Cholecystectomy and the risk for developing colorectal cancer and distal colorectal adenomas

Association of gallstone disease with risk of colorectal cancer: a systematic review and meta-analysis of observational studies

BACKGROUND

Numerous studies have assessed the association of gallstones or cholecystectomy (CE) with risk of colorectal cancer (CRC). However, the findings are mixed.

OBJECTIVE

To systematically review and meta-analyse the association between the presence of gallstone disease (GD), or CE and the incidence of CRC. Secondary endpoints were the risk based on type of exposure, study design, tumour subsites and sex.

METHODS

PubMed and EMBASE were searched from September 2020 to May 2021. The protocol was registered on the Open Science Foundation Platform. We identified and classified studies according to their design into prospective cohort, population-based case-control, hospital-based case-control and necropsy studies reporting CRC incidence among individuals with diagnosed GD or after CE (or both). Among 2157 retrieved studies, 65 (3%) met the inclusion criteria. We followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. Data were extracted by two independent reviewers. We evaluated the quality of the study according to the Newcastle-Ottawa Scale and only studies with a score of 6 and above were included in the final analyses. We pooled log-transformed odds ratios/risk ratios from the available adjusted models to estimate a summary relative risk (RR) and 95% confidence interval (CI) in a random-effects model. The primary outcome was overall CRC incidence. We also conducted secondary analyses according to sex and CRC subsites (proximal colon, distal colon and rectum). The outcome was measured by RRs with 95% CIs.

RESULTS

The overall association of GD and/or CE with CRC was RR = 1.15 (1.08; 1.24), primarily driven by hospital-based case-control studies [RR = 1.61 (1.29; 2.01)], whereas a more modest association was found in population-based case-control and cohort studies [RR = 1.10 (1.02; 1.19)]. Most hospital-based case-control and necropsy studies reported estimates that were adjusted for age and sex only, leaving room for residual confounding; therefore we restricted to population-based case-control and cohort studies for our subsequent analyses. Similar associations were found for women [RR = 1.21 (1.05; 1.4) and men (RR = 1.24 (1.06; 1.44)]. When assessed by CRC subsites, GD and CE were primarily associated with higher risk of proximal colon cancer [RR = 1.16 (1.07; 1.26)] but not distal colon cancer [RR = 0.99 (0.96; 1.03)] or rectal cancer [RR = 0.94 (0.89; 1.00)].

CONCLUSIONS

Gallstones are associated with a modestly increased risk of colon cancer, primarily in the proximal colon.

No association between cholecystectomy and risk of colorectal cancer: a meta-analysis of cohort studies

OBJECTIVE

Cohort studies have reported an association between colorectal cancer and cholecystectomy. However, the conclusions are inconsistent. Thus, this meta-analysis will quantify the risk of colorectal cancer following cholecystectomy.

METHODS

PubMed, EMBASE and Cochrane Library databases were searched for relevant cohort studies. The quality of individual observational studies was assessed using the Newcastle-Ottawa Quality Assessment Scale. The relative risk of colorectal cancer after cholecystectomy was calculated using STATA 14.0 software. Subgroup and sensitivity analyses were used to examine the source of heterogeneity. Funnel plots and Egger's test were finally performed to assess the publication bias.

RESULTS

This meta-analysis included 14 studies comprising 2,283,616 subjects. Pooled analysis indicated that cholecystectomy was not a risk factor for colorectal cancer (Colorectal: RR 1.06; 95% CI 0.75-1.51, p = 0.739 Colon: RR 1.30; 95% CI 0.88-1.93, p = 0.182 Rectal: RR 0.99; 95% CI 0.74-1.32, p = 0.932). Subgroup showed that patients are at an increased risk of sigmoid colon following cholecystectomy (RR 1.42; 95% CI 1.27-1.58, p = 0.000). Furthermore, it was shown that both females and males undergoing cholecystectomy may have higher risks of colon cancer (Female: RR = 1.47, 95% CI 1.01-2.14, P = 0.042 Male: RR = 1.32; 95% CI 1.07-1.63, P = 0.010), which is similarly observed in the right colon (Female: RR 1.99; 95% CI 1.31-3.03, p = 0.001, P = 0.017 Male: RR 1.68; 95% CI 0.81-3.49, p = 0.166).

CONCLUSIONS

No clear evidence to support the association between cholecystectomy and an increased risk of colorectal cancer. For patients with valid indications, timely cholecystectomy could be performed without the risk of colorectal cancer.

Does postcholecystectomy increase the risk of colorectal cancer?

With the increasing number of cholecystectomy and the high proportion of colorectal cancer in malignant tumors, the question of whether cholecystectomy is a risk factor for colorectal disease has been widely concerned. After reviewing the literature at home and abroad, the authors will summarize the research progress of the correlation between the occurrence of colorectal tumors after cholecystectomy, in order to provide help for the prevention and treatment of colorectal tumors.

Associations of cholecystectomy with the risk of colorectal cancer: a Mendelian randomization study

BACKGROUND

Cholecystectomy is a standard surgery for patients suffering from gallbladder diseases, while the causal effects of cholecystectomy on colorectal cancer (CRC) and other complications are still unknown.

METHODS

We obtained genetic variants associated with cholecystectomy at a genome-wide significant level ( P value <5 × 10 -8 ) as instrumental variables (IVs) and performed Mendelian randomization (MR) to identify the complications of cholecystectomy. Furthermore, the cholelithiasis was also treated as the exposure to compare its causal effects to those of cholecystectomy, and multivariable MR analysis was carried out to judge whether the effect of cholecystectomy was independent of cholelithiasis. The study was reported based on Strengthening the Reporting of Observational Studies in Epidemiology Using Mendelian Randomization guidelines.

RESULTS

The selected IVs explained 1.76% variance of cholecystectomy. Our MR analysis suggested that cholecystectomy cannot elevate the risk of CRC (odds ratio [OR] =1.543, 95% confidence interval [CI]: 0.607-3.924). Also, it was not significant in either colon or rectum cancer. Intriguingly, cholecystectomy might decrease the risk of Crohn's disease (OR = 0.078, 95% CI: 0.016-0.368) and coronary heart disease (OR = 0.352, 95% CI: 0.164-0.756). However, it might increase the risk of irritable bowel syndrome (IBS) (OR = 7.573, 95% CI: 1.096-52.318). Cholelithiasis could increase the risk of CRC in the largest population (OR = 1.041, 95% CI: 1.010-1.073). The multivariable MR analysis suggested that genetic liability to cholelithiasis could increase the risk of CRC in the largest population (OR = 1.061, 95% CI: 1.002-1.125) after adjustment of cholecystectomy.

CONCLUSIONS

The study indicated that cholecystectomy might not increase the risk of CRC, but such a conclusion needs further proving by clinical equivalence. Additionally, it might increase the risk of IBS, which should be paid attention to in clinical practice.

Cholecystectomy promotes the development of colorectal cancer by the alternation of bile acid metabolism and the gut microbiota

The incidence and mortality of colorectal cancer (CRC) have been markedly increasing worldwide, causing a tremendous burden to the healthcare system. Therefore, it is crucial to investigate the risk factors and pathogenesis of CRC. Cholecystectomy is a gold standard procedure for treating symptomatic cholelithiasis and gallstone diseases. The rhythm of bile acids entering the intestine is altered after cholecystectomy, which leads to metabolic disorders. Nonetheless, emerging evidence suggests that cholecystectomy might be associated with the development of CRC. It has been reported that alterations in bile acid metabolism and gut microbiota are the two main reasons. However, the potential mechanisms still need to be elucidated. In this review, we mainly discussed how bile acid metabolism, gut microbiota, and the interaction between the two factors influence the development of CRC. Subsequently, we summarized the underlying mechanisms of the alterations in bile acid metabolism after cholecystectomy including cellular level, molecular level, and signaling pathways. The potential mechanisms of the alterations on gut microbiota contain an imbalance of bile acid metabolism, cellular immune abnormality, acid-base imbalance, activation of cancer-related pathways, and induction of toxin, inflammation, and oxidative stress.

