The incidence of colon cancer among patients diagnosed with left colonic or sigmoid acute diverticulitis is higher than in the general population

Risk of Cancer in Patients With Diverticular Disease: A Population-Based Cohort Study

BACKGROUND & AIMS

Several studies have investigated the association between diverticular disease (DD) and colorectal cancer. However, whether there is an association between DD and malignancies other than those in the colorectum remains uncertain.

METHODS

For the 1978-2019 period, we conducted a nationwide, population-based cohort study using national Danish health care data. We followed patients with DD for up to 20 years, beginning 1 year after the date of DD diagnosis until the first occurrence of incident cancer, emigration, death, 20 years of follow-up, or December 31, 2019. We calculated cumulative incidence proportions of cancer and standardized incidence ratios (SIRs) comparing cancer incidence among patients with DD with that in the general population.

RESULTS

We identified 200,639 patients with DD, of whom 20,498 were diagnosed with cancer during the 1-20 years after their DD diagnosis. The SIRs were increased for most cancer sites except for those in the colorectum (SIR, 0.75; 95% confidence interval, 0.72-0.78). The highest SIRs were observed for cancers of the lung, bronchi, and trachea (SIR, 1.20; 95% confidence interval, 1.15-1.24) and kidney (SIR, 1.27; 95% confidence interval, 1.16-1.39).

CONCLUSIONS

Our findings show an increased long-term relative risk of cancer following a diagnosis of DD. These findings are likely caused by prevalence of numerous risk factors in patients with DD that confer an increased risk of cancer. The decreased relative risk of colorectal cancer might be explained by an increased likelihood of patients with DD undergoing colonoscopy with polypectomy.

Bovine meat and milk factor protein expression in tumor-free mucosa of colorectal cancer patients coincides with macrophages and might interfere with patient survival

Bovine milk and meat factors (BMMFs) are plasmid-like DNA molecules isolated from bovine milk and serum, as well as the peritumor of colorectal cancer (CRC) patients. BMMFs have been proposed as zoonotic infectious agents and drivers of indirect carcinogenesis of CRC, inducing chronic tissue inflammation, radical formation and increased levels of DNA damage. Data on expression of BMMFs in large clinical cohorts to test an association with co-markers and clinical parameters were not previously available and were therefore assessed in this study. Tissue sections with paired tumor-adjacent mucosa and tumor tissues of CRC patients [individual cohorts and tissue microarrays (TMAs) (n = 246)], low-/high-grade dysplasia (LGD/HGD) and mucosa of healthy donors were used for immunohistochemical quantification of the expression of BMMF replication protein (Rep) and CD68/CD163 (macrophages) by co-immunofluorescence microscopy and immunohistochemical scoring (TMA). Rep was expressed in the tumor-adjacent mucosa of 99% of CRC patients (TMA), was histologically associated with CD68+/CD163+ macrophages and was increased in CRC patients when compared to healthy controls. Tumor tissues showed only low stromal Rep expression. Rep was expressed in LGD and less in HGD but was strongly expressed in LGD/HGD-adjacent tissues. Albeit not reaching statistical significance, incidence curves for CRC-specific death were increased for higher Rep expression (TMA), with high tumor-adjacent Rep expression being linked to the highest incidence of death. BMMF Rep expression might represent a marker and early risk factor for CRC. The correlation between Rep and CD68 expression supports a previous hypothesis that BMMF-specific inflammatory regulations, including macrophages, are involved in the pathogenesis of CRC.

Risk for colorectal cancer after computed tomography verified acute diverticulitis: A retrospective cohort study with long-term follow-up

BACKGROUND AND OBJECTIVE

Colorectal cancer (CRC) can mimic acute diverticulitis and can thus be misdiagnosed. Therefore, colonic evaluation is recommended after an episode of acute diverticulitis. The aim of this study was to analyze the risk of CRC after computed tomography (CT) verified uncomplicated and complicated acute diverticulitis in short-term and, particularly, long-term follow-up to ensure the feasibility of the primary CT imaging in separating patients with uncomplicated and complicated acute diverticulitis.

