Prognostic relevance of prediagnostic weight loss and overweight at diagnosis in patients with colorectal cancer

Association between prediagnostic risk factors and survival after colorectal cancer diagnosis in Golesten cohort study

This study investigated the survival rates of colorectal cancer (CRC) and the association between several pre-diagnostic factors, including demographic, anthropometric, behavioral, nutritional, lifestyle, and medical history and CRC incidence and survival. Among 50,045 participants in the Golestan cohort study, 190 patients diagnosed with CRC during the follow-up period were included in this study. Cox regression and Kaplan-Meier were used for analysis. The CRC incidence risk was significantly higher in males (HR = 2.20; 1.54-3.14), adults aged 50-70 years (HR = 1.86, 1.36-2.55), adults aged 70 years and older (HR = 3.71; 2.13-6.44), and urban dwellers (HR = 1.74; 1.22-2.47). The 1-year, 2-year, and 5-year overall survival was 60.3%, 47.5%, and 35.2%, respectively. Higher pre-diagnostic socio-economic status (SES) was associated with a significantly decreased mortality (HR = 0.55; 0.34-0.89). While, age 70 years and older (HR = 2.79; 1.12-6.99), pre-diagnostic opium use (HR = 2.35; 1.36-4.07), and metastasis (HR = 2.97; 1.97-4.48) were associated with a significantly increased mortality. Health policies should be implemented to enhance healthcare services and screening programs in low-SES areas. The general population, especially males and adults aged 50 years and older should be informed about CRC screening, CRC symptoms, and healthy lifestyles and diets. Furthermore, there is a critical need to raise awareness about the harmful effects of opium on CRC.

Artificial intelligence generated 3D body composition predicts dose modifications in patients undergoing neoadjuvant chemotherapy for rectal cancer

PURPOSE

Chemotherapy administration is a balancing act between giving enough to achieve the desired tumour response while limiting adverse effects. Chemotherapy dosing is based on body surface area (BSA). Emerging evidence suggests body composition plays a crucial role in the pharmacokinetic and pharmacodynamic profile of cytotoxic agents and could inform optimal dosing. This study aims to assess how lumbosacral body composition influences adverse events in patients receiving neoadjuvant chemotherapy for rectal cancer.

METHODS

A retrospective study (February 2013 to March 2023) examined the impact of body composition on neoadjuvant treatment outcomes for rectal cancer patients. Staging CT scans were analysed using a validated AI model to measure lumbosacral skeletal muscle (SM), intramuscular adipose tissue (IMAT), visceral adipose tissue (VAT), and subcutaneous adipose tissue volume and density. Multivariate analyses explored the relationship between body composition and chemotherapy outcomes.

RESULTS

242 patients were included (164 males, 78 Females), median age 63.4 years. Chemotherapy dose reductions occurred more frequently in females (26.9% vs. 15.9%, p = 0.042) and in females with greater VAT density (-82.7 vs. -89.1, p = 0.007) and SM: IMAT + VAT volume ratio (1.99 vs. 1.36, p = 0.042). BSA was a poor predictor of dose reduction (AUC 0.397, sensitivity 38%, specificity 60%) for female patients, whereas the SM: IMAT + VAT volume ratio (AUC 0.651, sensitivity 76%, specificity 61%) and VAT density (AUC 0.699, sensitivity 57%, specificity 74%) showed greater predictive ability. Body composition didn't influence dose adjustment of male patients.

CONCLUSION

Lumbosacral body composition outperformed BSA in predicting adverse events in female patients with rectal cancer undergoing neoadjuvant chemotherapy.

Association of past obesity and BMI trajectories with cancer mortality: a prospective cohort study

OBJECTIVE

This study aimed to assess the association of past obesity and past BMI trajectories with cancer mortality in National Health and Nutrition Examination Survey.

METHODS

Past obesity was identified based on past maximum body weight, and trajectories of past BMI change were determined by latent class trajectory modeling (LCTM). Cox regression was used to assess the association of past obesity and past BMI trajectories with cancer mortality.

RESULTS

A total of 4,058 cancer patients participated in this study, of which 46.3% were past obesity, resulting in a significantly lower risk of cancer mortality compared to participants who were not past obesity (HR = 0.92, 95% CI: 0.92-0.93, P < 0.01). The LCTM identified five trajectories of past BMI, and compared with participants whose BMI remained in the normal range, the risk of death was 17% and 23% lower for participants in the "Long-term overweight" and "Long-term obesity" trajectory groups, respectively. In contrast, participants in the "Recent weight gain" and "Recent weight loss" trajectory groups had an increased risk of cancer death of 19% and 40%, respectively.

CONCLUSIONS

This study found that past obesity is consistent with the "obesity paradox." In furtherance, a moderately elevated and stable BMI might be associated with lower cancer mortality.

Candidate Genetic Loci Modifying the Colorectal Cancer Risk Caused by Lifestyle Risk Factors

INTRODUCTION

65%-70% of colorectal cancer (CRC) cases are considered sporadic; they arise under the influence of environmental factors in individuals lacking a family history of CRC. Low-risk genetic variants are believed to contribute to CRC risk, in tandem with lifestyle factors.

METHODS

Six hundred sixteen nonfamilial Swedish CRC cases with at least 1 of the following 5 risk factors: smoking, excessive alcohol consumption, physical inactivity, adherence to an unhealthy diet, and excess body weight were included in this study. A control group consisting of 1,642 healthy individuals was used. Cases and controls were genotyped from blood samples at the Centre for Inherited Disease Research at Johns Hopkins University within the Colorectal Transdisciplinary Study research collaboration, using the Illumina Infinium OncoArray-500 K BeadChip. Five separate genome-wide haplotype association analyses were performed, one for each risk factor. Logistic regression models were used to estimate associations between haplotypes (exposure) and CRC (outcome) in cases with lifestyle risk factors vs controls. Haplotypes with an odds ratio >1 were considered candidate risk markers, denoting an area of interest in the genome. A significance threshold of P < 5 × 10 -8 was used.

RESULTS

We found 17 haplotype regions significantly associated with CRC in cases vs controls. Several regions included genes linked to inflammation and tumor promotion.

DISCUSSION

We concluded that having certain genetic variants was associated with an increased risk of CRC compared with healthy controls among cases with known lifestyle risk factors. The interplay of lifestyle and genetic risk factors calls for further elucidation.

Combined prediagnostic lifestyle factors and survival of breast, colorectal and lung cancer in the Norwegian Women and Cancer (NOWAC) study: a prospective cohort study

BACKGROUND

With improvements in cancer treatment and early detection, the number of people living with cancer is increasing.

