Colonoscopy in colorectal-cancer screening for detection of advanced neoplasia

Is annual screening by fecal immunochemical test necessary after a recent colonoscopy?

Objective

The population-based colorectal cancer screening guidelines in Japan recommend an annual fecal immunochemical test (FIT). However, there is no consensus on the need for annual FIT screening for patients who recently performed a total colonoscopy (TCS). Therefore, we evaluated the repeated TCS results for patients with positive FIT after a recent TCS to assess the necessity of an annual FIT.

Methods

We reviewed patients with positive FIT in opportunistic screening from April 2017 to March 2022. The patients were divided into two groups: those who had undergone TCS within the previous 5 years (previous TCS group) and those who had not (non-previous TCS group). We compared the detection rates of advanced neoplasia and colorectal cancer between the two groups.

Results

Of 671 patients, 151 had received TCS within 5 years and 520 had not. The detection rates of advanced neoplasia in the previous TCS and non-previous TCS groups were 4.6% and 12.1%, respectively (p < 0.01), and the colorectal cancer detection rates were 0.7% and 1.5%, respectively (no significant difference). The adenoma detection rates were 33.8% in the previous TCS group and 40.0% in the non-previous TCS group (no significant difference).

Conclusions

Only a few patients were diagnosed with advanced neoplasia among the patients with FIT positive after a recent TCS. For patients with adenomatous lesions on previous TCS, repeated TCS should be performed according to the surveillance program without an annual FIT. The need for an annual FIT for patients without adenomatous lesions on previous TCS should be prospectively assessed in the future.

Differences between men and women with respect to colorectal cancer mortality despite screening colonoscopy

BACKGROUND AND AIMS

Women aged 55 to 59 years have a similar prevalence rate and number needed to screen for colorectal adenomas as men at a 10-year younger age. The aim of this study was to determine sex-specific differences in colorectal cancer mortality and estimate the association with adenomas at screening colonoscopy.

METHODS

This retrospective study analyzed 323,139 individuals who underwent colonoscopy within a national colorectal cancer screening program in Austria between January 2007 and December 2020.

RESULTS

Median patient age was 60 years (interquartile range, 54-67), and the sex distribution in all age groups was nearly identical. Men had significantly higher odds of having an adenoma or serrated polyp, low-risk polyp, high-risk polyp, or colorectal cancer detected at colonoscopy than women (odds ratio [OR] 1.83; 95% confidence interval [CI], 1.80-1.86; OR, 1.46; 95% CI, 1.44-1.49; OR, 1.74; 95% CI, 1.69-1.80; and OR, 1.87; 95% CI, 1.70-2.05, respectively). Strikingly, male sex, when compared with female sex, was associated with an almost 2-fold (hazard ratio, 1.67; 95% CI, 1.05-2.67) increased risk to die from colorectal cancer when an adenoma or serrated polyp was found at the screening colonoscopy and a 4-fold (hazard ratio, 4.14; 95% CI, 2.72-6.3) increased risk when a high-risk polyp was found at the screening colonoscopy. The cumulative incidence for death of colorectal cancer for 60-year-old individuals was 8.5-fold higher in men as compared with women. Markedly, this sex gap narrowed with increasing age, whereas the difference in deaths of other causes remained similar in all age groups.

CONCLUSIONS

Our findings strengthen the necessity of sex-specific screening recommendations. Importantly, further prospective studies should focus on sex differences in tumor biology to propose personalized surveillance guidelines.

Optimal timing of a colonoscopy screening schedule depends on adenoma detection, adenoma risk, adherence to screening and the screening objective: A microsimulation study

Colonoscopy-based screening provides protection against colorectal cancer (CRC), but the optimal starting age and time intervals of screening colonoscopies are unknown. We aimed to determine an optimal screening schedule for the US population and its dependencies on the objective of screening (life years gained or incidence, mortality, or cost reduction) and the setting in which screening is performed. We used our established open-source microsimulation model CMOST to calculate optimized colonoscopy schedules with one, two, three or four screening colonoscopies between 20 and 90 years of age. A single screening colonoscopy was most effective in reducing life years lost from CRC when performed at 55 years of age. Two, three and four screening colonoscopy schedules saved a maximum number of life years when performed between 49-64 years; 44-69 years; and 40-72 years; respectively. However, for maximum incidence and mortality reduction, screening colonoscopies needed to be scheduled 4-8 years later in life. The optimum was also influenced by adenoma detection efficiency with lower values for these parameters favoring a later starting age of screening. Low adherence to screening consistently favored a later start and an earlier end of screening. In a personalized approach, optimal screening would start earlier for high-risk patients and later for low-risk individuals. In conclusion, our microsimulation-based approach supports colonoscopy screening schedule between 45 and 75 years of age but the precise timing depends on the objective of screening, as well as assumptions regarding individual CRC risk, efficiency of adenoma detection during colonoscopy and adherence to screening.

Adenoma characteristics in the English Bowel Cancer Screening Programme

AIM

The English Bowel Cancer Screening Programme detects colorectal cancers and premalignant polyps in a faecal occult blood test-positive population. The aim of this work is to describe the detection rates and characteristics of adenomas within the programme, identify predictive factors influencing the presence or absence of carcinoma within adenomas and identify the factors predicting the presence of advanced colonic neoplasia in different colon segments.

METHOD

The Bowel Cancer Screening System was retrospectively searched for polyps detected during colonoscopies between June 2006 and June 2012, at which time a guaiac test was being used. Data on size, location and histological features were collected, and described. Univariate and multivariate analyses were used to determine the significant factors influencing the development of carcinoma within an adenoma.

RESULTS

A total of 229 419 polyps were identified; after exclusions 136 973 adenomas from 58 334 patients were evaluated. Over half were in the rectum or sigmoid colon. Subcentimetre adenomas accounted for 69.8% of the total. The proportion of adenomas containing advanced histological features increased with increasing adenoma size up to 35 mm, then plateaued. A focus of carcinoma was found in 2282 (1.7%) adenomas, of which 95.6% were located distally. Carcinoma was identified even in diminutive adenomas (0.1%). The proportion of adenomas containing cancer was significantly higher in women than men (2.0% vs. 1.5%, p < 0.001).

CONCLUSION

This national, prospectively captured dataset adds robust information about histological features of adenomas that convey an increased risk for colorectal cancer, and identifies caecal adenomas, high-grade dysplasia, increasing adenoma size, distal location and female sex as independent risk factors associated with carcinoma.

Engineering tumor-colonizing E. coli Nissle 1917 for detection and treatment of colorectal neoplasia

Bioengineered probiotics enable new opportunities to improve colorectal cancer (CRC) screening, prevention and treatment. Here, first, we demonstrate selective colonization of colorectal adenomas after oral delivery of probiotic E. coli Nissle 1917 (EcN) to a genetically-engineered murine model of CRC predisposition and orthotopic models of CRC. We next undertake an interventional, double-blind, dual-centre, prospective clinical trial, in which CRC patients take either placebo or EcN for two weeks prior to resection of neoplastic and adjacent normal colorectal tissue (ACTRN12619000210178). We detect enrichment of EcN in tumor samples over normal tissue from probiotic-treated patients (primary outcome of the trial). Next, we develop early CRC intervention strategies. To detect lesions, we engineer EcN to produce a small molecule, salicylate. Oral delivery of this strain results in increased levels of salicylate in the urine of adenoma-bearing mice, in comparison to healthy controls. To assess therapeutic potential, we engineer EcN to locally release a cytokine, GM-CSF, and blocking nanobodies against PD-L1 and CTLA-4 at the neoplastic site, and demonstrate that oral delivery of this strain reduces adenoma burden by ~50%. Together, these results support the use of EcN as an orally-deliverable platform to detect disease and treat CRC through the production of screening and therapeutic molecules.

Trend of the polyp and adenoma detection rate by sex and age in asymptomatic average-risk and high-risk individuals undergoing screening colonoscopy, 2012-2019

Adenoma detection rate (ADR) is an imperative quality measure for colorectal cancer (CRC) screening. This retrospective observational study aimed to determine the trend of polyp detection rate (PDR) and ADR in asymptomatic average- and high-risk participants in different age groups who underwent screening colonoscopy over the seven years from April 2012 to March 2019 in a tertiary gastroenterology referral center of Iran. Of 1676 participants, 51.8 % were men (mean age 52.3 years). The overall PDR and ADR were 22.7 %, and 13.5 %, respectively. Both Polyps and adenomas were more common in age groups 51-59 and ≥60 years in high-risk patients than in the corresponding groups of average-risk patients (p < 0.05). Also, both PDR and ADR were more frequent in men than in women among all studied age groups, but it was statistically significant only for the youngest age group (16.8 % versus 10.5 %, p < 0.05) for PDR and the oldest age group (19.7 % versus 13 %, p < 0.05) for ADR, respectively. The trend of total ADR was upward over 7 years in both average-risk (6.7 % to 13.3 %) and high-risk (9.8 % to 27 %) groups and across all age groups in both sexes. Multivariable logistic regression revealed that high-risk individuals had an elevated risk of adenoma compared with average-risk patients (OR: 1.6, p = 0.006). Substantial variation in thresholds of polyp and adenoma detection by age, sex, and risk categories emphasizes the need for a risk-adapted approach to CRC screening and prevention programs.

