Risk of Gastrointestinal Cancers among Patients with Appendectomy: A Large-Scale Swedish Register-Based Cohort Study during 1970-2009

Swedish national guidelines for diagnosis and management of acute appendicitis in adults and children

BACKGROUND

Acute appendicitis is one of the most common causes of acute abdominal pain. Differences in the management of this large group of patients has important consequences for the patients and the healthcare system. Controversies regarding the understanding of the natural course of the disease, the utility of new diagnostic methods, and alternative treatments have lead to large variations in practice patterns between centres. These national guidelines present evidence-based recommendations aiming at a uniform, safe and cost-efficient management of this large group of patients.

METHOD

A working group of six experts with broad clinical and research experience was formed. Additional expertise from outside was consulted during the process. A national survey revealed significant variations in the management of patients with suspicion of appendicitis. The evidence provided in published guidelines and reviews were extracted and systematically graded, according to the GRADE methodology. This was supplemented by additional more recent and more directed search of the literature. Patients treated for appendicitis were involved through interviews. The guidelines were reviewed by external experts before the final version was determined.

RESULTS

The guidelines cover an extensive number of issues: pathology, epidemiology, aetiology, natural history, clinical and laboratory diagnosis, diagnostic scoring systems, diagnostic imaging, treatment, nursing care, follow-up, quality registers and quality indicators, among others. Special considerations related to children and pregnant women are covered.

CONCLUSION

These national guidelines present an extensive and thorough review of the current knowledge base related to appendicitis, and provide up-to-date evidence-based recommendations for the management of this large group of patients.

No genetic causality between appendectomy and gastrointestinal cancers: a Mendelian randomization study and meta-analysis in European population

The impact of appendectomy on the risk of gastrointestinal cancers remains unknown. We aimed to systematically estimate the causal relationship between appendectomy and gastrointestinal cancers in the European population using two-sample Mendelian randomization (TSMR) study methods and meta-analysis. As part of the discovery cohort analysis, we identified independent genetic variants strongly associated with appendectomy from the UK Biobank (50,105 cases) to serve as instrumental variables (IVs). Summary-level data for gastrointestinal cancers were obtained from the FinnGen study. As the replication cohort, IVs associated with appendectomy were extracted in the FinnGen study (28,601 cases). The data for gastrointestinal cancers were obtained from the UK Biobank. Finally, meta-analyses were conducted to evaluate the combined causal effects of the MR results. We found no causal relationship between appendectomy and gastrointestinal cancers in both the discovery and replication cohorts. Finally, the meta-analysis revealed no causal association between appendectomy and gastrointestinal cancers. Our findings suggest no causal relationship exists between appendectomy and gastrointestinal cancers in the European population. This genetic evidence supports the conclusion from other observational studies that appendectomy does not affect the risk of gastrointestinal cancers in the European population.

The association of appendectomy with prognosis and tumor-associated macrophages in patients with colorectal cancer

The vermiform appendix plays an important role in colorectal immunity and the homeostasis of the gut microbiome. We aimed to evaluate the prognostic value of prior appendectomy for patients with colorectal cancer (CRC). This study revealed that prior appendectomy is an independent risk factor for the prognosis of patients with CRC, based on a multicentral CRC cohort. We further demonstrated that appendectomy induced a poor prognosis of CRC through the depletion of M1 macrophage cells in AOM-induced mice, which was confirmed in age-, sex-, and location-matched patients' cohorts and orthotopic model models with the CT26 cell line. Poor responses to anti-PD-1 immunotherapy were detected in patients with CRC with appendectomy, and cetuximab is an effective treatment for patients with appendectomy-associated colorectal cancer (APD-CRC) to improve their prognosis. Our study will provide a reference for developing treatment plans for a considerable number of patients with APD-CRC, which is of great clinical significance.