Alterations of Fungal Microbiota in Patients With Cholecystectomy

Increasing evidence suggests a high risk of gastrointestinal postoperative comorbidities (such as colorectal cancer) in patients with postcholecystectomy (PC). Although previous studies implicated the role of fungi in colon carcinogenesis, few reports focused on the fungal profile in patients with PC. We enrolled 104 subjects, including 52 patients with PC and 52 non-PC controls (CON), for fecal collection to detect the fungal composition by an internal transcribed spacer (ITS) 1 rDNA sequencing. Data showed that Candida (C.) glabrata and Aspergillus (A.) Unassigned were enriched, and Candida albicans was depleted in patients with PC. In addition, postoperative duration was the main factor to affect the fungal composition. Machine learning identified that C. glabrata, A. Unassigned, and C. albicans were three biomarkers to discriminate patients with PC from CON subjects. To investigate the fungal role in colon carcinogenesis, the subjects of the PC group were divided into two subgroups, namely, patients with PC without (non-CA) and with precancerous lesions or colorectal cancer (preCA_CRC), by histopathological studies. C. glabrata was found to be gradually accumulated in different statuses of patients with PC. In conclusion, we found fungal dysbiosis in patients with cholecystectomy, and the postoperative duration was a potent factor to influence the fungal composition. The accumulation of C. glabrata might be connected with carcinogenesis after cholecystectomy.

Increased Risk of Cancer after Cholecystectomy: A Nationwide Cohort Study in Korea including 123,295 Patients

Background/Aims

Contradictory findings on the association between cholecystectomy and cancer have been reported. We aimed to investigate the risk of all types of cancers or site-specific cancers in patients who underwent cholecystectomy using a nationwide dataset.

Methods

Subjects who underwent cholecystectomy from January 1, 2007, to December 31, 2014, who were older than 20 years and who underwent an initial baseline health check-up within 2 years were enrolled. Those who were diagnosed with any type of cancer before the enrollment or within 1 year after enrollment were excluded. Ultimately, patients (n=123,295) who underwent cholecystectomy and age/sex matched population (n=123,295) were identified from the database of the Korean National Health Insurance Service. The hazard ratio (HR) and 95% confidence interval (CI) for cancer were estimated, and Cox regression analysis was performed.

Results

The incidence of cancer in the cholecystectomy group was 9.56 per 1,000 personyears and that in the control group was 7.95 per 1,000 person-years. Patients who underwent cholecystectomy showed an increased risk of total cancer (adjusted HR, 1.19; 95% CI, 1.15 to 1.24; p<0.001), particularly leukemia and malignancies of the colon, liver, pancreas, biliary tract, thyroid, pharynx, and oral cavity. In the subgroup analysis according to sex, the risk of developing cancers in the pancreas, biliary tract, thyroid, lungs and stomach was higher in men than in women.

Conclusions

Physicians should pay more attention to the possibility of the occurrence of secondary cancers among patients who undergo cholecystectomy.

Gallbladder-preserving polypectomy for gallbladder polyp by embryonic-natural orifice transumbilical endoscopic surgery with a gastric endoscopy

Background and aims

Cholecystectomy is performed for most gallbladder polyps (GPs). However, cholecystectomy results concerning complications in some patients. For benign GPs, adoption of gallbladder-preserving surgery is worth to recommend. We describe our experiences performing gallbladder-preserving polypectomy for GPs by embryonic-natural orifice transumbilical endoscopic surgery (E-NOTES) with a gastric endoscopy.

Methods

This is a retrospective study of patients with GPs who underwent gallbladder-preserving polypectomy by E-NOTES with a gastric endoscopy from April 2018 to September 2019 in our hospital. The operative time, intraoperative hemorrhage, intraoperative and postoperative complications, gallbladder emptying function were obtained and analyzed.

Results

The procedure was performed successfully in all 12 patients with 5 cases of single polyp and 7 cases of multiple polyps. The range of GPs size was 2 mm to 15 mm. The mean operation time was (95.33 ± 23.08) minutes (55–135 min). There were no adverse events including heavy bleeding, mortality and conversion to open surgery during operation. All patients were discharged in 4–5 days after surgery without postoperative complications such as delayed bleeding, fever, peritonitis, intra-abdominal abscess and abdominal wall incisional hernia. All patients were followed up at 1, 3, 6, and 12 months postoperation who had almost no visible incision on the umbilical region, no recurrent GPs. The gallbladder emptying function decreased one month after surgery, and gradually improved 3, 6 and 12 months after surgery.

Conclusion

E-NOTES gallbladder-preserving polypectomy is a safe and effective option for patients with GPs and is close to scar-free surgery which can be performed in routine clinical practice.

Progress in the Study of Colorectal Cancer Caused by Altered Gut Microbiota After Cholecystectomy

Epidemiological studies have found an increased incidence of colorectal cancer (CRC) in people who undergo cholecystectomy compared to healthy individuals. After cholecystectomy, bile enters the duodenum directly, unregulated by the timing of meals. Disruption of the balance of bile acid metabolism and increased production of primary bile acids, which in turn affects the composition and abundance of intestinal microorganisms. The link among cholecystectomy, the gut microbiota, and the occurrence and development of CRC is becoming clearer. However, due to the complexity of the microbial community, the mechanistic connections are less well understood. In this review, we summarize the changes of gut microbiota after cholecystectomy and illuminate the potential mechanisms on CRC, such as inflammation and immune regulation, production of genotoxins, metabolism of dietary ingredients, activation of signaling pathways, and so on. By reviewing these, we aimed to unravel the interactions between the gut microbiota and its host and be better positioned to develop treatments for CRC after cholecystectomy.

The Association Between Cholecystectomy and Colorectal Cancer in the Female Gender

Colorectal carcinoma (CRC) has been of great interest among researchers, and multiple causes have been proposed and accepted; however, cholecystectomy (CMY) as a potential cause for CRC, particularly in the female gender has not been studied in detail, despite multiple evidence suggesting a positive association. This review is directed at investigating the association between CMY and CRC in the female gender and aims at finding a potential cause for this association.

CRC involves cancer of the sigmoid and rectum. The composition of the bile acids is altered in patients after CMY, and the resultant secondary bile acids (BA) without a functioning gall bladder are exposed directly to the intestines, which could lead to cancer. An increase in fecal secondary bile acids is also described as high in the CMY population and has been linked to cancer. Right-sided GI cancers were attributed to CMY, although many earlier studies did not find this to be true. It is interesting to note a strong association between CRC and CMY in the female western population.

De Novo Cancer Incidence after Cholecystectomy in Korean Population

Background: Cancer development after cholecystectomy remains debatable. We estimated the major cancer incidence rates after cholecystectomy stratified by age and sex. Methods: The records of 408,769 subjects aged >20 years were extracted from the National Health Insurance database from 2008 to 2016. The risks of major cancers were compared between the cholecystectomy and general populations using standardised incidence ratios (SIR). Results: The overall cancer incidence was comparable between cholecystectomy patients and the general population. However, patients aged <65 years who underwent cholecystectomy had a higher cancer risk than those aged ≥65 years and the general population (SIR 2.62; 95% confidence interval [CI] 2.15–3.08; SIR 1.36, 95% CI 1.32–1.40; and SIR 0.90, 95% CI 0.87–0.92 in men and SIR 1.91; 95% CI 1.71–2.10; SIR 1.07; 95% CI 1.03–1.10; and SIR 0.90; 95% CI 0.87–0.94 in women aged 20–34, 35–64, and ≥65 years at cholecystectomy). Colorectal and liver cancer incidences after cholecystectomy were higher than those in the general population regardless of age group and sex (SIR, 1.55 for colorectal cancer in men and women; SIR, 1.25 and 1.51 for liver cancer in men and women, respectively). However, for other major cancers, the risk was higher in patients who underwent cholecystectomy at a younger age than in those who underwent cholecystectomy at an age ≥65 years. Conclusion: Patients with cholecystectomy, especially those undergoing cholecystectomy at a younger age, need preventive strategies based on the cancer type.