OBJECTIVE

This study aimed to investigate the association between combined prediagnostic lifestyle factors, assessed by a Healthy Lifestyle Index (HLI) score, and mortality among women diagnosed with breast cancer (BC), colorectal cancer (CRC) and lung cancer (LC).

DESIGN

Prospective cohort.

SETTING

Women residing in Norway, general population.

PARTICIPANTS

Our analysis included 5032, 2468 and 1594 women from the Norwegian Women and Cancer study diagnosed with BC, CRC and LC, respectively, who responded to a questionnaire between 1996 and 2014.

EXPOSURE MEASURES

HLI score measured prior to cancer diagnosis. The HLI combines physical activity level, body mass index, smoking behaviour, alcohol consumption and dietary habits.

OUTCOME MEASURES

We estimated HRs and 95% CIs using Cox proportional hazard models for all-cause and site-specific cancer mortality.

RESULTS

After median follow-up times of 9.8, 7.1 and 5.9 years for BC, CRC and LC cases, respectively, there were 912, 902 and 1094 all-cause deaths; and 509 BC deaths, 679 CRC deaths and 961 LC deaths. For women diagnosed with BC, a 1-point HLI score increment was associated with a 6% lower all-cause mortality rate (HR: 0.94, 95% CI: 0.92 to 0.97). The data were compatible with no association for the estimated 3% lower BC mortality rate (HR: 0.97, 95% CI: 0.94 to 1.00) among women diagnosed with BC, and for the estimated 3% lower all-cause (HR: 0.97, 95% CI: 0.95 to 1.00) and 2% lower CRC mortality rates (HR: 0.98, 95% CI: 0.95 to 1.01) among women diagnosed with CRC. For women diagnosed with LC, prediagnostic HLI score was not associated with all-cause (HR: 1.00, 95% CI: 0.98 to 1.02) or LC mortality rates (HR: 1.00, 95% CI: 0.98 to 1.03).

CONCLUSIONS

We observed that a higher HLI score measured before cancer diagnosis was associated with lower all-cause and, possibly, lower BC mortality among Norwegian women diagnosed with BC; and a possible lower all-cause and CRC mortality among those diagnosed with CRC. Smoking was likely responsible for the observed associations.

The mortality burden of cachexia or weight loss in patients with colorectal or pancreatic cancer: A systematic literature review

Cancer-associated cachexia is a multifactorial wasting disorder characterized by anorexia, unintentional weight loss (skeletal muscle mass with or without loss of fat mass), progressive functional impairment, and poor prognosis. This systematic literature review (SLR) examined the relationship between cachexia and survival in patients with colorectal or pancreatic cancer in recent literature. The SLR was conducted following PRISMA guidelines. Embase® and PubMed were searched to identify articles published in English between 1 January 2016 and 10 October 2021 reporting survival in adults with cancer and cachexia or at risk of cachexia, defined by international consensus (IC) diagnostic criteria or a broader definition of any weight loss. Included publications were studies in ≥100 patients with colorectal or pancreatic cancer. Thirteen publications in patients with colorectal cancer and 13 with pancreatic cancer met eligibility criteria. Included studies were observational and primarily from Europe and the United States. Eleven studies (42%) reported cachexia using IC criteria and 15 (58%) reported any weight loss. An association between survival and cachexia or weight loss was assessed across studies using multivariate (n = 23) or univariate (n = 3) analyses and within each study across multiple weight loss categories. Cachexia/weight loss was associated with a statistically significantly poorer survival in at least one weight loss category in 16 of 23 studies that used multivariate analyses and in 1 of 3 studies (33%) that used univariate analyses. Of the 17 studies demonstrating a significant association, 9 were in patients with colorectal cancer and 8 were in patients with pancreatic cancer. Cachexia or weight loss was associated with significantly poorer survival in patients with colorectal or pancreatic cancer in nearly two-thirds of the studies. The classification of weight loss varied across and within studies (multiple categories were evaluated) and may have contributed to variability. Nonetheless, awareness of cachexia and routine assessment of weight change in clinical practice in patients with colorectal or pancreatic cancer could help inform prognosis and influence early disease management strategies.

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

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

Combined associations of a healthy lifestyle and body mass index with colorectal cancer recurrence and survival: a cohort study

PURPOSE

Colorectal cancer (CRC) risk is associated with modifiable lifestyle factors including smoking, physical inactivity, Western diet, and excess body weight. The impact of lifestyle factors on survival is less known. A cohort study was conducted to investigate the combined effects of a healthy lifestyle and body mass index on prognosis following CRC diagnosis.

METHODS

Treatment and follow-up data were collected from the patient files of 1098 participants from the Colorectal cancer low-risk study cohort including stage I-III CRC patients. A healthy lifestyle and BMI (HL) score was computed using self-reported data on smoking status, physical activity, adherence to a Mediterranean diet pattern, and BMI, and divided into four categories ranging from least to most healthy. Survival analyses were performed to assess recurrence-free survival and overall survival across categories of exposure, using the Kaplan-Meier method and Cox proportional hazards models adjusted for age, sex, and educational level.

RESULTS

Among 1098 participants with stage I-III CRC, 233 (21.2%) had an HL score of 0-1 (least healthy), 354 (32.2%) HL score of 2, 357 (32.5%) HL score of 3 and 154 (14.0) HL score 4 (most healthy). Patients with the healthiest lifestyle (HL score 4) compared to the least healthy (HL score 0-1) had an improved recurrence-free survival (HL 4 vs HL 0-1, HRadj 0.51 (95% CI 0.31-0.83) and overall survival (HL 4 vs HL 0-1, HRadj 0.52 (95% CI 0.38-0.70).

CONCLUSION

Adherence to a healthy lifestyle may increase the recurrence-free and overall survival of patients with stage I-III CRC.

Clinical impact of sarcopenia for overweight or obese patients with colorectal cancer

BACKGROUND

Sarcopenia, overweight and obesity are all dynamic changes in body composition, which may have a negative effect on the prognosis for patients with colorectal cancer. The aim of this study was to investigate the predictive role of sarcopenia on overweight or obese patients with colorectal cancer.

METHODS

We conducted an observative study on the population of overweight or obese patients with colorectal cancer who underwent curative surgeries in two centers between 2015 and 2021. They were grouped by the presence of sarcopenia. Propensity score match analysis was used to balance the baseline of clinicopathologic characteristics of the two groups. Then, the postoperative outcomes between the two groups were compared. Independent risk factors were evaluated for complications using univariate and multivariate analysis.

RESULTS

Of 827 patients enrolled, 126 patients were matched for analysis. Patients with sarcopenia had a higher incidence of total complication and medical complications, a higher rate of laparoscopic surgery performed and higher hospitalization costs. Old age (≥65 years, P = 0.012), ASA grade (III, P = 0.008) and sarcopenia (P = 0.036) were independent risk factors for total complications. ASA grade (III, P = 0.002) and sarcopenia (P = 0.017) were independent risk factors for medical complications.