Appendix removal affects the subsequent cancer risk in Asian adults: A territory-wide population-based cohort study

Human appendix is critical for the maintenance of intestinal homeostasis. Appendicectomy has been the optimal treatment of acute appendicitis, yet the cancer incidence after appendix removal remains unclear. In this territory-wide retrospective cohort study, adult participants who underwent appendicectomy from 2000 to 2018 were retrieved from a population database (n = 43,983), while matched reference participants were retrieved as controls (n = 85,853). After appendicectomy, the overall cancer risk was significantly increased (subdistribution hazard ratio (SHR) = 1.124) compared to the non-appendicectomy group. Appendicectomy-treated males had higher cancer risk than males without appendicectomy (SHR = 1.197), while such difference was not observed in female participants. Significant increase in cancer risk was also observed in elder participants (age >60) with appendicectomy (SHR = 1.390). Appendicectomy was positively correlated with the risk of digestive tract and respiratory cancers including colon (SHR = 1.440), pancreas (SHR = 1.930), and trachea, bronchus, and lung (SHR = 1.394). In contrast, the risk of liver cancer was markedly decreased after appendicectomy (SHR = 0.713). In conclusion, we reported the association of appendicectomy with subsequent cancer incidence. These findings highlight the potential complication after appendix removal and the necessity of post-operative management to monitor and prevent long-term adverse events.

Appendectomy and appendicitis do not increase colorectal cancer risk: evidence from Mendelian randomization

Background

Acute appendicitis (AA) is one of the most prevalent acute abdominal diseases and appendectomy is the definitive treatment of appendicitis. However, whether appendicitis and appendectomy cause colorectal cancer (CRC) is controversial. The results of observational studies are contradictory, but randomized controlled trials (RCT) cannot be conducted.

Methods

Data of appendectomy, AA, and CRC were obtained from the IEU Open GWAS project. We selected several Genome-wide association studies (GWAS) summary statistics for CRC: statistics for colon cancer (CC) were obtained from MRC-IEU and Neale lab, respectively; statistics for rectum cancer (RC) were obtained from MRC-IEU and FinnGen, respectively; statistics for CRC were provided by Sakaue S et al. Mendelian randomization (MR) was used to evaluate the causal relationships between exposure and outcomes. Inverse variance weighting (IVW) was the most important analysis method. Meta-analysis was used to summarize the results of IVW to increase the reliability and sensitivity analysis was used to evaluate the robustness of the results.

Results

According to the results of IVW, appendectomy did not increase risk of CC: MRC-IEU (OR:1.009, 95%CI:0.984-1.035, P=0.494), Neale lab (OR:1.016, 95%CI:0.993-1.040, P=0.174); Appendectomy also did not increase risk of RC: MRC-IEU(OR:0.994, 95%CI:0.974-1.014, P=0.538), FinnGen(OR:2.791, 95%CI:0.013-580.763, P=0.706); Appendectomy also did not increase risk of CRC: Sakaue S(OR:1.382, 95%CI:0.301-6.352, P=0.678). Appendicitis did not increase risk of CC: MRC-IEU(OR:1.000, 95%CI:0.999-1.001, P=0.641), Neale lab(OR:1.000, 95%CI:1.000-1.001, P=0.319); Appendicitis also did not increase risk of RC: MRC-IEU(OR:1.000, 95%CI:0.999-1.000, P=0.361), FinnGen(OR:0.903, 95%CI:0.737-1.105, P=0.321); Appendicitis also did not increase risk of CRC: Sakaue S (OR:1.018, 95%CI:0.950-1.091, P=0.609). The results of Meta-analysis also showed appendectomy (P=0.459) and appendicitis (P=0.999) did not increase the risk of CRC.

Conclusions

Appendectomy and appendicitis do not increase the risk of colorectal cancer. More clinical trials are needed in the future to verify the causal relationships.

Beyond a vestigial organ: effects of the appendix on gut microbiome and colorectal cancer

The role of appendectomy in the pathogenesis of colorectal cancer (CRC) is a recent topic of contention. Given that appendectomy remains one of the most commonly performed operations and a first-line management strategy of acute appendicitis, it is inherently crucial to elucidate the association between prior appendectomy and subsequent development of CRC, as there may be long-term health repercussions. In this review, we summarize the data behind the relationship of CRC in post-appendectomy patients, discuss the role of the microbiome in relation to appendectomy and CRC pathogenesis, and provide an appraisal of our current understanding of the function of the appendix. We seek to piece together the current landscape surrounding the microbiome and immunological changes in the colon post-appendectomy and suggest a direction for future research involving molecular, transcriptomic, and immunologic analysis to complement our current understanding of the alterations in gut microbiome.

