Appendectomy during childhood and adolescence and the subsequent risk of cancer in Sweden

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.

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 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.

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.

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.

Unexpected diagnosis of acute lymphoblastic leukemia in a 2-year-old with acute appendicitis - Case report

INTRODUCTION AND IMPORTANCE

Appendicitis is an extremely common surgical problem, especially in the pediatric population. However, leukemic infiltration of the appendix is rare and even more so is having acute appendicitis as the initial manifestation.

CASE PRESENTATION

The patient is a 2-year-old female with multiple febrile illnesses since birth, who presented to the emergency department with a 3-day history of abdominal pain, fever, and decreased appetite. Ultrasound of her right lower quadrant was consistent with acute appendicitis. A laparoscopic appendectomy was performed successfully without complication. However, pathological examination of the specimen revealed an appendix with partial involvement of B-lymphoblastic lymphoma/leukemia in a background of lymphoid hyperplasia. This prompted referral to a pediatric hematologist/oncologist. Further workup revealed abnormal immature cells on peripheral blood flow cytometry. Bone marrow biopsy confirmed a diagnosis of B-cell acute lymphoblastic leukemia.

CLINICAL DISCUSSION

Though acute appendicitis is very common and management is well documented, it is rare for pathological examination to uncover leukemia as an underlying etiology and to have acute appendicitis as the initial manifestation of hematologic malignancy. To our knowledge, very few similar events have occurred and been documented in the medical literature.

CONCLUSION

Physicians and surgeons should be aware that, though quite rare, leukemic infiltration of the appendix can occur and should be considered in the differential diagnosis of acute appendicitis. Notably, pathologic examination of the appendix may be particularly informative. Diligent follow-up of abnormal pathology is crucial in cases suggestive of underlying hematologic malignancy.

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.

Incidence and risk of sepsis following appendectomy: a nationwide population-based cohort study

Appendectomy is a frequently performed surgical procedure; however, long-term consequences have not been fully explored. We used a nationwide population-based cohort to determine whether patients undergoing appendectomy are at an increased risk of sepsis. Overall, 252,688 patients undergoing appendectomy and 252,472 matched controls were identified from the National Health Insurance Research Database in Taiwan. A propensity score analysis was used for matching age, sex, index year and comorbidities at a ratio of 1:1. Multiple Cox regression and stratified analyses were used to estimate the adjusted hazard ratio (aHR) of developing sepsis. Patients undergoing appendectomy had a 1.29 times (aHR: 1.29; 95% confidence interval [CI], 1.26-1.33) higher risk of developing sepsis than those not undergoing. Patients aged 20-49 years had a 1.58-fold higher risk of sepsis in the appendectomy cohort (aHR; 95% CI, 1.50-1.68). Also, having undergone appendectomy, patients had a higher likelihood of sepsis, regardless of sex and with or without comorbidities. Patients with <1 year follow-up showed a 1.98-fold risk of sepsis in the appendectomy cohort. Patients with 1-4 and ≥5 years follow-up showed a 1.29 and 1.11-fold risk of sepsis, respectively. Future research is required to elucidate the possible immuno-pathological mechanisms of these associations.

Prognostic significance of previous tonsillectomy after radical cystectomy for bladder cancer