CONCLUSIONS

Sarcopenia was prevalent among overweight or obese patients with colorectal cancer and was associated with negative postoperative outcomes. Early recognition of changes in body composition could help surgeons be well prepared for surgical treatment for overweight or obese patients.

Obesity paradox as a new insight from postoperative complications in gastric cancer

The obesity paradox is reported to exist in various diseases. However, obesity is a pivotal issue in gastric cancer (GC) patients because of the surgical difficulty related to postoperative abdominal infectious complications (PAIC). This study clarified the existence of the obesity paradox in GC. Between 1997 and 2015, 1536 consecutive patients underwent curative gastrectomy. Of all patients, 18.6% (285/1536) were obese and tended to have a better prognosis (P = 0.073). In patients without PAIC, obesity was a significant prognostic factor for 5-year overall survival (P = 0.017). PAIC was an independent poor prognostic factor in both obese and non-obese patients (P < 0.001; hazard ratio [HR] 4.22 and 1.82). In pStage II-III patients, there was a large and significant prognostic difference between non-PAIC and PAIC obese patients (P = 0.006; 5-year overall survival: 69.7% vs. 43.8%) related to the higher incidence of peritoneal recurrence in PAIC obese patients (P = 0.035; 31% vs. 10%). Whereas, there was a small prognostic difference between non-PAIC and PAIC non-obese patients (P = 0.102; 5-year overall survival: 56.5% vs. 51.9%). Although the obesity paradox is present in GC, PAIC had a more negative prognostic impact through peritoneal recurrence in obese GC patients.

Assessment of Body Mass Index, Polygenic Risk Score, and Development of Colorectal Cancer

IMPORTANCE

Excess weight, the prevalence of which is high and increasing in many countries, is linked to multiple adverse health outcomes, including increased colorectal cancer (CRC) risk. Better communication of health risks associated with excess weight might support efforts of prevention.

OBJECTIVE

To evaluate the individual and joint associations of body mass index (BMI) and polygenic risk with CRC, to assess potential interactions among them, and to quantify by how much increased polygenic risk for CRC can be offset by having a BMI within reference range.

DESIGN, SETTING, AND PARTICIPANTS

This population-based case-control study was conducted in the Rhine-Neckar region of southwest Germany, with recruitment from 2003 to 2017. Participants with both risk factor and genetic information were included for analysis. Data analysis was conducted from December 8, 2021, to February 17, 2022.

EXPOSURES

BMI was calculated as self-reported weight in kilograms approximately 10 years before diagnosis or interview and current height in meters squared. A polygenic risk score (PRS) was built based on 140 CRC-related risk loci.

MAIN OUTCOMES AND MEASURES

Individual and joint associations of BMI and PRS with CRC were estimated using multiple logistic regression. Associations of excess weight with CRC were quantified by adjusted odds ratios (aORs) and genetic risk equivalents (GREs), the equivalent outcomes conveyed by defined differences in PRS percentiles.

RESULTS

Among 9169 participants (median [IQR] age, 69 [62-76] years; 5589 [61.0%] male participants) included, 5053 had CRC and 4116 did not. BMI of 30 or greater was associated with higher odds of having CRC compared with BMI less than 25 (aOR, 1.71; 95% CI, 1.49-1.97), independent of PRS levels (P for interaction = .45). Participants with BMI of 30 or greater and a PRS in the highest tertile had higher odds of CRC compared with participants with BMI less than 25 and a PRS in the lowest tertile (aOR, 3.82; 95% CI, 3.03-4.82). The estimated association of BMI greater than 30 with CRC risk was equivalent to that of having a 41 (95% CI, 29-53)-percentile higher PRS. BMI of 30 or greater was particularly associated with stage IV CRC (aOR, 2.21; 95% CI, 1.71-2.84).

CONCLUSIONS AND RELEVANCE

These findings suggest that excess weight was associated with CRC regardless of PRS levels. The association of having a BMI within reference range may be similar to that of having a substantially lower polygenic risk for CRC.

Associations of cigarette smoking, alcohol drinking and body mass index with survival after colorectal cancer diagnosis by anatomic subsite: a prospective patient cohort study in Japan

BACKGROUND

Cigarette smoking, alcohol drinking and obesity are known to be risk factors for colorectal cancer. These factors may affect survival after diagnosis, but evidence has been inconsistent. We investigated subsite-specific associations between prediagnosis smoking, alcohol drinking and body mass index and survival in colorectal cancer.

METHODS

Subjects were 1300 patients (colon 778; rectum 502; concurrent 20) with histologically confirmed colorectal cancer diagnosed during 1997-2013 at a single institution in Japan. Histories of smoking and alcohol drinking, height and prediagnosis weight were assessed using a self-administered questionnaire. Using Cox proportional hazards model, hazard ratios and 95% confidence intervals of mortality were estimated.

RESULTS

During a median follow-up period of 6.7 years, 479 deaths were documented. Ever-smoking was associated with an increased risk of all-cause death among patients with colon cancer (hazard ratio: 1.47; 95% confidence interval: 1.07-2.02 compared with never-smoking). According to colon subsite, this increased risk was clear in patients with proximal colon cancer (hazard ratio: 2.09; 95% confidence interval: 1.28-3.40). There was no association between smoking and rectal cancer survival. Alcohol drinking was not associated with survival for either colon or rectal cancer. Among patients with rectal cancer, higher body mass index was associated with a lower risk of all-cause (Ptrend = 0.0006) and disease-specific death (Ptrend = 0.02). For colon cancer, lower body mass index tended to be associated with a higher risk of all-cause death (Ptrend = 0.05).

CONCLUSIONS

The results indicate that lifestyles identified as risk factors for colorectal cancer may impact differently on patient survival according to anatomic subsite.

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

CONTEXT

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

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTION

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

DATA EXTRACTION

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

DATA ANALYSIS

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

RESULTS

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

CONCLUSIONS

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

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020202320.