The Impact of Cholecystectomy on Long-Term Disease Outcomes and Quality of Life in Patients with Crohn's Disease

BACKGROUND

Cholecystectomy (CCY) is one of the most frequently performed abdominal surgeries. However, the impact of CCY in clinical settings with altered gastrointestinal physiology and anatomy, such as Crohn's disease (CD), has not been fully characterized. We sought to investigate clinical outcomes, disease severity, and quality of life of CD patients after CCY.

METHODS

We utilized a prospective, longitudinal registry of consented CD patients followed at a tertiary center. Crohn's disease patients that had or had not undergone CCY formed the 2 study groups. The absence or presence of gallbladder was confirmed with abdominal CT scans obtained during routine care. Multiyear clinical, biochemical, and histologic data were collected and analyzed.

RESULTS

Among 834 CD patients, 151 (18%) had undergone CCY. History of CCY was associated with higher disease activity (median Harvey-Bradshaw index; P < 0.001), more years with anemia (P = 0.048), lower albumin (P = 0.001), worse quality of life (mean Short Inflammatory Bowel Disease Questionnaire; P < 0.001), chronic abdominal pain (P < 0.001), higher risk for incident colonic dysplasia (P = 0.011), higher rates of annual hospital admissions (P = 0.004), and opioid use (P < 0.001). In multivariate analysis, CCY remained associated with higher disease activity (P < 0.001), lower albumin (P = 0.008), lower quality of life (P < 0.001), and more hospital admissions (P = 0.008), whereas CD patients with diseased ileum had higher risk for colonic dysplasia (P = 0.031).

CONCLUSIONS

CCY in CD patients was associated with multiple markers of disease activity and worse quality of life during multiyear follow up. This data suggests that CCY in CD patients may adversely impact the long-term clinical course.

Bacterial Alterations in Post-Cholecystectomy Patients Are Associated With Colorectal Cancer

Background: Although increasing evidences showed a correlation between cholecystectomy and the prevalence rate of colorectal cancer (CRC), and shed light on gut microbiota in colorectal pathogenesis, only a few studies focused on microbial alterations after cholecystectomy, and its sequent role in carcinogenesis and progression of CRC has not been reported. Thus, we aimed to investigate the bacterial alterations and tried to clarify their clinical significance.

Methods: 104 subjects were enrolled and divided into post-cholecystectomy patients (PC, n = 52) and healthy controls (HC, n = 52). To investigate the bacterial role in carcinogenesis, PC patients were further separated into preCA_CRC (patients with precancerous lesions and/or CRC, n = 9) and non-CA (patients without precancerous lesions and CRC, n = 43) based on the histopathology. Qualified stool samples were collected for 16S rRNA gene sequencing to analyze the bacterial profile.

Results: Our data showed noteworthy compositional and abundant alterations of bacterial microbiota in PC patients, characterized as Bacteroides ovatus, Prevotella copri, and Fusobacterium varium remarkably increased; Faecalibacterium prausnitzii, Roseburia faecis, and Bifidobacterium adolescentis significantly decreased. Additionally, the duration after cholecystectomy was the critical factor that affected bacterial composition. Machine learning-based analysis showed a pivotal role of Megamonas funiformis in discriminating PC from HC subjects and involving in the progression of CRC.

Conclusions: The bacterial dysbiosis may associate with CRC in PC patients, and the duration after cholecystectomy was highlighted as an important factor. Altered bacterial microbiota was likely to play a pivotal role in related-disease in the long-term follow-up of PC patients.

Screen-detected gallstone disease and risk of liver and pancreatic cancer: The Kailuan Cohort Study

BACKGROUND

Few studies have examined the risk of gastrointestinal cancers in screen-detected gallstone disease. This study aimed to investigate the association between screen-detected gallstone disease and gastrointestinal cancers using the Kailuan cohort, a population-based prospective cohort initiated in 2006.

METHODS

A total of 79 809 men who underwent gallbladder ultrasonography, were free of cancers in 2006 and did not have gastrointestinal cancers within one year were enrolled. A Cox proportional hazards model with age as the timescale was used to evaluate the association between screen-detected gallstone disease and gastrointestinal cancers.

RESULTS

We identified 1264 cases with gastrointestinal cancers, including 303 cases with liver cancer and 94 cases with pancreatic cancer. Screen-detected gallstone disease increased the risk of liver cancer, with an HR of 2.28 [95% confidence interval (CI): 1.20-4.33, P = .012]. The association was modified by the hepatitis B surface antigen status. A non-significant positive association was observed between pancreatic cancer and gallstone disease (HR 2.19, 95% CI: 0.95-5.05, P = .065). However, the HR became significant after those individuals with diabetes were excluded (HR 2.60, 95% CI: 1.12-6.01, P = .026).

CONCLUSION

Screen-detected gallstone disease may predict the risk for liver and pancreatic cancer.

Pathophysiological connections between gallstone disease, insulin resistance, and obesity

Obesity and cholesterol gallstone disease (GSD) are frequently coexisting diseases; therefore and considering the current worldwide obesity epidemics, a precise understanding of the pathophysiological relationships between GSD and insulin resistance (IR) is important. Classically, obesity has been understood as a risk factor for GSD and the gallbladder (GB) viewed as a simple bile reservoir, with no metabolic roles whatsoever. However, consistent evidence has showed that both GSD and cholecystectomy associates with fatty liver and IR, raising the possibility that the GB is indeed an organ with metabolic regulatory roles. Herein, we review the pathophysiological mechanisms by which GSD, IR, and obesity are interconnected, with emphasis in the actions of the GB as a regulator of bile acids kinetics and a hormone secreting organ, with metabolic actions at the systemic level. We also examine the relationships between increased hepatic lipogenic in IR states and GSD pathogenesis. We propose a model in which GSD and hepatic IR mutually interact to determine a state of dysregulated lipid and energy metabolism that potentiate the metabolic dysregulation of obesity.

Gallbladder Polyps Are Associated with Proximal Colon Polyps

Background

The association between gallbladder (GB) disease and colorectal precancerous lesions remains elusive. This study sought to explore the association between GB disease and colorectal neoplasms at different locations.

Methods

Patients who received general health checkup from January to December 2008 were included and subgrouped into three groups by polyp location: proximal, distal, and whole colon. GB disease and other known risk factors for colon cancer were compared and analyzed. Different types of polyps at different locations were further investigated.

Results

Of a total of 3136 patients (1776 men and 1360 women; mean age, 49.3 years) who had colon polyps, 212 (6.8%) had GB stone and 512 (16.3%) had GB polyps. Patients in the proximal colon polyp group had higher rates of GB polyps and stones. GB polyps were independently associated with proximal colon polyps, including both hyperplastic polyps (odds ratio, 1.523; P = 0.034) and adenomatous polyps (odds ratio, 1.351; P = 0.048). No relationship between GB polyps and distal or any colon polyps was observed. Irrespective of the polyp location (i.e., proximal, distal, or any part of the colon), GB stone did not show any association with colon polyp.

Conclusions

We suggested that GB polyps are associated with proximal colon polyps. Colonoscopy may be a more effective strategy for screening proximal precancerous lesions among patients with GB polyps. The association between GB disease and colon polyps demands further prospective investigation.

Relationship between remote cholecystectomy and incident Clostridioides difficile infection

OBJECTIVES

Cholecystectomy (CCY) is associated with increased faecal levels of secondary bile acids. Secondary bile acids confer resistance to Clostridioides difficile infection (CDI, formerly Clostridium difficile infection) in animal studies. This study tested the hypothesis that CCY confers protection against CDI by increasing gut levels of secondary bile acids.

METHODS

This was a retrospective case-control study. Adults hospitalized between January 2010 and June 2017 at our institution were included. CDI cases were defined as a positive stool PCR followed by anti-CDI treatment and were matched 1:1:1 with two control groups (those who tested negative for CDI and those who were not tested for CDI) by sex, age group, body mass index (BMI), and exposure to antibiotics. CCY was defined as a history of CCY at least 6 months prior to the index C. difficile test or the index admission date in the untested controls. Conditional logistic regression modelling was used to estimate the relationship between remote CCY and risk for CDI.

