Case-control study supports extension of surveillance interval after colonoscopic polypectomy to at least 5 yr

The association between colorectal sessile serrated adenomas/polyps and subsequent advanced colorectal neoplasia

PURPOSE

Colorectal cancer (CRC) screening guidelines recommend increased surveillance of individuals with sessile serrated adenomas/polyps (SSA/Ps), but there is uncertainty about the risk associated with SSA/Ps. We aimed to determine the association between SSA/Ps and subsequent advanced colorectal neoplasia.

METHODS

This case-control study included Kaiser Permanente Washington (KPWA) members who received an index colonoscopy between 1/1/1998 and 12/31/2007, and had hyperplastic polyps (HPs) or SSA/Ps but no conventional adenomas according to study pathologist histologic review. Subsequent pathology reports and biopsies through 1/1/2013 were reviewed for advanced colorectal neoplasia. We linked to the Seattle-Puget Sound Surveillance Epidemiology and End Results (SEER) registry to identify additional CRC cases. We used generalized estimating equations with a logit link to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for advanced colorectal neoplasia, comparing those with SSA/Ps to those with HPs.

RESULTS

There were 161 individuals with index SSA/Ps, 548 with HPs, and 918 subsequent endoscopies included in analyses. Of those with index SSA/Ps, 19 had subsequent advanced colorectal neoplasia; 39 with HPs had subsequent advanced colorectal neoplasia. Compared to those with HPs, those with SSA/Ps were not statistically significantly more likely to have subsequent advanced colorectal neoplasia (adjusted OR 1.79; CI 0.98-3.28). Polyp size ≥ 10 mm, right colon location, and the presence of multiple serrated polyps were also not associated with advanced colorectal neoplasia.

CONCLUSIONS

Our results suggest that there is not a strong association between SSA/Ps and subsequent advanced colorectal neoplasia during the 5 years following SSA/P removal.

Biomarker discovery study of inflammatory proteins for colorectal cancer early detection demonstrated importance of screening setting validation

OBJECTIVES

Most studies identifying inflammatory markers for early detection of colorectal cancer (CRC) were conducted using clinically manifest cases. We aimed to identify circulating inflammatory biomarkers for early detection of CRC and validate them in both a clinical setting and a true screening setting.

STUDY DESIGN AND SETTING

A total of 92 inflammatory proteins were quantified in baseline plasma samples from individuals clinically diagnosed with CRC and neoplasm-free controls matched on age and sex (training set). A multimarker panel was selected and evaluated in samples from another clinical setting (validation set C) and a screening setting (validation set S).

RESULTS

In the training set (N = 330), a five-biomarker signature was selected that provided an area under curve (AUC) of 0.85 and 60.9% sensitivity to detect CRC at 90% specificity. When this algorithm was applied to validation set C (N = 318), the AUC (0.80) and sensitivity (49.5%) at 90% specificity for CRC diagnosis were only slightly lower than those in the training set. By contrast, the diagnostic performance of the algorithm in validation set S (N = 126) from a true screening setting was much poorer, with an AUC of 0.59 and a sensitivity of 28.6% at 90% specificity.

CONCLUSIONS

An inflammation-related protein panel with apparently good diagnostic properties for CRC detection was identified and confirmed in an independent clinical validation set. However, the biomarker combination performed substantially worse in a validation sample from a true screening setting. Our results underline the importance of validation in screening settings subsequently to novel signature discovery for cancer early detection.