Consensus molecular subtype differences linking colon adenocarcinoma and obesity revealed by a cohort transcriptomic analysis

Colorectal cancer (CRC) is the third-leading cause of cancer-related deaths in the United States and worldwide. Obesity—a worldwide public health concern—is a known risk factor for cancer including CRC. However, the mechanisms underlying the link between CRC and obesity have yet to be fully elucidated in part because of the molecular heterogeneity of CRC. We hypothesized that obesity modulates CRC in a consensus molecular subtype (CMS)-dependent manner. RNA-seq data and associated tumor and patient characteristics including body weight and height data for 232 patients were obtained from The Cancer Genomic Atlas–Colon Adenocarcinoma (TCGA-COAD) database. Tumor samples were classified into the four CMSs with the CMScaller R package; body mass index (BMI) was calculated and categorized as normal, overweight, and obese. We observed a significant difference in CMS categorization between BMI categories. Differentially expressed genes (DEGs) between obese and overweight samples and normal samples differed across the CMSs, and associated prognostic analyses indicated that the DEGs had differing associations on survival. Using Gene Set Enrichment Analysis, we found differences in Hallmark gene set enrichment between obese and overweight samples and normal samples across the CMSs. We constructed Protein-Protein Interaction networks and observed differences in obesity-regulated hub genes for each CMS. Finally, we analyzed and found differences in predicted drug sensitivity between obese and overweight samples and normal samples across the CMSs. Our findings support that obesity impacts the CRC tumor transcriptome in a CMS-specific manner. The possible associations reported here are preliminary and will require validation using in vitro and animal models to examine the CMS-dependence of the genes and pathways. Once validated the obesity-linked genes and pathways may represent new therapeutic targets to treat colon cancer in a CMS-dependent manner.

Associations of weight changes with all-cause, cancer and cardiovascular mortality: A prospective cohort study

Objectives

Previous studies suggest that changes in body weight can lead to an increased risk of mortality in the general population, although the results are controversial. The current study sought to investigate this association further using data from the UK Biobank.

Study design

This is a large prospective population-based cohort study. Data were derived from the UK Biobank, with the initial assessments commencing between 2006 and 2010.

Methods

Proportional hazard models were used to assess the association between self-reported weight change and risk of all-cause, cancer and cardiovascular mortality. The effect of gender was also investigated.

Results

Of 433,829 participants with data for self-reported weight change, the mean age was 56 (standard deviation [SD]: 8.1) years and 55% were female. In total, 55% of participants reported no weight change, 28% gained weight, 15% lost weight, 2% did not know and 0.1% preferred not to give an answer. The median follow-up was 7.1 (interquartile range [IQR]: 6.4–7.8) years. Compared with participants with no weight change, those with weight loss had an increased risk of all-cause mortality (adjusted hazard ratio [HR] 1.25, 95% confident interval [CI] 1.18–1.32), cancer death (HR 1.17, 95% CI 1.08–1.27) and cardiovascular death (HR 1.26, 95% CI 1.12–1.43). Similarly, participants reporting weight gain also had an increased risk of all-cause mortality (HR 1.08, 95% CI 1.02–1.13), cancer death (HR 1.14, 95% CI 1.07–1.22) and cardiovascular death (HR 1.27, 95% CI 1.14–1.42). Participants who had a response ‘do not know’ or ‘prefer not to answer’ showed an increased risk of all-cause and cardiovascular mortality, particularly in men.

Conclusions

The results of this study highlight the importance of maintaining a stable weight in middle-aged adults. Further studies are needed to understand the pathophysiology of weight change and its effects on mortality.

Impact of a ketogenic diet intervention during radiotherapy on body composition: IV. Final results of the KETOCOMP study for rectal cancer patients

BACKGROUND & AIMS

Obesity and low muscle mass are associated with worse outcomes of colorectal cancer patients. We conducted a controlled trial to study the impact of a ketogenic diet (KD) based on natural foods versus an unspecified standard diet (SD) on body composition in rectal cancer patients undergoing radiotherapy.

METHODS

Patients with non-metastasized rectal cancer were allocated to either the KD (N = 24) or the SD (N = 25) group during radiotherapy. Body composition was measured weekly by bioimpedance analysis and analyzed using linear mixed effects models. Pathologic response in patients undergoing neoadjuvant treatment was evaluated at the time of surgery.

RESULTS

A total of 18 KD and 23 SD patients completed the study and were eligible for analysis. The SD group experienced no noteworthy changes in any body composition parameter. In contrast, patients in the KD group lost significant amounts of body weight and fat mass, averaging 0.5 and 0.65 kg/week (p < 0.0001). There was a rapid loss of intracellular water consistent with initial intramuscular glycogen and water depletion, but skeletal muscle tissue was conserved. Pathological tumor responses were somewhat greater in the KD group, with a larger mean Dworak regression grade (p = 0.072) and larger percentage of near-complete (yT0N0 or yT1N1) responses (43 versus 15%, p = 0.116) that almost reached statistical significance in intention-to-treat analysis (50% versus 14%, p = 0.018).

CONCLUSIONS

In rectal cancer patients undergoing curative radiotherapy, a KD significantly reduced body weight and fat mass while preserving skeletal muscle mass. We could demonstrate a trend for KDs contributing synergistically to pathological tumor response, a finding in line with preclinical data that warrants future confirmation in larger studies.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02516501, registered on August 06, 2015.

Prevention of Advanced Cancer by Vitamin D3 Supplementation: Interaction by Body Mass Index Revisited

Meta-analyses of randomized controlled trials (RCTs) have demonstrated a protective effect of vitamin D₃ (cholecalciferol) supplementation against cancer mortality. In the VITAL study, a RCT including 25,871 men ≥ 50 years and women ≥ 55 years, protective effects of vitamin D₃ supplementation (2000 IU/day over a median of 5.3 years) with respect to incidence of any cancer and of advanced cancer (metastatic cancer or cancer death) were seen for normal-weight participants but not for overweight or obese participants. We aimed to explore potential reasons for this apparent variation of vitamin D effects by body mass index. We conducted complementary analyses of published data from the VITAL study on the association of body weight with cancer outcomes, stratified by vitamin D₃ supplementation. Significantly increased risks of any cancer and of advanced cancer were seen among normal-weight participants compared to obese participants in the control group (relative risk (RR), 1.27; 95% confidence interval (CI), 1.07-1.52, and RR, 1.44; 95% CI, 1.04-1.97, respectively). No such patterns were seen in the intervention group. Among those with incident cancer, vitamin D₃ supplementation was associated with a significantly reduced risk of advanced cancer (RR, 0.86; 95% CI, 0.74-0.99). The observed patterns point to pre-diagnostic weight loss of cancer patients and preventive effects of vitamin D₃ supplementation from cancer progression as plausible explanations for the body mass index (BMI)-intervention interactions. Further research, including RCTs more comprehensively exploring the potential of adjuvant vitamin D therapy for cancer patients, should be pursued with priority.

Cancer survivorship, excess body fatness and weight-loss intervention-where are we in 2020?