METHODS

A retrospective cohort study was conducted in patients with CT-verified acute diverticulitis in 2003-2012. Data on CT findings and colonic evaluations were analyzed. The patients were divided into those with uncomplicated and complicated acute diverticulitis. Patient charts were reviewed 9-18 years after the initial acute diverticulitis episode.

RESULTS

The study population consisted of 270 patients. According to CT scans, 170 (63%) patients had uncomplicated acute diverticulitis and 100 (37%) had complicated acute diverticulitis. Further colonic evaluation was made in 146 (54%) patients. In the whole study population, CRC was found in 7 (2.6%) patients, but CRC was associated with acute diverticulitis in only 4 (1.5%) patients. The short-term risk for CRC was 0.6% (1/170) in uncomplicated acute diverticulitis and 3.0% (3/100) in complicated acute diverticulitis. No additional CRC was found in patients with complicated acute diverticulitis during the long-term follow-up and three cases of CRC found after uncomplicated acute diverticulitis had no observable association with previous diverticulitis.

CONCLUSIONS

In short-term follow-up, the risk of underlying CRC is very low in CT-verified uncomplicated acute diverticulitis but increased in complicated acute diverticulitis. Long-term follow-up revealed no additional CRCs associated with previous acute diverticulitis, indicating that the short-term results remain consistent also in the long run. These long-term results confirm that colonoscopy should be reserved for patients with complicated acute diverticulitis or with persisting or alarming symptoms.

Development and Validation of a Deep Learning Algorithm to Differentiate Colon Carcinoma From Acute Diverticulitis in Computed Tomography Images

Importance

Differentiating between malignant and benign etiology in large-bowel wall thickening on computed tomography (CT) images can be a challenging task. Artificial intelligence (AI) support systems can improve the diagnostic accuracy of radiologists, as shown for a variety of imaging tasks. Improvements in diagnostic performance, in particular the reduction of false-negative findings, may be useful in patient care.

Objective

To develop and evaluate a deep learning algorithm able to differentiate colon carcinoma (CC) and acute diverticulitis (AD) on CT images and analyze the impact of the AI-support system in a reader study.

Design, Setting, and Participants

In this diagnostic study, patients who underwent surgery between July 1, 2005, and October 1, 2020, for CC or AD were included. Three-dimensional (3-D) bounding boxes including the diseased bowel segment and surrounding mesentery were manually delineated and used to develop a 3-D convolutional neural network (CNN). A reader study with 10 observers of different experience levels was conducted. Readers were asked to classify the testing cohort under reading room conditions, first without and then with algorithmic support.

Main Outcomes and Measures

To evaluate the diagnostic performance, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for all readers and reader groups with and without AI support. Metrics were compared using the McNemar test and relative and absolute predictive value comparisons.

Results

A total of 585 patients (AD: n = 267, CC: n = 318; mean [SD] age, 63.2 [13.4] years; 341 men [58.3%]) were included. The 3-D CNN reached a sensitivity of 83.3% (95% CI, 70.0%-96.6%) and specificity of 86.6% (95% CI, 74.5%-98.8%) for the test set, compared with the mean reader sensitivity of 77.6% (95% CI, 72.9%-82.3%) and specificity of 81.6% (95% CI, 77.2%-86.1%). The combined group of readers improved significantly with AI support from a sensitivity of 77.6% to 85.6% (95% CI, 81.3%-89.3%; P < .001) and a specificity of 81.6% to 91.3% (95% CI, 88.1%-94.5%; P < .001). Artificial intelligence support significantly reduced the number of false-negative and false-positive findings (NPV from 78.5% to 86.4% and PPV from 80.9% to 90.8%; P < .001).

Conclusions and Relevance

The findings of this study suggest that a deep learning model able to distinguish CC and AD in CT images as a support system may significantly improve the diagnostic performance of radiologists, which may improve patient care.

Epidemiology of Diverticulitis and Prevalence of First-Ever Colorectal Cancer Postdiverticulitis in Adults in the United States: A Population-Based National Study

BACKGROUND

The incidence of acute diverticulitis is increasing, and previous studies showed a wide range of prevalence of colorectal cancer after diverticulitis. There is a lack of high-quality evidence to support performing colonoscopy after diverticulitis.