Introduction: To examine whether previous tonsillectomy (TE) impacts on survival after radical cystectomy (RC) for bladder cancer (BC).Patients and Methods: A total of 320 patients were staged cM0 and underwent RC for BC between 2002 and 2013. We retrospectively investigated whether patients had undergone TE prior to RC. Chi-square/Fisher-Exact test was carried out to compare clinicopathological features between the TE- and non-TE-group. Kaplan-Meier analysis with log-rank test was used to estimate recurrence-free survival (RFS) and multivariable Cox-regression analysis of risk factors of recurrence. The median follow-up was 31 months (interquartile range: 9-54).Results: A history of TE was present in 18 of the 320 patients (5.6%). All TEs were performed for benign conditions. TE prior to RC was associated with a history of appendectomy (p = 0.045), lower age at RC (p = 0.029), tumor unifocality (p < 0.001), advanced histopathological tumor stage (p = 0.015), non-pure urothelial carcinoma (p = 0.025), lymphovascular invasion (p = 0.035) and receipt of palliative chemotherapy (p = 0.004). The 3-year RFS was 39.2% for patients with previous TE and 62.4% for those without (p = 0.008). In multivariable analysis, adjusted for all significant parameters of univariable analysis, lymph-node tumor involvement (p = 0.017), positive surgical margins (p = 0.047), tumor grade (p = 0.032), advanced tumor stage (≥pT3a; p = 0.049) and a history of TE (p = 0.021) remained independent prognosticators of recurrence.Conclusion: In this series, previous TE was an independent predictor of recurrence after RC for BC. Further studies are needed to assess whether TE induces immunological alterations that might exert adverse effects on cancer progression of patients with invasive BC.

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.

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.

Risk of lymphoid neoplasms in a Swedish population-based cohort of 337,437 patients undergoing appendectomy

OBJECTIVE

Appendectomy remains one of the most common surgical procedures, but possible long-term consequences for health and disease are incompletely investigated. The appendix forms part of the secondary lymphoid system and appendectomy has been associated with increased risks of hematolymphoproliferative malignancies in some studies.

MATERIALS AND METHODS

We examined the risk of lymphoid neoplasms in a large cohort of 337,437 appendectomised patients <60 years of age in Sweden 1975-2009. We estimated relative risks of non-Hodgkin lymphoma (NHL) and major subtypes, Hodgkin lymphoma (HL), chronic lymphocytic leukaemia (CLL), myeloma, and acute lymphoblastic leukaemia (ALL) versus the general population using standardised incidence ratios (SIRs) with 95% confidence intervals (CIs).

RESULTS

There was no increased risk of NHL (SIR = 0.97, 95%CI 0.88-1.06), major NHL subtypes, CLL (SIR = 0.87, 95%CI 0.70-1.06), myeloma (SIR = 1.14, 95%CI 0.96-1.33) or ALL (SIR = 1.10, 95%CI 0.80-1.47) following appendectomy. An increased risk of HL was observed among patients diagnosed with appendicitis (SIR = 1.29, 95%CI 1.07-1.54, p=0.007), especially individuals aged <20 years at surgery (SIR = 1.43, 95%CI 1.11-1.82), and for the nodular sclerosis subtype of HL (SIR = 1.55, 95%CI 1.01-2.27). A marginally increased risk of myeloma was noted among men, but the association was limited to the first few years of follow-up.

CONCLUSION

Appendectomy is not associated with any notable increase in risk of lymphoid neoplasms. A small increased risk of HL following appendicitis (rather than appendectomy per se) could reflect a true association, or shared susceptibility to infection/inflammation among individuals prone to develop HL. The association observed for myeloma may be explained by chance or surveillance bias.

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

BACKGROUND

Removal of the appendix might induce physiological changes in the gastrointestinal tract, and subsequently play a role in carcinogenesis. Therefore, we conducted a nationwide register-based cohort study in Sweden to investigate whether appendectomy is associated with altered risks of gastrointestinal cancers.

METHODS

A population-based cohort study was conducted using the Swedish national registries, including 480,382 eligible patients followed during the period of 1970-2009 for the occurrence of site-specific gastrointestinal cancer (esophageal/gastric/colon/rectal cancer). Outcome and censoring information was collected by linkage to health and demography registers. We examined the incidence of appendectomy in Sweden using data from 1987-2009. We also calculated standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) to estimate the relative gastrointestinal cancer risk through comparison to the general population.