Earlier diagnosis and more effective treatments mean that the estimated number of cancer survivors in the United Kingdom is expected to reach 4 million by 2030. However, there is an increasing realisation that excess body fatness (EBF) is likely to influence the quality of cancer survivorship and disease-free survival. For decades, the discussion of weight management in patients with cancer has been dominated by concerns about unintentional weight loss, low body weight and interventions to increase weight, often re-enforced by the existence of the obesity paradox, which indicates that high body weight is associated with survival benefits for some types of cancer. However, observational evidence provides strong grounds for testing the hypothesis that interventions for promoting intentional loss of body fat and maintaining skeletal muscle in overweight and obese cancer survivors would bring important health benefits in terms of survival outcomes and long-term impact on treatment-related side effects. In this paper, we outline the need for studies to improve our understanding of the health benefits of weight-loss interventions, such as hypocaloric healthy-eating plans combined with physical activity. In particular, complex intervention trials that are pragmatically designed are urgently needed to develop effective, clinically practical, evidence-based strategies for reducing EBF and optimising body composition in people living with and beyond common cancers.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The Impact of Body Mass Index on the Clinicopathological and Prognostic Factors of Colorectal Cancer in Saudi Arabia

Background Obesity is a known risk factor of colorectal cancer (CRC); however, the relationship between obesity and clinicopathologic characteristics and prognosis of CRC remains unclear. This study aimed to investigate the relationship between body mass index (BMI) and clinicopathological and prognostic factors of CRC in Saudi Arabia. Method This was a retrospective cross-sectional study of patients with CRC diagnosed between 2014 and 2018 at King Abdulaziz University Hospital in Jeddah, Saudi Arabia. BMI was calculated by dividing the patient's weight in kilograms by height in meter squared and was classified according to the World Health Organization criteria. Statistical tests, including analysis of variance and chi-square tests, were used to investigate the relationship of each BMI category with clinicopathologic (histological type, degree of differentiation, tumor location, and medical comorbidities) and prognostic variables (TNM stage, lymph nodes involvement, and lymph nodes yield). Results Of 233 patients who were included, 60.1% were male and 39.9% were female patients, with a mean age (standard deviation) of 58.8 ± 13.7 (range: 26-99) years. The median BMI was 26.5 kg/m². Overall, 3%, 34.3%, 33.0%, and 29.6% patients were classified as underweight, normal weight, overweight, and obese, respectively. Furthermore, 57.1% (4/7), 39.2% (31/80), 38.7% (29/77), and 25.8% (17/69) of underweight, normal, overweight, and obese patients had Stage IV disease (p = 0.20). Of 16 patients with transverse colon cancer, 8 (50%) were obese (p = 0.38), and 1 (6%), 5 (31%), and 2 (13%) were underweight, normal weight, and overweight, respectively. Conclusion Underweight patients are more likely to present with metastatic CRC, while obese patients are more likely to present at earlier stages, although the difference was not statistically significant. BMI is not related to lymph node yield, histological type, or the degree of differentiation.

High body mass index is associated with an increased overall survival in rectal cancer

Background

The impact of increased body mass index (BMI) on clinical outcomes in locoregional rectal cancer is unknown.

Methods

This is a retrospective cohort study which included 453 consecutive rectal cancer patients undergoing definitive treatment, with confirmed stage I, II or III rectal adenocarcinoma. The association of BMI at diagnosis with overall survival (OS), cancer specific survival (CSS) and disease-free survival (DFS) was explored, controlling for key covariates using multivariable analyses. BMI as defined by the World Health Organization (WHO) is as follows: BMI <18.5-underweight; 18.5-24.9-normal; 25.0-29.9-pre-obesity; >30-obese.

Results

Overweight and obese patients had significantly better OS than underweight/normal weight patients (5-year OS 80% for overweight, 77% for obese, and 65% for underweight/normal weight patients, P=0.02). High BMI (>25) was significantly associated with improved OS in univariate [0.62 (0.4-0.8) P=0.007] and multivariable [0.65 (0.4-0.9) P=0.023] analyses. When stratified by stage, high BMI was associated with improved OS in stage III patients (P=0.0009), but not stage II (P=0.21) or stage I (0.54). High BMI was also significantly associated with improved CSS in univariate (HR 0.62, P=0.048) and multivariable analyses (HR 0.58, P=0.03).

Conclusions

In our study a BMI greater than 25 is significantly associated with a longer OS and CSS in patients with locoregional rectal cancer. These findings may be due to the reduced metabolic capacity for non-obese patients to deal with rectal cancer treatment as well as the burden of disease, however further research is needed to evaluate this.

Postoperative BMI Loss at One Year Correlated with Poor Outcomes in Chinese Gastric Cancer Patients

Purpose: The present study focused on the long-term prognostic value of dynamic body mass index (BMI) change in gastric cancer patients who underwent gastrectomy. Methods: Clinical data from a total of 576 gastric cancer patients who underwent radical gastrectomy were collected. Univariate and multivariate analyses were performed to demonstrate the association between dynamic BMI variables (BMI before surgery, 1 month, 6 months or 12 months after surgery) and prognosis (DFS and OS). The correlation between BMI loss after surgery and survival outcomes was also evaluated. Results: Post-operative BMI, especially BMI at one year after surgery (p<0.001), was an independent risk factor of recurrence and mortality, wherein patients with high-BMI (≥23) showed significantly better outcomes than patients with normal-BMI (18.5-23) (DFS, HR:0.49; 95% CI:0.31-0.78; OS, HR:0.30; 95% CI: 0.15-0.59). On the contrary, low-BMI (<18.5) patients presented with worse outcomes (DFS, HR: 1.34; 95% CI: 1.00-1.80; OS, HR: 1.68; 95% CI: 1.20-2.34). In addition, compared with moderate BMI loss (≤10%), severe postoperative BMI loss (>10%) at one year was independently associated with substantially worse prognosis for DFS (HR: 1.54; 95% CI: 1.15-2.08) and OS (HR: 1.45; 95% CI: 1.02-2.06). Subgroup analysis indicated that gender (p=0.03), extent of resection (p<0.001), tumor site (p=0.001) and perineural invasion (p=0.007) were associated with postoperative BMI loss at one year. The prognostic value of postoperative BMI loss at one year was consistent among most clinicopathological subgroups, except for tumor site (interaction p=0.025 for OS). Conclusion: In Chinese gastric cancer patients who underwent gastrectomy, higher postoperative BMI (≥ 23) was significantly associated with longer survival time, whereas severe BMI loss (>10%) at one year after surgery was associated with worse outcomes. Thus, body weight maintenance after treatment is important, and dynamic monitoring of body weight and nutritional status should be emphasized in clinical practice.

Estimation of Absolute Risk of Colorectal Cancer Based on Healthy Lifestyle, Genetic Risk, and Colonoscopy Status in a Population-Based Study

BACKGROUND & AIMS

Estimates of absolute risk of colorectal cancer (CRC) are needed to facilitate communication and better inform the public about the potentials and limits of cancer prevention.

