Randomized comparison of surveillance intervals after colonoscopic removal of newly diagnosed adenomatous polyps. The National Polyp Study Workgroup

Factors related to colorectal cancer in advanced adenomas and serrated polyps: a further step toward individualized surveillance

AIM

The risk of presenting synchronous or metachronous neoplasm, either adenoma or carcinoma, increases after an initial colonic lesion develops. It is known as tumor multicentricity and constitutes the rationale for surveillance programs. This study was designed to identify the clinical, pathologic, and molecular features related to previous or synchronous colorectal cancer (CRC) in patients with advanced adenomas (AA) or serrated polyps (SP).

PATIENTS AND METHODS

We carried out a prospective analysis of 4143 colonoscopies performed at our medical department between 1 September 2014 and 30 September 2015. Patients with AA/SP associated with previous or synchronous CRC are compared with patients with solitary AA/SP. We also performed immunohistochemical for the mismatch repair proteins in 120 AA or SP, 60 of them related to CRC.

RESULTS

Three-hundred and seventy-nine AA or SP were removed. Among these, 66 (17.3%) were associated with a previous (n=31) or synchronous CRC (n=35). Age older than or equal to 65 years (odds ratio: 1.15, 95% confidence interval: 1.05-1.26, P=0.002) and male sex (odds ratio: 2.13, 95% confidence interval: 1.3-3.49, P=0.003) were found to be independent predictive factors for CRC in patients with AA/SP by multivariate analysis. Only one of the 120 AA/SP available for immunohistochemical testing showed loss of staining and it was not related to CRC.

CONCLUSION

In patients with AA or SP, it is possible to identify a subgroup that is more likely to be associated with CRC and then prone to tumor multicentricity. These results have potential implications for establishing criteria for a more targeted surveillance.

Clinical Practice Guideline on Screening for Colorectal Cancer in Individuals With a Family History of Nonhereditary Colorectal Cancer or Adenoma: The Canadian Association of Gastroenterology Banff Consensus

BACKGROUND & AIMS

A family history (FH) of colorectal cancer (CRC) increases the risk of developing CRC. These consensus recommendations developed by the Canadian Association of Gastroenterology and endorsed by the American Gastroenterological Association, aim to provide guidance on screening these high-risk individuals.

METHODS

Multiple parallel systematic review streams, informed by 10 literature searches, assembled evidence on 5 principal questions around the effect of an FH of CRC or adenomas on the risk of CRC, the age to initiate screening, and the optimal tests and testing intervals. The GRADE (Grading of Recommendation Assessment, Development and Evaluation) approach was used to develop the recommendations.

RESULTS

Based on the evidence, the Consensus Group was able to strongly recommend CRC screening for all individuals with an FH of CRC or documented adenoma. However, because most of the evidence was very-low quality, the majority of the remaining statements were conditional ("we suggest"). Colonoscopy is suggested (recommended in individuals with ≥2 first-degree relatives [FDRs]), with fecal immunochemical test as an alternative. The elevated risk associated with an FH of ≥1 FDRs with CRC or documented advanced adenoma suggests initiating screening at a younger age (eg, 40-50 years or 10 years younger than age of diagnosis of FDR). In addition, a shorter interval of every 5 years between screening tests was suggested for individuals with ≥2 FDRs, and every 5-10 years for those with FH of 1 FDR with CRC or documented advanced adenoma compared to average-risk individuals. Choosing screening parameters for an individual patient should consider the age of the affected FDR and local resources. It is suggested that individuals with an FH of ≥1 second-degree relatives only, or of nonadvanced adenoma or polyp of unknown histology, be screened according to average-risk guidelines.

CONCLUSIONS

The increased risk of CRC associated with an FH of CRC or advanced adenoma warrants more intense screening for CRC. Well-designed prospective studies are needed in order to make definitive evidence-based recommendations about the age to commence screening and appropriate interval between screening tests.

Incidence and risk factors of advanced neoplasia after endoscopic mucosal resection of colonic laterally spreading lesions

PURPOSE

To investigate advanced neoplasia (AN) after endoscopic mucosal resection (EMR) of colonic laterally spreading lesions (LSLs).

METHODS

A retrospective study of patients who underwent injection-assisted EMR of colonic LSLs ≥ 10 mm was performed. Primary outcome was overall rate of AN at initial surveillance colonoscopy. Secondary outcomes were the rates of residual AN (rAN) at the EMR site and metachronous AN (mAN), and analysis of risk factors for AN, including effect of surveillance guidance.

RESULTS

Three hundred seventy-four patients underwent successful EMR for 388 LSLs. AN occurred in 66/374 (17.6%) patients on initial surveillance colonoscopy at median follow-up of 364.5 days. Two patients had both rAN and mAN, for a total of 68 instances of AN, including 30/374 (8.0%) cases of rAN and 38/374 (10.2%) cases of mAN. On multivariate analysis, use of piecemeal resection was associated with increased likelihood of residual AN (P = 0.003, OR 9.2, 95% CI 2.1-33.3). Twenty-nine out of thirty cases (96.7%) of rAN were successfully endoscopically managed at surveillance colonoscopy.

CONCLUSIONS

AN occurred in 17.6% of all patients at initial surveillance colonoscopy at a median of 1 year after EMR. Roughly half of the instances of AN were metachronous lesions. Our data support a 1-year surveillance interval after EMR of LSLs ≥ 10 mm with careful inspection of the entire colon, not just the prior resection site.

NF-κB-induced WIP1 expression promotes colorectal cancer cell proliferation through mTOR signaling

Colorectal cancer (CRC) is one of the major causes of cancer deaths worldwide. Wild-type p53-induced protein 1 (WIP1) is overexpressed in multiple human cancers and acted as an oncogene. This study was aimed to investigate the effect of WIP1 in colorectal cancer growth and analyzed underlying mechanisms. Herein, we determined WIP1 expression in CRC tissues and cell lines, as well as evaluated its detailed function in CRC cell proliferation. Several factors have been reported to mediate WIP1 effects; herein, we examined the involvement of mTOR and p21 in WIP1 regulation of CRC cell proliferation. Moreover, NF-κB has been regarded as a positive transcriptional regulator of WIP1 to activate its expression. NF-κB knockdown suppressed CRC cell proliferation, which could be reversed by WIP1 overexpression, through p21 and mTOR. Further, we examined the binding of NF-κB to the promoter region of WIP1. In CRC tissues, NF-κB expression was significantly up-regulated, and positively correlated with WIP1 expression, suggesting that inhibiting NF-κB expression to attenuate its activating effect on WIP1 expression presented a promising strategy of controlling excess proliferation of CRC cell. In summary, WIP1 promotes CRC proliferation through p21 and mTOR, both downstream targets of p53; NF-κB served as a positive transcriptional regulator of WIP1 to activate its expression and affect its function in CRC cells. Our finding provided a novel strategy for treatment for CRC.

The effect of small or diminutive adenomas at baseline colonoscopy on the risk of developing metachronous advanced colorectal neoplasia: KASID multicenter study

BACKGROUND

The clinical significance of diminutive or small adenomas remains ill defined.

AIMS

We evaluated the clinical impact of diminutive or small adenomas at baseline on the risk of developing metachronous advanced colorectal neoplasia (CRN).

METHODS

This multicenter, retrospective cohort study included 2252 patients with 1 or more colorectal adenomas at baseline and subsequent follow-up colonoscopy. Baseline colonoscopy findings were classified into 5 groups: 1 or 2 tubular adenomas (TAs) (<10 mm); 3-10 diminutive TAs (≤5 mm); 3-10 TAs, including 1 or 2 small adenomas (6-10 mm); 3-10 TAs, including 3 or more small adenomas; and advanced adenoma.

RESULTS

In multivariate analysis, after adjusting for possible confounding variables (age at baseline, sex, body mass index, smoking habits, family history of colorectal cancer, regular use of aspirin or NSAIDs, and adenoma location), 3-10 TAs including 3 or more small adenomas (hazard ratio [HR] = 2.36, p = 0.034) and advanced adenoma (HR = 2.14, p < 0.001) were independent predictors for the risk of developing metachronous advanced CRN. However, 3-10 diminutive TAs or 3-10 TAs, including 1 or 2 small adenomas, were not associated with this outcome.

CONCLUSIONS

Multiplicity of diminutive TAs, without advanced lesions, showed no clinical significance for risk of developing metachronous advanced CRN.

The incidence of colorectal cancer in patients with previously removed polyp(s)-a cross-sectional study

Background

Years ago, it was established that removal of adenomas will lead to a lower incidence of colorectal cancer. This study aims to establish the occurrence of colorectal cancer in unselected patients after index colonoscopy with polyp removal.

Methods

A prospectively collected dataset on colonoscopy covering 25 consecutive years was used. Patients in who during the index (first) procedure a polyp(s) was removed were included. Excluded were patients with colorectal cancer and patients belonging to Lynch families. In case of cancer time after the index and previous procedure, tumor stage, histology of earlier removed polyps, localization of the tumor and demographics were noted.

Results

In 1,617 patients polyp(s) were removed. Thirty (1.9%) patients developed colorectal cancer. In 18 cases adenomas were removed during prior endoscopies. Five patients only had hyperplastic polyp(s). Nine patients with cancer already were older than 75 years when the previous endoscopy was done. Patients with adenomas prior to the cancer were older compared with patients with hyperplastic polyps [mean (SD): 71.6 (5.8) versus 64.2 (10.5) years, P=0.046]. The majority of cancers were located in the proximal colon (75%). The time between diagnosing cancer and the previous colonoscopy was mean 70.6 months with a median of 60.0 months (range, 12.0-167.0 months).

