impact of diet-induced obesity on 5 fluorouracil-induced tumor and liver immune cell cytotoxicity

Obesity increases the risk for developing several cancers, including colorectal cancer (CRC), and is associated with liver perturbations, which likely impacts treatment tolerance. 5 fluorouracil (5FU) remains a first line treatment for CRC, but efficacy is hampered by interpatient variable responsiveness and off-target toxicities. The current study examined the impact of diet-induced obesity (DIO) on 5FU cytopenia and efficacy using two established CRC models: MC38 (C57BL/6) and C26 (CD2F1). DIO increased tumor size in both MC38 and C26. DIO reduced liver dihydropyrimidine dehydrogenase (dpyd) expression, the enzyme that catalyzes 5FU's catabolism to become inactive, in MC38 mice, but not in C26. 5FU remained efficacious against early MC38 and C26 tumor growth; however, 5FU-induced tumor and liver immune cell death was exacerbated following three cycles of 5FU with MC38. DIO caused dramatic changes to liver Kupffer cells (KCs), wherein there were increased prometastatic, immunosuppressive KCs in Obese Control and MC38. 5FU, however, depleted these KCs and increased inflammatory KCs in both Lean and Obese MC38. DIO yielded a milder obesity phenotype in CD2F1 mice, and 5FU-induced cytopenia was not different between Lean and Obese. DIO increased total liver KCs; however, C26 tumors increased liver KCs, which were normalized with 5FU treatment, irrespective of DIO. Although 5FU remained efficacious in both models of CRC and did not reduce survival, multiple cycles of 5FU monotherapy increased liver and tumor immune cell death in DIO mice. Altogether, obesity was not protective but rather exacerbated chemotherapy-induced cytotoxicity and promoted a prometastatic liver environment.NEW & NOTEWORTHY The current study aimed to examine the impact of obesity on tumorigenesis and 5FU safety and efficacy with two established murine models of colorectal cancer. Diet-induced obesity increased tumor burden in both models, and 5FU's antitumor efficacy remained and extended survival with both tumor models. Obese mice demonstrated increased 5FU-induced immune cell cytotoxicity following multiple cycles of 5FU with distinct changes to liver macrophages, suggesting an increased propensity for liver metastasis.

Involvement of the gut microbiota in cancer cachexia

Cancer cachexia, or the unintentional loss of body weight in patients with cancer, is a multiorgan and multifactorial syndrome with a complex and largely unknown etiology; however, metabolic dysfunction and inflammation remain hallmarks of cancer-associated wasting. Although cachexia manifests with muscle and adipose tissue loss, perturbations to the gastrointestinal tract may serve as the frontline for both impaired nutrient absorption and immune-activating gut dysbiosis. Investigations into the gut microbiota have exploded within the past two decades, demonstrating multiple gut-tissue axes; however, the link between adipose and skeletal muscle wasting and the gut microbiota with cancer is only beginning to be understood. Furthermore, the most used anticancer drugs (e.g. chemotherapy and immune checkpoint inhibitors) negatively impact gut homeostasis, potentially exacerbating wasting and contributing to poor patient outcomes and survival. In this review, we 1) highlight our current understanding of the microbial changes that occur with cachexia, 2) discuss how microbial changes may contribute to adipose and skeletal muscle wasting, and 3) outline study design considerations needed when examining the role of the microbiota in cancer-induced cachexia.

Can caloric restriction improve outcomes of elective surgeries?

Energy restriction (ER) is a nutrition method to reduce the amount of energy intake while maintaining adequate nutrition. In clinical medicine, applications of ER have been implicated in longevity, mortality, metabolic, immune, and psychological health. However, there are limited studies showing the clinical benefit of ER within the immediate surgical setting. A specific, clinically oriented summary of the potential applications of ER is needed to optimize surgery outcomes for patients. The purpose of this article is to examine how ER can be used for perioperative optimization to improve outcomes for the patient and surgeon. It will also explore how these outcomes can feasibly fit in with enhanced recovery after surgery protocols and can be used as a method for nutrition optimization in surgery. Despite evidence of caloric restriction improving outcomes in critically ill surgical patients, there is not enough evidence to conclude that ER, perioperatively across noncritically ill cohorts, improves postoperative morbidity and mortality in elective surgeries. Nevertheless, a contemporary account of how ER techniques may have a significant role in reducing risk factors of adverse surgical outcomes in this cohort, for example, by encouraging preoperative weight loss contributing to decreased operating times, is reviewed.