OBJECTIVE

We aimed to describe the incidence of first-ever diverticulitis and prevalence of first-ever colorectal cancer postdiverticulitis in the United States.

DESIGN

This is a retrospective cohort study.

SETTINGS

We queried a national database that contains data from 26 major integrated healthcare systems in the United States.

PATIENTS

We identified an aggregated patient cohort aged ≥18 years with a diagnosis of first-ever diverticulitis from February 2015 to February 2020, followed by first-ever colorectal cancer diagnosis, at least 1 day after and within 1 year of diverticulitis.

MAIN OUTCOME MEASURES

The incidence of first-ever diverticulitis was calculated. The prevalence and OR of first-ever colorectal cancer after diverticulitis were analyzed.

RESULTS

Among 31,778,290 individuals, we found the incidence of first-ever acute diverticulitis to be 2.9%. The prevalence of colorectal cancer within 1 year of first-ever acute diverticulitis was 0.57%, whereas the prevalence of colorectal cancer without a history of diverticulitis was 0.31% (OR = 1.8 (95% CI, 1.76-1.86)). The majority (92.3%) of the postdiverticulitis colorectal cancer were diagnosed within the first 6 months. The risk of colorectal cancer postdiverticulitis was higher in women (OR = 1.9), African Americans (OR = 2.0), and adults aged 18 to 65 years (OR = 2.3).

LIMITATIONS

We are unable to validate the diagnostic code because patient information in our database is deidentified.

CONCLUSIONS

Individuals are twice as likely to be diagnosed with colorectal cancer within 1 year of their first episode of acute diverticulitis compared with individuals without diverticulitis. We advocate for colonoscopy after the first occurrence of acute diverticulitis to screen for colorectal cancer, particularly for patients without a recent colonoscopy. See Video Abstract at http://links.lww.com/DCR/B412.

Computed tomography diagnosed first time diverticulitis and colorectal cancer

BACKGROUND

Computed tomography (CT) with intravenous contrast is the gold standard for diagnosing diverticulitis. Published results concerning follow-up colonoscopy after an episode of acute diverticulitis to rule out cancer are conflicting. This study aimed to evaluate the risk of underlying colonic malignancy in patients diagnosed with a first time diverticulitis with a state of the art CT investigation with intravenous contrast.

METHODS

Retrospective analysis of all patients with a first episode of diverticulitis diagnosed with CT at Danderyds Hospital, Stockholm, between January 1, 2015, and November 16, 2016. Data on modified Hinchey classification, age, sex, laboratory parameters, body mass index, and colonoscopy findings were recorded.

RESULTS

The study identified 518 patients with a CT-verified first time diverticulitis. Four hundred twenty-six (82%) of the 518 patients underwent follow-up colonoscopy and constitute our study cohort. CT showed that 402 patients had uncomplicated diverticulitis (modified Hinchey Ia), and 24 patients had complicated diverticulitis (modified Hinchey ≥Ib). Colonoscopy showed cancers in 2 (0.5%) of the 426 patients initially diagnosed as acute diverticulitis. In addition, 13 (3%) patients had advanced adenomas, and 121 (28%) patients had benign adenomas upon follow-up colonoscopy. Patients with CT-verified complicated diverticulitis (modified Hinchey ≥Ib) had a significantly higher risk for colon cancer compared with patients with an uncomplicated first time diverticulitis.

CONCLUSION

Our study supports routine follow-up colonoscopy after a first episode of CT-diagnosed complicated diverticulitis. In contrast, we do not find an increased risk for neoplasia in patients with uncomplicated diverticulitis.

Risk of colorectal cancer following CT-verified acute diverticulitis: a nationwide population-based cohort study

AIM

Routine colonoscopy to exclude colorectal cancer (CRC) after CT-verified acute diverticulitis is controversial. This study aimed to compare the incidence of CRC in patients with acute diverticulitis with that in the general population.