Conjoint analysis of clinical, imaging, and pathological features of schistosomiasis and colorectal cancer

This study aims to examine and compare clinical, radiological, and pathological data between colorectal cancer (CRC) patients with and without schistosomiasis and uncover distinctive CRC characteristics when accompanied by schistosomiasis. This retrospective study is based on data collected from 341 patients diagnosed with CRC post-surgery and pathology. Of these patients, 101 (Group A) were diagnosed with colorectal cancer co-occurring with schistosomiasis (CRC-S), while 240 patients (Group B) were diagnosed with colorectal cancer without concurrent schistosomiasis (CRC-NS). Both groups were compared and analyzed based on their clinical data, imaging-based TNM staging, lymph node metastasis, nerve invasion, vascular cancer thrombus, and histopathological differentiation. A Chi-squared test revealed a significant difference in gender distribution between the patients with CRC-S (Group A) and CRC-NS (Group B), with a p -value of 0.043 and χ2 = 4.115. Specifically, a higher incidence rate was observed among males in Group A. There was a difference in the overall distribution of TNM staging between the two groups (p = 0.034, χ2 = 6.764). After pairwise comparison, a statistically significant difference was observed in the T3 stage (p <0.05). The proportion of the T3 stage in Group A was significantly higher than that in Group B, indicating certain advantages. There was a difference in postoperative histopathological grading between the two groups (p = 0.005, χ2 = 10.626). After pairwise comparison, a statistically significant difference was observed between the well-differentiated adenocarcinoma and the moderately and poorly differentiated adenocarcinoma (p <0.05), with a higher proportion of welldifferentiated patients in Group A compared to Group B. There was no significant difference in age, lymph node metastasis, nerve invasion, and vascular invasion between the two groups of patients (p > 0.05). Among the 101 patients with CRC-S, 87 (86%) showed linear calcification on CT imaging. Patients with CRC-S are mainly male, with tumor staging mostly in the middle stage, high tumor differentiation, and low malignancy. CT imaging can help identify the presence of lumps and linear calcification indicative of schistosome deposits. MRI can early clarify TNM staging and determine the presence of lymph node metastasis and nerve and vascular invasion.

Measuring the observer (Hawthorne) effect on adenoma detection rates

Background and study aims An independent observer can improve procedural quality. We evaluated the impact of the observer (Hawthorne effect) on important quality metrics during colonoscopies. Patients and Methods In a single-center comparative study, consecutive patients undergoing routine screening or diagnostic colonoscopy were prospectively enrolled. In the index group, all procedural steps and quality metrics were observed and documented, and the procedure was video recorded by an independent research assistant. In the reference group, colonoscopies were performed without independent observation. Colonoscopy quality metrics such as polyp, adenoma, serrated lesions, and advanced adenoma detection rates (PDR, ADR, SLDR, AADR) were compared. The probabilities of increased quality metrics were evaluated through regression analyses weighted by the inversed probability of observation during the procedure. Results We included 327 index individuals and 360 referents in the final analyses. The index group had significantly higher PDRs (62.4% vs. 53.1%, P =0.02) and ADRs (39.4% vs. 28.3%, P =0.002) compared with the reference group. The SLDR and AADR were not significantly increased. After adjusting for potential confounders, the ADR and SLDR were 50% (relative risk [RR] 1.51; 95%, CI 1.05-2.17) and more than twofold (RR 2.17; 95%, CI 1.05-4.47) more likely to be higher in the index group than in the reference group. Conclusions The presence of an independent observer documenting colonoscopy quality metrics and video recording the colonoscopy resulted in a significant increase in ADR and other quality metrics. The Hawthorne effect should be considered an alternative strategy to advanced devices to improve colonoscopy quality in practice.

Colorectal cancer detection and treatment with engineered probiotics

Bioengineered probiotics enable new opportunities to improve colorectal cancer (CRC) screening, prevention and treatment strategies. Here, we demonstrate the phenomenon of selective, long-term colonization of colorectal adenomas after oral delivery of probiotic E. coli Nissle 1917 (EcN) to a genetically-engineered murine model of CRC predisposition. We show that, after oral administration, adenomas can be monitored over time by recovering EcN from stool. We also demonstrate specific colonization of EcN to solitary neoplastic lesions in an orthotopic murine model of CRC. We then exploit this neoplasia-homing property of EcN to develop early CRC intervention strategies. To detect lesions, we engineer EcN to produce a small molecule, salicylate, and demonstrate that oral delivery of this strain results in significantly increased levels of salicylate in the urine of adenoma-bearing mice, in comparison to healthy controls. We also assess EcN engineered to locally release immunotherapeutics at the neoplastic site. Oral delivery to mice bearing adenomas, reduced adenoma burden by ∼50%, with notable differences in the spatial distribution of T cell populations within diseased and healthy intestinal tissue, suggesting local induction of robust anti-tumor immunity. Together, these results support the use of EcN as an orally-delivered platform to detect disease and treat CRC through its production of screening and therapeutic molecules.

Rectal neuroendocrine tumors in a colon cancer screening colonoscopy program. Sixteen-year single institution experience

OBJECTIVES

Rectal neuroendocrine tumors (rNETs) are potentially malignant lesions. In our study, we aimed to retrospectively check whether the rectal neuroendocrine tumors were found in colonoscopy examinations carried out as a part of Polish colonoscopy screening program (PCSP).

MATERIALS AND METHODS

We retrospectively analyzed the colonoscopy and histopathological database of examinations conducted as a part of PCSP in our institution in the years 2005-2021. We also checked the method by which the tumor was removed, its characteristics based on photo documentations and followed up the patients.

RESULTS

The 10568 colonoscopy examinations were performed in PCSP in the years 2005-2021. Seven patients with a mean age of 53 with rNETs (1 in every 1510 colonoscopy) were detected. The polyp mean size was 5 mm. All the lesions were well differentiated tumors. First half of the colonoscopy examinations was performed in the years 2005-2012 and in that time three rNETs were detected, four rNETs were detected in the years 2012-2021. Even despite their typical appearance the neuroendocrine origin was not suspected in majority of cases and all tumors, except one, were removed with improper method. One of the patients underwent transanal endoscopic microsurgery of the scar. All patients are disease free in median follow-up of 108 months.

CONCLUSION

Rectal NETs are detected in the screening colonoscopy program. In majority of cases, they are not suspected by endoscopists on colonoscopy, but diagnosed after removal in histopathological examinations. There is a need of education of endoscopists in recognition and methods of treatment of rNETs.

Advanced serrated polyps as a target of screening: detection rate and positive predictive value within a fecal immunochemical test-based colorectal cancer screening population

BACKGROUND : Advanced serrated polyps (ASPs) have a comparable risk to advanced adenomas for progression to colorectal cancer (CRC). The yield of most CRC screening programs, however, is based on advanced adenomas and CRC only. We assessed the ASP detection rate, and positive predictive value (PPV) including ASPs in a fecal immunochemical test (FIT)-based screening program. METHODS : We analyzed the findings of follow-up colonoscopies of FIT-positive screenees in the Dutch CRC screening program from 2014 until 2020. Data were retrieved from the national screening and pathology database. An ASP was defined as any serrated polyp of ≥ 10 mm, sessile serrated lesion with dysplasia, or traditional serrated adenoma. The ASP detection rate was defined as the proportion of colonoscopies with ≥ 1 ASP. PPV was originally defined as the proportion of individuals with a CRC or advanced adenoma. The updated PPV definition included CRCs, advanced adenomas, and/or ASPs. RESULTS : 322 882 colonoscopies were included in the analyses. The overall detection rate of ASPs was 5.9 %. ASPs were detected more often in women than men (6.3 % vs. 5.6 %; P < 0.001). ASP detection rates in individuals aged 55-59, 60-64, 65-69, and 70 + were 5.2 %, 6.1 %, 6.1 %, and 5.9 %, respectively (P < 0.001). The PPV for CRCs and advanced adenomas was 41.1 % and increased to 43.8 % when including ASPs. The PPV increase was larger in women than in men (3.2 vs. 2.4 percentage points). CONCLUSIONS : 5.9 % of FIT-positive screenees had ASPs, but half of these were detected in combination with a CRC or advanced adenoma. Therefore, including ASPs results in a small increase in the yield of FIT-based screening.

Characteristics of adenomatous colorectal polyps among a Saudi population

Objectives

Colorectal cancer is a common cause of cancer-related mortality in KSA with a rising incidence. Although adenomatous polyps are well-recognized as precursors of colorectal cancer, local data are scarce. Therefore, in this study, we aimed to evaluate the characteristics of adenomatous colon polyps in the Saudi population.

Methods

We retrospectively reviewed the electronic databases of all patients who underwent colonoscopy for any indication between January 2015 and December 2019 at a tertiary care hospital. This study included adult patients who were found to have colorectal polyps with identified histopathology reports. We collected clinical and pathological data, including patient age, sex, and histopathological polyp characteristics. A p-value <0.05 was considered significant for descriptive and analytical statistics.

Results

A total of 184 patients with colorectal polyps with identified histopathology reports were included in the analysis. Of these, 130 (70.6%) patients were aged 50 years or older, and 135 (73.3%) were male. Among all polyps, 127 (69%) were adenomatous, 31 (16.8%) were hyperplastic, and 24 (13%) were inflammatory. For adenomatous polyps, 31 (24.4%) were observed in patients younger than 50 years, and high-grade dysplasia was observed in 23 (18%) polyps. Among patients with adenomatous polyps, the anatomical location was as follows: 27 (23%) in the cecum/ascending colon, 12 (9%) in the transverse colon, 45 (35%) in the descending/sigmoid colon, 25 (19%) in the rectum, and 18 (14%) at multiple sites. Age >50 years was significantly associated with adenomatous polyps (P = 0.03).

Conclusion

Approximately one-third of adenomatous polyps were detected proximal to the splenic flexure. Although adenomatous polyps were significantly associated with increasing age, 24% were observed in patients younger than 50 years of age. This finding supports the current recommendation to start screening at the age of 45.

Comparison of Quality Measures for Detection of Neoplasia at Screening Colonoscopy

BACKGROUND & AIMS

The proportion of colonoscopies with at least one adenoma (adenoma detection rate [ADR]) is inversely associated with colorectal cancer (CRC) risk and death. The aim of this study was to examine whether such associations exist for colonoscopy quality measures other than ADR.