The effect of bariatric surgery on reducing the risk of colorectal cancer: a meta-analysis of 3,233,044 patients

BACKGROUND

The published literature presents conflicting results regarding the impact of bariatric surgery on the incidence of colorectal cancer. There are important new studies that have addressed this question with longer follow-up.

OBJECTIVE

To investigate the effect of bariatric surgery on the risk of developing colorectal cancer in patients with obesity.

SETTING

Meta-analysis.

METHODS

PubMed and Scopus were searched for relevant articles. Articles published by November 2021 were retrieved; data were extracted according to the evidence-based PICO (population, intervention, control, outcome) model and analyzed using a random-effects model to estimate the pooled relative risk (RR) and its 95% confidence interval. The heterogeneity of studies was tested and quantified using Cochran's Q.

RESULTS

The initial search yielded 327 articles. After evaluation, 13 studies were analyzed. The thorough evaluation resulted in 13 articles, which were analyzed. A total number of 3,233,044 patients were included in the meta-analysis. The mean time of follow-up was 9.5 ± 7.9 years. The pooled estimate of the adjusted RR was .63 (95% confidence interval, .50-.79). Heterogeneity χ² was 107.96 (df = 12; P < .001; I² = 89%).

CONCLUSION

Patients who underwent bariatric surgery had a 37% reduction in the risk of developing colorectal cancer compared with patients with obesity who had no surgery.

Risk and survival in colorectal cancer with increasing body mass index: A nationwide population-based cohort study

AIM

The aim was to explore potential associations between the body mass index (BMI) and the risk of colorectal cancer (CRC), including subsites of the colon, and cancer-specific death.

METHODS

A registry-based cohort study was conducted with baseline data gathered from the Norwegian Tuberculosis Screening Programme, collected between 1963 and 1975, and linked to follow-up data from the Cancer Registry of Norway and the Norwegian Cause of Death Registry. Cox regression models were used to explore associations between BMI and CRC risk and cancer-specific death.

RESULTS

Of 1 723 692 included individuals, 76 616 developed CRC during 55 370 707 person-years of follow-up. In men, a 5 kg/m² increase in BMI was associated with an increased risk of colon cancer, including both right and left subsites, and rectal cancer. Allowing for nonlinearities, we found a U-shaped association for the right colon and an inverse U-shape for the left colon and rectum cancer. In women, a 5 kg/m² increase in BMI in early adulthood was associated with increased risk of colon cancer, including both subsites. In women, an increased risk of CRC death with increasing BMI was found for colon cancer.

CONCLUSIONS

Men of all ages have an increased risk of CRC with increasing BMI, with the highest risk for right-sided colon cancer. An increased risk for colon cancer was also found in women with high BMI in early adulthood. Furthermore, women of all age groups appeared to have an increased risk of CRC death with higher BMI.

Obesity reduced survival with 5-fluorouracil and did not protect against chemotherapy-induced cachexia or immune cell cytotoxicity in mice