RESULTS

The final study population was 7077 (2359 CDI cases, 2359 matched controls without CDI, and 2359 matched controls not tested for CDI). Rates of remote CCY did not differ among the three groups (14.4% vs. 15.5% vs. 14.2%) and this result was unchanged after adjusting for additional clinical factors (adjusted OR 0.90, 95% CI 0.76-1.06 comparing CDI cases vs. matched controls without CDI; adjusted OR 1.04, 95% CI 0.78-1.39 comparing CDI cases vs. matched controls not tested for CDI).

CONCLUSIONS

There was no association between remote CCY and risk for CDI.

The Risk of Colorectal Cancer After Cholecystectomy or Appendectomy: A Population-based Cohort Study in Korea

Objectives

We investigated the association between cholecystectomy or appendectomy and the subsequent risk of colorectal cancer (CRC) in the Korean population.

Methods

A retrospective cohort study was conducted with the National Health Insurance Service–National Sample Cohort of Korea; this sample was followed up from January 1, 2002, until the date of CRC incidence, loss to follow-up, or December 31, 2015. The exposure status of cholecystectomy and appendectomy was treated as a time-varying covariate. The calculated risk of CRC was stratified by follow-up period, and the association between these surgical procedures and CRC was investigated by a Cox regression model applying appropriate lag periods.

Results

A total of 707 663 individuals were identified for analysis. The study population was followed up for an average of 13.66 years, and 4324 CRC cases were identified. The hazard ratio (HR) of CRC was elevated in the first year after cholecystectomy (HR, 1.71; 95% confidence interval [CI], 1.01 to 2.89) and in the first year and 2-3 years after appendectomy (HR, 4.22; 95% CI, 2.87 to 6.20; HR, 2.34; 95% CI, 1.36 to 4.03, respectively). The HRs of CRC after applying 1 year of lag after cholecystectomy and 3 years of lag after appendectomy were 0.80 (95% CI, 0.57 to 1.13) and 0.77 (95% CI, 0.51 to 1.16), respectively.

Conclusions

The risk of CRC increased in the first year after cholecystectomy and appendectomy, implying the possibility of bias. When appropriate lag periods after surgery were applied, no association was found between cholecystectomy or appendectomy and CRC.

Minimally Invasive Cholecystolithotomy to Treat Cholecystolithiasis in Children: A Single-center Experience With 23 Cases

OBJECTIVE

Minimally invasive cholecystolithotomy is recently popularized treatment that may offer advantages over laparoscopic cholecystectomy, especially in China. However, there are few reports concerning the use of this technique in the pediatric population. This report describes our initial experience with minimally invasive cholecystolithotomy using laparoscopy combined with choledochoscopy to treat cholecystolithiasis in children.

MATERIALS AND METHODS

A retrospective review of 23 pediatric patients with cholecystolithiasis who underwent minimally invasive cholecystolithotomy using laparoscopy combined with choledochoscopy from January 2009 to December 2015 was performed.

RESULTS

The operations were successful in all 23 cases. None required conversion to conventional laparoscopic cholecystectomy. The average operative time was 68 minutes (range, 45 to 97 min). The average bleeding volume during surgery was 30 mL (range, 10 to 55 mL). The average length of hospital stay was 5.2 days (range, 3 to 7 d). There were no perioperative complications. All patients were followed for 9 to 12 months without any obvious gastrointestinal symptoms. None had a recurrence of stones in the gall bladder.

CONCLUSIONS

Minimally invasive cholecystolithotomy using laparoscopy combined with choledochoscopy is a safe and viable technique that may be used successfully in pediatric surgery.

Cholecystectomy can increase the risk of colorectal cancer: A meta-analysis of 10 cohort studies

OBJECTIVE

This study aimed to elucidate the effects of cholecystectomy on the risk of colorectal cancer (CRC) by conducting a meta-analysis of 10 cohort studies.

METHODS

The eligible cohort studies were selected by searching the PubMed and EMBASE databases from their origination to June 30, 2016, as well as by consulting the reference lists of the selected articles. Two authors individually collected the data from the 10 papers. When the data showed marked heterogeneity, we used a random-effects model to estimate the overall pooled risk; otherwise, a fixed effects model was employed.

RESULTS

The final analysis included ten cohort studies. According to the Newcastle-Ottawa Scale (NOS), nine papers were considered high quality. After the data of these 9 studies were combined, an increased risk of CRC was found among the individuals who had undergone cholecystectomy (risk ratio (RR) 1.22; 95% confidence interval (CI) 1.08-1.38). In addition, we also found a promising increased risk for colon cancer (CC) (RR 1.30, 95% CI 1.07-1.58), but no relationship between cholecystectomy and rectum cancer (RC) (RR 1.09; 95% CI 0.89-1.34) was observed. Additionally, in the sub-group analysis of the tumor location in the colon, a positive risk for ascending colon cancer (ACC) was found (RR 1.18, 95% CI 1.11-1.26). After combining the ACC, transverse colon cancer (TCC), sigmoid colon cancer (SCC) and descending colon cancer (DCC) patients, we found a positive relationship with cholecystectomy (RR 1.18, 95% CI 1.11-1.26). Furthermore, after combining the ACC and DCC patients, we also found a positive relationship with cholecystectomy (RR 1.28; 95% CI 1.11-1.26) in the sub-group analysis. In an additional sub-group analysis of patients from Western countries, there was a positive relationship between cholecystectomy and the risk of CRC (RR 1.20; 95% CI 1.05-1.36). Furthermore, a positive relationship between female gender and CRC was also found (RR 1.17; 95% CI 1.03-1.34). However, there was no relationship between gender and CC or RC. Furthermore, no publication bias was observed, and the sensitivity analysis indicated stable results.

CONCLUSIONS

This meta-analysis of 10 cohort studies revealed that cholecystectomy is associated with an increased risk for CRC, CC and ACC, particularly in Western countries. No relationship between cholecystectomy and RC was observed. There was no relationship between gender and either CC or RC, but a positive relationship between female gender and CRC was observed.

Risk Factors for Cholelithiasis

Gallstone disease is one of the most common public health problems in the United States. Approximately 10%-20% of the national adult populations currently carry gallstones, and gallstone prevalence is rising. In addition, nearly 750,000 cholecystectomies are performed annually in the United States; direct and indirect costs of gallbladder surgery are estimated to be $6.5 billion. Cholelithiasis is also strongly associated with gallbladder, pancreatic, and colorectal cancer occurrence. Moreover, the National Institutes of Health estimates that almost 3,000 deaths (0.12% of all deaths) per year are attributed to complications of cholelithiasis and gallbladder disease. Although extensive research has tried to identify risk factors for cholelithiasis, several studies indicate that definitive findings still remain elusive. In this review, predisposing factors for cholelithiasis are identified, the pathophysiology of gallstone disease is described, and nonsurgical preventive options are discussed. Understanding the risk factors for cholelithiasis may not only be useful in assisting nurses to provide resources and education for patients who are diagnosed with gallstones, but also in developing novel preventive measures for the disease.

The association between cholecystectomy and colorectal neoplasm in inflammatory bowel diseases: A population-based cohort study

Background & aims

Inflammatory bowel diseases (IBD) and cholecystectomy are associated with the risk of colorectal cancer (CRC). Our aim was to determine the association between cholecystectomy and the CRC risk in IBD.

Methods

We first obtained the Taiwan National Health Insurance Research Database (NHRID), which contains information on approximately 24.7 million insured individuals. A cohort study was conducted using the data from the NHIRD, and included cohort patients with IBD who had experienced a cholecystectomy between the years 1998 and 2010. The non-cholecystectomy cohort comprised the remaining IBD patients who had not undergone a cholecystectomy. Multivariate Cox proportional hazard regression analysis was used to determine the effects cholecystectomy have on the risks of developing CRC, as shown by Hazard Ratios (HRs) with 95% confidence intervals (CIs).