Risk of appendiceal malignancy in conservatively treated acute appendicitis

BACKGROUND AND AIMS

Appendectomy has historically been the standard treatment of acute appendicitis, but lately, conservative treatment of uncomplicated acute appendicitis with antibiotics has successfully been used in selected patients. Complicated acute appendicitis is often treated conservatively initially, but may benefit from interval appendectomy due to the higher risk of appendiceal malignancy and recurrence. Recommendations for follow-up after conservatively treated appendicitis vary. Furthermore, the risk of underlying malignancy and the necessity of routine interval appendectomy are unclear. This study aims to evaluate follow-up status, recurrence, and underlying appendiceal malignancy in conservatively treated uncomplicated and complicated acute appendicitis.

METHODS

This study included patients with conservatively treated acute appendicitis at Skåne University Hospital, Sweden during 2012-2019. Information on patient demographics at index admission and data on follow-up, recurrence, number of appendectomies after initial conservative treatment, and underlying malignancy were retrieved from medical charts.

RESULTS

The study cohort included 391 patients, 152 with uncomplicated and 239 with complicated acute appendicitis. Median time of study follow-up was 52 months. The recurrence risk was 23 (15.1%) after uncomplicated and 58 (24.3%) after complicated acute appendicitis (p = 0.030). During follow-up, 55 (23%) patients with complicated acute appendicitis underwent appendectomy. Appendiceal malignancies were found in 12 (5%) patients with previous complicated acute appendicitis versus no appendiceal malignancies after uncomplicated acute appendicitis (p = 0.002).

CONCLUSION

The risk of appendiceal malignancy and recurrent appendicitis was significantly higher in patients with complicated acute appendicitis compared with uncomplicated acute appendicitis.

Factors influencing advanced colorectal neoplasm anatomic site distribution in China: An epidemiological study based on colorectal cancer screening data

OBJECTIVE

Existing studies indicate that advanced colorectal neoplasms exhibit distinct clinical and biological traits based on anatomical sites. However, in China, especially for advanced colorectal neoplasms, there's limited information available on these traits. Our primary objective is to comprehensively study the characteristics of advanced colorectal neoplasm patients in different anatomical sites in China.

METHODS

We selected information from the colorectal cancer screening database in Tianjin, China, since 2010 as the study subject. We chose valid information from 3113 patients with comprehensive data and diagnosed advanced colorectal neoplasms (ANs) from a pool of 19,308 individuals to be included in the study. We then conducted further analysis to examine the correlation between these epidemiological data and tumor location.

RESULTS

Among the 3113 patients, neoplasms in the left side of the colon accounted for the largest proportion, while neoplasms in the right side of the colon had the smallest proportion, followed by rectal neoplasms. The highest proportion of advanced colorectal neoplasms was found among men. In the age group of 39-49 years old, the proportion of left late-stage advanced colon neoplasms was equal to that of right late-stage advanced colon neoplasms, while late-stage advanced rectal neoplasms increased with age. Smoking, drinking, and a history of colon cancer in first-degree relatives showed statistically significant associations with the location distribution of advanced colorectal neoplasms. A history of appendicitis, appendectomy, cholecystitis, or cholecystectomy did not significantly affect the location distribution of advanced colorectal neoplasms. However, among patients with such histories, there was a statistically significant relationship between advanced colon neoplasms on the right and those on the left and in the rectum. Similar results were observed for BMI.

CONCLUSION

Our research findings demonstrate that advanced colorectal neoplasms display unique epidemiological characteristics depending on their anatomical locations, and these distinctions deviate from those observed in Western populations. These insights contribute to a more comprehensive understanding of the topic and offer valuable guidance for future research in China. We advocate for further investigations centered on the anatomical location of colorectal neoplasms to enhance the precision of colorectal cancer (CRC) screening and treatment.

Appendectomy as part of Ladd's procedure: a systematic review and survey analysis

BACKGROUND

Ladd's Procedure has been the surgical intervention of choice in the management of congenital intestinal malrotation for the past century. Historically, the procedure included performing an appendectomy to prevent future misdiagnosis of appendicitis, since the location of the appendix will be shifted to the left side of the abdomen. This study consists of two parts. A review of the available literature on appendectomy as part of Ladd's procedure and then a survey sent to pediatric surgeons about their approach (to remove the appendix or not) while performing a Ladd's procedure and the clinical reasoning behind their approach.