Fluorouracil/5-flourouracil (5FU) is a first-line chemotherapy drug for many cancer types; however, its associated toxicities contribute to poor quality of life and reduced dose intensities negatively impacting patient prognosis. While obesity remains a critical risk factor for most cancers, our understanding regarding how obesity may impact chemotherapy's toxicities is extremely limited. C56BL/6 mice were given high fat (Obese) or standard diets (Lean) for 4 months and then subjected to three cycles of 5FU (5d-40 mg/kg Lean Mass, 9d rest) or PBS vehicle control. Shockingly, only 60% of Obese survived 3 cycles compared to 100% of Lean, and Obese lost significantly more body weight. Dihydropyrimidine dehydrogenase (DPD), the enzyme responsible for 5FU catabolism, was reduced in obese livers. Total white blood cells, neutrophils, and lymphocytes were reduced in Obese 5FU compared to Lean 5FU and PBS controls. While adipocyte size was not affected by 5FU in Obese, skeletal muscle mass and myofibrillar cross section area were decreased following 5FU in Lean and Obese. Although adipose tissue inflammatory gene expression was not impacted by 5FU, distinct perturbations to skeletal muscle inflammatory gene expression and immune cell populations (CD45+ Immune cells, CD45+CD11b+CD68+ macrophages and CD45+CD11b+Ly6clo/int macrophage/monocytes) were observed in Obese only. Our evidence suggests that obesity induced liver pathologies and reduced DPD exacerbated 5FU toxicities. While obesity has been suggested to protect against cancer/chemotherapy-induced cachexia and other toxicities, our results demonstrate that obese mice are not protected, but rather show evidence of increased susceptibility to 5FU-induced cytotoxicity even when dosed for relative lean mass.

Outcomes of right-sided and left-sided colon cancer after curative resection

The right and left side of the colon derived from the midgut and hindgut, respectively. Previous studies have reported different characteristics of right-sided colon cancer (RCC) and left-sided colon cancer (LCC), but oncological outcomes remain unclear. This study compared the outcomes of RCC and LCC. This retrospective study included 1017 patients who received curative colectomy for stage I-III colon cancer at a single institute between August 2008 and December 2019. Overall survival (OS) and time to recurrence (TTR) were analyzed as outcome measurements. No significant difference in the OS or TTR of patients with RCC and LCC were observed. In subgroup analysis, RCC was associated with shorter TTR than LCC in stage II colon cancer (HR 2.36, 95% confidence interval 1.24–4.48, p < 0.01). Multivariate analysis demonstrated that right sidedness, R1 resection, low body mass index (BMI) and adjuvant chemotherapy were independent factors for poor prognosis for stage II colon cancer. Low BMI, perineural invasion, higher T stage and N2 stage were independent factors for poor prognosis for stage III colon cancer. The results were confirmed by multivariate analysis after propensity score matching. Our study revealed that RCC was an independent risk factor for recurrence in stage II colon cancer.

Does the body mass index impact lymph node yield for colorectal cancer resection, and does operative approach influence this: a review of bi-national colorectal cancer audit database

BACKGROUND

Operating on an obese patient is technically more challenging. This study aimed to determine whether there was any correlation between lymph node (LN) harvesting and patient's BMI, and how the operative approach influences this.

METHODS

A retrospective analysis of the bi-national colorectal cancer audit (BCCA) database from 2008 to 2018 was performed.

RESULTS

In the analysis of the correlation between operative approach and number of lymph nodes, data on 22 963 patients were analyzed. The operative approach did not lead to a significant difference in the number of lymph nodes yielded, except for proctocolectomy and low anterior resection where laparoscopic approach yielded greater lymph nodes than open approach. Linear regression of BMI and number of lymph nodes harvested for each operation based on 3986 patients showed that BMI largely does not impact the lymph node yield. The exception was open left hemicolectomy/sigmoid colectomy and laparoscopic high anterior resection, where a unit increase in BMI led to a reduction in the number of lymph nodes harvested. However, the regression coefficient and reduction in number of lymph nodes were low (r2  = 0.11, r2  = 0.0108 and 0.41, 0.18 lymph nodes).

CONCLUSION

In colorectal cancer operations, the number of lymph nodes removed is largely not impacted by the patient's body mass index, regardless of which operative approach is taken.

Study protocol for an open labelled randomised controlled trial of perioperative oral nutrition supplement in breast and colorectal cancer patients undergoing elective surgery

Background

While it is well established that perioperative use of oral nutrition supplement (ONS) improves nutrition status among severely malnourished surgical cancer patients, the evidence requires further substantiation for non-severely malnourished patients with cancer. This protocol paper presents the rationale and design of a randomised controlled trial to evaluate the effectiveness of preoperative as well as an extended 90-day postoperative use of ONS on nutritional and clinical outcomes among patients undergoing elective surgery for breast and colorectal cancer.