Results

The incidence rate of CRC among IBD patients who had undergone a cholecystectomy (n = 525) was 1.75 per 1,000 person-years, compared to 1.41 per 1,000 person-years among IBD patients who had not had a cholecystectomy (n = 525). The adjusted HRs for CRC was found to be 0.76 (95% CI 0.25–2.32) for IBD patients having received a cholecystectomy, after adjusting for age, gender, and comorbidities. By type of IBD, neither ulcerative colitis nor Crohn’s diseases are associated with CRC after a cholecystectomy adjusted HR (2.78 [95% CI 0.54–14.3]) and (0.13 [95% CI 0.01–1.49]).

Conclusion

In Taiwan, cholecystectomies are not associated with a risk of CRC in patients with IBD.

Gallstones: new insights into an old story

Gallstones, particularly cholesterol gallstones, are common in Western populations and may cause symptoms such as biliary colic or complications such as acute cholecystitis or gallstone pancreatitis. Recent studies have allowed for a better understanding of the risk of symptoms or complications in patients with gallstones. In addition, newer data suggest an association of gallstones with overall mortality, cardiovascular disease, gastrointestinal cancers, and non-alcoholic fatty liver disease. Knowledge of appropriate indications and timing of cholecystectomy, particularly for mild biliary pancreatitis, has gradually accumulated. Lastly, there are exciting possibilities for novel agents to treat or prevent cholesterol stone disease. This review covers new advances in our understanding of the natural history, clinical associations, and management of gallstone disease.

Can gallbladder polyps predict colorectal adenoma or even neoplasia? A systematic review

OBJECTIVE

The purpose of the present systematic review is to identify whether an association between gallbladder polyps and colorectal adenoma or neoplasia exists.

DATA SOURCES

We conducted a systematic review searching the Medline (1966-2016), Scopus (2004-2016), ClinicalTrials.gov (2008-2016) and Cochrane Central Register of Controlled Trials CENTRAL (1999-2016) databases together with reference lists from included studies.

STUDY ELIGIBILITY CRITERIA

All prospective and retrospective observational cohort studies were included.

RESULTS

Four studies were finally included which included 17,437 patients. The association between gallbladder polyps and colorectal adenoma or even neoplasia is not unanimously supported. However, a possible association is clearly depicted. According to one study it seems that this correlation seems to become significant only when the gallbladder polyps exceed the size of 5 mm. However, the impact of size of gallbladder polyps was not investigated in the remaining studies.

CONCLUSION

According to the results of our systematic review there is some evidence to support the hypothesis that gallbladder polyps might adequately predict future risk of colorectal neoplasia. At present, however, current knowledge is very limited and the available data scarce. In this context further studies are necessary to be carried out, before the presence of gallbladder polyps on ultrasound can be recommended as an indication to perform a screening colonoscopy on the same patient.

Functions of the Gallbladder

The gallbladder stores and concentrates bile between meals. Gallbladder motor function is regulated by bile acids via the membrane bile acid receptor, TGR5, and by neurohormonal signals linked to digestion, for example, cholecystokinin and FGF15/19 intestinal hormones, which trigger gallbladder emptying and refilling, respectively. The cycle of gallbladder filling and emptying controls the flow of bile into the intestine and thereby the enterohepatic circulation of bile acids. The gallbladder also largely contributes to the regulation of bile composition by unique absorptive and secretory capacities. The gallbladder epithelium secretes bicarbonate and mucins, which both provide cytoprotection against bile acids. The reversal of fluid transport from absorption to secretion occurs together with bicarbonate secretion after feeding, predominantly in response to an adenosine 3',5'-cyclic monophosphate (cAMP)-dependent pathway triggered by neurohormonal factors, such as vasoactive intestinal peptide. Mucin secretion in the gallbladder is stimulated predominantly by calcium-dependent pathways that are activated by ATP present in bile, and bile acids. The gallbladder epithelium has the capacity to absorb cholesterol and provides a cholecystohepatic shunt pathway for bile acids. Changes in gallbladder motor function not only can contribute to gallstone disease, but also subserve protective functions in multiple pathological settings through the sequestration of bile acids and changes in the bile acid composition. Cholecystectomy increases the enterohepatic recirculation rates of bile acids leading to metabolic effects and an increased risk of nonalcoholic fatty liver disease, cirrhosis, and small-intestine carcinoid, independently of cholelithiasis. Among subjects with gallstones, cholecystectomy remains a priority in those at risk of gallbladder cancer, while others could benefit from gallbladder-preserving strategies. © 2016 American Physiological Society. Compr Physiol 6:1549-1577, 2016.

Is it necessary to perform prophylactic cholecystectomy for all symptomatic gallbladder polyps diagnosed with ultrasound?

OBJECTIVE

The main aim of this study is to determine the necessity of cholecystectomy in patients with ultrasound diagnosed symptomatic polypoid lesions of the gallbladder.

MATERIAL AND METHODS

The data of 82 patients with polypoid lesions of the gallbladder who had cholecystectomy between 2000 and 2012 were analyzed retrospectively with preoperative ultrasound and histopathology results.

RESULTS

The mean age was 48.05±11.18 years (range 25-74 years). All patients underwent preoperative ultrasound examination. Eighteen (22%) of the 82 patients were asymptomatic; their polypoid lesions of the gallbladder were detected with ultrasound during a check-up or other reasons. In 45 (55%) of cases pathology reported no polypoid lesions of the gallbladder. Right upper quadrant or epigastric pain was the most common symptom (41.46%) that led to hepatobiliary ultrasound, the other symptom was dyspepsia (36.59%). On preoperative ultrasound evaluation, 22 patients had multiple polyps, and 9 of these 22 patients had at least 3 polyps.

CONCLUSION

There is an inaccuracy of ultrasound to detect polypoid lesions of the gallbladder. After diagnosing polypoid lesions of the gallbladder by using standard ultrasound, further pre-operative diagnostic tests are needed to help discriminating benign lesions from malignant ones, which may prevent unnecessary surgery regardless of symptoms.

The Risk of Colorectal Neoplasia in Patients with Gallbladder Diseases

Cholecystectomy is associated with an increased risk of colorectal cancer, but little is known about the relationship between gallbladder disease and colorectal adenoma. Gallbladder polyps and colorectal neoplasia (CRN) share several risk factors such as obesity, diabetes and metabolic syndrome, which might account for their association. In this study, we investigated whether asymptomatic patients with gallbladder disease are at increased risk of CRN and identified the factors to their association. The study population consisted of 4,626 consecutive, asymptomatic individuals drawn from a prospective health check-up cohort who underwent both ultrasonography and colonoscopy screening. The prevalence of CRNs in patients with gallbladder polyps or gallstones was significantly higher than that in the control group (32.1% vs. 26.8%; P = 0.032, 35.8% vs. 26.9%; P = 0.020). A multivariate regression analysis showed that gallbladder polyps were an independent risk factor for CRN [adjusted odds ratio (OR): 1.29; 95% confidence interval (CI); 1.03-1.62] whereas gallstones were not (adjusted OR: 1.14; 95% CI: 0.79-1.63). The adjusted OR for the risk of CRN was 1.12 for gallbladder polyps < 5 mm (95% CI, 0.85-1.46) and 1.79 for gallbladder polyps ≥ 5 mm (95% CI, 1.15-2.77). The prevalence of CRN increased with increasing polyp size (P trend = 0.022). Our results suggest that colorectal neoplasia is significantly related to gallbladder polyps, especially those ≥ 5 mm.

Cholecystectomy and the risk of alimentary tract cancers: A systematic review

AIM: To investigate the association between cholecystectomy and gastro-intestinal tract (GIT) cancers.

METHODS: We conducted a systematic review according to the PRISMA guidelines. A MEDLINE search was performed with predefined search criteria for English Language articles on the association between cholecystectomy and GIT cancers. Additional articles were retrieved by manual search of references. All relevant articles were accessed in full text. Data on study type; cases; controls; country; effect estimate; adjustments for confounders and quality of publication were extracted. The quality of the publications were scored by adherence to the STROBE checklist. The data for each part of the GIT were presented in separate tables.