RESULTS

We noted an overall decrease in the age-standardized incidence of appendectomy among the entire Swedish population from 189.3 to 105.6 per 100,000 individuals between 1987 and 2009. Grouped by different discharge diagnosis, acute appendicitis, incidental appendectomy, and entirely negative appendectomy continuously decreased over the study period, while the perforation ratio (18%-23%) stayed relatively constant. Compared to the general population, no excess cancer risk was observed for gastrointestinal cancers under study with the exception of a marginally elevated risk for esophageal adenocarcinoma (SIR 1.32, 95% CI 1.09-1.58).

CONCLUSIONS

In Sweden, the incidence of appendectomy and acute appendicitis has decreased during 1987-2009. No excess gastrointestinal cancer risks were observed among these appendectomized patients, with the possible exception of esophageal adenocarcinoma.

Common immune-related exposures/conditions and risk of non-Hodgkin lymphoma: a case-control study of disease-discordant twin pairs

We evaluated the association between common immune system-altering experiences and non-Hodgkin lymphoma (NHL) risk using a case-control study of 162 like-sex twin pairs discordant for NHL, identified from the International Twin Study. Information on medical history and evidence of childhood exposure to microbes was obtained by questionnaire from 1998 to 2002. Conditional logistic regression was used to estimate odds ratios and 95% confidence intervals. Intra-twin-pair agreement between twins on individual exposures was high (76%-97%). A negative association between NHL and seasonal hay fever (odds ratio (OR) = 0.28, 95% confidence interval (CI): 0.10, 0.75) and certain allergies (OR = 0.29, 95% CI: 0.13, 0.68) was observed. The number of atopic diseases was negatively associated with NHL (P for trend = 0.0003). A history of infectious mononucleosis was negatively associated with NHL risk (OR = 0.35, 95% CI: 0.14, 0.90). NHL risk was associated with more frequent childhood exposure to microbes during early life (P for trend = 0.04). No differences in association by NHL subtype were observed, although statistical power for these comparisons was low. These observations support the hypothesis that immune-related exposures, especially atopy, are associated with decreased NHL risk. Use of the within-twin-pair study design mitigates confounding by genome, family structure, and unmeasured characteristics of early childhood factors.

Appendicitis as an early manifestation of subsequent malignancy: an asian population study

BACKGROUND & AIMS

Cancer risk after appendectomy in patients with appendicitis remains unclear. This study examined the role of appendicitis as an early manifestation harbingering the distant malignancy.

METHODS

From the insurance claims data of Taiwan, we identified a cohort of 130,374 patients newly received appendectomy from 2000-2009, without cancer diagnosis. A comparison cohort of 260,746 persons without appendectomy and cancer was selected from the same database, frequency matched by age, sex, comorbidity and index year. We monitored subsequent cancers with a12-month follow-up.

RESULTS

Over all, 1406 and 616 cancer cases were identified in the appendectomy cohort and comparisons, respectively, with all cancers incidence rate 4.64-fold higher in the appendectomy cohort (9.06 vs. 1.96 per 1000 person-months). Digestive and female genital organs harbored 80.9% of cancer cases in the appendectomy cohort. The Cox model measured site-specific hazard ratio (HR) was the highest for female genital cancers (23.3), followed by cancers of colorectum (14.7), small intestine (10.1), pancreas (7.40), lymphoma (5.89) and urinary system (4.50), all significant at 0.001 level. The HR of all cancers decreased from 13.7 within 3 months after appendectomy to 1.37 in 7-12 months after the surgery. In general, relative to the comparison cohort, younger appendectomy patients tended to have a higher HR than older patients.

CONCLUSIONS

The high incident cancers identified soon after appendectomy suggest the acute appendicitis is the early sign of distant metastatic malignancy. The risk of colorectal cancer, female genital cancer and haemopoietic malignancy deserve attention.

Risk factors of intrahepatic cholangiocarcinoma in patients with hepatolithiasis: a case-control study

BACKGROUND

Why 3.3% to 10% of all patients with hepatolithiasis develop intrahepatic cholangiocarcinoma (ICC) remains unknown. We carried out a hospital-based case-control study to identify risk factors for the development of ICC in patients with hepatolithiasis in China.