Conclusions

It is concluded that follow-up after removal of polyps in normal daily practice is associated with a low incidence of developing colorectal cancer.

Clinical and endoscopic evaluations of sessile serrated adenoma/polyps with cytological dysplasia

BACKGROUND AND AIM

Although sessile serrated adenoma/polyps (SSA/Ps) are considered to be premalignant lesions and rapidly progress to carcinomas after they develop cytological dysplasia (CD), a treatment strategy for SSA/Ps in Asian countries is still being debated and has not yet been established. The present study aimed to propose a treatment strategy for SSA/Ps.

METHODS

Histopathological data of patients, who underwent colonoscopy at our center between January 2011 and December 2016, were reviewed. Data of patients with ≥ 1 SSA/P were retrieved, and clinicopathological characteristics were retrospectively analyzed.

RESULTS

A total of 281 patients with 326 SSA/Ps, including 258 patients who had 300 SSA/Ps without CD (SSA/Ps-CD[-]) and 23 patients who had 26 SSA/Ps with CD (SSA/Ps-CD[+]), were evaluated in this study. Although SSA/Ps-CD(+) were often found in older female patients and in the proximal colon, there were no significant differences between SSA/Ps-CD(-) and SSA/Ps-CD(+). Endoscopic morphological findings, such as large or small nodules on the surface and partial protrusion of the lesions, were significantly more common in SSA/Ps-CD(+) than in SSA/Ps-CD(-). Although the diagnostic ability of nodule/protrusion in lesions to predict CD within SSA/Ps was very high with an accuracy of 93.9% and a negative predictive value of 95.4%, sensitivity was low at 46.2%. SSA/Ps-CD(+) were significantly larger than SSA/Ps-CD(-), and the rate of CD within SSA/Ps significantly increased with lesion size (≤ 5 mm, 0%; 6-9 mm, 6.0%; ≥ 10 mm, 13.6%).

CONCLUSION

The study proposes removing all SSA/Ps ≥ 6 mm in order to remove high-risk SSA/Ps-CD(+), with high sensitivity.

Family history of colorectal cancer in first-degree relatives and metachronous colorectal adenoma

OBJECTIVES

Little is known about the relationship between having a first-degree relative (FDR) with colorectal cancer (CRC) and risk for metachronous colorectal adenoma (CRA) following polypectomy.

METHODS

We pooled data from seven prospective studies of 7697 patients with previously resected CRAs to quantify the relationship between having a FDR with CRC and risk for metachronous adenoma.

RESULTS

Compared with having no family history of CRC, a positive family history in any FDR was significantly associated with increased odds of developing any metachronous CRA (OR = 1.14; 95% CI = 1.01-1.29). Higher odds of CRA were observed among individuals with an affected mother (OR = 1.27; 95% CI = 1.05-1.53) or sibling (OR = 1.34; 95% CI = 1.11-1.62) as compared with those without, whereas no association was shown for individuals with an affected father. Odds of having a metachronous CRA increased with number of affected FDRs, with ORs (95% CIs) of 1.07 (0.93-1.23) for one relative and 1.39 (1.02-1.91) for two or more. Younger age of diagnosis of a sibling was associated with higher odds of metachronous CRA, with ORs (95% CIs) of 1.66 (1.08-2.56) for diagnosis at <54 years; 1.34 (0.89-2.03) for 55-64 years; and 1.10 (0.70-1.72) for >65 years (p-trend = 0.008). Although limited by sample size, results for advanced metachronous CRA were similar to those for any metachronous CRA.

CONCLUSIONS

A family history of CRC is related to a modestly increased odds of metachronous CRA. Future research should explore whether having a FDR with CRC, particularly at a young age, should have a role in risk stratification for surveillance colonoscopy.

Risk Factors and Patient Care in Post-Polypectomy Surveillance Colonoscopy

This paper highlights the potential importance of family history as an independent risk factor in those with a personal history of adenomas. It also raises important questions for future study about maternal versus paternal risk in CRC. However, we should be cautious about making changes to practice based on these data alone. In the future, such data could be used to generate individualized recommendations for post-polypectomy surveillance to ensure that we deliver the right care to the right patient at the right time.

A Multicenter Study of Colorectal Adenomas Rationale, Objectives, Methods and Characteristics of the Study Cohort

Background and Aims

The Multicenter Study of Colorectal Adenomas (SMAC) is a retrospective-prospective cohort study involving four Gastrointestinal Endoscopy Units in Italy. The main aim of the study is to evaluate the relationship between clinical and pathologic information at index colonoscopy and subsequent incidence of adenoma and colorectal carcinoma. We report the rationale, objectives and methods of the study, including patient characteristics at initial presentation.

Methods

All patients were consecutively identified from the endoscopy registries of the four Centres from January 1, 1985 to December 31, 1992. Inclusion criteria were: age 18-69 years, endoscopy performed with adequate toilette at least up to the rectosigmoid junction, and removal of all detectable polyps. Exclusion criteria were: familial adenomatous polyposis, inflammatory bowel diseases, adenocarcinoma in adenoma with infiltrated margins, previous invasive cancer at any site, colon resection and geographic inaccessibility.

Results

Out of 20,071 patients who underwent endoscopy at the four Centres, 11,959 fulfilled the eligibility criteria (5,892 males and 6,067 females, mean age = 51.1 ± 11.6 years). The main reasons for exclusion were age (n = 4,020) and previous or present colorectal cancer (n = 2,389). Symptoms were the most common reason for referral (72.3%), while post-polypectomy follow-up and positive fecal occult blood accounted for most of the remaining cases. A pancolonoscopy was performed in 3,088 patients (25.8%), while a left-sided endoscopy was performed in 7,887 (66%). A total number of 4,810 polyps were removed from 2,699 patients (2,994 adenomas, 1,580 hyperplastic polyps and 236 polyps lost after resection). A significant association (p < 0.001) between age and the endoscopic findings was observed. The subjects without polyps (n = 9,198) had the lowest age (mean = 49.9; 95%CL = 49.6 - 50.1) followed by the patients with hyperplastic polyps (n = 661; mean age = 52.3; 95%CL = 51.5-53.1), and the patients with adenomas (n = 1,732; mean age = 56.2; 95%CL = 55.8 - 56.6), and the patients with hyperplastic polyps and adenomas (n = 306; mean age = 57.2; 95%CL = 56.3 - 58.2). Polyps were diagnosed more frequently in males than in females (28.6% versus 17.0%; p < 0.0001).

Conclusion

This study provides some insights in the natural history of colorectal cancer and stresses the need to develop adequate strategies in the follow-up of subjects after either positive or negative colonoscopy.

Risk of Colorectal Cancer following Colonoscopic Polypectomy

Aims and Background

To follow a cohort of patients who had undergone polypectomies in order to assess the overall risk of subsequent colorectal cancer in relation with various adenomas characteristics.

Methods

A total of 1,063 patients with adenomatous polyps of the large intestine were treated between 1979 and 1996 at the National Cancer Institute of Milan, during a screening program for colorectal carcinoma. Data on patients who had undergone colonoscopies were collected prospectively. The relation between colorectal cancer and adenomas characteristics was assessed by computing the hazard ratio (HR) values and corresponding confidence intervals (95% CI), according to Cox.

Results

Of the 1,063 patients who met the eligibility requirements, 672 had single adenomas (63.2%) and 391 had multiple adenomas (36.8%). Histological examination revealed 743 cases of tubular adenoma, 196 cases of tubulo-villous adenoma, and 96 cases of villous adenoma. High-grade dysplasia was found in 3.1% of the cases. During the 8,906 persons/year of follow-up, adenocarcinomas of the large bowel developed in 11 patients. Several adenomas’ characteristics at index polypectomy were significant predictors of colorectal cancer occurrence. In univariate analysis the risk of colon cancer was significantly related with multiple adenomas (HR 4.2, 95% CI 1.1-6.5), high-grade dysplasia adenomas (HR 10.0, 95% CI 2.6-38.1) and with adenomas larger than 2 cm (HR 5.0, 95% CI 1.2-20.4). A multivariate stepwise procedure confirmed that the presence of multiple adenomas and presence of high-grade dysplasia are the most important predictors of carcinomas. Hazard ratios for colorectal cancer occurrence, from multivariate Cox's model, were 5.1 (95% CI 1.2-19.9) for multiple compared to single adenomas, and 13.0 (95% CI 3.6-50.7) for adenomas with high-grade dysplasia compared to those with low-grade dysplasia.

Conclusions

High-grade dysplasia, number and size of adenomas were confirmed as the major cancer predictors. Based on this conclusion, a subgroup of patients, who may benefit from intensive surveillance colonoscopy, can be identifiable.

Postoperative adjuvant chemotherapy is associated with a lower incidence of colorectal adenomas in patients with previous colorectal cancer

BACKGROUND AND AIMS

The effects of chemotherapeutic agents on the development of colorectal adenomas in patients with previous colorectal cancer (CRC) are not defined. Therefore, we evaluated the potential effect of adjuvant chemotherapy on the incidence of colorectal adenomas in patients with previous CRC.

METHODS

We selected patients with low-risk stage II CRC with or without postoperative 5-fluorouracil-based adjuvant chemotherapy to reduce selection bias. Among 1808 patients with stage II CRC who underwent colonoscopic surveillance after curative resection of CRC between 2006 and 2013, 192 patients were retrospectively enrolled in this study after matching for age and sex. The patients were divided into 96 patients receiving and 96 patients not receiving 5-fluorouracil-based chemotherapy.