METHODS

The study consists of 2 parts: (1) a systematic review was performed to extract articles that fulfill the inclusion criteria; (2) a short online survey was designed and sent by email to 168 pediatric surgeons. The questions in the survey were centered on whether a surgeon performs an appendectomy as part of the Ladd's procedure or not, as well as their reasoning behind either choice.

RESULTS

The literature search yielded five articles, the data from the available literature are inconsistent with performing appendectomy as part of Ladd's procedure. The challenge of leaving the appendix in place has been briefly described with minimal to no focus on the clinical reasoning. The survey demonstrated that 102 responses were received (60% response rate). Ninety pediatric surgeons stated performing an appendectomy as part of the procedure (88%). Only 12% of pediatric surgeons are not performing appendectomy during Ladd's procedure.

CONCLUSION

It is difficult to implement a modification in a successful procedure like Ladd's procedure. The majority of pediatric surgeons perform an appendectomy as part of its original description. This study has identified gaps in the literature pertaining to analyze the outcomes of performing Ladd's procedure without an appendectomy which should be explored in future research.

Risk of colorectal cancer after appendectomy: A systematic review and meta-analysis

BACKGROUND AND AIM

Appendectomy is associated with various diseases, but whether it increases the risk of colorectal cancer (CRC) remains uncertain. We conducted a systematic review and meta-analysis aimed at investigating the suggested correlation between appendectomy and CRC.

METHODS

Systematic retrieval was performed using the PubMed, Embase, Cochrane library, Web of Science, and ClinicalTrials.gov databases up to May 4, 2022, for studies reported the influence of appendectomy on CRC, colon cancer (CC) or rectal cancer (RC). Odd ratios (ORs) and 95% confidence intervals (CIs) of CRC after appendectomy were pooled using the random effects model. Subgroup analyses were carried on by region, sex, and tumor location.

RESULTS

Our search identified 1743 articles, of which 22 studies from three continents published between 1964 and 2022 were eligible for inclusion. Overall, people with appendectomy had a higher risk of CRC (OR = 1.31; 95% CI [1.05, 1.62]). But the risk for Europeans was not significant (OR = 0.94; 95% CI [0.87, 1.02]; I²  = 0%), while for Americans and Asians, appendectomy would increase the risk of CRC (OR = 1.68; 95% CI [1.15, 2.44]; I²  = 65% and OR = 1.46; 95% CI [1.04, 2.05]; I²  = 98%), especially in females and in developing countries. It is worth noting that appendectomy might be a protective factor for CC in European women (OR = 0.87; 95% CI [0.77, 0.98]; I²  = 0%).

CONCLUSIONS

Appendectomy may be a risk factor for CRC, with varying degrees in different populations. More high-quality cross-regional studies are needed for better clinical decision making.

Risk of colorectal cancer in patients with appendicitis over the age of 40 years

AIM

Acute appendicitis in late adulthood is hypothesized to be associated with an increased risk of colorectal cancer (CRC). This study aimed to establish whether patients over the age of 40 years presenting with appendicitis had an increased risk of being diagnosed with CRC over the subsequent 3 years.

METHOD

This is a retrospective review of patients aged 40 years and over presenting to Canterbury District Health Board with appendicitis from January 2010 to December 2015. Clinical details were obtained for these patients and cross-referenced with the New Zealand Cancer Registry for the 3 years following diagnosis. The incidence ratio rate (IRR) and standardized incidence ratio (SIR) were calculated by establishing the incidence of CRC in this cohort and comparing it with the Canterbury population data.

RESULTS

A total of 1099 patients met the inclusion criteria. The majority (75%) underwent CT as part of their initial work-up. The rate of colonoscopy increased with age from around 10% between 40 and 49 years to 27% for those 70 years and over. Eleven cases of CRC were identified, resulting in an IRR 2.35 (95% CI 1.17-4.21). The SIR for this population was 3.28 (95% CI 1.82-5.92).

CONCLUSION

The rate of CRC is significantly increased compared with the background population in this cohort. The results of this study support luminal investigation of adults aged 40 years and over who present with acute appendicitis as CT alone was insufficient to detect the pathology.