METHODS

Eighty-seven patients with pathologically diagnosed hepatolithiasis associated with ICC and 228 with hepatolithiasis alone matched by sex, age (+/-2 years), hospital admittance and place of residence were interviewed during the period of 2000-2008. Odds ratios (OR) and 95% confidence intervals (CI) were calculated for each risk factor.

RESULTS

Among the patients with hepatolithiasis associated with ICC, the mean age was 57.7 years and 61.0% were female. Univariate analysis showed that the significant risk factors for ICC development in hepatolithiasis were smoking, family history of cancer, appendectomy during childhood (under age 20), and duration of symptoms >10 years. In multivariate stepwise logistic regression analysis, smoking (OR=1.931, 95% CI: 1.000-3.731), family history of cancer (OR=5.175, 95% CI: 1.216-22.022), and duration of symptoms >10 years (OR=2.348, 95% CI: 1.394-3.952) were independent factors.

CONCLUSION

Smoking, family history of cancer and duration of symptoms >10 years may be risk factors for ICC in patients with hepatolithiasis.

Appendectomy and cancer risk in Jewish BRCA1 and BRCA2 mutation carriers

Previous studies suggested that appendectomy may affect cancer risk in the general population. No data on the effect of appendectomy on cancer risk in BRCA1 and BRCA2 carriers is available. Data on appendectomy, cancer type, and age at diagnosis were collected from BRCA1 (n = 677) and BRCA2 (n = 270) female Jewish Israeli mutation carriers counseled in a single medical center. Data were also collected on 225 consecutive ovarian cancer cases treated at the same medical center. Overall, 367/947 (38.7%) of mutation carriers had breast cancer (age at diagnosis 44.1 ± 10.4 years), 142 (15.0%) ovarian cancer (53.6 ± 10.1 years), and 438 (46.25%) were asymptomatic carriers (age at counseling 41.4 ± 11.2 years). Mean age at diagnosis of consecutive ovarian cancer cases was 53.6 ± 10.1 years. Of mutation carriers, 28/367 breast cancer cases (7.6%), 15/142 ovarian cancer cases (10.6%), and 11/438 asymptomatic carriers (2.5%) underwent prior appendectomy (P = 0.001 for breast/ovarian cancer when compared with asymptomatic carriers). In all but two cases, appendectomy was performed more than 10 years before cancer diagnosis or age at counseling. Of ovarian cancer patients, 12/225 (5.3%) underwent appendectomy, and in 10 appendectomy was performed 10 years or more before ovarian cancer diagnosis (P = 0.068 when compared with inherited ovarian cancer cases). This study suggests that prior appendectomy is more frequently noted in BRCA1 and BRCA2 carriers with breast and ovarian cancer than in unaffected mutation carriers. The mechanism for this association is elusive, and future analyses of ethnically diverse mutation carriers are needed to validate these results.

[Laparoscopy for suspected appendicitis. Should an appendix that appears normal be removed?]

The question whether an appendix found to be macroscopically normal at laparoscopy for suspected appendicitis should be removed remains open to debate. Potential advantages of appendicectomy in all cases include early diagnosis of neoplastic lesions that cannot be detected macroscopically, diagnosis and cure of neurogenic appendicectomy, avoidance of diagnostic confusion in later episodes of abdominal pain, and prevention of appendicitis developing later in life. Therefore, adopting a strategy of always removing the appendix even if it is found to be uninflamed at laparoscopy seems justified as long as it does not imply an increase in postoperative morbidity. We retrospectively studied all patients undergoing laparoscopic appendicectomy in which a "normal appendix" was found and all patients undergoing diagnostic laparoscopy in our hospital during a 7-year period. Our data as well as a critical review of the literature show that removal of the appendix does not increase morbidity compared to simple diagnostic laparoscopy and should always be done when performing laparoscopy for suspected acute appendicitis.