Methods

Patients with primary breast and colorectal cancer undergoing elective surgery are recruited from two tertiary hospitals. Eligible patients are assigned into one of the three intervention arms: (i) Group SS will receive ONS in addition to their normal diet up to 14 days preoperatively and postoperatively up to discharge; (ii) Group SS-E will receive ONS in addition to their normal diet up to 14 days preoperatively, postoperatively up to discharge and for an extended 90 days after discharge; and (iii) Group DS will receive ONS in addition to their normal diet postoperatively up to discharge from the hospital. The ONS is a standard formula fortified with lactium to aid in sleep for recovery. The primary endpoints include changes in weight, body mass index (BMI), serum albumin and prealbumin levels, while secondary endpoints are body composition (muscle and fat mass), muscle strength (handgrip strength), energy and protein intake, sleep quality, haemoglobin, inflammatory markers (transferrin, high sensitivity C-reactive protein, interleukin-6), stress marker (saliva cortisol), length of hospital stay and postoperative complication rate.

Discussion

This trial is expected to provide evidence on whether perioperative supplementation in breast and colorectal cancer patients presenting with high BMI and not severely malnourished but undergoing the stress of surgery would be beneficial in terms of nutritional and clinical outcomes.

Trial registration

ClinicalTrial.gov NCT04400552. Registered on 22 May 2020, retrospectively registered

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05716-5.

Impact of Visceral Fat on Survival and Metastasis of Stage III Colorectal Cancer

Background/Aims

Previous studies have investigated the relationship between visceral obesity and the risk of colorectal tumors. Visceral obesity may affect the outcome of colorectal cancer (CRC), including survival and metastasis. We investigated the associations between visceral adipose tissue and oncologic outcomes in stage III CRC.

Methods

Four hundred seventy-two patients with stage III CRC were identified. Subcutaneous and visceral adipose tissue areas were measured volumetrically via computed tomography for each patient at different levels of the lumbar spine. After adjusting for age, sex, and other clinical factors, the effects of visceral adipose tissue area on mortality and recurrence were assessed using Cox proportional hazard regression.

Results

In univariate and multivariate analyses, a higher visceral adipose tissue to total adipose tissue (VT) ratio (hazard ratio [HR], 1.041; 95% CI, 1.008 to 1.075; p=0.015) and higher visceral adipose tissue to subcutaneous adipose tissue (VS) ratio (HR, 1.016; 95% CI, 1.005 to 1.028; p=0.006) were both associated with poor CRC-specific survival. Interestingly, in the evaluation of each site of recurrence, a higher VT ratio (HR, 1.069; 95% CI, 1.010 to 1.131; p=0.020) and higher VS ratio (HR, 1.024; 95% CI, 1.003 to 1.045; p=0.023) were both related to a higher risk of peritoneal seeding and tumor recurrence. The VT ratio at the L3-L4 level was significantly associated with a higher risk of peritoneal seeding and tumor recurrence (HR, 4.969; 95% CI, 1.303 to 18.949; p=0.019), while other levels showed no such relationship.

Conclusions

Visceral obesity is closely related to increased risks of CRC-specific mortality and peritoneal seeding metastasis in stage III CRC patients.

High-fat diet-fed ovariectomized mice are susceptible to accelerated subcutaneous tumor growth potentially through adipose tissue inflammation, local insulin-like growth factor release, and tumor associated macrophages

Background: The association between obesity and colorectal cancer (CRC) risk has been well established. This relationship appears to be more significant in men than in women, which may be attributable to sex hormones. However, controlled animal studies to substantiate these claims and the mechanisms involved are lacking.

Materials and Methods: MC38 murine colon adenocarcinoma cells were injected subcutaneously into high-fat diet (HFD) fed male, female and ovariectomized (OVX) female C57BL/6 mice.

Results: HFD increased tumor growth (main effect) that was consistent with metabolic perturbations (P < 0.01). HFD OVX mice exhibited the most significant tumor growth compared to HFD male and female mice (p < 0.05) and this was associated with increased subcutaneous adipose tissue (p < 0.05). Further, the subcutaneous adipose tissue depots within HFD OVX mice exhibited more severe macrophage associated inflammation compared to female (P < 0.01), but not male mice. Conditioned media from subcutaneous adipose tissue of HFD OVX contained higher IGF-1 levels compared to male (P < 0.01), but not female mice. Finally, HFD OVX mice had increased M2-like gene expression in their tumor-associated macrophages (TAMs) compared to female mice (P < 0.01).