METHODS

Using data from a large population-based case-control study in Germany (Darmkrebs: Chancen der Verhütung durch Screening [DACHS] study, which began in 2003) and population registry data, we calculated 30-year absolute risk estimates for development of CRC based on a healthy lifestyle score (derived from 5 modifiable lifestyle factors: smoking, alcohol consumption, diet, physical activity, and body fatness), a polygenic risk score (based on 90 single-nucleotide polymorphisms), and colonoscopy history.

RESULTS

We analyzed data from 4220 patients with CRC and 3338 individuals without CRC. Adherence to a healthy lifestyle and colonoscopy in the preceding 10 years were associated with a reduced relative risk of CRC in men and women. We observed a higher CRC risk in participants with high or intermediate genetic risk scores. For 50-year-old men and women without a colonoscopy, the absolute risk of CRC varied according to the polygenic risk score and the healthy lifestyle score (men, 3.5%-13.4%; women, 2.5%-10.6%). For 50-year-old men and women with a colonoscopy, the absolute risk of developing CRC was much lower but still varied according to the polygenic risk score and the healthy lifestyle score (men, 1.2%-4.8%; women, 0.9%-4.2%). Among all risk factor profiles, the 30-year absolute risk estimates consistently decreased with adherence to a healthy lifestyle.

CONCLUSIONS

In a population-based study, we found that a colonoscopy can drastically reduce the absolute risk of CRC and that the genetically predetermined risk of CRC can be further reduced by adherence to a healthy lifestyle. Our results show the magnitude of CRC prevention possible through colonoscopy and lifestyle at a predefined genetic risk. This observational study has been registered in the German Clinical Trials Register (DRKS00011793), which is a primary registry in the World Health Organization Registry Network.

The association of serum lipid levels with colorectal cancer recurrence

BACKGROUND

Biologic and epidemiologic evidence suggests that tumor cells depend on reprogrammed lipid metabolic function for survival and growth. Lipids may promote tumor recurrence by providing energy needed for proliferation. Studies have found associations of serum lipids with cancer incidence, mortality, and disease-free mortality, though they have yet to evaluate the prognostic potential of serum lipids for colorectal cancer (CRC) recurrence.

METHODS

341 Danish CRC patients who underwent surgical resection were actively followed between 2003-2011 from date of surgery until December 31, 2012, or death. Serum lipids including low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG), were collected at regular intervals. Lipids were assigned as time-varying exposures evaluated with a one-year lag. Cox proportional hazards models were used to assess recurrence rate, adjusting for clinically relevant covariates. A restricted analysis was performed in a group of non-statin users (n = 236).

RESULTS

Among 341 CRC patients, increased HDL-C appeared to have a beneficial impact on recurrence-free survival (RFS) for CRC patients, especially among statin users (hazard ratio [HR] for 0.1 mmol/L increase = 0.58; 95 % confidence interval [CI]: 0.43, 0.78). Increased LDL-C and TG were not associated with RFS. Increased lipids showed a near-null effect on CRC recurrence [e.g. HR (95 % CI) for 0.1 mmol/L increase LDL = 1.01 (0.97, 1.19)] among non-statin users.

CONCLUSION

Serum lipid levels of LDL-C and TG do not appear to be associated with CRC recurrence. Further investigation of the role of HDL-C in CRC recurrence may be of interest based on the suggestive inverse association observed here.

The association between patient body mass index and perioperative outcomes following radical cystectomy: An analysis using the American College of Surgeons National Surgical Quality Improvement Program database

INTRODUCTION

Radical cystectomy is a highly morbid procedure, with 30-day perioperative complication rates approaching 50%. Our objective was to determine the effect of patients' body mass index (BMI) on perioperative outcomes following radical cystectomy for bladder cancer.

METHODS

We identified 3930 eligible patients who underwent radical cystectomy for non-metastatic bladder cancer using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. The primary exposure was preoperative BMI, categorically operationalized in four strata according to the World Health Organization criteria: <18.5 kg/m², 18.5-25 kg/m², 25-30 kg/m², and >30 kg/m². Our primary outcome was major perioperative complication comprising mortality, reoperation, cardiac event, or neurological event.

RESULTS

BMI was significantly associated with rates of major complications (p=0.003): major complications were experienced by 17.0% of patients with BMI <18.5 kg/m², 7.8% of patients with BMI 18.5-25 kg/m², 7.9% of patients with BMI 25-30 kg/m², and 10.8% of patient with BMI >30 kg/m². Following multivariable adjustment for relevant demographic, comorbidity, and treatment factors, compared to patients with BMI 18.5-25 kg/m², patients with BMI <18.5 kg/m² (odds ratio [OR] 2.28, 95% confidence interval [CI] 1.07-4.78) and BMI >30 kg/m² (OR 1.59, 95% CI 1.17-2.16) were significantly more likely to experience a major complication in the 30 days following cystectomy. Among the secondary outcomes, significant differences were identified in rates of pulmonary complications (p=0.003), infectious complications (p<0.001), bleeding requiring transfusion (p=0.01), and length of stay (p=0.001).

CONCLUSIONS

Patients who are outside of a normal BMI range are more likely to experience major complications following radical cystectomy for bladder cancer.

Optimal Body Mass Index Cut-off Point for Predicting Colorectal Cancer Survival in an Asian Population: A National Health Information Database Analysis

The optimal body mass index (BMI) range for predicting survival in Asian colorectal cancer patients is unknown. We established the most appropriate cut-off point of BMI to predict better survival in Asian colorectal cancer patients using a two-stage approach. Two cohorts of colorectal cancer patients were included in this study: 5815 hospital-based development cohort and 54,043 nationwide validation cohort. To determine the optimal BMI cut-off point at diagnosis, the method of Contal and O’Quigley was used. We evaluated the association between BMI and overall survival (OS) using the Cox proportional hazard model. During a median follow-up of 5.7 and 5.1 years for the development and the validation cohort, 1180 (20.3%) and 10,244 (19.0%) deaths occurred, respectively. The optimal cut-off of BMI identified as 20.2 kg/m² (p_log-rank < 8.0 × 10⁻¹⁶) for differentiating between poorer and better OS in the development cohort. When compared to the patients with a BMI < 20.2 kg/m², the patients with a BMI ≥ 20.2 kg/m² had a significantly better OS (HR = 0.62, 95% CI = 0.54–0.72, p = 1.1 × 10⁻¹⁰). The association was validated in the nationwide cohort, showing better OS in patients with a BMI ≥ 20.2 kg/m² (HR = 0.64, 95% CI = 0.60–0.67, p < 0.01). We suggest the use of a BMI value of 20.2 kg/m² to predict survival in Asian colorectal cancer patients.