RESULTS: Seventy-five studies and 5 meta-analyses satisfied the predefined criteria for inclusion and were included in this review. There were inconsistent reports and no strong evidence of an association between cholecystectomy and cancers of the oesophagus (Adenocarcinoma), pancreas, small bowel and right-sided colon cancers. In squamous cancer of the oesophagus, cancers of the stomach, liver, bile ducts, small bowel and left sided colon cancers, good quality studies suggested a lack of association with cholecystectomy. Equally, distal colon and rectal cancers were found not to be associated with cholecystectomy. Several mechanisms for carcinogenesis/promotion of carcinogensis have been proposed. These have focused on a role for bile salts in carcinogenesis with several potential mutagenic molecular events and gut metabolic hormones signaling cell proliferation or initiation of carcinogenesis.

CONCLUSION: This is a comprehensive review of the association between GIT cancers and cholecystectomy. This review found no clear association between cholecystectomy and GIT cancers.

Cancer risk in patients with cholelithiasis and after cholecystectomy: a nationwide cohort study

BACKGROUND

This study examined the association of cholelithiasis post-cholecystectomy with subsequent cancers and evaluated the risk of cancer in patients with both cholelithiasis and cholecystectomy.

METHODS

The Taiwanese National Health Insurance Research Database was used to identify 15545 newly diagnosed cholelithiasis patients from 2000 to 2010, and 62180 frequency-matched non-cholelithiasis patients. A total of 5850 (37.6 %) with cholelithiasis patients received a cholecystectomy. The risk of developing cancer after cholecystectomy was measured using the Cox proportional-hazards model.

RESULTS

The incidence of developing cancer in the cholelithiasis cohort was 1.52-fold higher than that in the comparison cohort (p < 0.001). Compared with patients aged 20-34 years, patients in older age groups had a higher risk of developing cancer. The hazard ratio (HR) for developing gallbladder, extrahepatic bile duct, pancreatic, liver, stomach, and colorectal cancer was 59.3, 10.7, 3.12, 1.90, 1.71, and 1.36-fold higher for patients with cholelithiasis, respectively. After a cholecystectomy, the HR for developing stomach and colorectal cancer was 1.81-fold and 1.56-fold, respectively. The incidence rate ratio was higher for the first 5 years and over 5 years (5.05 and 4.46, respectively) (95 % confidence interval 4.73-5.39 and 4.11-4.84, respectively) in proximal colon and stomach cancer patients with cholecystectomies.

CONCLUSIONS

Cholelithiasis patients have a higher risk of gastrointestinal cancer, particularly of gallbladder and extrahepatic bile duct cancer. Post-cholecystectomy patients have a risk of colorectal and stomach cancer within the first 5 years and persisting after 5 years, respectively. This paper proposes strategies for preventing gastrointestinal cancer.

Gallstones, cholecystectomy, and risk of digestive system cancers

Gallstones and cholecystectomy may be related to digestive system cancer through inflammation, altered bile flux, and changes in metabolic hormone levels. Although gallstones are recognized causes of gallbladder cancer, associations with other cancers of the digestive system are poorly established. We used the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database (1992-2005), which includes 17 cancer registries that cover approximately 26% of the US population, to identify first primary cancers (n = 236,850) occurring in persons aged ≥66 years and 100,000 cancer-free population-based controls frequency-matched by calendar year, age, and gender. Odds ratios and 95% confidence intervals were calculated using logistic regression analysis, adjusting for the matching factors. Gallstones and cholecystectomy were associated with increased risk of noncardia gastric cancer (odds ratio (OR) = 1.21 (95% confidence interval (CI): 1.11, 1.32) and OR = 1.26 (95% CI: 1.13, 1.40), respectively), small-intestine carcinoid (OR = 1.27 (95% CI: 1.01, 1.60) and OR = 1.78 (95% CI: 1.41, 2.25)), liver cancer (OR = 2.35 (95% CI: 2.18, 2.54) and OR = 1.26 (95% CI: 1.12, 1.41)), and pancreatic cancer (OR = 1.24 (95% CI: 1.16, 1.31) and OR = 1.23 (95% CI: 1.15, 1.33)). Colorectal cancer risk associated with gallstones and cholecystectomy decreased with increasing distance from the common bile duct (P-trend < 0.001). Hence, gallstones and cholecystectomy are associated with the risk of cancers occurring throughout the digestive tract.

Risk of hepato-biliary cancer after cholecystectomy: a nationwide cohort study

BACKGROUND

Epidemiologic studies have identified cholecystectomy as a possible risk factor for cancers in Western countries. The aim of this study was to estimate the risk of hepato-biliary cancer after cholecystectomy in Taiwan.

METHODS

Based on the Taiwan National Health Insurance Research Database, 2,590 cholecystectomized patients without prior cancers in the period 1996-2008 were identified from a cohort dataset of 1,000,000 randomly sampled individuals. The standard incidence ratio (SIR) of each cancer was calculated.

RESULTS

After a median follow-up of 4.82 years, 67 liver cancer and 17 biliary tract cancer patients were diagnosed. Patients who received cholecystectomy had higher risks of liver cancer (SIR, 3.29) and biliary tract cancer (SIR, 8.50). Cholecystectomized patients aged ≤60 years had higher risks of liver cancer (SIR, 11.14) and biliary tract cancer (SIR, 55.86) compared to those aged >60 years (SIR, 2.31 and 5.67). Female cholecystectomized patients had higher risks of liver cancer (SIR, 4.18) and biliary tract cancer (SIR, 10.56) than males (SIR, 2.96 and 7.26). Cholecystectomized patients with cirrhosis had higher SIR of liver cancer than patients without cirrhosis (SIR, 33.84 vs. 1.41).

CONCLUSIONS

Cholecystectomy may be associated with an increased risk of hepato-biliary cancer. Further and regular surveillance should be performed on such patients.

Association between cholecystectomy and intestinal cancer: a national record linkage study

OBJECTIVE

To investigate the risk of intestinal cancer in a cohort of people who had undergone cholecystectomy for gallstones, and in a cohort of people who had been hospitalized for gallbladder disease but had not undergone cholecystectomy.

BACKGROUND

Some investigators have suggested that cholecystectomy increases the risk of intestinal cancer. Despite extensive study, the evidence remains inconclusive. If there is doubt about safety, the question arises of whether patients considering the operation should be told of a possible risk. It is also increasingly clear that there are noncausal associations between gallstones and intestinal cancer.

METHOD

Analysis of record-linked hospital admission and mortality statistics for England from 1998 to 2008; calculation of ratio of rates of cancers in the cholecystectomy cohort and the gallbladder disease cohort compared with a control cohort.

RESULTS

: In the first year after cholecystectomy, the rate ratios for cancer of the small intestine, colon, and rectum were significantly high at, respectively, 4.6 (95% confidence interval 3.9-5.5), 2.0 (1.9-2.1), and 1.7 (1.6-1.9). Rates of these cancers were also significantly high in people with gallstones without cholecystectomy. By 8 to 10 years after cholecystectomy, rate ratios had declined to nonsignificant levels.

CONCLUSIONS

These cancers are associated with gallstones. The highest elevation of risk of cancer after cholecystectomy was at the shortest time interval after operation. Thereafter, the level of risk in the cholecystectomy and control cohorts gradually converged. The association in this study, between cholecystectomy and intestinal cancer, is very unlikely to be causal. Intestinal cancers are, on occasion, initially misdiagnosed as gallbladder disease.

Gallstones are associated with colonic adenoma: a meta-analysis

BACKGROUND

Increased levels of secondary bile acids after gallstone disease and cholecystectomy are believed to increase the risk of colorectal cancer. It remains unclear whether there is a similar risk of developing adenomas. The aim of this meta-analysis was to determine the risk of developing colonic adenomas following gallstone disease or cholecystectomy.

METHODS

The study was based on a systematic search of PubMed, MEDLINE, EMBASE, and Current Contents (1950-2012). Selection criteria were developed to sort for studies exploring the relationship between cholelithiasis, cholecystectomy, and colonic adenoma in an adult population. A random-effects model was used to generate pooled odds ratios (OR) and 95 % confidence intervals (CI). Publication bias and heterogeneity were assessed.