Conclusions: This work provides evidences suggesting adiposity, adipose specific IGF-1, macrophage associated adipose inflammation, and TAMs as potential mechanisms driving obesity-enhanced CRC in females lacking ovarian hormones.

Factors Associated with Colorectal Cancer Among Jordanians: a Case- Control Study

Objective: In recent years, the incidence of colorectal cancer (CRC) in Jordan has been on the rise. We aimed to determine associations with lifestyle factors, demographic and clinical variables. Methods: This case-control study included 102 patients diagnosed with CRC and 198 age and gender matched healthy subjects as controls. Cases were purposefully sampled; however, the control group were selected by simple random sampling of a cross-section of the population in Northern Jordan. Participating cases and controls completed an anonymous questionnaire inquiring about their demographic characteristics, lifestyle factors, and clinical variables. Data about the medical history and diagnosis of participating cases were obtained from the cases themselves and confirmed by reviewing their medical records. Results: In the cross tabulation analysis, the Chi square test showed that diabetes and hypertension were significantly associated with CRC (P <0.05). Additionally, regression modeling revealed that age ≥ 45 years (OR=10.93), positive family history for CRC (OR=5.53), physical inactivity (OR=7.4), cigarette smoking (OR=3.71), and having other types of cancer (OR=13.61) were all associated with increased risk of CRC. Conclusions: Physical inactivity and cigarette smoking are among the top modifiable risk factors for CRC among Jordanians. Moreover, diabetes and hypertension were found to be statistically significant risk factors in univariate, but not multivariate analysis. More effective strategies for elevating awareness and prevention are required at both national and international levels. Improving screening strategies is needed for early detection of CRC in Jordan.

FOXR2 Promotes the Proliferation, Invasion, and Epithelial-Mesenchymal Transition in Human Colorectal Cancer Cells

Forkhead box R2 (FOXR2), a member of the FOX gene family, has not been very well investigated for its role in cancer. A recent study has shown that FOXR2 is highly expressed in breast cancer samples and is associated with poor prognosis. In addition, FOXR2 was identified as an oncogene in medulloblastoma. Nevertheless, whether FOXR2 plays a role in colorectal cancer (CRC) remains unclear. In the present study, we conducted several in vitro and in vivo studies to investigate the expression and effect of FOXR2 in CRC. The study results demonstrated that FOXR2 was upregulated in CRC tissues and cells. Downregulation of FOXR2 inhibited CRC cell proliferation, invasion, and the epithelial-mesenchymal transition (EMT) phenotype in vitro and also suppressed CRC cell growth and metastasis in vivo. Furthermore, downregulation of FOXR2 remarkably reduced the protein expression of Shh, Gli1, and Ptch1 in SW480 cells. Taken together, our data suggested that FOXR2 significantly promoted proliferation, invasion, and EMT of CRC cells. All these findings provided evidence for the role of FOXR2 as an oncogene in CRC development.

Consumption of Lake Ontario sport fish and the incidence of colorectal cancer in the New York State Angler Cohort Study (NYSACS)