METHOD

Patients with an emergency admission for diverticular disease to any Norwegian hospital between 1 January 2008 and 31 December 2010 were included through identification in the Norwegian Patient Registry using International Classification of Diseases (ICD-10) codes K57.1-9. To estimate the age-specific distribution of CT-verified acute uncomplicated diverticulitis (AUD) and acute complicated diverticulitis (ACD) in this nationwide study population, numbers from the largest Norwegian emergency hospital were used. Patients diagnosed with CRC within 1 year following their admission for acute diverticulitis were detected through cross-matching with the Cancer Registry of Norway. Based on both Norwegian age-specific incidence of CRC and estimated age-specific distribution of CT-verified diverticulitis, standard morbidity ratios (SMRs) were calculated.

RESULTS

A total of 7473 patients with emergency admissions for diverticular disease were identified (estimated CT-verified AUD n = 3523, ACD n = 1206); of these 155 patients were diagnosed with CRC within 1 year. Eighty had a CT-verified diverticulitis at index admission [41 AUD (51.3%); 39 ACD (49.7%)]. Compared with the general population, the SMR was 6.6 following CT-verified AUD and 16.3 following ACD, respectively.

CONCLUSION

In the first year after CT-verified acute diverticulitis, especially after ACD, the risk of CRC is higher than in the general population. This probably represents misdiagnosis of CRC as acute diverticulitis. Follow-up colonoscopy should be recommended to all patients admitted with acute diverticulitis.

Comment on: Should a colonoscopy be offered routinely to patients with CT proven acute diverticulitis? A retrospective cohort study and meta-analysis of best available evidence

Latest evidence indicates that patients with acute diverticulitis have higher prevalence of colorectal cancer than reference patients. Therefore, colonoscopy should be offered after an episode of acute diverticulitis.

European Society of Coloproctology: guidelines for the management of diverticular disease of the colon

AIM

The goal of this European Society of Coloproctology (ESCP) guideline project is to give an overview of the existing evidence on the management of diverticular disease, primarily as a guidance to surgeons.

METHODS

The guideline was developed during several working phases including three voting rounds and one consensus meeting. The two project leads (JKS and EA) appointed by the ESCP guideline committee together with one member of the guideline committee (WB) agreed on the methodology, decided on six themes for working groups (WGs) and drafted a list of research questions. Senior WG members, mostly colorectal surgeons within the ESCP, were invited based on publication records and geographical aspects. Other specialties were included in the WGs where relevant. In addition, one trainee or PhD fellow was invited in each WG. All six WGs revised the research questions if necessary, did a literature search, created evidence tables where feasible, and drafted supporting text to each research question and statement. The text and statement proposals from each WG were arranged as one document by the first and last authors before online voting by all authors in two rounds. For the second voting ESCP national representatives were also invited. More than 90% agreement was considered a consensus. The final phrasing of the statements with < 90% agreement was discussed in a consensus meeting at the ESCP annual meeting in Vienna in September 2019. Thereafter, the first and the last author drafted the final text of the guideline and circulated it for final approval and for a third and final online voting of rephrased statements.

RESULTS

This guideline contains 38 evidence based consensus statements on the management of diverticular disease.

CONCLUSION

This international, multidisciplinary guideline provides an up to date summary of the current knowledge of the management of diverticular disease as a guidance for clinicians and patients.

Prevalence of colorectal cancer and advanced adenoma in patients with acute diverticulitis: implications for follow-up colonoscopy

BACKGROUND AND AIMS

Guidelines recommend colonoscopy after an episode of diverticulitis to exclude neoplasia but the effectiveness of testing is uncertain. Patients with complicated diverticulitis may be at higher risk for neoplasia, but most patients have uncomplicated disease. We examined the incidence of colorectal cancer (CRC) and advanced adenoma (AA) in patients with diverticulitis compared with patients undergoing screening colonoscopy.

METHODS

CT scans from January 1, 2008, to May 1, 2013, at the University of Pittsburgh Medical Center (UPMC) were reviewed to identify those with confirmed acute diverticulitis. Subsequent surgical, colonoscopy, and pathology reports were abstracted to identify those with a diagnosis of AA and CRC. The incidence of neoplasia was compared with that reported for screening colonoscopy from a meta-analysis (n = 68,324), and from colonoscopy examinations at UPMC between 2013 and 2015 (n = 28,573).