METHODS

We used data from the Polish Colorectal Cancer Screening Program collected in 2000-2011. For all endoscopists who performed ≥100 colonoscopies we calculated detection rates of adenomas (ADR), polyps (PDR), and advanced adenomas (≥10 mm/villous component/high-grade dysplasia [AADR]); and number of adenomas per colonoscopy (APC) and per colonoscopy with ≥1 adenoma (APPC). We followed patients until CRC diagnosed before recommended surveillance, death, or December 31, 2019. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional-hazard models. We used Harrell's C statistic to compare the predictive power of the quality measures.

RESULTS

Data on 173,287 patients (median age, 56 years; 37.8% male) and 262 endoscopists were used. During a median follow-up of 10 years and 1,490,683 person-years, we identified 395 CRCs. All quality measures were significantly associated with CRC risk and death. The relative reductions in CRC risk were as follows: for ADR ≥24.9% (reference <12.1%; HR, 0.41; 95% CI, 0.25-0.66), PDR ≥42.7% (reference <19.9%; HR, 0.35; 95% CI, 0.24-0.51), AADR ≥9.1% (reference <4.1%; HR, 0.69; 95% CI, 0.49-0.96), APC ≥0.37 (reference <0.15; HR, 0.35; 95% CI, 0.21-0.58), and APPC ≥1.54 (reference <1.19; HR, 0.54; 95% CI, 0.35-0.83). AADR was the only quality measure with significantly lower predictive power than ADR (Harrell's C, 59.7 vs 63.4; P = .001). Similar relative reductions were observed for CRC death.

CONCLUSIONS

This large observational study confirmed the inverse association between ADR and CRC risk and death. The PDR and APC quality measures appear to be comparable with ADR.

Early detection and prognosis prediction for colorectal cancer by circulating tumour DNA methylation haplotypes: A multicentre cohort study

BACKGROUND

Early detection and prognosis prediction of colorectal cancer (CRC) can significantly reduce CRC-related mortality. Recently, circulating tumour DNA (ctDNA) methylation has shown good application foreground in the early detection and prognosis prediction of multiple tumours.

METHODS

This multicentre cohort study evaluated ctDNA methylation haplotype patterns based on archived plasma samples (collected between 2010 and 2018) from 1138 individuals at two medical centres: Fudan University Shanghai Cancer Center (Shanghai, China) and Southern Medical University Nanfang Hospital (Guangzhou, Guangdong, China), including 366 healthy individuals, 182 patients with advanced adenoma (AA), and 590 patients with CRC. Samples were processed using the ColonES assay, a targeted bisulfite sequencing method that detects ctDNA methylation haplotype patterns in 191 genomic regions. Among these 1138 samples, 748 were used to develop a classification model, and 390 served as a blinded cohort for independent validation. The study is registered at https://register.clinicaltrials.gov with the unique identifier NCT03737591.

RESULTS

The model obtained from unblinded samples discriminated patients with CRC or AA from normal controls with high accuracy. In the blinded validation set, the ColonES assay achieved sensitivity values of 79.0% (95% confidence interval (CI), 66%-88%) in AA patients and 86.6% (95% CI, 81%-91%) in CRC patients with a specificity of 88.1% (95% CI, 81%-93%) in healthy individuals. The model area under the curve (AUC) for the blinded validation set was 0.903 for AA samples and 0.937 for CRC samples. Additionally, the prognosis of patients with high preoperative ctDNA methylation levels was worse than that of patients with low ctDNA methylation levels (p = 0.001 for relapse-free survival and p = 0.004 for overall survival).

INTERPRETATION

We successfully developed and validated an accurate, noninvasive detection method based on ctDNA methylation haplotype patterns that may enable early detection and prognosis prediction for CRC.

FUNDING

The Grant of National Natural Science Foundation of China (No.81871958), National Natural Science Foundation of China (No. 82203215), Shanghai Science and Technology Committee (No. 19140902100), Scientific Research Fund of Fudan University (No.IDF159052), Shanghai Municipal Health Commission (SHWJRS 2021-99), and Shanghai Sailing Program (22YF1408800).

Adoption of Optimal Small (6-9 mm) Colorectal Polyp Resection Technique Over Time

BACKGROUND

Cold snare polypectomy (CSP) is the preferred resection technique for small (6-9 mm) polyps due to lower rate of incomplete resection compared to cold forceps polypectomy (CFP) and improved safety profile over hot snare polypectomy (HSP).

AIMS

To describe resection techniques for small (6-9 mm) polyps and determine factors associated with sub-optimal technique.

METHODS

This was retrospective cohort study of colonoscopies performed by gastroenterological and surgical endoscopists from 2012 to 2019 where at least one 6-9 mm polyp was removed. Patient, provider, and procedure characteristics were collected. Univariate and multivariate regression analyses were performed to determine factors associated with sub-optimal technique.

RESULTS

In total, 773 colonoscopies where 1,360 6-9 mm polyps removed by 21 endoscopists were included. CSP was used for 1,122 (82.5%), CFP for 61 (4.5%), and HSP for 177 (13.0%). Surgeon specialty was associated with CFP use (aOR 7.81; 95% CI 3.02-20.16). Polyp location in left colon (aOR 1.65; 95% CI 1.17-2.33) and pedunculated morphology (aOR 12.76; 95% CI 7.24-22.50) were associated with HSP. There was a significant increase in overall CSP use from 30.4% in 2012 to 96.8% in 2019.

CONCLUSIONS

82.5% of all 6-9 mm polyps removed from 2012 to 2019 were removed using a cold snare with significant increase in CSP from 2012 to 2019. Differences in how optimal technique was adopted over time based on specialty highlight the need for standardized practice guidelines and quality monitoring.

Comparison of complete resection rates in cold snare polypectomy using two different wire diameter snares: A randomized controlled study

BACKGROUND AND AIM

Cold snare polypectomy (CSP) is a standard treatment for small colorectal polyps. This study examined the effect of different snare wire diameters on complete histological resection rate, resection depth, and CSP safety.

METHODS

This randomized controlled trial was conducted at two institutions between June 2019 and March 2021. Eligible colorectal polyps (≤10 mm) were randomly assigned in a 1:1 ratio to receive either CSP with a conventional snare made of normal-diameter wire (0.40 mm) or CSP with a dedicated snare made of thin wire (0.23 mm). The primary endpoint was the complete resection rate determined on histological assessment of the resected specimen.

RESULTS

In total, 254 lesions in 152 patients were included, with 128 and 126 lesions assigned to the normal-diameter wire snare group and the thin-wire snare group, respectively. No significant differences were observed in patient characteristics between the two groups. The histological complete resection rate was significantly higher in the thin-wire snare group than in the normal-diameter wire snare group (70.0% vs 81.0%, P = 0.04). The normal-diameter wire snare group had significantly more cases of unclear horizontal margin evaluation than the thin-wire snare group (28.1% vs 15.9%, P = 0.02). No significant differences were observed between the two groups in the muscularis mucosa and submucosa of the resected specimens or the thickness of the submucosa in the resected specimens.

CONCLUSIONS

CSP with a dedicated thin-wire snare provides more specimens that can be evaluated at the horizontal end and increases the histological complete resection rate.

Development and validation of an artificial intelligence-based system for predicting colorectal cancer invasion depth using multi-modal data

OBJECTIVES

Accurate endoscopic optical prediction of the depth of cancer invasion is critical for guiding an optimal treatment approach of large sessile colorectal polyps but was hindered by insufficient endoscopists expertise and inter-observer variability. We aimed to construct a clinically applicable artificial intelligence (AI) system for the identification of presence of cancer invasion in large sessile colorectal polyps.

METHODS

A deep learning-based colorectal cancer invasion calculation (CCIC) system was constructed. Multi-modal data including clinical information, white light (WL) and image-enhanced endoscopy (IEE) were included for training. The system was trained using 339 lesions and tested on 198 lesions across three hospitals. Man-machine contest, reader study and video validation were further conducted to evaluate the performance of CCIC.

RESULTS

The overall accuracy of CCIC system using image and video validation was 90.4% and 89.7%, respectively. In comparison with 14 endoscopists, the accuracy of CCIC was comparable with expert endoscopists but superior to all the participating senior and junior endoscopists in both image and video validation set. With CCIC augmentation, the average accuracy of junior endoscopists improved significantly from 75.4% to 85.3% (P = 0.002).

CONCLUSIONS

This deep learning-based CCIC system may play an important role in predicting the depth of cancer invasion in colorectal polyps, thus determining treatment strategies for these large sessile colorectal polyps.

15-Year Benefits of Sigmoidoscopy Screening on Colorectal Cancer Incidence and Mortality : A Pooled Analysis of Randomized Trials

BACKGROUND

The effectiveness of screening for colorectal cancer (CRC) by sex and age in randomized trials is uncertain.

OBJECTIVE

To evaluate the 15-year effect of sigmoidoscopy screening on CRC incidence and mortality.

DESIGN

Pooled analysis of 4 large-scale randomized trials of sigmoidoscopy screening.

SETTING

Norway, the United States, the United Kingdom, and Italy.

PARTICIPANTS

Women and men aged 55 to 64 years at enrollment.

INTERVENTION

Sigmoidoscopy screening.

MEASUREMENTS

Primary end points were cumulative incidence rate ratio (IRR) and mortality rate ratio (MRR) and rate differences after 15 years of follow-up comparing screening versus usual care in intention-to-treat analyses. Stratified analyses were done by sex, cancer site, and age at screening.

RESULTS

Analyses comprised 274 952 persons (50.7% women), 137 493 in the screening and 137 459 in the usual care group. Screening attendance was 58% to 84%. After 15 years, the rate difference for CRC incidence was 0.51 cases (95% CI, 0.40 to 0.63 cases) per 100 persons and the IRR was 0.79 (CI, 0.75 to 0.83). The rate difference for CRC mortality was 0.13 deaths (CI, 0.07 to 0.19 deaths) per 100 persons, and the MRR was 0.80 (CI, 0.72 to 0.88). Women had less benefit from screening than men for CRC incidence (IRR for women, 0.84 [CI, 0.77 to 0.91]; IRR for men, 0.75 [CI, 0.70 to 0.81]; P = 0.032 for difference) and mortality (MRR for women, 0.91 [CI, 0.77 to 1.17]; MRR for men, 0.73 [CI, 0.64 to 0.83]; P = 0.025 for difference). There was no statistically significant difference in screening effect between persons aged 55 to 59 years and those aged 60 to 64 years.