Fish consumption is hypothesized to reduce the risk of colorectal cancer. Nonetheless, consuming sport fish from the Great Lakes increases exposure to certain persistent organic pollutants, namely polychlorinated biphenyls (PCBs) and organochlorine insecticides, which may increase the risk of cancer. Evidence that exposure to persistent organic pollutants is associated with colorectal cancer is sparse. We examined colorectal cancer incidence in the New York State Angler Cohort Study (NYSACS), a prospective cohort of 17,110 anglers and spouses age 18-40 years at enrollment. In 1991, participants completed a mailed self-administered questionnaire that ascertained the number of years that fish from Lake Ontario were consumed, as well as potential confounders. Forty-one histologically confirmed first primary incident colorectal cancers diagnosed as of December 31, 2008 were identified via the New York State Cancer Registry. Vital status was ascertained by linkage with the Social Security Administration Death File. Rate ratios (RR) and 95% confidence intervals (CI) were calculated with Poisson regression, adjusting for age, pack-years of smoking, and sex. Compared with never consumers, colorectal cancer incidence was statistically non-significantly lower among consumers of Lake Ontario sport fish (RR=0.66; 95% CI: 0.35; 1.24). Incidence of colon cancer was lower among Lake Ontario sport fish consumers (RR=0.45, 95%CI: 0.20; 1.00). We did not observe any evidence of effect measure modification by sex or age. Although consumption of Lake Ontario sport fish may have an inverse association with colorectal cancer risk, inferences are complicated by a small number of cases and a lack of information regarding potential confounders including other dietary factors. However, our results do not provide support for the hypothesis that consumption of contaminated sport fish increases the risk of colorectal cancer.

A DASH dietary pattern and the risk of colorectal cancer in Canadian adults

INTRODUCTION

Colorectal cancer (CRC) is a high incidence cancer affecting many Canadian adults each year. Diet is important in the etiology of CRC with many dietary components identified as potential risk factors. The Dietary Approaches to Stop Hypertension (DASH) diet is a well-established pattern to characterize overall eating. The purpose of this study was to characterize a DASH pattern within the Canadian context and to assess its relationship to the risk of CRC in Canadian adults.

METHODS

Unconditional multiple logistic regression with control for confounding variables was performed using data from the National Enhanced Cancer Surveillance Study. Dietary intake was captured for this case-control study through a food frequency questionnaire (FFQ) and categorized into a DASH score ranging from 0 to 10 representing a poor to a strong DASH pattern respectively.

RESULTS

Consuming a strong DASH pattern of eating (score ≥ 8) was not common in the 3161 cases and 3097 controls. Overall, only 10.8% of men and 13.6% of women had a strong DASH pattern. Multivariate analysis demonstrated a trend for decreasing risk of CRC in men with increasing DASH scores (p value for trend = .007). Men with a strong DASH score had a 33% reduction in risk of CRC compared to those with a low DASH score. There were no significant trends for women for CRC or for colon or rectal cancers separately.

CONCLUSION

Our findings are similar to other researchers suggesting a benefit with a strong DASH pattern associated with a decreased risk of CRC, especially in men. Research should further investigate our gender-based differences.

Association of obesity and overweight with overall survival in colorectal cancer patients: a meta-analysis of 29 studies

PURPOSE

Previous studies that assessed the relationship between obesity, overweight, and survival in colorectal cancer (CRC) have provided conflicting results. Therefore, we quantitatively summarized existing evidence to estimate the association between obesity/overweight and overall survival (OS) in CRC patients and explored potentially important sources of variability.

METHODS

Eligible studies were identified via PubMed and EMBASE searches. The summary hazard ratio (sHR) was estimated using a fixed-effects or random-effects model according to the heterogeneity between the studies. Meta-regression and subgroup analyses were performed to explore potential sources of heterogeneity.

RESULTS

A total of 29 eligible studies, with 51,303 CRC patients, were finally included. The overall analysis showed worse OS among obese patients [sHR 1.10, 95 % confidence intervals (CI) 1.06-1.15], but not among overweight patients (sHR 0.92, 95 % CI 0.86-1.00), than in normal-weight patients. Considerable heterogeneity was observed across studies, which was primarily attributed to the timing of body mass index (BMI) assessment (meta-regression p < 0.05). The association between obesity and worse OS was strengthened when BMI was assessed before diagnosis (sHR 1.30, 95 % CI, 1.17-1.44). Conversely, post-diagnostic, in particular post-treatment, overweight was associated with a better OS (sHR 0.79, 95 % CI 0.70-0.91). Other factors, including gender, geographic location, and stage, may also modify the prognostic value of obesity or overweight.

CONCLUSIONS

Obese but not overweight patients appear to have worse OS than normal-weight patients with CRC. The associations of obesity and overweight with OS in CRC patients majorly depend upon the timing of BMI assessment.