A retrospective study about incidental appendectomy during the laparoscopic treatment of intussusception

PURPOSE

We aim to see incidental appendectomy (IA) was worth or not during the laparoscopic treatment of intussusception.

METHODS

This study included forty-eight patients who underwent a laparoscopic procedure for idiopathic intussusception without intestinal resection between April 2014 and April 2021. The Chi-square or Fisher's exact tests for categorical variables and the Student t-test for continuous variables were used to analyze and compare patient characteristics.

RESULTS

IA was performed on 63% (30/48) of patients after surgical reduction, while 18 (37%), did not. Patients who underwent IA had a higher total cost (16,618 ± 2,174 vs.14,301 ± 5,206, P = 0.036), and a longer mean operation duration (59 ± 19 vs.45 ± 21, P = 0.025). The distribution of the PO time, length of hospital stay, PCs, and RI did not differ significantly. The histopathological evaluation of the 30 resected appendices revealed five (17%) with signs of acute inflammation, 20 (66%) with chronic signs of inflammation, and five (17%) with inconspicuous appendices.

CONCLUSION

IA is linked to a longer average operation time and a higher total cost. There is insufficient evidence to recommend IA during laparoscopic intussusception treatment. The risks and benefits of IA need further study.

Appendectomy Is Associated With Alteration of Human Gut Bacterial and Fungal Communities

Recent research has revealed the importance of the appendix in regulating the intestinal microbiota and mucosal immunity. However, the changes that occur in human gut microbial communities after appendectomy have never been analyzed. We assessed the alterations in gut bacterial and fungal populations associated with a history of appendectomy. In this cross-sectional study, we investigated the association between appendectomy and the gut microbiome using 16S and ITS2 sequencing on fecal samples from 30 healthy individuals with prior appendectomy (HwA) and 30 healthy individuals without appendectomy (HwoA). Analysis showed that the gut bacterial composition of samples from HwA was less diverse than that of samples from HwoA and had a lower abundance of Roseburia, Barnesiella, Butyricicoccus, Odoribacter, and Butyricimonas species, most of which were short-chain fatty acids-producing microbes. The HwA subgroup analysis indicated a trend toward restoration of the HwoA bacterial microbiome over time after appendectomy. HwA had higher gut fungi composition and diversity than HwoA, even 5 years after appendectomy. Compared with those in samples from HwoA, the abundance correlation networks in samples from HwA displayed more complex fungal–fungal and fungal–bacterial community interactions. This study revealed a marked impact of appendectomy on gut bacteria and fungi, which was particularly durable for fungi.

Features of colorectal cancer in China stratified by anatomic sites: A hospital-based study conducted in university-affiliated hospitals from 2014 to 2018

OBJECTIVE

The clinical and biological characteristics of colorectal cancer have been found to differ depending on the anatomic site of the cancer. However, for Chinese patients, there is limited information on the proportion of cases at each site and the related features. In this study, we explored the location, distribution and other features of colorectal cancers at each anatomic site in Chinese patients.

METHODS

We conducted a hospital-based study using hospitalization summary reports from 10 Peking University-affiliated hospitals from 2014 to 2018; the reports covered a total of 2,097,347 hospitalizations. Incident cases were chosen as the study population, and their epidemiological features were further analyzed.

RESULTS

A total of 20,739 colorectal cancer patients were identified. Rectum was the most common location (48.3%) of the cancer, whereas the proportions of patients with distal and proximal colon cancer were 24.5% and 18.6%, respectively. Patients with rectal cancer were predominantly male and were the youngest for all anatomical sites (each P<0.001). The highest proportion of emergency admissions, the longest hospital stays and the highest hospitalization costs were found in patients with proximal colon cancer (each P<0.001). The proximal colon cancer subgroup included the highest proportions of patients with medical histories of cholecystectomy, cholecystolithiasis and/or gallbladder polyps and appendectomy (P=0.009, P<0.001 and P<0.001, respectively). The distal colon cancer subgroup included the highest proportions of patients with medical histories of diabetes and hypertension (P<0.001, respectively).