LIMITATION

Data from the U.K. trial were less granular because of privacy regulations.

CONCLUSION

This pooled analysis of all large randomized trials of sigmoidoscopy screening demonstrates a significant and sustained effect of sigmoidoscopy on CRC incidence and mortality for 15 years.

PRIMARY FUNDING SOURCE

Health Fund of South-East Norway.

Post-EMR for colorectal polyps, thermal ablation of defects reduces adenoma recurrence: A meta-analysis

Background and study aims  Adenoma recurrence is one of the key limitations of endoscopic mucosal resection (EMR), which occurs in 15 % to 30 % of cases during first surveillance colonoscopy. The main hypothesis behind adenoma recurrence is leftover micro-adenomas at the margins of post-EMR defects. In this systematic review and meta-analysis, we evaluated the efficacy of snare tip soft coagulation (STSC) at the margins of mucosal defects to reduce adenoma recurrence and bleeding complications. Methods  Electronic databases such as PubMed and the Cochrane library were used for systematic literature search. Studies with polyps only resected by piecemeal EMR and active treatment: with STSC, comparator: non-STSC were included. A random effects model was used to calculate the summary of risk ratio and 95 % confidence intervals. The main outcome of the study was to compare the effect of STSC versus non-STSC with respect to adenoma recurrence at first surveillance colonoscopy after thermal ablation of post-EMR defects. Results  Five studies were included in the systematic review and meta-analysis. The total number patients who completed first surveillance colonoscopy (SC1) in the STSC group was 534 and in the non-STSC group was 514. The pooled adenoma recurrence rate was 6 % (37 of 534 cases) in the STSC arm and 22 % (115 of 514 cases) in the non-STSC arm, (odds ratio [OR] 0.26, 95 % confidence interval [CI], 0.16-0.41, P  = 0.001). The pooled delayed post-EMR bleeding rate 19 % (67 of 343) in the STSC arm and 22 % (78 of 341) in the non-STSC arm (OR 0.82, 95 %CI, 0.57-1.18). Conclusions  Thermal ablation of post-EMR defects significantly reduces adenoma recurrence at first surveillance colonoscopy.

Cost Effectiveness of Mailed Outreach Programs for Colorectal Cancer Screening: Analysis of a Pragmatic, Randomized Trial

BACKGROUND & AIMS

Clinical guidelines for colorectal cancer (CRC) screening suggest use of either stool-based tests or colonoscopy - modalities that differ in recommended screening intervals, adherence, and costs. We know little about the long-term cost differences in population-health outreach strategies to promote these strategies.

METHODS

We conducted a cost-effectiveness analysis to compare 2 mailed outreach strategies to increase CRC screening from a pragmatic, randomized clinical trial: mailed fecal immunochemical test (FIT) kits vs invitations to complete a screening colonoscopy. We built a 10-year Markov chain Monte Carlo microsimulation model to account for differences in screening intervals, adherence, and costs.

RESULTS

Mailed FIT kits had a lower 10-year average per-person cost of screening relative to colonoscopy invitations ($1139 vs $1725) but with 10.89 fewer months of compliance and 60 fewer advanced neoplasia detected (37 advanced adenomas and 23 CRC). Incremental cost effectiveness ratios for colonoscopy invitations compared with mailed FIT kits were $55.23, $15.84, and $25.48 per additional covered month, advanced adenoma, and CRC, respectively. Although FIT was the preferred strategy at low willingness-to-pay thresholds, the 2 strategies were equal at a willingness-to-pay threshold of $41.31 per covered month gained.

CONCLUSION

Mailed FIT or colonoscopy invitations are both options to improve CRC screening completion and advanced neoplasia detection, and the choice of outreach strategy may differ by a health system's willingness-to-pay threshold. Mailed FIT kits are less expensive than colonoscopy invitations but result in fewer months of screening compliance and advanced neoplasia detected.

A two-phase approach to re-calibrating expensive computer simulation for sex-specific colorectal neoplasia development modeling

Background

Medical evidence from more recent observational studies may significantly alter our understanding of disease incidence and progression, and would require recalibration of existing computational and predictive disease models. However, it is often challenging to perform recalibration when there are a large number of model parameters to be estimated. Moreover, comparing the fitting performances of candidate parameter designs can be difficult due to significant variation in simulated outcomes under limited computational budget and long runtime, even for one simulation replication.

Methods

We developed a two-phase recalibration procedure. As a proof-of-the-concept study, we verified the procedure in the context of sex-specific colorectal neoplasia development. We considered two individual-based state-transition stochastic simulation models, estimating model parameters that govern colorectal adenoma occurrence and its growth through three preclinical states: non-advanced precancerous polyp, advanced precancerous polyp, and cancerous polyp. For the calibration, we used a weighted-sum-squared error between three prevalence values reported in the literature and the corresponding simulation outcomes. In phase 1 of the calibration procedure, we first extracted the baseline parameter design from relevant studies on the same model. We then performed sampling-based searches within a proper range around the baseline design to identify the initial set of good candidate designs. In phase 2, we performed local search (e.g., the Nelder-Mead algorithm), starting from the candidate designs identified at the end of phase 1. Further, we investigated the efficiency of exploring dimensions of the parameter space sequentially based on our prior knowledge of the system dynamics.

Results

The efficiency of our two-phase re-calibration procedure was first investigated with CMOST, a relatively inexpensive computational model. It was then further verified with the V/NCS model, which is much more expensive. Overall, our two-phase procedure showed a better goodness-of-fit than the straightforward employment of the Nelder-Mead algorithm, when only a limited number of simulation replications were allowed. In addition, in phase 2, performing local search along parameter space dimensions sequentially was more efficient than performing the search over all dimensions concurrently.

Conclusion

The proposed two-phase re-calibration procedure is efficient at estimating parameters of computationally expensive stochastic dynamic disease models.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12911-022-01991-7.

Longitudinal assessment of colonoscopy adverse events in the prospective Cooperative Studies Program no. 380 colorectal cancer screening and surveillance cohort

BACKGROUND AND AIMS

Data are limited regarding colonoscopy risk during long-term, programmatic colorectal cancer screening and follow-up. We aimed to describe adverse events during follow-up in a colonoscopy screening program after the baseline examination and examine factors associated with increased risk.

METHODS

Cooperative Studies Program no. 380 includes 3121 asymptomatic veterans aged 50 to 75 years who underwent screening colonoscopy between 1994 and 1997. Periprocedure adverse events requiring significant intervention were defined as major events (other events were minor) and were tracked during follow-up for at least 10 years. Multivariable odds ratios (ORs) were calculated for factors associated with risk of follow-up adverse events.

RESULTS

Of 3727 follow-up examinations in 1983 participants, adverse events occurred in 105 examinations (2.8%) in 93 individuals, including 22 major and 87 minor events (examinations may have had >1 event). Incidence of major events (per 1000 examinations) remained relatively stable over time, with 6.1 events at examination 2, 4.8 at examination 3, and 7.2 at examination 4. Examinations with major events included 1 perforation, 3 GI bleeds requiring intervention, and 17 cardiopulmonary events. History of prior colonoscopic adverse events was associated with increased risk of events (major or minor) during follow-up (OR, 2.7; 95% confidence interval, 1.6-4.6).

CONCLUSIONS

Long-term programmatic screening and surveillance was safe, as major events were rare during follow-up. However, serious cardiopulmonary events were the most common major events. These results highlight the need for detailed assessments of comorbid conditions during routine clinical practice, which could help inform individual decisions regarding the utility of ongoing colonoscopy follow-up.

Computer-Aided Detection Improves Adenomas per Colonoscopy for Screening and Surveillance Colonoscopy: A Randomized Trial

BACKGROUND & AIMS

Colonoscopy for colorectal cancer screening is endoscopist dependent, and colonoscopy quality improvement programs aim to improve efficacy. This study evaluated the clinical benefit and safety of using a computer-aided detection (CADe) device in colonoscopy procedures.

METHODS

This randomized study prospectively evaluated the use of a CADe device at 5 academic and community centers by US board-certified gastroenterologists (n = 22). Participants aged ≥40 scheduled for screening or surveillance (≥3 years) colonoscopy were included; exclusion criteria included incomplete procedure, diagnostic indication, inflammatory bowel disease, and familial adenomatous polyposis. Patients were randomized by endoscopist to the standard or CADe colonoscopy arm using computer-generated, random-block method. The 2 primary endpoints were adenomas per colonoscopy (APC), the total number of adenomas resected divided by the total number of colonoscopies; and true histology rate (THR), the proportion of resections with clinically significant histology divided by the total number of polyp resections. The primary analysis used a modified intention-to-treat approach.

RESULTS

Between January and September 2021, 1440 participants were enrolled to be randomized. After exclusion of participants who did not meet the eligibility criteria, 677 in the standard arm and 682 in the CADe arm were included in a modified intention-to-treat analysis. APC increased significantly with use of the CADe device (standard vs CADe: 0.83 vs 1.05, P = .002; total number of adenomas, 562 vs 719). There was no decrease in THR with use of the CADe device (standard vs CADe: 71.7% vs 67.4%, P for noninferiority < .001; total number of non-neoplastic lesions, 284 vs 375). Adenoma detection rate was 43.9% and 47.8% in the standard and CADe arms, respectively (P = .065).

CONCLUSIONS

For experienced endoscopists performing screening and surveillance colonoscopies in the United States, the CADe device statistically improved overall adenoma detection (APC) without a concomitant increase in resection of non-neoplastic lesions (THR).

CLINICALTRIALS

gov registration: NCT04754347.

Colonoscopy Needs for Implementation of a Colorectal Cancer Screening Program in Ukraine

BACKGROUND

In Ukraine, there is no established colorectal cancer screening program. We aimed to project the number of screening colonoscopies needed for implementation of various CRC screening strategies in Ukraine.