RESULTS

Forty patients (41.7%) exhibited colorectal adenomas among 96 patients who received adjuvant chemotherapy, compared with 50 patients (52.1%) with colorectal adenomas among 96 patients who received surgery only. The incidence rate of advanced adenoma was significantly lower in the chemotherapy group than in the nonchemotherapy group (3.1% vs 10.4%, P = .044). After adjustment for clinically relevant factors such as body mass index, aspirin use, metformin use, number of follow-up colonoscopies, and operation type, adjuvant chemotherapy was found to be associated with a decreased incidence of advanced adenoma (odds ratio, .151; 95% confidence interval, .035-.653; P = .011) in patients with stage II CRC.

CONCLUSIONS

The results showed that chemotherapy in patients with CRC may be associated with a lower risk of colorectal advanced adenoma development.

Diagnostic yield is not influenced by the timing of screening endoscopy: morning versus afternoon

BACKGROUND

Previous studies have shown the colonoscopy quality affected by the endoscopist's fatigue. This study was aimed to evaluate this potential factor in a colorectal cancer-screening cohort of Chinese patients.

METHODS

The attendances at department of gastroenterology for colorectal cancer screening between 2013 and 2015 were retrospectively analyzed. The procedure time-of-day and hours elapse were recorded. The primary outcome was defined as adenoma detection rate (ADR).

RESULTS

A total of 1342 screening colonoscopies were performed by 19 gastroenterologists in the study. Detection rates were 7.7% for all polyps and 20.0% for adenomas. Time-of-day was not significantly associated with ADR. With time elapsing, the first climax for ADR was presented at 09:00-10:00, and persistently rose again after the lunch break. Significant inclined trend in ADR was noted for each hour blocks of a full day (p =  .0021).

CONCLUSIONS

The procedure time-of-day, morning versus afternoon, did not affect the diagnostic efficacy of screening endoscopy in Chinese patients.

Adenoma detection rate influences the risk of metachronous advanced colorectal neoplasia in low-risk patients

BACKGROUND AND AIMS

In individuals with either no or 1 to 2 nonadvanced adenomas, future risks of advanced colorectal neoplasia (AN) vary according to clinical risk factors. However, little is known about the association between the adenoma detection rate (ADR) and the risk for metachronous AN in patients with low-risk adenomas.

METHODS

We identified 7171 participants with no or 1 to 2 nonadvanced adenomas at first-time screening colonoscopy. The risk of metachronous AN was investigated at surveillance colonoscopy, according to clinical characteristics and the ADR.

RESULTS

In multivariate analysis the risk for metachronous AN was strongly associated with increasing age, male sex, increasing number of adenomas, and the ADR of the endoscopist. With the ADR modeled as a continuous variable, each 1.0% increase in the rate of ADR predicted a 3.0% decrease in the risk of metachronous AN (adjusted odds ratio [OR], .97; 95% confidence interval [CI], .95-.99). With the ADR modeled using a binary cut-off (32%), the risk of metachronous AN was reduced in patients of endoscopists with an ADR ≥32% (adjusted OR, .53; 95% CI, .35-.83). Moreover, the risk of metachronous AN was reduced (adjusted OR, .66; 95% CI, .46-.95) in patients of endoscopists with an ADR in the highest tertile, compared with patients of endoscopists with ADRs in the lowest tertile. The impact of ADR on metachronous AN was significant for patients with low-risk adenomas rather than patients with no adenoma.

CONCLUSIONS

In patients with low-risk adenomas, the ADR of the endoscopist was inversely associated with the risk of metachronous AN.

Optimal colonoscopy surveillance interval period for the adenoma patients who had an adequate polypectomy at baseline colonoscopy

The role of surveillance colonoscopy has long been established: it reduces both the incidence and the mortality of colorectal cancer. We aimed to assess the optimal colonoscopy surveillance interval period for the adenoma patients who underwent an adequate polypectomy at baseline colonoscopy to avoid overuse or underuse of colonoscopy. A retrospective study was carried out on the baseline adenoma patients who had had at least two completed colonoscopy examinations during the years 2000-2013 in the Digestive Endoscopy Center of the First Affiliated Hospital of Kunming Medical University. All the patients had a complete polypectomy of adenomas at baseline. Data on the patients' demographics and colorectal findings were extracted from a specially designed colonoscopy database. The end point was the finding of adenoma during the subsequent surveillance colonoscopy; an analysis was carried out to identify recurrence factors and the optimal colonoscopy surveillance interval period. A total of 765 (463 men, 302 women, average age 56.51±11.95) eligible patients were included in the study. Three hundred and twelve patients had adenoma and 453 had no adenoma after surveillance colonoscopies (the frequency of repeat colonoscopy is 1-10, average 1.73±1.24). The diameter of adenomas found on the follow-up colonoscopy was 0.2-3.0 cm (average 0.54±0.30 cm). The number of adenomas was 1-11 (2.21±1.53) and the surveillance adenoma interval period was 0.5-13 years (2.64±2.36 years). A total of 576 patients had baseline nonadvanced adenomas. Male sex, age older than 50 years, and more than two different intestine segment adenomas were the risk factors for recurrence. The optimal colonoscopy surveillance interval period is 2.85 years (95% confidence interval: 2.53-3.17) according to the recurrence rate of 5% adenomas. One hundred and eighty-nine patients had baseline advanced adenomas. Male sex, diameter of adenomas less than 1.0 cm, and adenomas in the right colon or the whole colon were the risk factors for recurrence. The optimal colonoscopy surveillance interval period is 2.06 years (95% confidence interval: 1.71-2.45) according to the recurrence rate of 5% adenomas. The optimal colonoscopy surveillance interval period is 3 years or so for the adenoma patients who had an adequate polypectomy at baseline colonoscopy. Male sex, age older than 50 years, less than 1.0 cm adenomas diameter and the right colon, or multisegment intestine adenomas were the risk factors for recurrence. This has significance for guiding the follow-up colonoscopy interval time of the patients with intestine adenomas.

Molecular characterization of colorectal adenomas with and without malignancy reveals distinguishing genome, transcriptome and methylome alterations

The majority of colorectal cancer (CRC) arises from precursor lesions known as polyps. The molecular determinants that distinguish benign from malignant polyps remain unclear. To molecularly characterize polyps, we utilized Cancer Adjacent Polyp (CAP) and Cancer Free Polyp (CFP) patients. CAPs had tissues from the residual polyp of origin and contiguous cancer; CFPs had polyp tissues matched to CAPs based on polyp size, histology and dysplasia. To determine whether molecular features distinguish CAPs and CFPs, we conducted Whole Genome Sequencing, RNA-seq, and RRBS on over 90 tissues from 31 patients. CAPs had significantly more mutations, altered expression and hypermethylation compared to CFPs. APC was significantly mutated in both polyp groups, but mutations in TP53, FBXW7, PIK3CA, KIAA1804 and SMAD2 were exclusive to CAPs. We found significant expression changes between CAPs and CFPs in GREM1, IGF2, CTGF, and PLAU, and both expression and methylation alterations in FES and HES1. Integrative analyses revealed 124 genes with alterations in at least two platforms, and ERBB3 and E2F8 showed aberrations specific to CAPs across all platforms. These findings provide a resource of molecular distinctions between polyps with and without cancer, which have the potential to enhance the diagnosis, risk assessment and management of polyps.

Quality is the Key for Emerging Issues of Population-Based Colonoscopy Screening

Colonoscopy is currently regarded as the gold standard and preferred method of screening for colorectal cancer (CRC). However, the benefit of colonoscopy screening may be blunted by low participation rates in population-based screening programs. Harmful effects of population-based colonoscopy screening may include complications induced by colonoscopy itself and by sedation, psychosocial distress, potential over-diagnosis, and socioeconomic burden. In addition, harmful effects of colonoscopy may increase with age and comorbidities. As the risk of adverse events in population-based colonoscopy screening may offset the benefit, the adverse events should be managed and monitored. To adopt population-based colonoscopy screening, consensus on the risks and benefits should be developed, focusing on potential harm, patient preference, socioeconomic considerations, and quality improvement of colonoscopy, as well as efficacy for CRC prevention. As suboptimal colonoscopy quality is a major pitfall of population-based screening, adequate training and regulation of screening colonoscopists should be the first step in minimizing variations in quality. Gastroenterologists should promote quality improvement, auditing, and training for colonoscopy in a population-based screening program.

Detection rate and proximal shift tendency of adenomas and serrated polyps: a retrospective study of 62,560 colonoscopies

PURPOSE

The purpose of this study is to estimate the detection rates of adenomas and serrated polyps and to identify proximalization and associate risk factors in patients from Southern China.

METHODS

Consecutive patients undergoing colonoscopy from 2004 to 2013 in Guangzhou were included. The proportions of proximal adenomas to advanced adenomas and serrated polyps were compared and potential predictors were evaluated.

RESULTS

Colonoscopies (n = 62,560) were performed, and 11,427 patients were diagnosed with polyps. Detection rates for adenomas, hyperplastic polyps, and serrated adenomas were 12.0, 2.5, and 0.2 patients per 100 colonoscopies. When comparing the 1st (2004-2008) to the 2nd period (2009-2013), adenoma and serrated polyp detection in proximal and distal colon both increased significantly (proximal colon [adenoma 3.9 vs. 6.1 patients/100 colonoscopies, P < 0.001; serrated polyp 0.4 vs. 1.1 patients/100 colonoscopies, P < 0.001]; distal colon [adenoma 6.6 vs. 7.2 patients/100 colonoscopies, P = 0.003; serrated polyp 1.2 vs. 2.4 patients/100 colonoscopies, P < 0.001]). Advanced adenoma detection increased over these two periods only in proximal colon (1st vs. 2nd period: 1.5 vs. 2.4 patients/100 colonoscopies, P < 0.001), not the distal colon (P = 0.114). Multivariate analyses showed that diagnostic period was an independent predictor for adenoma proximalization (OR = 1.36, 95% CI 1.25-1.48, P < 0.001), but not for advanced adenomas (P = 0.117) or serrated polyps (P = 0.928).