Impact of BMI on postoperative outcomes in patients undergoing proctectomy for rectal cancer: a national surgical quality improvement program analysis

BACKGROUND

There is a mounting body of evidence that suggests worsened postoperative outcomes at the extremes of BMI, yet few studies investigate this relationship in patients undergoing proctectomy for rectal cancer.

OBJECTIVE

We aimed to examine the relationship between BMI and short-term outcomes after proctectomy for cancer.

DESIGN

This was a retrospective study comparing the outcomes of patients undergoing proctectomy for rectal cancer as they relate to BMI.

SETTINGS

The American College of Surgeons-National Surgical Quality Improvement Program database was queried for this study.

PATIENTS

Patients included were those who underwent proctectomy for rectal neoplasm between 2005 and 2011.

MAIN OUTCOME MEASURES

Study end points included 30-day mortality and overall morbidity, including the receipt of blood transfusion, venous thromboembolic disease, wound dehiscence, renal failure, reintubation, cardiac complications, readmission, reoperation, and infectious complications (surgical site infection, intra-abdominal abscess, pneumonia, and urinary tract infection). Univariate logistic regression was used to analyze differences among patients of varying BMI ranges (kg/m; ≤20, 20-24, 25-29, 30-34, and ≥35). When significant differences were found, multivariable logistic regression, adjusting for preoperative demographic and clinical variables, was performed.

RESULTS

A total of 11,995 patients were analyzed in this study. The incidences of overall morbidity, wound infection, urinary tract infection, venous thromboembolic event, and sepsis were highest in those patients with a BMI of ≥35 kg/m (OR, 1.63, 3.42, 1.47, 1.64, and 1.50). Wound dehiscence was also significantly more common in heavier patients. Patients with a BMI <20 kg/m had significantly increased rates of mortality (OR, 1.72) and sepsis (OR, 1.30).

LIMITATIONS

This study was limited by its retrospective design. Furthermore, it only includes patients from the American College of Surgeons-National Surgical Quality Improvement Program database, limiting its generalizability to nonparticipating hospitals.

CONCLUSIONS

Obese and underweight patients undergoing proctectomy for neoplasm are at a higher risk for postoperative complications and death.

Effect of body mass index in patients undergoing resection for gastric cancer: a single center US experience

INTRODUCTION

With rising obesity in the USA, the impact of body mass index (BMI) on survival in gastric cancer remains unclear.

METHODS

An institutional database of patients undergoing surgical evaluation for gastric cancer was reviewed. Patients were stratified by the following BMI: <18.5, 18.5-25, 25.1-30, and >30. Clinicopathologic factors and overall survival (OS) were analyzed.

RESULTS

From 1997 to 2012, 222 patients underwent exploration for gastric adenocarcinoma. 186 (84%) had BMI recorded: nine (5%) <18.5, 72 (39%) 18.5-25, 62 (33%) 25.1-30, and 43 (23%) >30. One hundred thirty-five (73%) ultimately underwent resection. Although American Society of Anesthesiology score and blood loss were not associated with increasing BMI, operative time was longer, p = 0.02. Proximal location, perineural invasion, lymphovascular invasion, positive surgical margins, and positive lymph nodes (LN+) were all associated with worse OS but not with increased BMI. Although increased BMI was associated with a lower lymph node count, p = 0.004, the number of LN + and final pathologic stage were not associated with BMI. Additionally, use of neoadjuvant or adjuvant chemotherapy was not associated with BMI. Median OS was 22 months. Median OS was improved with increased BMI: 21 months for <18.5, 13 months 18.5-25, 28 months 25-30, and 34 months >30, p = 0.02. Disease-free survival (DFS) was similar: 2 months for <18.5, 7 months 18.5-25, 15 months 25.1-30, and 15 months >30, p = 0.02.

CONCLUSION

Although BMI may impact the technical difficulty of resection for gastric cancer, increasing BMI is not associated with more advanced disease. In this experience, increased BMI does not adversely impact OS or DFS.