METHODS

We modified a previously developed Markov microsimulation model to reflect the natural history of adenoma and CRC progression among average-risk 50-74-year-olds. We simulated colonoscopies needed for the following screening strategies: no screening, fecal occult blood test yearly, FOBT yearly with flexible sigmoidoscopy every 5 years, FS every 5 years, fecal immunohistochemistry test (FIT) yearly, or colonoscopy every 10 years. Assuming 80% screening adherence, we estimated colonoscopies required at 1 and 5 years depending on the implementation rate. In one-way sensitivity analyses, we varied implementation rate, screening adherence, sensitivity, and specificity.

RESULTS

Assuming an 80% screening adherence and complete implementation (100%), besides a no screening strategy, the fewest screening colonoscopies are needed with an FOBT program, requiring on average 6,600 and 26,800 colonoscopies per 100,000 persons at 1 and 5 years post-implementation, respectively. The most screening colonoscopies are required with a colonoscopy program, requiring on average 76,600 and 101,000 colonoscopies per 100,000 persons at 1 and 5 years post-implementation, respectively. In sensitivity analyses, the biggest driver of number of colonoscopies needed was screening adherence.

CONCLUSIONS

The number of colonoscopies needed and therefore the potential strain on the healthcare system vary substantially by screening test. These findings can provide valuable information for stakeholders on equipment needs when implementing a national screening program in Ukraine.

Noninvasive early detection of colorectal cancer by hypermethylation of the LINC00473 promoter in plasma cell-free DNA

BACKGROUND

Current noninvasive assays have limitations in the early detection of colorectal cancer. We evaluated the clinical utility of promoter methylation of the long noncoding RNA LINC00473 as a noninvasive biomarker to detect colorectal cancer and associated precancerous lesions.

METHODS

We evaluated the epigenetic regulation of LINC00473 through promoter hypermethylation in colorectal cancer cell lines using bisulfite genomic sequencing and expression analyses. DNA methylation of LINC00473 was analyzed in primary colorectal tumors using 450K arrays and RNA-seq from The Cancer Genome Atlas (TCGA). Tissue-based findings were validated in several independent cohorts of colorectal cancer and advanced colorectal polyp patients by pyrosequencing. We explored the clinical utility of LINC00473 methylation for the early detection of colorectal cancer in plasma cell-free DNA by quantitative methylation-specific PCR and droplet digital PCR.

RESULTS

LINC00473 showed transcriptionally silencing due to promoter hypermethylation in colorectal cancer cell lines and primary tumors. Methylation of the LINC00473 promoter accurately detected primary colorectal tumors in two independent clinical cohorts, with areas under the receiver operating characteristic curves (AUCs) of 0.94 and 0.89. This biomarker also identified advanced colorectal polyps from two other tissue-based clinical cohorts with high diagnostic accuracy (AUCs of 0.99 and 0.78). Finally, methylation analysis of the LINC00473 promoter in plasma cell-free DNA accurately identified patients with colorectal cancer and advanced colorectal polyps (AUCs of 0.88 and 0.84, respectively), which was confirmed in an independent cohort of patients.

CONCLUSIONS

Hypermethylation of the LINC00473 promoter is a new promising biomarker for noninvasive early detection of colorectal cancer and related precancerous lesions.

Metabolic obesity phenotypes: a friend or foe of digestive polyps?-An observational study based on National Inpatient Database

OBJECTIVE

Obesity is associated with an increased risk of digestive polyps, whereas all obesity are not created equally. The role of metabolic states in occurrence risks of polyps among individuals with varying degrees of obesity remains unknown. Our study aimed to evaluate the association between metabolic obesity phenotypes and the occurrence of digestive polyps.

RESEARCH DESIGN AND METHODS

Data from 9,278,949 patients between 2016 and 2018 from the National Inpatient Sample (NIS) database, a nationally representative database of all discharges from US health-care hospitals, were analyzed. According to obesity phenotype, the study population was classified into four groups: metabolically healthy nonobese (MHNO), metabolically unhealthy nonobese (MUNO), metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO). We calculated the incidence rates of various digestive polyps (stomach/duodenum, colon and rectum polyps) among these participants by searching the hospital records for ICD-10 diagnosis codes indicating each gastric, duodenum, colon or rectal polyps. The multiple stepwise regression analysis and further in-depth subgroup analysis were used to determine the associations between metabolic obesity phenotypes and the occurrence of digestive polyps.

RESULTS

In the total or female population, those with the MUNO and MUO phenotypes had significantly higher prevalence of digestive polyps compared with individuals with the MHNO or MHO phenotypes (all p < 0.05) and a significant difference was not found between MUNO and MUO phenotypes (p > 0.05). Obese subjects seem to be more likely to develop stomach and duodenum polyps or colon polyps than non-obese subjects in metabolically healthy people of males (MHO vs. MHNO, p < 0.05), whereas obesity status seems to have little effect on the occurrence of digestive polyps in metabolically healthy people of females (MHO vs. MHNO, p>0.05). After adjusting for the potential confounders, the MHO, MUNO and MUO phenotypes were all risk factors for stomach and duodenum polyps (OR = 1.46, 95% CI: 1.36-1.58, p< 0.01; OR = 1.19, 95% CI: 1.14-1.25, p< 0.01; OR = 1.44, 95% CI: 1.35-1.55, p< 0.01, respectively) or colon polyps (OR = 1.28, 95% CI: 1.21-1.35, p< 0.01; OR = 1.18, 95% CI: 1.14-1.22, p< 0.01; OR = 1.46, 95% CI: 1.38-1.54, p< 0.01, respectively) compared with the MHNO phenotype，especially in menopausal female. Interestingly, we also observed in further in-depth subgroup analysis that metabolic abnormalities may have a greater impact on the occurrence of digestive polyps than obesity (all p < 0.05).

CONCLUSIONS

Both metabolic abnormities and obesity were associated with a higher risk of digestive polyps. The effect of metabolism on digestive polyp occurrence may be stronger than that of obesity, highlighting the importance of abnormal metabolic status modification regardless of obesity status. Clinical intervention should not only focus on obesity, but also on metabolic abnormalities to decrease digestive polyp risk.

Risk factors and prediction algorithm for advanced neoplasia on screening colonoscopy for average-risk individuals

BACKGROUND

Screening with colonoscopy for all average-risk population is probably not cost-effective due to the limited sources and over-generalization of the risk, and risk stratification can be used to optimize colorectal cancer screening.

OBJECTIVES

We aimed to assess risk factors for advanced neoplasia (AN) and a classification tree algorithm to predict the risk.

DESIGN

This is a retrospective cross-sectional study.

METHODS

This study was composed of consecutive asymptomatic average-risk individuals undergoing first screening colonoscopy between 2008 and 2019. Detailed characteristics including background diseases, habits, and medications were collected. We used multivariable logistic regression to investigate the associations between clinical variables and the presence of AN and built a classification algorithm to predict AN.

RESULTS

A total of 3856 patients were included (73.2% male, median age 55). Adenoma and AN detection rate were 15.8% and 3.4%, respectively. On multivariable analysis, predictors of AN [odds ratio (OR), 95% confidence interval (CI)] were age (1.04, 1.01-1.06, p = 0.003), male sex (2.69, 1.56-4.64, p < 0.001), and smoking (1.97, 1.38-2.81, p  < 0.001). A classification tree algorithm showed that smoking was the most important risk factor for prediction of AN (4.9% versus 2.4%, p < 0.001), followed by age with a cutoff value of 60 in the smokers (8.4% versus 3.8%, p = 0.001) and 50 in the non-smokers (2.9% versus 0.9%, p = 0.004).

CONCLUSION

Smoking habits, old age, and male gender are highly associated with an increased risk for AN and should be incorporated in the individualized risk-assessment to adapt a screening program.

Endoscopic follow-up of mucosal defect after hot versus cold snare polypectomy in animal model

BACKGROUND AND AIM

Cold snare polypectomy (CSP) has received increasing attention in recent years, but few studies have assessed defect repair after polypectomy. Therefore, we compared the repair of mucosal defect after CSP and hot snare polypectomy (HSP) in a rabbit model.

METHODS

Resection of normal colonic mucosa using both HSP and CSP were performed in 40 male New Zealand white rabbits by an experienced endoscopist. Follow-up colonoscopy was performed after 7 and 15 days by another endoscopist. We assessed mucosal defect repair, status of healing, scar formation, and intraoperative or delayed complications (including perforation and bleeding).

RESULTS

Eight animals died of intraoperative or delayed perforation; follow-up colonoscopy was performed in 32 animals. On follow-up colonoscopy at 7 days after operation, 78.1% cases in the CSP group showed healing of mucosal defect compared with none in the HSP group (P < 0.001); mucosal repair score in the CSP group was significantly higher than HSP group (P < 0.001). On follow-up colonoscopy at 15 days, mucosal defect after CSP had completely healed in all cases (100%) versus 96.9% after HSP (P = 0.313). Among these healed defects, scar formation was observed in 2 of 32 cases in the CSP group compared with 19 of 31 in the HSP group (P < 0.001). Intraoperative perforation rate was significantly higher in the HSP group (15% vs 2.5%; P = 0.048).

CONCLUSIONS

Mucosal defect repair after CSP is quicker compared with HSP and is more likely to result in scarless healing. HSP is more likely to cause perforation in the thin colon walls.