CONCLUSIONS

Adenomas and serrated polyps were increasingly detected throughout the colon, whereas advanced adenomas were only in proximal colon. A proximal shift tendency detected by colonoscopy was observed for adenomas, but not advanced adenomas or serrated polyps, in Southern China. The screening for proximal polyps should be emphasized and colonoscopy might be a preferred initial screening tool.

[Quality is the Key for Emerging Issues of Population-based Colonoscopy Screening]

Colonoscopy is currently regarded as the gold standard and preferred method of screening for colorectal cancer (CRC). However, the benefit of colonoscopy screening may be blunted by low participation rate in population-based screening program. Harmful effects of population-based colonoscopy screening may include complications induced by colonoscopy itself and by sedation, psychosocial distress, potential over-diagnosis and socioeconomic burden. In addition, harmful effect of colonoscopy may increase with age and comorbidity. As the adverse event risk in population-based colonoscopy screening may offset benefit of the screening colonoscopy, the adverse events associated with screening colonoscopy should be well managed and monitored. To adopt population-based colonoscopy screening, consensus for the risk and benefits of screening colonoscopy should be formed for its potential harms, patient preference, socioeconomic considerations, quality improvement of colonoscopy as well as its efficacy for CRC prevention. As the suboptimal colonoscopy quality is a major pitfall of population-based colonoscopy screening, adequate training and provider regulation for screening colonoscopists should be the first step to minimize the variation of quality between colonoscopists. Gastroenterologists should lead quality improvement, auditing, and training associated with colonoscopy in a population-based colonoscopy screening program.

Three-year colonoscopy surveillance after polypectomy in Korea: a Korean Association for the Study of Intestinal Diseases (KASID) multicenter prospective study

Background/Aims

Colonoscopic surveillance is currently recommended after polypectomy owing to the risk of newly developed colonic neoplasia. However, few studies have investigated colonoscopy surveillance in Asia. This multicenter and prospective study was undertaken to assess the incidence of advanced adenoma based on baseline adenoma findings at 3 years after colonoscopic polypectomy.

Methods

A total of 1,323 patients undergoing colonoscopic polypectomy were prospectively assigned to 3-year colonoscopy surveillance at 11 tertiary endoscopic centers. Relative risks for advanced adenoma after 3 years were calculated according to baseline adenoma characteristics.

Results

Among 1,323 patients enrolled, 387 patients (29.3%) were followed up, and the mean follow-up interval was 31.0±9.8 months. The percentage of patients with advanced adenoma on baseline colonoscopy was higher in the surveillance group compared to the non-surveillance group (34.4% vs. 25.7%). Advanced adenoma recurrence was observed in 17 patients (4.4%) at follow-up. The risk of advanced adenoma recurrence was 2 times greater in patients with baseline advanced adenoma than in those with baseline non-advanced adenoma, though the difference was not statistically significant (6.8% [9/133] vs. 3.1% [8/254], P=0.09). Advanced adenoma recurrence was observed only in males and in subjects aged ≥50 years. In contrast, adenoma recurrence was observed in 187 patients (48.3%) at follow-up. Male sex, older age (≥50 years), and multiple adenomas (≥3) at baseline were independent risk factors for adenoma recurrence.

Conclusions

A colonoscopy surveillance interval of 3 years in patients with baseline advanced adenoma can be considered appropriate.

Quality is the key for emerging issues of population-based colonoscopy screening

Colonoscopy is currently regarded as the gold standard and preferred method of screening for colorectal cancer (CRC). However, the benefit of colonoscopy screening may be blunted by low participation rates in population-based screening programs. Harmful effects of population-based colonoscopy screening may include complications induced by colonoscopy itself and by sedation, psychosocial distress, potential over-diagnosis, and socioeconomic burden. In addition, harmful effects of colonoscopy may increase with age and comorbidities. As the risk of adverse events in population-based colonoscopy screening may offset the benefit, the adverse events should be managed and monitored. To adopt population-based colonoscopy screening, consensus on the risks and benefits should be developed, focusing on potential harm, patient preference, socioeconomic considerations, and quality improvement of colonoscopy, as well as efficacy for CRC prevention. As suboptimal colonoscopy quality is a major pitfall of population-based screening, adequate training and regulation of screening colonoscopists should be the first step in minimizing variations in quality. Gastroenterologists should promote quality improvement, auditing, and training for colonoscopy in a population-based screening program.

Role of baseline adenoma characteristics for adenoma recurrencein patients with high-risk adenoma

Background/aim: The present observational study aimed to determine the predictive value of 3-year recurrence adenoma characteristics at baseline conventional colonoscopy in patients with high-risk adenoma.Materials and methods: A total of 47 patients with high-risk adenoma at baseline colonoscopy were followed up and underwent a surveillance colonoscopy at 3 years. Correlations between adenoma recurrence and baseline adenoma characteristics (size, number, histological features, and location) were analyzed.Results: Among 135 patients with high-risk adenoma, 47 patients (35%) who underwent surveillance colonoscopy at 3 years following baseline colonoscopy were included in the study. In these 47 patients, at least one new adenoma was detected in 19 (40.4%) patients, and new advanced adenomas were detected in 5 (10.6%) patients during the surveillance colonoscopy. No significant difference was found in patients who had adenoma recurrence versus those who did not in terms of size of adenomas (P = 0.143), number of adenomas (P = 0.562), histological properties of adenomas (P = 0.658), or locations of adenomas (P = 0.567).Conclusion: Baseline adenoma characteristics were not associated with the recurrence of adenomas or advanced adenomas in patients with high-risk adenoma.

Clinical impact of surveillance colonoscopy using magnification without diminutive polyp removal

BACKGROUND AND AIM

In Western countries, endoscopic removal of all adenomas during colonoscopy is recommended. The present study evaluates the usefulness of magnifying colonoscopy without removal of diminutive (≤5 mm) colorectal polyps.

METHODS

Patients with diminutive polyps who were observed for over 5 years using magnification at Hiroshima University Hospital were selected retrospectively. Lesions ≥6 mm in size, depressed lesions, and lesions with type V pit pattern were indications for endoscopic resection. We investigated the characteristics of lesions indicated for endoscopic resection detected on surveillance colonoscopy and the risk factors for the incidence of lesions indicated for endoscopic resection.

RESULTS

A total of 706 consecutive patients were enrolled. Sixty-eight lesions indicated for endoscopic resection were detected, averaging 9.0 ± 4.8 mm, and 33 (49%) lesions were located in the right colon. Pathological diagnoses were adenoma, Tis carcinoma, and T1 carcinoma in 58 (85%), eight (12%), and two (3%) lesions, respectively. Five lesions were considered to grow from previously detected diminutive polyps. Relative risks for the incidence of a lesion indicated for endoscopic resection were 1.76 (95% confidence interval [CI], 1.004-3.23) for males compared with females, 3.76 (95% CI, 2.03-7.50) for more than three polyps at initial colonoscopy compared with one polyp, and 2.84 (95% CI, 1.43-5.24) for patients with carcinoma at initial colonoscopy compared with patients with no lesion indicated for endoscopic resection. Nine carcinomas were resected endoscopically.

CONCLUSION

Diminutive low-grade adenomas detected by using magnifying colonoscopy may not necessarily require removal.

Early genetic aberrations in patients with sporadic colorectal cancer

Chromosome instability (CIN) is widely observed in both sporadic and hereditary colorectal cancer (CRC). Defects in APC and WNT signaling are primarily associated with CIN in hereditary CRC, but the genetic causes for CIN in sporadic CRC remain elusive. Using high-density SNP array and exome data from The Cancer Genome Atlas (TCGA), we characterized loss of heterozygosity (LOH) and copy number variation (CNV) in the peripheral blood, normal colon, and corresponding tumor tissue in 15 CRC patients with proficient mismatch repair (MMR) and 24 CRC patients with deficient MMR. We found a high frequency of 18q LOH in tumors and arm-specific enrichment of genetic aberrations on 18q in the normal colon (primarily copy neutral LOH) and blood (primarily copy gain). These aberrations were specific to the sporadic, pMMR CRC. Though in tumor samples genetic aberrations were observed for genes commonly mutated in hereditary CRC (eg, APC, CTNNB1, SMAD4, BRAF), none of them showed LOH or CNV in the normal colon or blood. DCC located on 18q21.1 topped the list of genes with genetic aberrations in the tumor. In an independent cohort of 13 patients subjected to Whole Genome Sequencing (WGS), we found LOH and CNV on 18q in adenomatous polyp and tumor tissues. Our data suggests that patients with sporadic CRC may have genetic aberrations preferentially enriched on 18q in their blood, normal colon epithelium, and non-malignant polyp lesions that may prove useful as a clinical marker for sporadic CRC detection and risk assessment.