CONCLUSIONS

The patterns of colorectal cancer observed in this study differ from those reported for Western patients and show a significantly higher proportion of patients with rectal cancer. Different epidemiological features were also found based on anatomic sites. Further studies based on tumor location should be conducted to facilitate more accurate screening and treatment.

Dose-Effect Relationship Between Gastric Cancer and Common Digestive Tract Symptoms and Diagnoses in Anhui, China

Background

Early prevention and diagnosis are key to reducing the huge burden of gastric cancer (GC). Nearly half of the population worldwide are suffering from some form of digestive tract conditions (symptoms/diagnoses, DTCs) but their relations with GC are not well understood. We aim to explore the relationships (especially dose–effect relationships) between GC and DTCs.

Methods

This study used data from a community-based case–control study in Anhui, China during 2016–2019 and performed multivariate conditional logistic regression modeling of the associations between GC and DTCs.

Results

A total of 2255 participants (451 cases and 1804 controls) completed the study. Statistically significant relations (P<0.05) were found between GC and the presence of gastroesophageal reflux [odds ratio (OR)=1.41], odynophagia (OR=1.87), stomach discomfort (OR=1.86), poor appetite (OR=2.01) and Helicobacter pylori (H. pylori) infection (OR=4.39). When the DTCs were divided into duration grades, all these ORs presented an increasing trend (P<0.05), being 1.89 to 2.45 for gastroesophageal reflux, 1.63 to 3.78 for stomach discomfort, 2.36 to 5.29 for poor appetite, and 3.95 to 10.03 for H. pylori infection. When the DTCs were divided into severity grades, the ORs also witnessed an increasing trend (P<0.05), being 1.69 to 2.52 for gastroesophageal reflux, 2.44 to 3.56 for stomach discomfort, and 2.22 to 2.75 for poor appetite. When the DTCs were divided into duration-severity grades, the ORs displayed a much steeper increasing trend, being 0.49 to 4.96 for gastroesophageal reflux, 1.50 to 6.33 for odynophagia, 0.47 to 3.32 for stomach discomfort, and 0.40 to 10.47 for poor appetite. In contrast, the ORs for the lower DTCs were generally tested without statistical significance.

Conclusion

The study revealed consistent dose–effect associations between GC and duration of gastroesophageal reflux, stomach discomfort, poor appetite, and H. pylori infection; severity of gastroesophageal reflux, stomach discomfort and poor appetite; and duration-severity of gastroesophageal reflux, odynophagia, stomach discomfort and poor appetite. These should inform future prevention, diagnosis and further research in patients with GC.

Long-term effects of appendectomy in humans: is it the optimal management of appendicitis?

INTRODUCTION

Appendectomy remains the gold standard for treating uncomplicated and complicated appendicitis. However, the vermiform appendix may play a significant role in the immune system (secondary immune function) and maintain a reservoir of the normal microbiome for the human body. The aim of this study was to summarize the long-term effects after appendectomy and discuss whether appendectomy is suitable for all appendicitis patients.

AREAS COVERED

A comprehensive and unbiased literature search was performed in PubMed. The terms 'appendix,' 'appendicitis,' 'appendectomy,' and 'endoscopic retrograde appendicitis therapy' were searched in the title and/or abstract. This review summarizes the long-term effects of appendectomy on some diseases in humans and describes three methods including appendectomy, medical treatment, and an 'organ-sparing' technique, named endoscopic retrograde appendicitis therapy (ERAT) to treat appendicitis.

EXPERT OPINION

Appendectomy remains the first-line therapy for appendicitis. The patient's problem is appendix, not appendicitis. If we treat appendicitis, the problem should be resolved. During COVID-19, an initial antibiotic treatment of mild appendicitis represents a promising strategy. For patients who are worried about the long-term adverse effect after appendectomy and have a strong desire to preserve the appendix and are aware of the risk of appendicitis recurrence, medical treatment, or ERAT could be proposed.