Development of a Field Guide for Assessing Readiness to Implement Evidence-Based Cancer Screening Interventions in Primary Care Clinics

Evidence-based interventions, including provider assessment and feedback, provider reminders, patient reminders, and reduction of structural barriers, improve colorectal cancer screening rates. Assessing primary care clinics' readiness to implement these interventions can help clinics use strengths, identify barriers, and plan for success. However, clinics may lack tools to assess readiness and use findings to plan for successful implementation. To address this need, we developed the Field Guide for Assessing Readiness to Implement Evidence-Based Cancer Screening Interventions (Field Guide) for the Centers for Disease Control and Prevention's (CDC's) Colorectal Cancer Control Program (CRCCP). We conducted a literature review of evidence and existing tools to measure implementation readiness, reviewed readiness tools from selected CRCCP award recipients (n = 35), and conducted semi-structured interviews with key informants (n = 8). We sought feedback from CDC staff and recipients to inform the final document. The Field Guide, which is publicly available online, outlines 4 assessment phases: 1) convene team members and determine assessment activities, 2) design and administer the readiness assessment, 3) evaluate assessment data, and 4) develop an implementation plan. Assessment activities and tools are included to facilitate completion of each phase. The Field Guide integrates implementation science and practical experience into a relevant tool to bolster clinic capacity for implementation, increase potential for intervention sustainability, and improve colorectal cancer screening rates, with a focus on patients served in safety net clinic settings. Although this tool was developed for use in primary care clinics for cancer screening, the Field Guide may have broader application for clinics and their partners for other chronic diseases.

Start of an era: circulating cell-free DNA for early detection of cancers

Effective screening modalities are currently available for only a small subset of cancers, and they generally have suboptimal performance with complicated procedures. Therefore, there is an urgent need to develop simple, accurate, and non-invasive methods for early detection of cancers. Genetic and epigenetic alterations in plasma circulating cell-free DNA (cfDNA) have shown the potential to revolutionize methods of early detection of cancers and facilitate subsequent diagnosis to improve survival of patients. The medical interest in cfDNA assays has been inspired by emerging single- and multi-early detection of cancers studies. This review summarizes current technological and clinical advances, in the hopes of providing insights into the development and applications of cfDNA assays in various cancers and clinical scenarios. The key phases of clinical development of biomarkers are highlighted, and the future developments of cfDNA-based liquid biopsies in early detection of cancers are outlined. It is hoped that this study can boost the potential integration of cfDNA-based early detection of cancers into the current clinical workflow.

•

Liquid biopsy, characterized by minimal invasiveness and user friendliness, can identify multiple cancers at the early stage and localize the tissue of origin

•

The state-of-the-art technology facilitates the application of circulating cell-free DNA (cfDNA) assays in the early detection of cancers

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cfDNA assays are expected to be integrated into the clinical workflow after technological refinement and clinical trial validation

•

The development and application strategies of cfDNA assays in various cancers and clinical scenarios can vary, and the harm-and-benefit should be balanced carefully

The relative effectiveness of fecal immunochemical test-based colorectal cancer screening to detect adenomas and cancer in different demographic and socioeconomic groups. A nationwide cohort study

INTRODUCTION

This study aimed at analyzing the relative effectiveness in removal of adenomas and detection of cancer of implementing colorectal cancer (CRC) screening in different demographic and socioeconomic groups.

METHODS

This register-based retrospective cohort study included residents aged 50-72 years. Those randomly selected to be invited for CRC screening from 1 March 2014 to 30 June 2015 were classified as invited; those invited from 1 January 2016 to 31 December 2017 were classified as not yet invited. Strata-specific relative risks (RRs) of having adenomas removed and CRC detected were estimated.

RESULTS

A total of 1 343 090 individuals were included. The RR of having adenomas removed were higher among men compared with women [RRwomen = 6.41 (95% confidence interval [CI]: 5.08-8.09), RRmen = 7.74 (95% CI: 6.16-9.73), P < 0.01] and among Danes compared with immigrants [RRDanes = 4.71 (95% CI: 3.73-5.93), RRWestern = 4.76 (95% CI: 3.39-6.69), RRnon-Western = 3.35 (95% CI: 2.39-4.69), P = 0.03]. Regarding detection of CRC, the effectiveness increased with increasing age ranging from RR = 1.53 (95% CI: 0.93- 2.51) to RR = 1.97 (95% CI: 1.22-3.17) (P = 0.04) and was higher among men compared with women (RRwomen = 1.75 (95% CI: 1.10-2.76), RRmen = 2.07 (95% CI: 1.32-3.26), P = 0.02.

CONCLUSION

Attention must be paid to the potential differences in screening effectiveness among diverse subpopulations; first, by securing equal opportunities for participation across subpopulations and second, by considering sex and age-specific screening programs.

Adenoma to Colorectal Cancer Estimated Transition Rates Stratified by BMI Categories—A Cross-Sectional Analysis of Asymptomatic Individuals from Screening Colonoscopy Program

Simple Summary

Most colorectal cancers assumedly develop from precursor lesions, i.e., colorectal adenomas (adenoma-carcinoma sequence). Epidemiological and clinical data supporting this hypothesis are limited. Therefore, the aim of the present study was to estimate relative dynamics of colorectal adenoma-carcinoma sequence for groups of screenees stratified by body mass. We have analyzed 163,129 individuals that underwent screening colonoscopy and calculated adjusted prevalences of colorectal adenomas and colorectal. Based on that data we have found that obese individuals are more likely to develop adenomas, advanced adenomas and early CRC but less likely to progress to advanced CRC. Therefore, this study provides new evidence that obesity paradox exists for colorectal cancer.

Abstract

Most colorectal cancers (CRC) assumedly develop from precursor lesions, i.e., colorectal adenomas (adenoma-carcinoma sequence). Epidemiological and clinical data supporting this hypothesis are limited. Therefore, the aim of the present study is to estimate relative dynamics of colorectal adenoma-carcinoma sequence for groups of screenees stratified by BMI (body mass index) based on prevalence data from Polish Colonoscopy Screening Program (PCSP). We performed a cross-sectional analysis of database records of individuals who entered the national opportunistic colonoscopy screening program for CRC in Poland. We calculated prevalence of adenomas and CRCs adjusted for sex, 5-year age group, family history of CRC, smoking, diabetes and use of aspirin, hormonal therapy and proton-pump inhibitors use. Thereafter we calculated estimated transition rate (eTR) with confidence intervals (CIs) defined as adjusted prevalence of more advanced lesion divided by adjusted prevalence of less advanced lesion. All analyzes were stratified according to the BMI categories: normal (BMI 18.0 to <25.0), overweight (BMI 25.0 to <30.0) and obese (BMI ≥ 30.0). Results are reported in the same respective order. After exclusions we performed analyses on 147,385 individuals. We found that prevalence of non-advanced adenomas is increasing with BMI category (12.19%, 13.81%, 14.70%, respectively; p < 0.001). Prevalence of advanced adenomas was increasing with BMI category (5.20%, 5.77%, 6.61%, respectively; p < 0.001). Early CRCs prevalence was the highest for obese individuals (0.55%) and the lowest for overweight individuals (0.44%) with borderline significance (p = 0.055). For advanced CRC we found that prevalence seems to be inversely related to BMI category, however no statistically significant differences were observed (0.35%, 0.31%, 0.28%; p = 0.274). eTR for non-advanced adenoma to advanced adenoma is higher for obese individuals than for overweight individuals with bordering CIs (42.65% vs. 41.81% vs. 44.95%) eTR for advanced adenoma to early CRC is highest for normal individuals, however CIs are overlapping with remaining BMI categories (9.02% vs. 7.67% vs. 8.39%). eTR for early CRC to advanced CRC is lower for obese individuals in comparison to both normal and overweight individuals with marginally overlapping CIs (73.73% vs. 69.90% vs. 50.54%). Obese individuals are more likely to develop adenomas, advanced adenomas and early CRC but less likely to progress to advanced CRC. Therefore, this study provides new evidence that obesity paradox exists for colorectal cancer.

Real-world local recurrence rate after cold polypectomy in colorectal polyps less than 10 mm using propensity score matching

BACKGROUND

Cold polypectomy (CP) is a simple and safe procedure for polyps less than 10 mm in size; however, there is concern about local recurrence following CP because of unidentified margins of excised specimens and the lack of tumor suppression effect by coagulation. Some clinical trials have evaluated local persistent recurrence; their results suggest that a higher rate of local recurrence has not been documented so far. There were few reports that observed the course over long periods of time after CP in clinical practice.

AIM

To evaluate the presence of local recurrence following CP and hot polypectomy (HP) using propensity score matching.

METHODS

We analyzed 275 patients who underwent polypectomy for non-pedunculated colorectal polyps less than 10 mm (959 Lesions) between October 2016 and 2017 and underwent follow-up endoscopy subsequently. We divided them into the CP group (706 Lesions), wherein CP was performed, and the HP group (253 Lesions), wherein HP was performed. Using propensity score matching, we extracted 215 Lesions in each group and evaluated the local recurrence and content of CP in the real clinic and adverse events using medical records.

RESULTS

After propensity score matching, there were no significant differences in the patients’ and their endoscopic background (age, use of antithrombotics, indications, size, morphology, location of polyps, and polypectomy device) between the groups. The mean duration between colorectal polypectomy and the next follow-up colonoscopy was 17.5 ± 7.1 (range, 6-39) mo in the CP group and 15.7 ± 6.0 (range, 6-35) mo in the HP group, which was significantly longer in the CP group (P = 0.005). The local recurrence rate was 0.93% in the CP group and 0.93% in the HP group, without a significant difference (P = 0.688). Additionally, no differences were observed in the macroscopic en bloc resection rate, histopathological complete resection rate, and pathological results between the groups. Adverse events did not occur in either group.

CONCLUSION

Local recurrence after CP was equivalent to that following HP in clinical practice. CP is useful and safe in the treatment of non-pedunculated polyps of less than 10 mm.