Hyperthermia exposure induces apoptosis and inhibits proliferation in HCT116 cells by upregulating miR-34a and causing transcriptional activation of p53

Hyperthermia, as an anticancer therapeutic strategy, presents notable advantages in conjunction with irradiation and/or chemotherapy in the treatment of cancer by promoting apoptosis and inhibiting proliferation. A number of studies have documented that hyperthermia inhibits cancer progression through transcriptional activation of p53, which promotes cell cycle arrest and apoptosis. However, the underlying molecular mechanisms of hyperthermia-regulated apoptosis and proliferation dependent on p53 remain largely unknown. To investigate the effects and molecular mechanism of hyperthermia on the apoptosis and proliferation of colorectal carcinoma (CRC) HCT116 cells, the present study assessed cell apoptosis and proliferation following exposure to hyperthermia (42°C for 2–4 h). The results indicated that, compared with the control group at 0 h, hyperthermia exposure for 2 and 4 h induced the apoptosis of HCT116 cells (P<0.05), inhibited cell proliferation by causing cell cycle arrest at G1/G0 phase (P<0.05), and significantly increased microRNA (miR)-34a expression (P<0.05), but not miR-34b, miR-34c, miR-215 and miR-504 expression. The transcriptional activity of p53 on its consensus sequence and downstream target genes, namely p21, B cell lymphoma 2-associated X protein, mouse double minute 2 homolog, p53 upregulated modulator of apoptosis and growth arrest and DNA-damage-inducible 45α, was subsequently detected. The data indicated significantly higher transcriptional activity of p53 following hyperthermia exposure for 2 and 4 h (P<0.05), and these observations were similar to the effects of transfection with miR-34a mimics in HCT116 cells. Furthermore, transfection with miR-34a antagomiR supressed hyperthermia-induced apoptosis and promoted cell cycle progression following hyperthermia exposure when compared with transfection controls (P<0.05). Collectively, these findings indicate that miR-34a may serve an important role in hyperthermia-regulated apoptosis and proliferation in HCT116 cells by influencing the transcriptional activity of p53.

Clinical impact of non-alcoholic fatty liver disease on the occurrence of colorectal neoplasm: Propensity score matching analysis

The effect of non-alcoholic fatty liver disease (NAFLD) on the occurrences of colorectal neoplasm (CRN) at surveillance colonoscopy is rarely evaluated. We retrospectively reviewed medical records of 1,023 patients who had both index and surveillance colonoscopy at a single institution. The cumulative occurrence rates of overall and advanced CRN at the time of surveillance colonoscopy were compared between patients with and without NAFLD using propensity score matching analysis. In an analysis of matched cohort of 441 patients, the cumulative rates of overall CRN occurrence at 3 and 5 years after index colonoscopy were higher in subjects with NAFLD than in those without NAFLD (9.1% vs. 5.0% & 35.2% vs. 25.3%, P = 0.01). Cox regression analysis showed that NAFLD independently increased the risk of overall CRN occurrence with marginal significance (adjusted hazard ratio [aHR]: 1.31 95% CI: 1.01-1.71, P = 0.05). Additionally, NAFLD was associated with the development of 3 or more adenomas at the time of surveillance colonoscopy (aHR: 2.49, 95% CI: 1.20-5.20, P = 0.02). In subgroup analysis based on index colonoscopy risk categories, the effect of NAFLD on the overall CRN occurrence at the time of surveillance colonoscopy was confined to the normal group (aHR: 1.47, 95% CI: 1.05-2.06, P = 0.02). Regarding advanced CRN occurrences at the time of surveillance colonoscopy, age was the only significant risk factor (aHR: 1.06, 95% CI: 1.02-1.10, P = 0.001). NAFLD was associated with overall CRN occurrence, especially in patients with no adenoma at the index colonoscopy. NAFLD may be considered for the determination of the time-interval for surveillance colonoscopy, especially the patients with negative index colonoscopy findings.

Variability in, and factors associated with, sizing of polyps by endoscopists at a large community practice

BACKGROUND AND AIMS

 Accurate sizing of polyps at time of colonoscopy is critical for determining surveillance intervals. Endoscopists routinely over- or underestimate the size of polyps at colonoscopy. We evaluated the variability in sizing of polyps among multiple endoscopists, and the effect of patient and physician related factors on polyp size estimation in a large community-based practice.

METHODS

 Adult patients who underwent a colonoscopy with polypectomy at five endoscopy centers in Minneapolis/St. Paul by one of 52 endoscopists in 2013 were included in this study. Association of patient, physician, and procedure related factors on polyp sizing was assessed.

RESULTS

 In the study time frame, 38 624 colonoscopies were performed at five ambulatory endoscopy centers. Of these, 16 336 had one or more polyp removed with size information available, and were included in this analysis. There was significant inter-physician variation for estimating polyp sizes larger than 5 mm (intraclass correlation coefficient [ICC] 0.13). Older patient age (OR 1.08, 95 %CI 1.06 - 1.11), and male physician gender (OR 1.92, 95 %CI 1.26 - 2.94) were associated with increased odds of physicians sizing polyps as larger in size. Surveillance procedures had a higher odds of larger polyp sizing compared to screening (OR 0.91, 95 %CI 0.86 - 0.97) and diagnostic procedures (OR 0.86, 95 %CI 0.78 - 0.94).

CONCLUSION

 In a large community setting, variation of polyp sizing estimates exists between physicians. Male physicians were more likely to size polyps as larger in size. Older patients and patients undergoing surveillance procedures were more likely to have polyps that were sized as larger in size.

Genetic Biopsy for Prediction of Surveillance Intervals after Endoscopic Resection of Colonic Polyps: Results of the GENESIS Study

Background and objective

Current surveillance strategies for colorectal cancer following polypectomy are determined by endoscopic and histopathological factors. Such a distinction has been challenged. The present study was designed to identify molecular parameters in colonic polyps potentially defining new sub-groups at risk.

Methods

One hundred patients were enrolled in this multicentre study. Polyps biopsies underwent formalin-free processing (PAXgene, PreAnalytiX) and targeted next generation sequencing (38 genes (QIAGEN), NextSeq 500 platform (Illumina)). Genetic and histopathological analyses were done blinded to other data.

Results

In 100 patients, 224 polyps were removed. Significant associations of genetic alterations with endoscopic or histological polyp characteristics were observed for BRAF, KRAS, TCF7L2, FBXW7 and CTNNB1 mutations. Multivariate analysis revealed that polyps ≥ 10 mm have a significant higher relative risk for harbouring oncogene mutations (relative risk 3.467 (1.742-6.933)). Adenomas and right-sided polyps are independent risk factors for CTNNB1 mutations (relative risk 18.559 (2.371-145.245) and 12.987 (1.637-100.00)).

Conclusions

Assessment of the mutational landscape of polyps can be integrated in the workflow of current colonoscopy practice. There are distinct genetic patterns related to polyp size and location. These results suffice to optimise individual risk calculation and may help to better define surveillance intervals.

Histopathological analysis of cold snare polypectomy and its indication for colorectal polyps 10-14 mm in diameter

BACKGROUND AND AIM

Cold snare polypectomy (CSP) is commonly used for treating colorectal polyps <10 mm in diameter. We evaluated the analysis and safety of CSP for larger polyps.

METHODS

We retrospectively analyzed 1006 colorectal polyps resected with CSP. Indication for CSP was polyps 2-14 mm that were diagnosed as benign neoplastic polyp by magnifying endoscopy. Various clinicopathological characteristics were analyzed. Multivariate analyses were used to determine the independent risk factors for failure of complete CSP resection. With respect to polyp size, we compared the therapeutic outcomes between polyps <10 mm and ≥10 mm. Additionally, the presence of muscularis mucosa in resected specimens was analyzed.

RESULTS

Rates of en bloc resection and postoperative hemorrhage were 98.8% and 0.1%, respectively. Seven hundred and ninety-one neoplastic lesions were analyzed and negative margins were found in 70.5% of the lesions, Multivariate analysis showed that non-polypoid morphology, histology of intramucosal cancer + high-grade adenoma and sessile serrated adenoma and polyp were significant factors for incomplete resection. With respect to the difference between lesions ≥10 mm than in those <10 mm, rates of cancer and positive/unclear margins were significantly higher (5.0% vs 0.9%, P < 0.001; 40.6% vs 27.7%, P = 0.007) in the ≥10 mm with rates of postoperative hemorrhage not significantly different (0.8% vs 0.0%). Additionally, the loss of muscularis mucosa was found in 27.8% of all lesions.

CONCLUSION

CSP is a safe procedure for polyps 2-14 mm. However, CSP has limitations in terms of the histopathological margin and loss of muscularis mucosa in specimens.

Risk factors of nonadherence to colonoscopy surveillance after polypectomy and its impact on clinical outcomes: a KASID multicenter study

BACKGROUND

An optimal surveillance program is important to prevent advanced colorectal neoplasm. In this context, we have evaluated the cumulative risk of high-risk adenoma (HRA) or colorectal cancer (CRC) according to surveillance interval time after polypectomy. In addition, we assessed risk factors for late surveillance to determine whether late surveillance can impact the risk of subsequent advanced colorectal neoplasm.

METHODS

This was a multicenter retrospective cohort study involving 3562 subjects who had undergone removal of at least one adenoma at the index colonoscopy and who subsequently underwent a surveillance colonoscopy. The subjects were classified into an early, appropriate or late group depending on the timing of the surveillance colonoscopy, performed using modified U.S.

RESULTS

With 3% of the study population with LRA and HRA at the index colonoscopy going on to develop HRA or CRC, the estimated surveillance intervals calculated would be 6.3 [95% confidence interval (CI) 5.42-7.10] years and 3.1 (95% CI 2.61-4.45) years, respectively. The predictors of late surveillance were female gender [odd ratio (OR) 1.21; 95% CI 1.04-1.40], having undergone the procedure in small-to-medium-sized cities (OR 1.92; 95% CI 1.36-2.72) and HRA at index colonoscopy (OR 1.37; 95% CI 1.19-1.59). The risk factors for subsequent HRA or CRC were late surveillance (OR 1.34; 95% CI 1.03-1.74), male gender (OR 2.13; 95% CI 1.54-2.95), having undergone the procedure in small-to-medium-sized cities (OR 1.63; 95% CI 1.11-2.40) and HRA at index colonoscopy (OR 2.60; 95% CI 2.04-3.33).