Impact of Appendectomy on Gut Microbiota

Background: Considered vestigial from the classic point of view, the vermiform appendix has long been the subject of intensive studies. The recent understanding of appendix function in the context of unique architecture and bacterial complexity and density allows considering it as a safehouse for intestinal biodiversity. Methods: This review analyzes and assesses the current state of scientific knowledge regarding the role of the vermiform appendix in normal gut microbiota maintenance as a crucial factor of host homeostasis. It also highlights the difference in microbial composition between the large bowel and the appendix, as well as the association between the surgical excision, appendectomy, and dysbiosis-induced diseases. In addition, the review discusses the results of epidemiologic studies on appendectomy as a risk factor for the initiation of gastrointestinal carcinogenesis. It also highlights the association between appendectomy and a series of chronic inflammatory and neurologic disorders, including inflammatory bowel disease.

A link between appendectomy and gastrointestinal cancers: a large-scale population-based cohort study in Korea

An association between appendectomy and subsequent gastrointestinal (GI) cancer development has been postulated, although the evidence is limited and inconsistent. To provide clarification, we investigated the link between appendectomy and GI cancers in a large nationwide appendectomy cohort. This cohort was derived from the claims database of the National Health Insurance Service in South Korea and comprised 158,101 patients who had undergone appendectomy between 2007 and 2014. A comparison cohort of 474,303 subjects without appendectomy was selected after 1:3 matching by age and sex. The incidence of GI cancers after appendectomy was observed, and risk factors for GI cancers were determined by using a multivariable-adjusted proportional hazards model. Appendectomy did not significantly increase the incidence of GI cancers in the overall population (1.529 and 1557 per 1000 person-years in the non-appendectomy and appendectomy cohorts, respectively). However, appendectomy significantly increased the incidence of GI cancers in subgroups consisting of elderly (≥ 60 years) patients (adjusted HR, 1.102; 95% confidence interval, 1.011-1.201; p = 0.028) or women (adjusted HR, 1.180; 95% confidence interval, 1.066-1.306; p = 0.001).

Evaluating the distribution of the locations of colorectal cancer after appendectomy and cholecystectomy

Backgrounds

The number of appendectomies and cholecystectomies performed is gradually increasing worldwide. An increasing incidence of colorectal cancer (CRC) after appendectomy and cholecystectomy has been reported, but the location of tumors in certain segments of the colon and rectum after appendectomy and cholecystectomy is still uncertain. We aimed to evaluate the distribution of the locations of colorectal cancer after appendectomy and/or cholecystectomy in patients who underwent CRC surgery.

Methods

We reviewed the medical records of patients who had undergone CRC surgery between 2015 and 2017 for the presence of previous appendectomy/cholecystectomy. Data were collected from the Colorectal Data Base of the University of Szeged, Department of Surgery.

Results

Surgery for CRC was performed in 640 patients during the study period. Data of 604 patients were analyzed. Appendectomy was performed in 100 patients (16.6%), cholecystectomy in 65 (10.8%), and both interventions in 18 (3%) before the CRC surgery. Out of those patients who underwent appendectomy alone, 92 (92%) had undergone appendectomy more than 10 years before the CRC surgery. Also in these 100 patients, the prevalence of right-sided colon cancer (CC) was 35% (n = 35), in comparison with the prevalence among the 504 other patients (20.4%, n = 103). The prevalence of right-sided CC among patients who underwent cholecystectomy alone was 36.9% (n = 24), in comparison with 21.2% (n = 114) of the 539 other patients.

Conclusions

A significant left to right side shift in CRC was noted among patients who had previously undergone appendectomy/cholecystectomy. Because right-sided CC has a worse prognosis, the role of incidental appendectomy and routine cholecystectomy seems that need re-evaluation.

Appendicitis as a manifestation of colon cancer: should we image the colon after appendicectomy in patients over the age of 40 years?

BACKGROUND

Appendicitis can be secondary to caecal pathology (polyp or cancer). Increasing age is a risk factor for malignancy coexisting with appendicitis. There is an increased coexistence of cancer post-appendicectomy in patients aged 50-54 years. This study investigates whether post-appendicectomy patients aged over 40 years should receive further colorectal imaging and follow-up.

METHODS

Retrospective data were collected for 1633 patients aged 40 years and over who underwent appendicectomy in a 10-year period (1st January 2004-31st December 2014). Data were analysed for patients with histological confirmation of acute appendicitis. Incidental appendicular tumours were excluded.