Opportunistic Colonoscopy Cancer Screening Pays off in Romania-A Single-Centre Study

Colorectal cancer (CRC) is the third most diagnosed cancer in men (after prostate and lung cancers) and in women (after breast and lung cancer). It is the second cause of cancer death in men (after lung cancer) and the third one in women (after breast and lung cancers). It is estimated that, in EU-27 countries in 2020, colorectal cancer accounted for 12.7% of all new cancer diagnoses and 12.4% of all deaths due to cancer. Our study aims to assess the opportunistic colorectal cancer screening by colonoscopy in a private hospital. A secondary objective of this study is to analyse the adenoma detection rate (ADR), polyp detection rate (PDR), and colorectal cancer (CRC) detection rate. We designed a retrospective single-centre study in the Gastroenterology Department of Saint Mary Hospital. The study population includes all individuals who performed colonoscopies in 2 years, January 2019–December 2020, addressed to our department by their family physician or came by themselves for a colonoscopy. One thousand seven hundred seventy-eight asymptomatic subjects underwent a colonoscopy for the first time. The mean age was 59.0 ± 10.9, 59.5% female. Eight hundred seventy-three polyps were found in 525 patients. Five hundred and twenty-five had at least one polyp, 185 patients had two polyps, 87 had three polyps, and 40 patients had more than three polyps. The PDR was 49.1%, ADR 39.0%, advanced adenomas in 7.9%, and carcinomas were found in 5.4% of patients. In a country without any colorectal cancer screening policy, polyps were found in almost half of the 1778 asymptomatic patients evaluated in a single private center, 39% of cases adenomas, and 5.4% colorectal cancer. Our study suggests starting screening colonoscopy at the age of 45. A poor bowel preparation significantly impacted the adenoma detection rate.

Designing a Predictive Model for Colorectal Neoplasia Diagnosis Based on Clinical and Laboratory Findings in Colonoscopy Candidate Patients

BACKGROUND

Health authorities have expanded two strategies to diminish CRC-related influence: CR screening and improve diagnostic process in symptomatic patients. The aim of the current study is to design a predictive model to identify the most important risk factors that can efficiently predict patients who have high risk of colorectal neoplasia.

METHOD

A cross-sectional study was constructed to include all patients who had positive test for FIT or had one or more risk factors for colorectal cancer based on the guidelines of detecting high-risk groups for colorectal cancer in Iran. Multivariable binary logistic regression model was constructed for prediction of colorectal neoplasia. We used sensitivity, specificity, positive and negative predictive value, and positive and negative likelihood ratio to check the accuracy. The Hosmer-Lemeshow test, chi-square test, and p value were used to determine the precision of model.

RESULT

Following an AIC stepwise selection model, only nine potential variables, namely gender, watery diarrhea, IBD, abdominal pain, melena, body mass index, depression drug, anti-inflammatory drug, and age, were found to be a predictor of colorectal neoplasia. The best cut-point probability in the final model was 0.27 and results of sensitivity and specificity, based on maximizing these two criteria, were 66% and 62%, respectively.

CONCLUSION

Overall, our model prediction was comparable with other risk prediction models for colorectal cancer. It had a modest discriminatory power to distinguish an individual's neoplasia colorectal risk.

Endoscopic management of delayed bleeding after polypectomy of small colorectal polyps: two or more clips may be safe

Background

The resection of small colorectal polyps (≤10 mm) is routine for endoscopists. However, the management of one of its main complications, namely delayed (within 14 days) postpolypectomy bleeding (DPPB), has not been clearly demonstrated. We aimed to assess the role of coloscopy in the management of DPPB from small colorectal polyps and identify the associated factors for initial hemostatic success.

Methods

We conducted a retrospective study of 69 patients who developed DPPB after the removal of colorectal polyps of ≤10 mm and underwent hemostatic colonoscopy at the Sixth Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) between April 2013 and June 2021. Demographics, clinical variables, and colonoscopic features were collected independently. We applied univariate and multivariate analyses to assess factors associated with initial hemostatic success.

Results

General colonoscopy without oral bowel preparation was successfully performed in all the patients, with a median duration of 23.9 (12.5–37.9) minutes. Among 69 patients, 62 (89.9%) achieved hemostasis after initial hemostatic colonoscopy and 7 (10.1%) rebled 2.7 ± 1.1 days after initial colonoscopic hemostasis and had rebleeding successfully controlled by one additional colonoscopy. No colonoscopy-related adverse events occurred. Multivariate analysis showed that management with at least two clips was the only independent prognostic factor for initial hemostatic success (odds ratio, 0.17; 95% confidence interval, 0.03–0.91; P = 0.04). All the patients who had at least two clips placed at the initial hemostatic colonoscopy required no further hemostatic intervention.

Conclusions

Colonoscopy is a safe, effective, and not too time-consuming approach for the management of patients with DPPB of small colorectal polyps and management with the placement of at least two hemoclips may be beneficial.

Prevalence of Advanced Colorectal Neoplasia in Veterans: Effects of Age, Sex, and Race/Ethnicity

GOAL

We sought to quantify the independent effects of age, sex, and race/ethnicity on risk of colorectal cancer (CRC) and advanced neoplasia (AN) in Veterans.

STUDY

We conducted a retrospective, cross-sectional study of Veterans aged 40 to 80 years who had diagnostic or screening colonoscopy between 2002 and 2009 from 1 of 14 Veterans Affairs Medical Centers. Natural language processing identified the most advanced finding and location (proximal, distal). Logistic regression was used to examine the adjusted, independent effects of age, sex, and race, both overall and in screening and diagnostic subgroups.

RESULTS

Among 90,598 Veterans [mean (SD) age 61.7 (9.4) y, 5.2% (n=4673) were women], CRC and AN prevalence was 1.3% (n=1171) and 8.9% (n=8081), respectively. Adjusted CRC risk was higher for diagnostic versus screening colonoscopy [odds ratio (OR)=3.79; 95% confidence interval (CI), 3.19-4.50], increased with age, was numerically (but not statistically) higher for men overall (OR=1.53; 95% CI, 0.97-2.39) and in the screening subgroup (OR=2.24; 95% CI, 0.71-7.05), and was higher overall for Blacks and Hispanics, but not in screening. AN prevalence increased with age, and was present in 9.2% of men and 3.9% of women [adjusted OR=1.90; 95% CI, 1.60-2.25]. AN risk was 11% higher in Blacks than in Whites overall (OR=1.11; 95% CI, 1.04-1.20), was no different in screening, and was lower in Hispanics (OR=0.74; 95% CI, 0.55-0.98). Women had more proximal CRC (63% vs. 39% for men; P=0.03), but there was no difference in proximal AN (38.3% for both genders).

CONCLUSIONS

Age and race were associated with AN and CRC prevalence. Blacks had a higher overall prevalence of both CRC and AN, but not among screenings. Men had increased risk for AN, while women had a higher proportion of proximal CRC. These findings may be used to tailor when and how Veterans are screened for CRC.

The classification capability of the Asia Pacific Colorectal Screening score in Korea: an analysis of the Cancer Screenee Cohort

OBJECTIVES

This study aimed to validate a simple risk assessment tool for estimating the advanced colorectal neoplasia (ACN) risk at colonoscopy screenings and potential factors relevant for implementing this tool in the Korean population.

METHODS

Our study analyzed data from the Cancer Screenee Cohort Study conducted by the National Cancer Center in Korea. The risk level was assessed using the Asia Pacific Colorectal Screening (APCS) score developed by the Asia-Pacific Working Group on Colorectal Cancer. Logistic regression models were used to examine the associations between colorectal-related outcomes and the risk level by APCS score. The discriminatory performance of the APCS score for various colorectal-related outcomes was assessed using C-statistics.

RESULTS

In 12,520 individuals, 317 ACN cases and 4,528 adenoma cases were found. The APCS tool successfully classified the study population into different risk groups, and significant differences in the ACN rate and other outcomes were observed. The APCS score demonstrated acceptable discrimination capability with area under the curve values ranging from 0.62 to 0.65 for various outcomes. The results of the multivariate logistic regression model revealed that the high-risk group had a 3.1-fold higher risk of ACN (95% confidence interval, 2.08 to 4.67) than the average-risk group. Body mass index (BMI) was identified as a significant predictor of ACN in both multivariate and subgroup analyses.

CONCLUSIONS

Our study highlighted significant differences in colorectal-related screening outcomes by colorectal risk level measured using the APCS score, and BMI could be used to improve the discriminatory capability of the APCS score.

Colonoscopy polyp detection and classification: Dataset creation and comparative evaluations

Colorectal cancer (CRC) is one of the most common types of cancer with a high mortality rate. Colonoscopy is the preferred procedure for CRC screening and has proven to be effective in reducing CRC mortality. Thus, a reliable computer-aided polyp detection and classification system can significantly increase the effectiveness of colonoscopy. In this paper, we create an endoscopic dataset collected from various sources and annotate the ground truth of polyp location and classification results with the help of experienced gastroenterologists. The dataset can serve as a benchmark platform to train and evaluate the machine learning models for polyp classification. We have also compared the performance of eight state-of-the-art deep learning-based object detection models. The results demonstrate that deep CNN models are promising in CRC screening. This work can serve as a baseline for future research in polyp detection and classification.

Colorectal Cancer after Kidney Transplantation: A Screening Colonoscopy Case-Control Study

The incidence of colorectal cancer in kidney transplant recipients has been previously reported with conflicting results. In this study, we investigated if the incidence of colorectal advanced neoplasms in kidney transplant recipients, evaluated with screening colonoscopy, was higher than in healthy individuals. One-hundred sixty kidney transplant recipients undergoing screening colonoscopy were compared with 594 age- and sex-matched healthy individuals. Advanced colorectal neoplasia was found in 22 patients (13.7%), including four patients (2.5%) with colorectal cancer. Compared with the healthy population, kidney transplant recipients did not have an increased risk of developing a colorectal cancer (OR 0.69; 95% CI 0.236–2.063, p = 0.688) although it developed at a younger age. In contrast, kidney transplant recipients had a higher risk of developing an advanced adenoma compared with the control group (OR 1.65; 95% CI 0.930–2.981, p = 0.04). In conclusion, kidney transplant recipients did not have an increased incidence of colorectal cancer compared with healthy population. However, transplant patients displayed a higher incidence of colorectal adenomas, suggesting that screening colonoscopy in kidney transplant recipients should be expanded to include even younger recipients (<50 years old).