Role of dysregulated expression of leptin and leptin receptors in colorectal carcinogenesis

Leptin is a multifunctional adipose-derived cytokine that plays a critical role in bodyweight homeostasis and energy balance. Plasma level of leptin is an indicator of the amount of energy stored in adipose tissues. Recently, leptin and leptin receptor dysregulation have been reported in a variety of malignant cells including colorectal cancers (CRCs). There are growing evidence that leptin may be the link between obesity and CRC carcinogenesis. Leptin influence the growth and proliferation of cancer cells via activation of various growth and survival signaling pathways including JAK/STAT, PI3-kinase/AKT, and/or MAP kinases. In this review, current understanding of leptin and its receptor's roles in the pathogenesis of colonogenic cancer has been described.

Gemifloxacin, a fluoroquinolone antimicrobial drug, inhibits migration and invasion of human colon cancer cells

Gemifloxacin (GMF) is an orally administered broad-spectrum fluoroquinolone antimicrobial agent used to treat acute bacterial exacerbation of pneumonia and bronchitis. Although fluoroquinolone antibiotics have also been found to have anti-inflammatory and anticancer effects, studies on the effect of GMF on treating colon cancer have been relatively rare. To the best of our knowledge, this is the first report to describe the antimetastasis activities of GMF in colon cancer and the possible mechanisms involved. Results have shown that GMF inhibits the migration and invasion of colon cancer SW620 and LoVo cells and causes epithelial mesenchymal transition (EMT). In addition, GMF suppresses the activation of NF- κ B and cell migration and invasion induced by TNF- α and inhibits the TAK1/TAB2 interaction, resulting in decreased I κ B phosphorylation and NF- κ B nuclear translocation in SW620 cells. Furthermore, Snail, a critical transcriptional factor of EMT, was downregulated after GMF treatment. Overexpression of Snail by cDNA transfection significantly decreases the inhibitory effect of GMF on EMT and cell migration and invasion. In conclusion, GMF may be a novel anticancer agent for the treatment of metastasis in colon cancer.

Hyperglycaemia-induced chemoresistance of prostate cancer cells due to IGFBP2

Clinically relevant prostate cancer (PCa) is more frequent in Westernised societies and increasingly men have co-morbidities associated with a Western lifestyle, primarily diabetes, characterised by hyperinsulinaemia and hyperglycaemia. IGFs and their binding proteins (IGFBPs) are important mediators of the effects of nutrition on growth and play a key role in the development of PCa. We used DU145, PC3 and LNCaP PCa cell lines to examine how hyperglycaemia altered their response to docetaxel. Trypan Blue dye-exclusion assay was used to determine the percentage of cell death. Protein abundance was determined using western immunoblotting. Levels of IGFBP2 were measured using an ELISA. IGFBP2 gene silencing was achieved using siRNA technology. DNA methylation was assessed using combined bisulphide restriction analysis. Acetylation status of histones H3 and H4 associated with IGFBP2 gene was assessed using chromatin immunoprecipitation assay. Hyperglycaemia reduced docetaxel-induced apoptosis by 40% for DU145 cells and by 88% for LNCaP cells. This reduced cell death was mediated by a glucose-induced up-regulation of IGFBP2, as silencing IGFBP2 negated the survival effect of high glucose. Glucose increased IGFBP2 via increasing the acetylation of histones associated with the IGFBP2 gene promoter. This finding could have important implications in relation to therapeutic strategies as epigenetic modulation could be reversible.

Obesity and cancer--the update 2013

Progress of the last five years regarding "Obesity and Cancer" with preference to cohort studies was reviewed for cancer of the colorectum, breast, endometrium, renal cell, and adenocarcinomas of the esophagus and compared to the knowledge reviewed in the year 2008. The new studies are mostly confirming what has been known also 5 years ago. Gender seems to play a role in colorectal cancer in that risk due to body fatness is much lower in women than in men. Body fatness at young adulthood is particularly related to risk of renal cancer whereas attained body fatness at a later stage of adulthood is driving the risk for postmenopausal breast and endometrial cancer. Fat distribution is playing a strong role for risk of adenocarcinoma of the esophagus and to a lesser extent also for colon cancer. Prediagnostic body fatness plays also a role in cancer recurrence and survival.