Association of BMI and major molecular pathological markers of colorectal cancer in men and women

BACKGROUND

Observational studies have consistently shown that a high BMI is associated with increased risk of colorectal cancer (CRC). However, the underlying mechanisms linking obesity to CRC remain unclear.

OBJECTIVES

To investigate the associations of BMI and CRC by major molecular pathological subtypes of CRC.

METHODS

This analysis included 2407 cases and 2454 controls from a large German population-based case-control study. Information on recent weight and height as well as other demographic and lifestyle data were obtained by standardized interviews. Multinomial logistic regression was used to estimate ORs and 95% CIs for the associations between BMI and risk of CRC by major molecular pathological features: microsatellite instability (MSI), CpG island methylator phenotype (CIMP), B-Raf proto-oncogene serine/threonine kinase (BRAF) mutation, and Kirsten rat sarcoma viral oncogene homolog gene (KRAS) mutation.

RESULTS

Among women, a higher BMI was differentially and more strongly associated with risk of MSI CRC (OR per 5 kg/m2: 1.69; 95% CI: 1.34, 2.12; Pheterogeneity ≤ 0.001), CIMP-high CRC (OR per 5 kg/m2: 1.57; 95% CI: 1.30, 1.89; Pheterogeneity ≤ 0.001), BRAF-mutated CRC (OR per 5 kg/m2: 1.56; 95% CI: 1.22, 1.99; Pheterogeneity = 0.04), and KRAS-wildtype CRC (OR per 5 kg/m2: 1.35; 95% CI: 1.17, 1.54; Pheterogeneity = 0.01), compared with the risk of CRC in subjects with the molecular feature counterpart. In men, no meaningful differences in CRC risk were observed for the investigated molecular feature pairs. For the association of BMI with MSI CRC, we observed effect modification by sex (Pinteraction = 0.04). Also, in women, the risk of CRC with the serrated pathway features was more strongly increased with higher BMI than risk of CRC with the traditional pathway features (OR per 5 kg/m2: 1.73; 95% CI: 1.28, 2.34; Pheterogeneity = 0.01).

CONCLUSIONS

In women, the relation between BMI and MSI-high CRC seems to be stronger than that between BMI and microsatellite-stable CRC. However, a validation in an independent cohort is needed. This observational study was registered at the German Clinical Trials Register (http://www.drks.de; study ID: DRKS00011793), an approved primary register in the WHO network.

Healthy Lifestyle Factors Associated With Lower Risk of Colorectal Cancer Irrespective of Genetic Risk

BACKGROUND & AIMS

The combined effects of healthy lifestyle factors on colorectal cancer (CRC) risk are unclear. We aimed to develop a healthy lifestyle score, to investigate the joint effects of modifiable lifestyle factors on reduction of CRC risk and determine whether associations differ with genetic risk.

METHODS

We collected data from a large population-based case-control study in Germany and used multiple logistic regression analyses to examine associations between the healthy lifestyle score (derived from 5 modifiable lifestyle factors: smoking, alcohol consumption, diet, physical activity, and body fatness) and CRC risk. We created a genetic risk score, based on 53 risk variants, to investigate the association of the healthy lifestyle score and risk of CRC, stratified by genetic risk.

RESULTS

We included 4092 patients with CRC and 3032 individuals without CRC (controls) in our analysis. In adjusted models, compared with participants with 0 or 1 healthy lifestyle factor, participants with 2 (odds ratio [OR] 0.85; 95% confidence interval [CI] 0.67-1.06), 3 (OR 0.62; 95% CI 0.50-0.77), 4 (OR 0.53; 95% CI 0.42-0.66), or 5 (OR 0.33; 95% CI 0.26-0.43) healthy lifestyle factors had increasingly lower risks of CRC (P trend <.0001). We found no differences among subgroups stratified by genetic risk score, history of colonoscopy, or family history of CRC. Overall, 45% of CRC cases (95% CI 34%-53%) could be attributed to nonadherence to all 5 healthy lifestyle behaviors.

CONCLUSIONS

In a large population-based case-control study, we identified a combination of lifestyle factors that appears to reduce risk of CRC, regardless of the patient's genetic profile. These results reinforce the importance of primary prevention of CRC.

Pre-to-post diagnosis weight trajectories in colorectal cancer patients with non-metastatic disease

PURPOSE

Previous studies have shown that > 50% of colorectal cancer (CRC) patients treated with adjuvant chemotherapy gain weight after diagnosis. This may affect long-term health. Therefore, prevention of weight gain has been incorporated in oncological guidelines for CRC with a focus on patients that undergo adjuvant chemotherapy treatment. It is, however, unknown how changes in weight after diagnosis relate to weight before diagnosis and whether weight changes from pre-to-post diagnosis are restricted to chemotherapy treatment. We therefore examined pre-to-post diagnosis weight trajectories and compared them between those treated with and without adjuvant chemotherapy.

METHODS

We included 1184 patients diagnosed with stages I-III CRC between 2010 and 2015 from an ongoing observational prospective study. At diagnosis, patients reported current weight and usual weight 2 years before diagnosis. In the 2 years following diagnosis, weight was self-reported repeatedly. We used linear mixed models to analyse weight trajectories.

RESULTS

Mean pre-to-post diagnosis weight change was -0.8 (95% CI -1.1, -0.4) kg. Post-diagnosis weight gain was + 3.5 (95% CI 2.7, 4.3) kg in patients who had lost ≥ 5% weight before diagnosis, while on average clinically relevant weight gain after diagnosis was absent in the groups without pre-diagnosis weight loss. Pre-to-post diagnosis weight change was similar in patients treated with (-0.1 kg (95%CI -0.8, 0.6)) and without adjuvant chemotherapy (-0.9 kg (95%CI -1.4, -0.5)).

CONCLUSIONS

Overall, hardly any pre-to-post diagnosis weight change was observed among CRC patients, because post-diagnosis weight gain was mainly observed in patients who lost weight before diagnosis. This was observed independent of treatment with adjuvant chemotherapy.

The colorectal cancer epidemic: challenges and opportunities for primary, secondary and tertiary prevention

Colorectal cancer (CRC) is both one of the most common and one of the most preventable cancers globally, with powerful but strongly missed potential for primary, secondary and tertiary prevention. CRC incidence has traditionally been the highest in affluent Western countries, but it is now increasing rapidly with economic development in many other parts of the world. CRC shares several main risk factors, such as smoking, excessive alcohol consumption, physical inactivity and being overweight, with other common diseases; therefore, primary prevention efforts to reduce these risk factors are expected to have multiple beneficial effects that extend beyond CRC prevention, and should have high public health impact. A sizeable reduction in the incidence and mortality of CRC can also be achieved by offering effective screening tests, such as faecal immunochemical tests, flexible sigmoidoscopy and colonoscopy, in organised screening programmes which have been implemented in an increasing number of countries. Countries with early and high uptake rates of effective screening have exhibited major declines in CRC incidence and mortality, in contrast to most other countries. Finally, increasing evidence shows that the prognosis and quality of life of CRC patients can be substantially improved by tertiary prevention measures, such as the administration of low-dose aspirin and the promotion of physical activity.