The conversion factor for predicting adenoma detection rate from polyp detection rate varies according to colonoscopy indication and patient sex

The adenoma detection rate (ADR) is the primary quality indicator for colonoscopies. The polyp detection rate (PDR) is available from administrative data and does not depend on histology verification. The correlation between PDR and ADR and the ADR/PDR conversion factor in preventive colonoscopies were evaluated. In the prospective study, asymptomatic individuals aged 45-75 years with preventive colonoscopy in 2012-2016 were included. Spearman's correlation coefficient was used to assess PDR/ADR for each endoscopist. Conversion factor predicting ADR from PDR was obtained by linear regression and subsequently compared with adenoma to polyp detection rate quotient. One thousand six hundred fourteen preventive colonoscopies performed by 16 endoscopists in 8 screening colonoscopy centres in the Czech Republic were analysed. Correlation between PDR and ADR in all preventive colonoscopies was high and statistically significant (Rs 0.82; P < 0.001). There was a strong correlation between PDR and ADR in men (Rs 0.74; P = 0.002) and in screening colonoscopies (Rs 0.85; P < 0.001). The conversion factor to convert ADR from PDR was 0.72 in all preventive colonoscopies, 0.76 in FOBT+ colonoscopies and 0.67 in screening colonoscopies. ADR may be replaced by PDR in the assessment of colonoscopy quality. The value of the conversion factor varies according to colonoscopy indication and gender of examined individuals; in this Czech study, it was 0.72 in all preventive colonoscopies. The minimum requested ADR of 25 % corresponds to a PDR of 35 %, when converted with the appropriate conversion factor.

Dynamics of changes in colorectal cancer incidence in the Podkarpackie region (Poland) in the years 1963-2014

Introduction

Colorectal cancer (CRC) in Podkarpackie in Poland is the third most common cancer in males (12.6% cancer diagnoses), and second among women (10.1% of recognised cancers).

Aim

An analysis of the trends in CRC incidence in the years 1963-2014 in Podkarpackie in the south-east of Poland.

Material and methods

A total of 19,460 CRC cases recorded in the period 1963–2014 in the National Cancer Registry as ICD C18-C21 cases were analysed.

Results

The overall cancer incidence rate in Podkarpackie Province was 20.4 in men and 16.8 in women per 100 thousand, and was lower than the Polish population by 12.4% for men and by 17.6% for women, respectively, in comparison to general Polish population rates. The mean age of CRC diagnosis grew from 64.0 years in males and 64.5 years in females in 1963–1969 to 67.6 and 68.4 years in 2010–2014, respectively.

Conclusions

In 1964–2014 the CRC incidence rate in the Podkarpackie region increased 12.7-fold in males and 8.1-fold in females. There was an observed stable growth of average annual increase in the CRC incidence rate in men in 1963–1999, but since 2000 a decline in this rate has been observed. In females there was a tendency towards increased average CRC incidence rate in Podkarpackie since 2000, while in the whole country the female population presented a stable decrease of this coefficient.

Derivation and validation of a predictive model for advanced colorectal neoplasia in asymptomatic adults

OBJECTIVE

Knowing risk for advanced colorectal neoplasia (AN) could help patients and providers choose among screening tests, improving screening efficiency and uptake. We created a risk prediction model for AN to help decide which test might be preferred, a use not considered for existing models.

DESIGN

Average-risk 50-to-80-year olds undergoing first-time screening colonoscopy were recruited from endoscopy units in Indiana. We measured sociodemographic and physical features, medical and family history and lifestyle factors and linked these to the most advanced finding. We derived a risk equation on two-thirds of the sample and assigned points to each variable to create a risk score. Scores with comparable risks were collapsed into risk categories. The model and score were tested on the remaining sample.

RESULTS

Among 3025 subjects in the derivation set (mean age 57.3 (6.5) years; 52% women), AN prevalence was 9.4%. The 13-variable model (c-statistic=0.77) produced three risk groups with AN risks of 1.5% (95% CI 0.72% to 2.74%), 7.06% (CI 5.89% to 8.38%) and 27.26% (CI 23.47% to 31.30%) in low-risk, intermediate-risk and high-risk groups (p value <0.001), containing 23%, 59% and 18% of subjects, respectively. In the validation set of 1475 subjects (AN prevalence of 8.4%), model performance was comparable (c-statistic=0.78), with AN risks of 2.73% (CI 1.25% to 5.11%), 5.57% (CI 4.12% to 7.34%) and 25.79% (CI 20.51% to 31.66%) in low-risk, intermediate-risk and high-risk subgroups, respectively (p<0.001), containing proportions of 23%, 59% and 18%.

CONCLUSION

Among average-risk persons, this model estimates AN risk with high discrimination, identifying a lower risk subgroup that may be screened non-invasively and a higher risk subgroup for which colonoscopy may be preferred. The model could help guide patient-provider discussions of screening options, may increase screening adherence and conserve colonoscopy resources.

Colonoscopy screening and surveillance guidelines

The Colonoscopy Screening and Surveillance Guidelines were developed by the Japan Gastroenterological Endoscopy Society as basic guidelines based on the scientific methods. The importance of endoscopic screening and surveillance for both detection and post-treatment follow-up of colorectal cancer has been recognized as essential to reduce disease mortality. There is limited high-level evidence in this field; therefore, we had to focus on the consensus of experts. These clinical practice guidelines consist of 20 clinical questions and eight background knowledge topics that have been determined as the current guiding principles.

Oligometastasis: Past, Present, Future

In this review, we discuss the oligometastatic state, with a focus on its current and future relevance within the field of radiation therapy. We first outline the scope of the problem and the evolving understanding of metastatic disease existing along a spectrum. We then transition to a discussion of the clinical data that led to the formulation of the oligometastatic hypothesis, delving in some detail into the clinical factors associated with improved outcomes in the setting of local therapy-whether surgical or radiotherapeutic. In particular, we highlight the marked limitations of using clinical criteria alone to determine the absence or presence of true extracranial oligometastatic disease. After this, we briefly discuss the radiation therapy literature that has recently demonstrated benefits in cancer-specific outcomes with ablative treatment of oligometastatic disease. We emphasize data in the setting of non-small cell lung cancer and prostate cancer and briefly discuss the importance of our enhanced ability to detect occult metastatic disease with improved imaging technologies. After noting that resulted and ongoing prospective trials of ablative radiation therapy use the most rudimentary of oligometastatic classifiers-number of metastases-as their inclusion criteria, we transition to our core argument: a growing body of preclinical and translational work aims to refine the definition of oligometastatic disease using molecular features. We address genomic, epigenetic, and immunologic features that have, across histology, demonstrated an improved ability to prognosticate when combined with classic clinical correlates of oligometastatic disease. We also discuss studies that suggest particular molecular targets which, when manipulated for therapeutic purposes, have the potential to revert the polymetastatic phenotype to the oligometastatic one. We conclude with what we believe are the repercussions of this work for radiation therapy trials and clinical practice, and the importance of enriching and supporting these inquiries for the future of our field.

Risk factors for metachronous adenoma in patients with stage I/II colorectal cancer after radical surgery

Background

It is important to implement a preventive strategy for early detection and endoscopic removal of metachronous adenoma in patients with colorectal cancer (CRC). Here, we retrospectively explored the associated factors of metachronous adenoma in these patients.

Methods

This study recruited 551 patients with stage I and II CRC who underwent radical surgery between January 1, 2012 and July 1, 2017 with postoperative colonoscopic surveillance. Data on clinicopathological characteristics and surveillance colonoscopies were obtained from medical records. Univariate analysis by Kaplan-Meier method and multivariate analysis by Cox proportional hazards model were used to identify the factors associated with metachronous adenoma.

Results

Metachronous adenoma was detected in 110 (20.0%) patients. In these patients, 94.5% (104/110) had metachronous adenoma within 3 years postoperatively. Age, synchronous adenoma, hypertension, tumor stage, and surgical resection were correlated with metachronous adenoma in patients with stage I-II CRC after radical resection (log rank test, P<0.05). Multivariate analyses showed that synchronous adenoma (HR =2.515, 95% CI: 1.691-3.742, P<0.01); stage II (HR =2.066, 95% CI: 1.329-3.210, P<0.01); and left-side colorectal resection (HR =2.207, 95% CI: 1.292-3.772, P<0.01) were independent risk factors.

Conclusions

Synchronous adenoma, left-side colorectal resection, and stage II cancer are independent risk factors of metachronous adenoma in patients with previous stage I and II CRC. In patients with risk factors, an enhanced colonoscopic strategy might be needed for early detection and timely endoscopic removal of metachronous adenoma.

Body composition among patients undergoing surgery for colorectal cancer

Introduction

Nutritional status assessment is an important part of preoperative patient evaluation, but the standard anthropometric parameters do not appear to be adequate.

Aim

To determine the changes in the values of bioelectrical impedance analysis (BIA) parameters in patients 3 months after undergoing surgery for colorectal cancer (CRC).

Material and methods

BIA and nutritional status assessment parameters were determined in 80 patients prior to undergoing surgery for CRC. The results 3 months after surgery for 64 of those patients were then compared with their initial assessments.

Results

According to standard WHO ranges, 54% of the patients were diagnosed as being overweight and 29% as obese. The percentage of patients categorized as obese amounted to 56% when this was defined as high fat mass. Moderate sarcopaenia, defined as a low skeletal muscle index (SMI) or low percentage of skeletal muscle mass, was diagnosed in 21% and 29% of patients, respectively. Patients with postoperative weakness that made it impossible for them to attend the control visit had a lower preoperative skeletal muscle mass (p = 0.01) and SMI value (p = 0.001). Parameters of BIA did not discriminate patients with postoperative complications, which occurred in 23% of individuals enrolled.

Conclusions

A significant proportion of the patients undergoing surgery for CRC were overweight or obese, which could mask the sarcopaenia that presented in 21–29% of them. Sarcopaenia was the only parameter predictive of a postoperative decrease in performance status.