CONCLUSIONS

Women, having undergone the procedure in small-to-medium-sized cities and the presence of an HRA at the index colonoscopy were found to be independent risk factors for late surveillance colonoscopy. Late surveillance is significantly predictive of subsequent HRA or CRC.

Factors Associated With Shorter Colonoscopy Surveillance Intervals for Patients With Low-Risk Colorectal Adenomas and Effects on Outcome

BACKGROUND & AIMS

Endoscopists do not routinely follow guidelines to survey individuals with low-risk adenomas (LRAs; 1-2 small tubular adenomas, < 1 cm) every 5-10 years for colorectal cancer; many recommend shorter surveillance intervals for these individuals. We aimed to identify the reasons that endoscopists recommend shorter surveillance intervals for some individuals with LRAs and determine whether timing affects outcomes at follow-up examinations.

METHODS

We collected data from 1560 individuals (45-75 years old) who participated in a prospective chemoprevention trial (of vitamin D and calcium) from 2004 through 2008. Participants in the trial had at least 1 adenoma, detected at their index colonoscopy, and were recommended to receive follow-up colonoscopy examinations at 3 or 5 years after adenoma identification, as recommended by the endoscopist. For this analysis we collected data from only participants with LRAs. These data included characteristics of participants and endoscopists and findings from index and follow-up colonoscopies. Primary endpoints were frequency of recommending shorter (3-year) vs longer (5-year) surveillance intervals, factors associated with these recommendations, and effect on outcome, determined at the follow-up colonoscopy.

RESULTS

A 3-year surveillance interval was recommended for 594 of the subjects (38.1%). Factors most significantly associated with recommendation of 3-year vs a 5-year surveillance interval included African American race (relative risk [RR] to white, 1.41; 95% confidence interval [CI], 1.14-1.75), Asian/Pacific Islander ethnicity (RR to white, 1.7; 95% CI, 1.22-2.43), detection of 2 adenomas at the index examination (RR vs 1 adenoma, 1.47; 95% CI, 1.27-1.71), more than 3 serrated polyps at the index examination (RR=2.16, 95% CI, 1.59-2.93), or index examination with fair or poor quality bowel preparation (RR vs excellent quality, 2.16; 95% CI, 1.66-2.83). Other factors that had a significant association with recommendation for a 3-year surveillance interval included family history of colorectal cancer and detection of 1-2 serrated polyps at the index examination. In comparisons of outcomes, we found no significant differences between the 3-year vs 5-year recommendation groups in proportions of subjects found to have 1 or more adenomas (38.8% vs 41.7% respectively; P = .27), advanced adenomas (7.7% vs 8.2%; P = .73) or clinically significant serrated polyps (10.0% vs 10.3%; P = .82) at the follow-up colonoscopy.

CONCLUSIONS

Possibly influenced by patients' family history, race, quality of bowel preparation, or number or size of polyps, endoscopists frequently recommend 3-year surveillance intervals instead of guideline-recommended intervals of 5 years or longer for individuals with LRAs. However, at the follow-up colonoscopy, similar proportions of participants have 1 or more adenomas, advanced adenomas, or serrated polyps. These findings support the current guideline recommendations of performing follow-up examinations of individuals with LRAs at least 5 years after the index colonoscopy.

A randomised controlled trial to assess the cost-effectiveness of intensive versus no scheduled follow-up in patients who have undergone resection for colorectal cancer with curative intent

BACKGROUND

Intensive follow-up after surgery for colorectal cancer is common practice but lacks a firm evidence base.

OBJECTIVE

To assess whether or not augmenting symptomatic follow-up in primary care with two intensive methods of follow-up [monitoring of blood carcinoembryonic antigen (CEA) levels and scheduled imaging] is effective and cost-effective in detecting the recurrence of colorectal cancer treatable surgically with curative intent.

DESIGN

Randomised controlled open-label trial. Participants were randomly assigned to one of four groups: (1) minimum follow-up (n = 301), (2) CEA testing only (n = 300), (3) computerised tomography (CT) only (n = 299) or (4) CEA testing and CT (n = 302). Blood CEA was measured every 3 months for 2 years and then every 6 months for 3 years; CT scans of the chest, abdomen and pelvis were performed every 6 months for 2 years and then annually for 3 years. Those in the minimum and CEA testing-only arms had a single CT scan at 12-18 months. The groups were minimised on adjuvant chemotherapy, gender and age group (three strata).

SETTING

Thirty-nine NHS hospitals in England with access to high-volume services offering surgical treatment of metastatic recurrence.

PARTICIPANTS

A total of 1202 participants who had undergone curative treatment for Dukes' stage A to C colorectal cancer with no residual disease. Adjuvant treatment was completed if indicated. There was no evidence of metastatic disease on axial imaging and the post-operative blood CEA level was ≤ 10 µg/l.

MAIN OUTCOME MEASURES

Primary outcome Surgical treatment of recurrence with curative intent. Secondary outcomes Time to detection of recurrence, survival after treatment of recurrence, overall survival and quality-adjusted life-years (QALYs) gained.

RESULTS

Detection of recurrence During 5 years of scheduled follow-up, cancer recurrence was detected in 203 (16.9%) participants. The proportion of participants with recurrence surgically treated with curative intent was 6.3% (76/1202), with little difference according to Dukes' staging (stage A, 5.1%; stage B, 7.4%; stage C, 5.6%; p = 0.56). The proportion was two to three times higher in each of the three more intensive arms (7.5% overall) than in the minimum follow-up arm (2.7%) (difference 4.8%; p = 0.003). Surgical treatment of recurrence with curative intent was 2.7% (8/301) in the minimum follow-up group, 6.3% (19/300) in the CEA testing group, 9.4% (28/299) in the CT group and 7.0% (21/302) in the CEA testing and CT group. Surgical treatment of recurrence with curative intent was two to three times higher in each of the three more intensive follow-up groups than in the minimum follow-up group; adjusted odds ratios (ORs) compared with minimum follow-up were as follows: CEA testing group, OR 2.40, 95% confidence interval (CI) 1.02 to 5.65; CT group, OR 3.69, 95% CI 1.63 to 8.38; and CEA testing and CT group, OR 2.78, 95% CI 1.19 to 6.49. Survival A Kaplan-Meier survival analysis confirmed no significant difference between arms (log-rank p = 0.45). The baseline-adjusted Cox proportional hazards ratio comparing the minimum and intensive arms was 0.87 (95% CI 0.67 to 1.15). These CIs suggest a maximum survival benefit from intensive follow-up of 3.8%. Cost-effectiveness The incremental cost per patient treated surgically with curative intent compared with minimum follow-up was £40,131 with CEA testing, £43,392 with CT and £85,151 with CEA testing and CT. The lack of differential impact on survival resulted in little difference in QALYs saved between arms. The additional cost per QALY gained of moving from minimum follow-up to CEA testing was £25,951 and for CT was £246,107. When compared with minimum follow-up, combined CEA testing and CT was more costly and generated fewer QALYs, resulting in a negative incremental cost-effectiveness ratio (-£208,347) and a dominated policy.

LIMITATIONS

Although this is the largest trial undertaken at the time of writing, it has insufficient power to assess whether or not the improvement in detecting treatable recurrence achieved by intensive follow-up leads to a reduction in overall mortality.

CONCLUSIONS

Rigorous staging to detect residual disease is important before embarking on follow-up. The benefit of intensive follow-up in detecting surgically treatable recurrence is independent of stage. The survival benefit from intensive follow-up is unlikely to exceed 4% in absolute terms and harm cannot be absolutely excluded. A longer time horizon is required to ascertain whether or not intensive follow-up is an efficient use of scarce health-care resources. Translational analyses are under way, utilising tumour tissue collected from Follow-up After Colorectal Surgery trial participants, with the aim of identifying potentially prognostic biomarkers that may guide follow-up in the future.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN41458548.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 32. See the NIHR Journals Library website for further project information.

CT colonography: role in FOBT-based screening programs for colorectal cancer

Computed tomographic colonography (CTC) is a minimally invasive imaging examination for the colon, and is safe, well tolerated and accurate for the detection of colorectal cancer (CRC) and advanced adenoma. While the role of CTC as a primary test for population screening of CRC is under investigation, the fecal occult blood test (FOBT) has been recommended for population screening of CRC in Europe. Subjects with positive FOBT are invited to undergo total colonoscopy, which has some critical issues, such as suboptimal compliance, contraindications and the possibility of an incomplete exploration of the colon. Based on available data, the integration of CTC in FOBT-based population screening programs for CRC may fall into three scenarios. First, CTC is recommended in FOBT-positive subjects when colonoscopy is refused, incomplete or contraindicated. For these indications CTC should replace double-contrast barium enema. Second, conversely, CTC is not currently recommended as a second-level examination prior to colonoscopy in all FOBT-positive subjects, as this strategy is most probably not cost-effective. Finally, CTC may be considered instead of colonoscopy for surveillance after adenoma removal, but specific studies are needed.

The clinical effectiveness of different surveillance strategies to prevent colorectal cancer in people with intermediate-grade colorectal adenomas: a retrospective cohort analysis, and psychological and economic evaluations

BACKGROUND

The UK guideline recommends 3-yearly surveillance for patients with intermediate-risk (IR) adenomas. No study has examined whether or not this group has heterogeneity in surveillance needs.

OBJECTIVES

To examine the effect of surveillance on colorectal cancer (CRC) incidence; assess heterogeneity in risk; and identify the optimum frequency of surveillance, the psychological impact of surveillance, and the cost-effectiveness of alternative follow-up strategies.

DESIGN

Retrospective multicentre cohort study.

SETTING

Routine endoscopy and pathology data from 17 UK hospitals (n = 11,944), and a screening data set comprising three pooled cohorts (n = 2352), followed up using cancer registries.