The relationship between body mass index changes during chemotherapy and prognosis of patients with advanced colorectal cancer: A retrospective cohort study

We investigated the relationships between body mass index change (ΔBMI) and prognoses and clinical effects of patients with advanced colorectal cancer (CRC).From January 2008 to December 2012, 224patients with stage IV CRC were diagnosed in our hospital, and their clinical and pathological data were collected for this retrospective study. These patients were divided into lowΔ BMI group (ΔBMI ≤-0.45 kg/m) and high ΔBMI (ΔBMI >-0.45 kg/m) group.After 2 cycles of chemotherapy, there were no significant differences between prediagnosis BMI, ΔBMI, and clinical effects (P = .196; P = .59).There was also no significant difference in median progression-free survival of the high ΔBMI and low ΔBMI groups (P = .530). The overall survival (OS) time of the high ΔBMI group was significantly longer than that of the low ΔBMI group (P = .002). Family history (P = .041), eastern cooperative oncology group performance status (ECOG PS) score (P = .001), ΔBMI (P = .023), and carcinoembryonic antigen, (P = 0.02) were independent predictive factors of OS rates in patients with CRC. The relative risk was 0.72-fold for patients with CRC patients with high ΔBMI levels, relative to those with lower ΔBMI levels.Our results demonstrate that ΔBMI decreases predict poor prognoses for patients with advanced CRC, and elevated ΔBMI was a predictive factor for high survival rate. Thus, ΔBMI appears to be an independent predictive factor of CRC survival rates.

The obesity paradox in cancer: clinical insights and perspectives

A series of evidence demonstrated that obesity represents an established risk factor for an increase in the incidence of multiple cancer types and for poor cancer survival. Nevertheless, recent studies suggested that, in a series of cancers, patients with a normal body mass index (BMI) have worse outcomes than obese patients. This phenomenon, named 'obesity paradox' or 'reverse epidemiology' in cancer, is not well understood and presents controversial aspects. Therefore, this review aims to explore the available studies concerning the relationship between obesity and cancer incidence or survival and to highlight the hypothetical explanations and the methodological framework. In this regard, we underline the limits of BMI as a potential marker of adiposity and the relevance to assessing body composition, beyond the body size. Further studies are needed to define the impact of obesity in cancer patients, to tailor weight management after cancer diagnosis and to hopefully improve overall clinical outcome.

Comparison of Basic and Ensemble Data Mining Methods in Predicting 5-Year Survival of Colorectal Cancer Patients

INTRODUCTION

Colorectal cancer (CRC) is one of the most common malignancies and cause of cancer mortality worldwide. Given the importance of predicting the survival of CRC patients and the growing use of data mining methods, this study aims to compare the performance of models for predicting 5-year survival of CRC patients using variety of basic and ensemble data mining methods.

METHODS

The CRC dataset from The Shahid Beheshti University of Medical Sciences Research Center for Gastroenterology and Liver Diseases were used for prediction and comparative study of the base and ensemble data mining techniques. Feature selection methods were used to select predictor attributes for classification. The WEKA toolkit and MedCalc software were respectively utilized for creating and comparing the models.

RESULTS

The obtained results showed that the predictive performance of developed models was altogether high (all greater than 90%). Overall, the performance of ensemble models was higher than that of basic classifiers and the best result achieved by ensemble voting model in terms of area under the ROC curve (AUC= 0.96).

CONCLUSION

AUC Comparison of models showed that the ensemble voting method significantly outperformed all models except for two methods of Random Forest (RF) and Bayesian Network (BN) considered the overlapping 95% confidence intervals. This result may indicate high predictive power of these two methods along with ensemble voting for predicting 5-year survival of CRC patients.

Lifestyle after Colorectal Cancer Diagnosis in Relation to Survival and Recurrence: A Review of the Literature

PURPOSE OF REVIEW

This review summarizes the evidence regarding diet, physical activity, smoking, and body composition after colorectal cancer (CRC) diagnosis in relation to all-cause and CRC-specific mortality and disease recurrence and gives suggestions for future research directions.

RECENT FINDINGS

Overall, this review suggests that some, albeit not all, of the well-known modifiable risk factors for cancer incidence might also be associated with CRC survival. CRC prognosis appears to be worse with increased physical inactivity, smoking, or being underweight after CRC diagnosis. Emerging evidence suggests that diets associated with a positive energy balance, e.g., high consumption of sugar-sweetened beverages, may negatively impact survival in CRC survivors. In contrast, there is currently little evidence to support the recommendation to limit red and processed meat or alcohol intake after CRC diagnosis. Whether being overweight and obese after CRC diagnosis improves or worsens CRC prognosis remains controversial and may depend on the measure used to assess body fatness.

SUMMARY

Further research on post-diagnosis lifestyle patterns is needed to understand the multifactorial influence on CRC prognosis. Disease recurrence and the development of comorbidities should be included as key outcomes in future studies and lifestyle should preferably be repeatedly measured.

Positive Effect of Higher Adult Body Mass Index on Overall Survival of Digestive System Cancers Except Pancreatic Cancer: A Systematic Review and Meta-Analysis

High body mass index (BMI) has been inconsistently associated with overall survival (OS) of digestive system cancers (DSCs). This meta-analysis was conducted to investigate whether high BMI was associated with DSCs prognosis. 34 studies were accepted, with a total of 23,946 DSC cases. Hazard ratios (HRs) with 95% confidence intervals (95% CIs) for OS in BMI categories from individual studies were extracted and pooled by random-effect model. The overall HR of DSCs except pancreatic cancer for OS of adult overweight cases was 0.76 (95% CI = 0.67–0.85). DSC individuals except pancreatic cancer with adult obesity were at decreased risk for OS (HR = 0.85, 95% CI = 0.72–0.98). Among DSC patients except pancreatic cancer, the overall HR for the highest versus the lowest BMI category was 0.82 (95% CI = 0.71–0.92). Additionally, comparing the highest and lowest BMI categories, the combined HR of pancreatic cancer was 1.22 (95% CI = 1.01–1.43). Our meta-analysis suggested an increased OS among adult overweight and obese DSC survivors except pancreatic cancer. Overweight and obesity in adulthood may be important prognostic factors that indicate an increased survival from DSC patients except pancreatic cancer.