RESULTS

Of the 1,276 studies identified, 14 were suitable for final analysis. There were 253,059 subjects in total, 42,543 of whom were diagnosed with colonic adenoma, and 28,281 of whom had gallstones or underwent cholecystectomy. There was a significant risk of developing colonic adenoma if gallstones were present (OR = 2.26; 95 % CI = 1.83-2.81). A risk was also seen with cholecystectomy (OR = 1.15; 95 % CI = 1.04-1.26), but this risk was negated when only adjusted odds were selected (OR = 1.01; 95 % CI = 0.91-1.12). No publication bias and only low levels of heterogeneity existed.

CONCLUSIONS

Gallstones increase the risk of colonic adenoma. No association exists with cholecystectomy.

New understandings about gallbladder function

The function of the gallbladder is to store and concentrate bile. Due to the high incidence of diseases such as gallstones, cholecystectomy has become one of the most common surgical procedures. Although cholecystectomy is a successful treatment for most patients, the loss of gallbladder function may contribute to chronic diarrhea and increase the incidence of proximal colon cancer, pancreatic cancer, hepatocellular carcinoma and esophageal adenocarcinoma. With the development of endoscopic technology and introduction of drugs that may prevent recurrence of gallstones, cholecystolithotomy with gall bladder preservation has become another choice for symptomatic gallstones, and it preserves the function of the gallbladder after the removal of gallstones. This may avoid the complications associated with the loss of gallbladder function.

Gallstone disease in children

Gallstone disease in children is evolving, and for the previous 3 decades, the frequency for surgery has increased greatly. This is in part because of improved diagnostic modalities, but also changing pathology, an increased awareness of emerging comorbidities, such as childhood obesity, and other associated risk factors. This article outlines the pathophysiology, genetics, and predisposing factors for developing gallstones and includes a review of the literature on the current and more novel medical and surgical techniques to treat this interesting disease.

Gallstone disease is associated with rectal cancer: a meta-analysis

BACKGROUND

Increased levels of secondary bile acids after cholecystectomy and cholelithiasis are believed to increase the risk of colorectal cancer, and several studies have suggested that the risk of colorectal cancer may be the greatest proximally. Numerous conflicting studies have been published and it remains unclear whether the risk is apparent in the rectum. This meta-analysis aims to determine the risk of developing rectal cancer following gallstone disease or cholecystectomy.

METHODS

The prospective protocol included a literature search of PubMed, MEDLINE, EMBASE, and Current Contents (1950-2011). Selection criteria were developed to sort for studies exploring the relationship between cholelithiasis, cholecystectomy, and rectal cancer in an adult population. A random-effects model was used to generate pooled odds ratios (OR) and 95% confidence intervals (CI). Publication bias and heterogeneity were assessed.

RESULTS

Of the 2358 studies identified, 42 were suitable for final analysis. There were 1,547,506 subjects in total, 14,226 diagnosed with rectal cancer, and 496,552 with gallstones or cholecystectomy. There was a statistically significant risk of rectal cancer following cholelithiasis (OR = 1.33; 95% CI = 1.02-1.73), though no risk was apparent following cholecystectomy (OR = 1.14; 95% CI = 0.92-1.41).

CONCLUSIONS

Cholelithiasis increases the risk of rectal cancer. No association exists between cholecystectomy and rectal cancer.

Meta-analysis of observational studies on cholecystectomy and the risk of colorectal adenoma

AIM

Cholecystectomy has been suggested as a risk factor for colorectal cancer. However, the association of cholecystectomy and the risk of colorectal adenoma (CRA) remains unclear. We conducted a meta-analysis of observational studies to explore this relationship.

METHODS

We identified studies by a literature search of MEDLINE and EMBASE through 30 September 2011, and by searching the reference lists of pertinent articles. Summary relative risks (SRRs) with their 95% confidence intervals (CIs) were calculated with a random-effects model. Between-study heterogeneity was assessed using Cochran's Q statistic and the I2.

RESULTS

A total of 10 studies (including 4061 CRA cases) were included in this meta-analysis. Analysis of these 10 studies found that no effect of cholecystectomy on the risk of CRAs was shown (SRR, 1.17; 95% CI: 0.93-1.48), with no significant heterogeneity among these studies (P heterogeneity=0.106, I2=37.9%). This null association was seen in both men and women (men: SRR=1.00, 95% CI: 0.58-1.73; women: SRR=1.39, 95% CI: 0.95-2.04).

CONCLUSION

The results of this meta-analysis suggest that there is no positive association between previous cholecystectomy and the risk of CRA development in both men and women.

Colorectal cancer screening and prevention in women

Colorectal cancer (CRC) is the third most common cause of cancer in women. Screening for CRC increases early detection of cancer and premalignant polyps and decreases morbidity from this disease. However, adherence to the screening guidelines continues to remain inadequate both at the physician and patient levels. Several factors are of special importance to women. Presence of prior gynecological malignancies may increase the risk of CRC in women. Furthermore, new studies have shown other factors such as obesity and smoking to increase the risk of CRC in women. This article highlights issues unique to women with regards to CRC and outlines special considerations for determining screening intervals in women, identifies factors that make screening more difficult in women, and reviews studies that identify preventative strategies which, together with screening, may reduce the burden of CRC.

Performance value of high risk factors in colorectal cancer screening in China

AIM: To analyze the performance value of high risk factors in population-based colorectal cancer (CRC) screening in China.

METHODS: We compared the performance value of the immunochemical fecal occult blood test (iFOBT) and other high risk factors questionnaire in a population sample of 13 214 community residents who completed both the iFOBT and questionnaire investigation. Patients with either a positive iFOBT and/or questionnaire were regarded as a high risk population and those eligible were asked to undergo colonoscopy.

RESULTS: The iFOBT had the highest positive predictive value and negative predictive value in screening for advanced neoplasia. The iFOBT had the highest sensitivity, lowest number of extra false positive results associated with the detection of one extra abnormality for screening advanced neoplasias and adenomas. A history of chronic cholecystitis or cholecystectomy, chronic appendicitis or appendectomy, and chronic diarrhea also had a higher sensitivity than a history of adenomatous polyps in screening for advanced neoplasias and adenomas. The sensitivity of a history of chronic cholecystitis or cholecystectomy was highest among the 10 high risk factors in screening for non-adenomatous polyps. A history of chronic appendicitis or appendectomy, chronic constipation, chronic diarrhea, mucous and bloody stool, CRC in first degree relatives, malignant tumor and a positive iFOBT also had higher sensitivities than a history of adenomas polyps in screening for non-adenomatous polyps. Except for a history of malignant tumor in screening for non-adenomatous polyps, the gain in sensitivity was associated with an increase in extra false positive results associated with the detection of one extra abnormality.

CONCLUSION: The iFOBT may be the best marker for screening for advanced neoplasias and adenomas. Some unique high risk factors may play an important role in CRC screening in China.

A previous cholecystectomy increases the risk of developing advanced adenomas of the colon

BACKGROUND

There is limited data assessing the relationship between cholecystectomy and colorectal adenomatous polyps (AP). Our aim was to determine if cholecystectomy was associated with an increased prevalence of advanced AP in male veterans.

METHODS

The relationship of whether prior cholecystectomy modified the natural history of AP was investigated in a retrospective study. The patients were divided into two groups: 1) those with AP and a history of cholecystectomy, and 2) those with AP, but without a history of cholecystectomy. Factors in each group associated with advanced AP were examined by univariate analysis (UA) and stepwise logistic regression analysis to determine independent predictors of aggressive clinical characteristics of polyps. Statistical significance was determined at a P < or = 0.05.

RESULTS

We identified a total of 1234 patients with AP (cases = 127, controls = 1107). The mean age of patients was 64.1 +/- 1.9 (standard deviation) years. By UA, those with a prior cholecystectomy had a greater mean number of AP (4.2 vs. 3.5; P = 0.04) and more advanced polyps (P = 0.037) than those without a cholecystectomy. By logistic regression, prior cholecystectomy was associated with more advanced AP (OR = 1.5 [1.0-2.2]; P = 0.04). Patients who had a cholecystectomy were 51% more likely to have advanced AP. There appeared to be a trend towards increased time from cholecystectomy being associated with advanced polyps (9.69 years vs. 8.99 years, P = 0.056).