RESULTS

One thousand fifty-five (64%) patients had histological confirmation of acute appendicitis (median age 52 years; range 40-96 years). Six hundred three patients (57%) were aged 40-54 years; 452 patients (43%) were aged 55 years or over. Twenty-six (2.5%) patients were investigated post-appendicectomy. Three (11.5%) had caecal pathology: 2 adenocarcinoma, 1 benign caecal polyp. Ten (2.2%) patients aged 55 years or over had caecal pathology. Seven (1.6%) were diagnosed with caecal cancer. No patients below age 54 years were diagnosed with caecal cancer. The incidence of caecal cancer in the study population was 0.66% (40-54.9 years 0%; 55 years and over 1.6%). Patients aged 55 years or over were more likely to develop caecal pathology than patients aged 40-54 years (p = 0.006). The odds ratio of developing caecal pathology was 6.8 times greater (95% CI 1.49-31.29) in people aged 55 years and over.

CONCLUSIONS

Patients aged 55 years or over who have undergone appendicectomy should be offered colonoscopy to exclude coexistent caecal pathology.

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.

Long-Term Complications of Appendectomy: A Systematic Review

BACKGROUND AND AIMS

Appendectomy is a common surgical procedure, but no overview of the long-term consequences exists. Our aim was to systematically review the long-term complications of appendectomy for acute appendicitis.

MATERIALS AND METHODS

This systematic review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A protocol was registered on PROSPERO (CRD42017064662). The databases PubMed and EMBASE were searched for original reports on appendectomy with n ≥ 500 and follow-up >30 days. The surgical outcomes were ileus and incisional hernia; other outcomes were inflammatory bowel disease, cancer, fertility, and mortality.

RESULTS

We included 37 studies. The pooled estimate of the ileus prevalence was 1.0% over a follow-up period of 4.6 (range, 0.5-15) years. Regarding incisional hernia, we found a pooled estimate of 0.7% prevalence within a follow-up period of 6.5 (range, 1.9-10) years. Ulcerative colitis had a pooled estimate of 0.15% prevalence in the appendectomy group and 0.19% in controls. The opposite pattern was found regarding Crohn's disease with a pooled estimate of 0.20% prevalence in the appendectomy group and 0.12% in controls. No clear pattern was found regarding most of the examined cancers in appendectomy groups compared with background populations. Pregnancy rates increased after appendicitis compared with controls in most studies. Mortality was low after appendectomy.

CONCLUSION

Appendectomy had a low prevalence of long-term surgical complications. We did not find any significant other long-term complications, though the prevalence of Crohn's disease was higher and the prevalence of ulcerative colitis was lower after appendectomy than in controls. Appendectomy did not impair fertility.

Appendicitis before Age 20 Years Is Associated with an Increased Risk of Later Prostate Cancer

Background: Appendicitis before age 20 years has been observed to influence the risk of several inflammatory conditions, possibly through underlying immunological mechanisms. Inflammation has further been suggested to be involved in prostate cancer development. We therefore hypothesized that immunological characteristics signaled by appendicitis before late adolescence might influence the risk of later prostate cancer, and aimed to evaluate this association in a population-based study.Methods: We identified a large cohort of Swedish men who underwent assessment for military conscription around the age of 18 years (n = 242,573). Medical diagnoses at time of conscription were available through the Swedish Military Conscription Register. The Swedish Cancer Register was used to identify diagnoses of prostate cancer. Multivariable adjusted Cox regression analyses were used to estimate HR and 95% confidence intervals (95% CIs) for the association between appendicitis and prostate cancer.Results: During a median of 36.7 years of follow-up, 1,684 diagnoses of prostate cancer occurred. We found a statistically significant association between appendicitis and overall prostate cancer (adjusted HR 1.70; 95% CI, 1.08-2.67). The risk was notably increased for advanced (HR 4.42; 95% CI, 1.74-11.22) and lethal (HR 8.95; 95% CI, 2.98-26.91) prostate cancer.Conclusions: These results suggest that a diagnosis of appendicitis before adulthood potentially signals underlying immune characteristics and a pattern of inflammatory response relevant to prostate cancer risk.Impact: The study lends support to the proposed role of inflammation in prostate carcinogenesis, and adds another area of investigation potentially relevant to prostate cancer development. Cancer Epidemiol Biomarkers Prev; 27(6); 660-4. ©2018 AACR.