SUBJECTS

Patients with IR adenoma(s) (three or four small adenomas or one or two large adenomas).

PRIMARY OUTCOMES

Advanced adenoma (AA) and CRC detected at follow-up visits, and CRC incidence after baseline and first follow-up.

METHODS

The effects of surveillance on long-term CRC incidence and of interval length on findings at follow-up were examined using proportional hazards and logistic regression, adjusting for patient, procedural and polyp characteristics. Lower-intermediate-risk (LIR) subgroups and higher-intermediate-risk (HIR) subgroups were defined, based on predictors of CRC risk. A model-based cost-utility analysis compared 13 surveillance strategies. Between-group analyses of variance were used to test for differences in bowel cancer worry between screening outcome groups (n = 35,700). A limitation of using routine hospital data is the potential for missed examinations and underestimation of the effect of interval and surveillance.

RESULTS

In the hospital data set, 168 CRCs occurred during 81,442 person-years (pys) of follow-up [206 per 100,000 pys, 95% confidence interval (CI) 177 to 240 pys]. One surveillance significantly lowered CRC incidence, both overall [hazard ratio (HR) 0.51, 95% CI 0.34 to 0.77] and in the HIR subgroup (n = 9265; HR 0.50, 95% CI 0.34 to 0.76). In the LIR subgroup (n = 2679) the benefit of surveillance was less clear (HR 0.62, 95% CI 0.16 to 2.43). Additional surveillance lowered CRC risk in the HIR subgroup by a further 15% (HR 0.36, 95% CI 0.20 to 0.62). The odds of detecting AA and CRC at first follow-up (FUV1) increased by 18% [odds ratio (OR) 1.18, 95% CI 1.12 to 1.24] and 32% (OR 1.32, 95% CI 1.20 to 1.46) per year increase in interval, respectively, and the odds of advanced neoplasia at second follow-up increased by 22% (OR 1.22, 95% CI 1.09 to 1.36), after adjustment. Detection rates of AA and CRC remained below 10% and 1%, respectively, with intervals to 3 years. In the screening data set, 32 CRCs occurred during 25,745 pys of follow-up (124 per 100,000 pys, 95% CI 88 to 176 pys). One follow-up conferred a significant 73% reduction in CRC incidence (HR 0.27, 95% CI 0.10 to 0.71). Owing to the small number of end points in this data set, no other outcome was significant. Although post-screening bowel cancer worry was higher in people who were offered surveillance, worry was due to polyp detection rather than surveillance. The economic evaluation, using data from the hospital data set, suggested that 3-yearly colonoscopic surveillance without an age cut-off would produce the greatest health gain.

CONCLUSIONS

A single surveillance benefited all IR patients by lowering their CRC risk. We identified a higher-risk subgroup that benefited from further surveillance, and a lower-risk subgroup that may require only one follow-up. A surveillance interval of 3 years seems suitable for most IR patients. These findings should be validated in other studies to confirm whether or not one surveillance visit provides adequate protection for the lower-risk subgroup of intermediate-risk patients.

STUDY REGISTRATION

Current Controlled Trials ISRCTN15213649.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Risk stratification of individuals with low-risk colorectal adenomas using clinical characteristics: a pooled analysis

OBJECTIVE

For individuals with 1-2 small (<1 cm) low-risk colorectal adenomas, international guidelines range from no surveillance to offering surveillance colonoscopy in 5-10 years. We hypothesised that the risks for metachronous advanced neoplasia (AN) among patients with low-risk adenomas differ based on clinical factors distinct from those currently used.

DESIGN

We pooled data from seven prospective studies to assess the risk of metachronous AN. Two groups with 1-2 small adenomas were defined based on guidelines from the UK (n=4516) or the European Union (EU)/US (n=2477).

RESULTS

Absolute risk of metachronous AN ranged from a low of 2.9% to a high of 12.2%, depending on specific risk factor and guideline used. For the UK group, the highest absolute risks for metachronous AN were found among individuals with a history of prior polyp (12.2%), villous histology (12.2%), age ≥70 years (10.9%), high-grade dysplasia (10.9%), any proximal adenoma (10.2%), distal and proximal adenoma (10.8%) or two adenomas (10.1%). For the EU/US group, the highest absolute risks for metachronous AN were among individuals with a history of prior polyp (11.5%) or the presence of both proximal and distal adenomas (11.0%). In multivariate analyses, strong associations for increasing age and history of prior polyps and odds of metachronous AN were observed, whereas more modest associations were shown for baseline proximal adenomas and those with villous features.

CONCLUSIONS

Risks of metachronous AN among individuals with 1-2 small adenomas vary according to readily available clinical characteristics. These characteristics may be considered for recommending colonoscopy surveillance and require further investigation.

Indomethacin therapy effective in a patient with depletion syndrome from secretory villous adenoma

This paper details the case of a 26-year-old woman with depletion syndrome and the effectiveness of her treatment with indomethacin. Villous adenomas are benign neoplasms with a high incidence of becoming malignant. A small percentage of villous adenomas are known to cause depletion syndrome, also referred to as the McKittrick-Wheelock syndrome, a condition characterised by secretory diarrhoea, dehydration, hyponatremia, hypokalaemia, hypochloraemia, metabolic acidosis and acute renal failure. Prostaglandin-E2 mediates the hypersecretion mechanism observed in depletion syndrome, and can be inhibited by cyclo-oxygenase inhibitors. This case study measured the effectiveness of prostaglandin inhibition on a patient with oral and parenteral electrolyte replacement refractory depletion syndrome. Fluid loss and prostaglandin levels were measured before and after pharmacological treatment. This case demonstrates a 49% decrease in rectal effluent and a marked commensurate decrease in daily replenishment requirements within 48 hours of indomethacin treatment initiation, resulting in subsequent electrolyte stabilisation.

Dietary fibre for the prevention of recurrent colorectal adenomas and carcinomas

BACKGROUND

This is an update of the Cochrane review published in 2002.Colorectal cancer (CRC) is a major cause of morbidity and mortality in industrialised countries. Experimental evidence has supported the hypothesis that dietary fibre may protect against the development of CRC, although epidemiologic data have been inconclusive.

OBJECTIVES

To assess the effect of dietary fibre on the recurrence of colorectal adenomatous polyps in people with a known history of adenomatous polyps and on the incidence of CRC compared to placebo. Further, to identify the reported incidence of adverse effects, such as abdominal pain or diarrhoea, that resulted from the fibre intervention.

SEARCH METHODS

We identified randomised controlled trials (RCTs) from Cochrane Colorectal Cancer's Specialised Register, CENTRAL, MEDLINE and Embase (search date, 4 April 2016). We also searched ClinicalTrials.gov and WHO International Trials Registry Platform on October 2016.

SELECTION CRITERIA

We included RCTs or quasi-RCTs. The population were those having a history of adenomatous polyps, but no previous history of CRC, and repeated visualisation of the colon/rectum after at least two-years' follow-up. Dietary fibre was the intervention. The primary outcomes were the number of participants with: 1. at least one adenoma, 2. more than one adenoma, 3. at least one adenoma greater than or equal to 1 cm, or 4. a new diagnosis of CRC. The secondary outcome was the number of adverse events.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data, assessed trial quality and resolved discrepancies by consensus. We used risk ratios (RR) and risk difference (RD) with 95% confidence intervals (CI) to measure the effect. If statistical significance was reached, we reported the number needed to treat for an additional beneficial outcome (NNTB) or harmful outcome (NNTH). We combined the study data using the fixed-effect model if it was clinically, methodologically, and statistically reasonable.

MAIN RESULTS

We included seven studies, of which five studies with 4798 participants provided data for analyses in this review. The mean ages of the participants ranged from 56 to 66 years. All participants had a history of adenomas, which had been removed to achieve a polyp-free colon at baseline. The interventions were wheat bran fibre, ispaghula husk, or a comprehensive dietary intervention with high fibre whole food sources alone or in combination. The comparators were low-fibre (2 to 3 g per day), placebo, or a regular diet. The combined data showed no statistically significant difference between the intervention and control groups for the number of participants with at least one adenoma (5 RCTs, n = 3641, RR 1.04, 95% CI 0.95 to 1.13, low-quality evidence), more than one adenoma (2 RCTs, n = 2542, RR 1.06, 95% CI 0.94 to 1.20, low-quality evidence), or at least one adenoma 1 cm or greater (4 RCTs, n = 3224, RR 0.99, 95% CI 0.82 to 1.20, low-quality evidence) at three to four years. The results on the number of participants diagnosed with colorectal cancer favoured the control group over the dietary fibre group (2 RCTS, n = 2794, RR 2.70, 95% CI 1.07 to 6.85, low-quality evidence). After 8 years of comprehensive dietary intervention, no statistically significant difference was found in the number of participants with at least one recurrent adenoma (1 RCT, n = 1905, RR 0.97, 95% CI 0.78 to 1.20), or with more than one adenoma (1 RCT, n = 1905, RR 0.89, 95% CI 0.64 to 1.24). More participants given ispaghula husk group had at least one recurrent adenoma than the control group (1 RCT, n = 376, RR 1.45, 95% CI 1.01 to 2.08). Other analyses by types of fibre intervention were not statistically significant. The overall dropout rate was over 16% in these trials with no reasons given for these losses. Sensitivity analysis incorporating these missing data shows that none of the results can be considered as robust; when the large numbers of participants lost to follow-up were assumed to have had an event or not, the results changed sufficiently to alter the conclusions that we would draw. Therefore, the reliability of the findings may have been compromised by these missing data (attrition bias) and should be interpreted with caution.