Blood transfusion, anesthesia, surgery and risk of non-Hodgkin lymphoma in a population-based case-control study

The incidence of NHL has increased dramatically since at least the 1950s, and during this timeframe there has been a major increase in the use of blood transfusions, invasive surgical procedures and anesthesia, all of which can impact immune function. We evaluated these factors with NHL risk in a population-based study of 759 cases and 589 frequency-matched controls. Risk factor data were collected during in-person interviews. Unconditional logistic regression was used to estimate ORs and 95% CIs, adjusted for the matching factors. History of transfusion was associated with a 26% higher risk of NHL (95% CI 0.91-1.73), and the elevated risk was specific to transfusions first given 5-29 years before the reference date (OR = 1.69; 95% CI 1.08-2.62) and transfusions given for a medical condition (OR = 2.09; 95% CI 1.03-4.26). The total number of surgeries and dental procedures (OR = 1.53 for 26+ surgeries compared to 0-6; 95% CI 1.02-2.29) and to a lesser extent the total number of exposures to general or local/regional anesthesia (OR = 1.35 for 24+ times compared to 0-6; 95% CI 0.91-2.02) were positively associated with risk of NHL. Inclusion of transfusion and surgery or transfusion and anesthesia in the same model did not attenuate these associations. All results were broadly consistent for both DLBCL and follicular subtypes. Blood transfusions were associated with NHL risk, but appear to be a marker for underlying medical conditions. Multiple surgical procedures and/or repeated administration of anesthesia have not been previously reported to be associated with risk of NHL and these exposures warrant further evaluation.

The epidemiology of non-Hodgkin lymphoma

Non-Hodgkin lymphoma (NHL) includes a group of more than 20 different malignant lymphoproliferative diseases that originate from lymphocytes. Rates of NHL have increased dramatically over the past few decades, although the rate of increase has recently slowed. It is now the sixth most common cancer in Australia. Globally, it is somewhat more common in men than in women, and rates are highest in North America and Australia. The causes of the increase in NHL rates are largely unknown. The best described risk factor for NHL is immune deficiency; rates of NHL are greatly increased, with relative risks of 10-100 or more, in people with immune deficiency associated with immune suppressive therapy after transplantation, HIV/AIDS, and congenital conditions. In addition, some NHL subtypes are associated with specific infections. These include immune-deficiency-associated central nervous system NHL (Epstein-Barr virus); gastric mucosa-associated lymphoid tissue NHL (Helicobacter pylori); adult T-cell leukemia/lymphoma (human T-lymphotrophic virus type 1) and body cavity-based lymphoma (human herpesvirus 8). However, these specific infections account for a very small proportion of total NHL incidence. In addition to immune deficiency and infection, other immune-related conditions are increasingly being recognised as related to NHL risk. Specific autoimmune conditions, including rheumatoid arthritis, systemic lupus erythema, Sjogren's syndrome, psoriasis and coeliac disease are associated with moderately increased risk of NHL. On the other hand, allergic and atopic conditions and their correlates such as early birth order, appear to be associated with a decreased risk of NHL.A variety of other exposures are less strongly related to NHL risk. These include occupational exposures, including some pesticides, herbicides, and solvents. Recently, two studies have reported that sun exposure is associated with a decreased risk of NHL. Smoking appears to be weakly positively associated with risk of follicular NHL, and alcohol intake is associated with a decreased risk of NHL. The pooled analysis of several case-control studies of NHL risk that are currently in the field promises to help clarify which of these risk factors are real, and will contribute to the elucidation of the mechanisms of how disorders of the immune system, and other factors, are related to NHL risk.

Laparoscopy in the pediatric and adolescent population

The use of laparoscopy by gynecologists in treating pediatric and adolescent patients is a relatively new phenomenon. This article discusses the specialized instrumentation necessary for operating on these patients and preoperative considerations and generalized techniques unique to this population. Although laparoscopy has a myriad of uses, the main focus is on the diagnosis and treatment of pelvic pain, adnexal masses, and pelvic inflammatory disease. Incidental appendectomy in these patients is also discussed.