RESULTS

A total of 5167 abdominal/pelvic CT scan reports identified 978 patients with acute diverticulitis, among which 474 (48.5%) patients had undergone at least 1 colonoscopy or gastrointestinal surgery to April 2015. The CRC rate in patients with diverticulitis (13/474, 2.7%) was significantly higher (P < .0001) compared with both the meta-analysis (0.8%) and UPMC (0.3%). The AA rate (19/474, 4.0%) was similar to the rate in the meta-analysis (5.0%, P = .39) but significantly lower than at UPMC (7.7%, P = .003). The incidence of AA or CRC in complicated diverticulitis (10/141, 7.1%) did not differ significantly (P = .85) from the incidence of AA or CRC in uncomplicated diverticulitis (22/332, 6.6%).

CONCLUSIONS

CRC after diverticulitis was significantly higher than that observed at screening colonoscopy and was not limited to complicated disease. Colonoscopy is advisable after the diagnosis of diverticulitis.

Risk of Colorectal Cancer in Patients With Acute Diverticulitis: A Systematic Review and Meta-analysis of Observational Studies

BACKGROUND & AIMS

We performed a systematic review and meta-analysis to assess the prevalence of colorectal cancer in patients with acute diverticulitis.

METHODS

We searched MEDLINE from inception through November 2nd, 2017 for studies reporting the prevalence of colorectal cancer in patients with diverticulitis, identified based on the protocol CRD42017083272. This systematic review was conducted in accordance to the MOOSE guidelines. Pooled prevalence values were obtained by random effects models and robustness was tested by leave-one out sensitivity analyses. Heterogeneity was assessed using the Q-test and quantified based on I2 value. The critical appraisal of included studies was performed using the Newcastle-Ottawa scale.

RESULTS

Our final analysis included 31 studies, comprising 50,445 patients. The pooled prevalence of colorectal cancer was 1.9% (95% CI, 1.5%-2.3%). Patients with complicated diverticulitis had a significantly higher risk for colorectal cancer (prevalence, 7.9%; 95% CI, 3.9%-15.3%) than patients with uncomplicated diverticulitis (prevalence, 1.3%; 95% CI, 0.1%-2%), corresponding to a pooled prevalence ratio of 6.7 (95% CI, 2.5-18.3). Subgroup analyses did not find significant difference in prevalence when separately pooling studies according to ranking on the Newcastle-Ottawa scale, geographical location or length of follow-up. Meta-regression did not find any association between age and colorectal cancer. Among patients who underwent endoscopy, the pooled prevalence of polyps was 22.7% (95% CI, 19.6%-26.0%), of advanced adenomas was 4.4% (95% CI, 3.4%-5.8%), of adenomas was 14.2% (95% CI, 11.7%-17.1%), and of hyperplastic polyps was 9.2% (95% CI, 7.6%-11.2%).

CONCLUSION

In a meta-analysis of observational studies of patients with acute diverticulitis, we found the pooled prevalence of colorectal cancer to be 1.9%. The risk of colorectal cancer was significantly higher in patients with complicated diverticulitis than in patients with uncomplicated diverticulitis.

Changing theories on the pathogenesis and risk factors for diverticulitis

Diverticulitis was thought to be a simple complication of an even simpler disease (diverticulosis), but may in fact result from an entirely new set of complex pathologies. Considering diverticulitis is increasing in annual incidence and becoming more prevalent in younger populations, the implications of appropriate management become more vital than ever. This article reviews old and new understandings of diverticulitis and current recommendations for prevention and clinical management.