AUTHORS' CONCLUSIONS

There is a lack of evidence from existing RCTs to suggest that increased dietary fibre intake will reduce the recurrence of adenomatous polyps in those with a history of adenomatous polyps within a two to eight year period. However, these results may be unreliable and should be interpreted cautiously, not only because of the high rate of loss to follow-up, but also because adenomatous polyp is a surrogate outcome for the unobserved true endpoint CRC. Longer-term trials with higher dietary fibre levels are needed to enable confident conclusion.

Colon adenoma features and their impact on risk of future advanced adenomas and colorectal cancer

AIM

To review the evidence on the association between specific colon adenoma features and the risk of future colonic neoplasia [adenomas and colorectal cancer (CRC)].

METHODS

We performed a literature search using the National Library of Medicine through PubMed from 1/1/2003 to 5/30/2015. Specific Medical Subject Headings terms (colon, colon polyps, adenomatous polyps, epidemiology, natural history, growth, cancer screening, colonoscopy, CRC) were used in conjunction with subject headings/key words (surveillance, adenoma surveillance, polypectomy surveillance, and serrated adenoma). We defined non-advanced adenomas as 1-2 adenomas each < 10 mm in size and advanced adenomas as any adenoma ≥ 10 mm size or with > 25% villous histology or high-grade dysplasia. A combined endpoint of advanced neoplasia included advanced adenomas and invasive CRC.

RESULTS

Our search strategy identified 592 candidate articles of which 8 met inclusion criteria and were relevant for assessment of histology (low grade vs high grade dysplasia, villous features) and adenoma size. Six of these studies met the accepted quality indicator threshold for overall adenoma detection rate > 25% among study patients. We found 254 articles of which 7 met inclusion criteria for the evaluation of multiple adenomas. Lastly, our search revealed 222 candidate articles of which 6 met inclusion criteria for evaluation of serrated polyps. Our review found that villous features, high grade dysplasia, larger adenoma size, and having ≥ 3 adenomas at baseline are associated with an increased risk of future colonic neoplasia in some but not all studies. Serrated polyps in the proximal colon are associated with an increased risk of future colonic neoplasia, comparable to having a baseline advanced adenoma.

CONCLUSION

Data on adenoma features and risk of future adenomas and CRC are compelling yet modest in absolute effect size. Future research should refine this risk stratification.

Surveillance after colorectal polyp removal

Surveillance colonoscopy is aimed to reduce CRC incidence and mortality by removing adenomas and detecting CRC in early stage. However, colonoscopy is an invasive and expensive procedure and surveillance colonoscopy should be targeted at those who are most likely to benefit at the minimum frequency required to protect for cancer. Surveillance recommendations are based on guidelines, but the recommendations in those guidelines are based on moderate to low quality evidence and adherence to these guidelines is poor. As surveillance colonoscopy is one of the main indications for colonoscopy and surveillance colonoscopies are filling colonoscopy lists, the current surveillance practice results in spending lots of money and capacity in a suboptimal way. Randomized controlled trials to compare surveillance intervals are not available. However, current evidence based on several case-control and cohort studies suggests there is no need for surveillance in patients with low-risk adenomas, i.e. 1-2 adenomas smaller than 10 mm. Patients with 3 or more adenomas or any adenoma larger than 10 mm seem to be the ones at real risk for metachronous adenomas or cancer. In those patients, surveillance colonoscopy is indicated at 3 years after baseline until ongoing studies will confirm the safety of enlarging this interval. Randomized controlled trials and experimental research are important in order to provide the necessary scientific evidence for the optimization of follow-up strategies for patients with adenomas and serrated polyps.

Adenoma Detection Rate: I Will Show You Mine if You Show Me Yours

BACKGROUND

Colorectal cancer (CRC) is the first cause of cancer-related mortality in Portugal. CRC screening reduces disease-specific mortality. Colonoscopy is currently the preferred method for screening as it may contribute to the reduction of CRC incidence. This beneficial effect is strongly associated with the adenoma detection rate (ADR).

AIM

Our aim was to evaluate the quality of colonoscopy at our unit by measuring the currently accepted quality parameters and publish them as benchmarking indicators.

METHODS

From 5,860 colonoscopies, 654 screening procedures (with and without previous fecal occult blood testing) were analyzed.

RESULTS

The mean age of the patients was 66.4 ± 7.8 years, and the gender distribution was 1:1. The overall ADR was 36% (95% confidence interval [CI] 32-39), the mean number of adenomas per colonoscopy was 0.66 (95% CI 0.56-0.77), and the sessile serrate lesion detection rate was 1% (95% CI 0-2). The bowel preparation was rated as adequate in 496 (76%) patients. The adjusted cecal intubation rate (CIR) was 93.7% (95% CI 91.7-95.8). Most colonoscopies were performed under monitored anesthesia care (53%), and 35% were unsedated. The use of sedation (propofol or midazolam based) was associated with a higher CIR with an odds ratio of 3.60 (95% CI 2.02-6.40, p < 0.001).

CONCLUSION

Our data show an above-standard ADR. The frequency of poor bowel preparation and the low sessile serrated lesion detection rate were acknowledged, and actions were implemented to improve both indicators. Quality auditing in colonoscopy should be compulsory, and while many units may do so internally, this is the first national report from a high-throughput endoscopy unit.

A Review of Outcomes for Colorectal Adenomas

OBJECTIVES

Using data from former reports, this study reviews and analyzes the outcomes of tumor recurrence, tumor progression, and tumor-specific survival of patients with colorectal adenomas.

METHODS

Data were collected from 32 longitudinal studies of outcomes after the first diagnosis of colorectal adenoma and collected as individual patient results, that is, as failure times from the first tumor to the three outcomes. Altogether, there were 45,286 patients, including 22,148 for the outcome of additional adenomas, 23,796 for the outcome of progression to invasive carcinoma, and 2,602 for the outcome of disease-specific survival (some patients were available for more than one outcome).

RESULTS

In these data, the mean time to additional adenomas was 6 years, the mean time to invasive carcinoma was 15.9 years, and the mean tumor-specific survival time was 21.9 years.

CONCLUSIONS

Although greater than 50% of those with colorectal adenomas will have additional adenomas, few progress to invasive tumor or die of colorectal cancer.

Consequences of Increasing Time to Colonoscopy Examination After Positive Result From Fecal Colorectal Cancer Screening Test

BACKGROUND & AIMS

Delays in diagnostic testing after a positive result from a screening test can undermine the benefits of colorectal cancer (CRC) screening, but there are few empirical data on the effects of such delays. We used microsimulation modeling to estimate the consequences of time to colonoscopy after a positive result from a fecal immunochemical test (FIT).

METHODS

We used an established microsimulation model to simulate an average-risk United States population cohort that underwent annual FIT screening (from ages 50 to 75 years), with follow-up colonoscopy examinations for individuals with positive results (cutoff, 20 μg/g) at different time points in the following 12 months. Main evaluated outcomes were CRC incidence and mortality; additional outcomes were total life-years lost and net costs of screening.

RESULTS

For individuals who underwent diagnostic colonoscopy within 2 weeks of a positive result from an FIT, the estimated lifetime risk of CRC incidence was 35.5/1000 persons, and mortality was 7.8/1000 persons. Every month added until colonoscopy was associated with a 0.1/1000 person increase in cancer incidence risk (an increase of 0.3%/month, compared with individuals who received colonoscopies within 2 weeks) and mortality risk (increase of 1.4%/month). Among individuals who received colonoscopy examinations 12 months after a positive result from an FIT, the incidence of CRC was 37.0/1000 persons (increase of 4%, compared with 2 weeks), and mortality was 9.1/1000 persons (increase of 16%). Total years of life gained for the entire screening cohort decreased from an estimated 93.7/1000 persons with an almost immediate follow-up colonoscopy (cost savings of $208 per patient, compared with no colonoscopy) to 84.8/1000 persons with follow-up colonoscopies at 12 months (decrease of 9%; cost savings of $100/patient, compared with no colonoscopy).

CONCLUSIONS

By using a microsimulation model of an average-risk United States screening cohort, we estimated that delays of up to 12 months after a positive result from an FIT can produce proportional losses of up to nearly 10% in overall screening benefits. These findings indicate the importance of timely follow-up colonoscopy examinations of patients with positive results from FITs.

Laparoscopic-assisted colonoscopy: results and follow-up endoscopic success

AIM

Incomplete colonoscopy occurs in 8-10% of attempted examinations. An incomplete colonoscopy is usually followed by radiological evaluation of the large bowel to complete the colonic assessment. Patients then found to have polyps of > 1 cm represent a significant management dilemma. This study describes our experience using laparoscopy to facilitate complete colonoscopy and polypectomy in patients with fixed angulation and the success of subsequent colonoscopies.

METHOD

All patients from 2008 to 2012 with an incomplete colonoscopy because of fixed angulation and with polyps detected by subsequent imaging underwent standard laparoscopy with colonic mobilization by division of adhesions to facilitate direct vision. Completion of colonoscopy and polypectomy, intra-operative complications, postoperative morbidity and successful standard follow-up colonoscopy were studied.

RESULTS

Twelve patients underwent the procedure. Complete colonoscopy to caecum was successful in all, with a median of 2 (range 1-5) polyps per patient and a mean polyp size of 22 mm. One iatrogenic enterotomy was repaired immediately, with no sequelae. Ten patients have since undergone colonoscopy under sedation, with complete colonic evaluation possible in nine of the patients.

CONCLUSION

Laparoscopic-assisted colonoscopy allows safe polypectomy in patients with incomplete colonoscopy, without the need for segmental resection. This less-invasive procedure yields recovery times similar to those of colonoscopy alone, avoiding the morbidity of a segmental resection with the added benefit of successful routine colonoscopy in the future.