Molecular characteristics of colorectal serrated polyps and hyperplastic polyps: A STROBE compliant article

The serrated neoplasia pathway of colorectal carcinogenesis is characterized by BRAF mutation and aberrant DNA methylation, which have not been reported on Korean patients. The aim of this study was to investigate BRAF mutation and DNA methylation in colorectal serrated polyps and the right colon.Between 2005 and 2013, 146 colon polyps (47 tubular adenomas [TAs], 53 traditional serrated adenomas [TSAs], 17 sessile serrated adenomas/polyps [SSAs], and 29 hyperplastic polyps in the proximal colon [PHPs]) were collected from patients. Paraffin-embedded colon polyp tissue was used for DNA extraction. BRAF V600E mutation was identified through polymerase chain reaction (PCR) and pyrosequencing assay. The methylation status of the long interspersed nucleotide element-1, insulin-like growth factor binding protein 7 (IGFBP7), mutL homolog 1 (hMLH1), and CD133 genes were evaluated through disulfite conversion, PCR, and pyrosequencing assay.BRAF V600E mutation was found in 2.1% of TAs, 47.2% of TSAs, 41.2% of SSAs, and 20.7% of PHPs. TSA and SSA had higher BRAF mutation rates than did TA (P < 0.0001). TSA had higher BRAF mutation rates than did PHP (P = 0.018). IGFBP7 hypermethylation was found in 17% of TAs, 37.7% of TSAs, 88.2% of SSAs, and 37.5% of PHPs. TSA and SSA had higher hypermethylation of IGFBP7 than did TA (P = 0.021 and P < 0.0001, respectively). SSA had higher hypermethylation of IGFBP7 than did PHP (P = 0.002). hMLH1 hypermethylation was found in 2.1% of TAs, 5.7% of TSAs, 0% of SSAs, and 0% of PHPs. CD133 hypermethylation was found in 21.3% of TAs, 9.4% of TSAs, 35.3% of SSAs, and 17.4% of PHPs.BRAF mutation and methylation in TSA and SSA are different from those in PHP in Koreans. These findings suggested that PHP may have different molecular characteristics compared with other serrated polyps.

Prediction of colorectal cancer diagnosis based on circulating plasma proteins

Non-invasive detection of colorectal cancer with blood-based markers is a critical clinical need. Here we describe a phased mass spectrometry-based approach for the discovery, screening, and validation of circulating protein biomarkers with diagnostic value. Initially, we profiled human primary tumor tissue epithelia and characterized about 300 secreted and cell surface candidate glycoproteins. These candidates were then screened in patient systemic circulation to identify detectable candidates in blood plasma. An 88-plex targeting method was established to systematically monitor these proteins in two large and independent cohorts of plasma samples, which generated quantitative clinical datasets at an unprecedented scale. The data were deployed to develop and evaluate a five-protein biomarker signature for colorectal cancer detection.

Evaluation of the diagnostic value of 64 simultaneously measured autoantibodies for early detection of gastric cancer

Autoantibodies against tumor-associated antigens (TAAs) have been suggested as biomarkers for early detection of gastric cancer. However, studies that systematically assess the diagnostic performance of a large number of autoantibodies are rare. Here, we used bead-based multiplex serology to simultaneously measure autoantibody responses against 64 candidate TAAs in serum samples from 329 gastric cancer patients, 321 healthy controls and 124 participants with other diseases of the upper digestive tract. At 98% specificity, sensitivities for the 64 tested autoantibodies ranged from 0–12% in the training set and a combination of autoantibodies against five TAAs (MAGEA4 + CTAG1 + TP53 + ERBB2_C + SDCCAG8) was able to detect 32% of the gastric cancer patients at a specificity of 87% in the validation set. Sensitivities for early and late stage gastric cancers were similar, while chronic atrophic gastritis, a precursor lesion of gastric cancer, was not detectable. However, the 5-marker combination also detected 26% of the esophageal cancer patients. In conclusion, the tested autoantibodies and combinations alone did not reach sufficient sensitivity for gastric cancer screening. Nevertheless, some autoantibodies, such as anti-MAGEA4, anti-CTAG1 or anti-TP53 and their combinations could possibly contribute to the development of cancer early detection tests (not necessarily restricted to gastric cancer) when being combined with other markers.