Risk of colorectal cancer in patients with diverticular disease

Colorectal cancer constitutes an important burden on the healthcare system. Screening at-risk populations to reduce colorectal cancer-related morbidity and mortality has become part of good clinical practice. However, recommendations regarding subgroups of patients with diverticular disease are subject to controversy. Herein, we review the most recent literature regarding the prevalence of colorectal cancer in patients with diverticular disease, diverticulitis and uncomplicated diverticulitis. The recent literature does not identify diverticular disease as a long-term risk factor for colorectal cancer. However, the risk of colorectal cancer is increased in the short-term period after hospitalization related to diverticular disease. According to a recent systematic review and meta-analysis, the prevalence of colorectal cancer is 1.6% in patients with acute diverticulitis who underwent colonoscopy. The risk of having colorectal cancer after an episode of acute diverticulitis is 44-fold higher than that of an age- and gender-adjusted reference population. Despite lower among patients with uncomplicated episode, the risk of colorectal cancer remains 40-fold higher in that subpopulation than that in the reference population. To conclude, the recent literature describes an increased risk of colorectal cancer among patients with acute diverticulitis compared to the reference population. Colonoscopy is therefore recommended in patients with diverticulitis to exclude colorectal cancer.

High Probability of an Underlying Colorectal Cancer Among Patients Treated for Acute Diverticulitis. A Population-Based Cohort Follow-Up Study

INTRODUCTION

Patients treated conservatively for acute diverticulitis (AD) are recommended colonic assessment to rule out an underlying Colorectal cancer (CRC). This has been questioned in patients with a CT diagnosis of uncomplicated AD. We analyzed the frequency of CRC and compared the characteristics of the CRC patients with controls.

METHOD

A cohort of patients treated conservatively for AD during 2005-2011 was identified through an administrative database. Patients diagnosed with CRC within 1 year after the index admission and four randomly selected controls were identified. The patients' files were reviewed to verify the diagnosis and obtain information about the clinical characteristics and the management. A blinded review was performed of CT examinations. The expected number of CRC was calculated from age, sex, and period-specific incidence data. The characteristics of the CRC patients were compared with the controls in a nested case-control study.

RESULTS

890 patients (298 men and 592 women) were treated conservatively for AD. 12 patients were diagnosed with CRC within 1 year, and ten of them in the sigmoid, giving a Standardized Incidence Ratio of 20.0 (95 % CI 10.2-35.7, p<0.001) for sigmoidal cancer. All CRC patients were aged over 70 years. The cancer was missed in six CT scans at the primary reading and in five at the blinded review.

CONCLUSION

Patients conservatively treated for AD are at high risk for an underlying CRC, especially if older than 70 years, which motivates routine follow-up. A CT diagnosis of uncomplicated AD does not rule out CRC.

An 18-Year Nationwide Cohort Study on The Association Between Diverticulitis and Colon Cancer

OBJECTIVE

To investigate the association between diverticulitis and colon cancer in a large, nationwide cohort study.

BACKGROUND

Diverticulitis is a common disease, especially in the Western world. Previous articles have investigated the association between diverticulitis and colon cancer with inconclusive results.

METHODS

We conducted a population-based cohort study based on longitudinal Danish national registers with data from the period 1995 to 2012. Data were extracted from comprehensive Danish national registers containing information from both public and private hospitals. Patients with diverticulitis were identified from the registers and matched by sex and age (± 1 year) with a ratio of 1:10 to people who did not have a registration of diverticulitis or diverticulosis. Main outcome was the event of colon cancer. Subgroup analyses were performed to investigate the effect of colonoscopies and treatment on the colon cancer rate after diverticulitis.

RESULTS

A total of 445,456 people were included, of whom 40,496 had a diagnosis of diverticulitis. The incidence of colon cancer in the group with diverticulitis (4.3%) and the group without diverticulitis (2.3%) differed significantly (P < 0.001) with an incidence rate ratio of 1.86 (95% confidence interval, CI, 1.77-1.96). When adjusted for possible confounders, the association between diverticulitis and cancer remained significant with an odds ratio (OR) of 2.20 (95% CI 2.08-2.32) (P < 0.001). Those with diverticulitis, who had no colonoscopy, had an increased risk of colon cancer compared with those without both diverticulitis and colonoscopy with an OR of 2.72 (95% CI 2.64-2.94) (P < 0.001).

CONCLUSIONS

We found a strong association between development of diverticulitis and colon cancer. This raises several questions regarding the possible causal association and warrants further studies. Patients with diverticulitis should undergo endoscopic surveillance for colon cancer.