CONCLUSIONS

A prior cholecystectomy was independently associated with an increased risk of developing advanced AP. Also, there appeared to be a trend toward a greater prevalence of advanced lesions as postcholecystectomy time increased.

Bile acids inhibit NAD+-dependent 15-hydroxyprostaglandin dehydrogenase transcription in colonocytes

Multiple lines of evidence have suggested a role for both bile acids and prostaglandins (PG) in gastrointestinal carcinogenesis. Levels of PGE(2) are determined by both synthesis and catabolism. Previously, bile acid-mediated induction of cyclooxygenase-2 (COX-2) was found to stimulate PGE(2) synthesis. NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH), the key enzyme responsible for the catabolism of PGE(2), has been linked to colorectal carcinogenesis. In this study, we determined whether bile acids altered the expression of 15-PGDH in human colon cancer cell lines. Treatment with unconjugated bile acids (chenodeoxycholate and deoxycholate) suppressed the transcription of 15-PGDH, resulting in reduced amounts of 15-PGDH mRNA, protein, and enzyme activity. Conjugated bile acids were less potent suppressors of 15-PGDH expression than unconjugated bile acids. Treatment with chenodeoxycholate activated protein kinase C (PKC), leading in turn to increased extracellular signal-regulated kinase (ERK) 1/2 activity. Small molecules that inhibited bile acid-mediated activation of PKC and ERK1/2 also blocked the downregulation of 15-PGDH. Bile acids induced early growth response factor-1 (Egr-1) and Snail, a repressive transcription factor that bound to the 15-PGDH promoter. Silencing Egr-1 or Snail blocked chenodeoxycholate-mediated downregulation of 15-PGDH. Together, these data indicate that bile acids activate the signal transduction pathway PKC --> ERK1/2 --> Egr-1 --> Snail and thereby suppress 15-PGDH transcription. Bile acids appear to increase the release of PGs from cells by downregulating catabolism in addition to stimulating synthesis. These results provide new mechanistic insights into the link between bile acids and gastrointestinal carcinogenesis.

Cholelithiasis is a risk factor for colorectal adenoma

OBJECTIVES

Postcholecystectomy patients show moderate risk of colorectal cancer. However, few studies have investigated the relationship between cholelithiasis and colorectal adenoma. We examined this possibility through a combination of colonoscopy and ultrasonography in asymptomatic Japanese.

METHODS

We reviewed a subgroup of subjects drawn from a prospective annual colonoscopy screening survey. Subjects who underwent both ultrasonography and colonoscopy, and completed a questionnaire regarding lifestyle habits were entered. We investigated whether subjects with cholelithiasis or a previous cholecystectomy showed an increased risk of colorectal adenoma, as compared with subjects with normal gallbladders.

RESULTS

Data of 4,458 subjects (men 3,053, women 1,405, mean age +/- SD 46.1 +/- 8.62 yr) were analyzed. Cholelithiasis was detected in 206 subjects, 4,189 subjects had normal gallbladders, and 63 subjects had cholecystectomies. The prevalence of colorectal adenoma was 29.6% (61/206) in subjects with cholelithiasis, which was significantly higher when compared with normal subjects, with a prevalence of 17.7% (741/4,189, P < 0.001). In cholecystectomy patients, only 15.9% (10/63) developed colorectal adenomas, which was not significantly different from the control group. In a multivariate analysis controlling for sex, age, family history of colorectal cancer, alcohol, smoking, and body mass index, cholelithiasis was shown to be an independent risk factor for colorectal adenoma (adjusted OR 1.57, 95% CI 1.14-2.18). Cholelithiasis was strongly associated with multiple (> or = 3 lesions, adjusted OR 2.39, 95% CI 1.21-4.72) and left-sided colorectal adenomas (adjusted OR 1.82, 95% CI 1.28-2.59).

CONCLUSIONS

Cholelithiasis is a risk factor for colorectal adenoma.

Importance of postpolypectomy surveillance and postpolypectomy compliance to follow-up screening--review of literature

INTRODUCTION

Approximately 150,000 people are diagnosed with colorectal cancer each year and 56,000 may die from it annually in the United States. Colorectal cancer is the second leading cause of cancer deaths in the USA and yet, when diagnosed at an early stage, it is one of the most preventable cancers. According to the US Preventive Services Task Force, initial screening for colorectal cancer is recommended in people above 50 years of age with average risk and earlier in people with a strong family history and other risk factors. Adenomatous polyps are considered as precursors of colorectal cancer. Removal of polyps and postpolypectomy surveillance reduces the overall mortality from colorectal cancer.

DISCUSSION

According to updated guidelines in 2006, a 3-year-follow-up colonoscopy is recommended in patients with adenomatous polyps>or=1 cm. An important factor in the surveillance and prevention of colorectal cancer in postpolypectomy patients is compliance with follow-up colonoscopy. In the present article, we provide an overview of the importance of postpolypectomy surveillance and summarize the compliance data for postpolypectomy surveillance. Compliance to postpolypectomy surveillance varies from one study to another and it should be expected that the compliance with follow-up would be low outside of clinical trials. Some measures that can improve patient compliance include patient education regarding a need of follow-up screening, reminder letters, and alerts in patient's charts.

CONCLUSION

In conclusion, effective surveillance screening with good patient compliance in postpolypectomy patients will contribute significantly in reducing colon cancer morbidity and mortality.

Cholecystectomy and the risk of colorectal adenomas

Cholecystectomy has been identified as a risk factor for colorectal cancer, yet little attention has been given to the relationship between cholecystectomy and colorectal adenomas. Utilizing data collected in two large cross-sectional studies of colorectal adenoma risk factors, we examined the association between cholecystectomy and colorectal adenomas. In the adjusted logistic regression model, both men and women showed no effect of cholecystectomy on risk of colorectal adenomas (men: OR 0.67 [95% CI 0.30-1.47]; women: OR 1.46 [95% CI 0.92-2.29]). No effect was seen when examining the time since cholecystectomy for men. There was a slight association found for women who had a cholecystectomy less than 10 years prior (OR 2.02 [95% CI 1.06-3.87]) but no association was seen in women with cholecystectomy at least 10 years prior (OR 1.14 [95% CI 0.62-2.09]). Thus, we conclude that, although cholecystectomy is a risk factor for colorectal cancer, cholecystectomy is not a risk factor for colorectal adenomas.

The comparison of the risk factors and clinical manifestations of proximal and distal colorectal cancer

PURPOSE

Colorectal cancers in the proximal or distal site have distinct clinical characteristics. In this study, the authors compared the risk factors of proximal and distal colorectal cancer.

METHODS

A 16-page questionnaire was administered to 529 patients with colorectal cancer before operation. Cancers were classified as proximal or distal relative to the splenic flexure. Of these 529 patients, 6 patients were excluded because of the presence of synchronous colorectal cancers. Data of the 523 patients were analyzed.

RESULTS

Total numbers of proximal and distal cancers were 123 and 400. The proportion of patients with Type 2 diabetes was significantly higher for distal cancer (P = 0.034), whereas a greater proportion of patients with proximal cancer had a gallstone history (P = 0.005). Multivariate analysis revealed Type 2 diabetes to be a risk factor for distal colorectal cancer (P = 0.027) and cholelithiasis to be a risk factor for proximal cancer (P = 0.049). The odds ratio for distal colorectal cancer among males with Type 2 diabetes was 4.1 (95 percent confidence interval, 1.4-12.1). On the other hand, a gallstone history was more associated with proximal colon cancer, especially in females (odds ratio = 5.5; 95 percent confidence interval, 1.4-20.9).

CONCLUSIONS

A comparison of the risk factors of proximal and distal colorectal cancer showed that Type 2 diabetes is associated with distal colorectal cancer in males and that cholelithiasis is associated with proximal colon cancer in females.