Optimizing post-polypectomy surveillance: A practical guide for the endoscopist

Several gastrointestinal societies strongly recommend colonoscopy surveillance after endoscopic and surgical resection of colorectal neoplasms. Common denominators to these recommendations include: high-quality baseline colonoscopy before inclusion in a surveillance program; risk stratification based on clinicopathological profiles to guide surveillance intervals; and endoscopist responsibility for providing surveillance advice. Considerable variability also exists between guidelines (i.e. regarding risk classification and surveillance intervals). In this review, we examine key factors for quality of post-polypectomy surveillance practice, in particular bowel preparation, endoscopic findings at baseline examination and adherence to surveillance recommendations. Frequently asked questions by the practising endoscopist are addressed.

Systematic review with meta-analysis: the incidence of advanced neoplasia after polypectomy in patients with and without low-risk adenomas

BACKGROUND

Patients with one to two tubular adenomas <1 cm in size without high-grade dysplasia (low-risk group) are considered at low risk for colorectal cancer. However, it is uncertain whether they have the same risk of subsequent advanced neoplasia as those with no neoplasia at baseline colonoscopy.

AIM

To compare incidence of metachronous advanced neoplasia between patients in the low-risk adenoma group and those without neoplasia at index colonoscopy.

METHODS

Relevant publications were identified by MEDLINE/EMBASE and other databases for the period 1992-2013. Studies comparing the incidence of post-polypectomy advanced neoplasia (adenomas ≥10 mm/high-grade dysplasia/villous or cancer) between the low-risk group and patients without colorectal neoplasia at the first colonoscopy were included. Detection rates for advanced neoplasia at endoscopic surveillance were extracted. Study quality was ascertained according to Newcastle-Ottawa Scale. Forest plot was produced based on random-effect models. Inter-study heterogeneity was assessed using the I(2) statistic.

RESULTS

Seven studies provided data on 11 387 patients. Mean surveillance periods ranged between 2 and 5 years. Altogether, 267 patients with post-polypectomy advanced neoplasia were detected in the two groups. The incidence of advanced neoplasia was 1.6% (119/7308) in those without neoplasia and 3.6% (148/4079) in those with low-risk adenoma, respectively, corresponding to a relative risk of 1.8 (95% CI: 1.3-2.6). Inter-study heterogeneity was only moderate (I(2) : 37%). No publication bias was present.

CONCLUSIONS

Patients with low-risk adenomas at baseline had a higher risk of metachronous advanced neoplasia than the group with no adenomas at baseline, though the absolute risk was low in both groups.

Well adjusted qualitative immunochemical faecal occult blood tests could be a promising alternative for inexpensive, high-quality colorectal cancer screening

Immunochemical faecal occult blood tests (iFOBTs) have been shown to have higher sensitivity to detect colorectal cancer (CRC) and its precursors than traditional guaiac-based faecal occult blood tests, but are more costly and require specific laboratory equipment. A number of qualitative iFOBTs have been developed, but their performance varied widely because of the large variation in positivity thresholds used for test positivity. We aimed to evaluate the performance of qualitative iFOBTs with well adjusted positivity thresholds in the screening setting. In a study of 229 participants who underwent screening colonoscopy in Germany (45 patients with CRC, 65 with advanced adenoma and 119 free of colorectal neoplasms), we evaluated the performance of two qualitative iFOBTs at five different positivity thresholds and compared it with the performance of a quantitative iFOBT. Receiver operating characteristic curves were constructed. The areas under the curve, and the sensitivity and specificity of the tests, were calculated. For both qualitative tests, sensitivities were around 30% for advanced adenoma and 80% for CRC at very high levels of specificity (98-99%). Comparison of results with the receiver operating characteristic curves for the quantitative test indicated that the qualitative tests yielded similarly high levels of sensitivity at comparable levels of specificity. In conclusion, with appropriate adjustment of positivity thresholds ensuring the levels of specificity required in population-based screening, qualitative, office-based iFOBTs can be an economic, qualitatively comparable alternative to quantitative iFOBTs.

Comparative evaluation of nine faecal immunochemical tests for the detection of colorectal cancer

BACKGROUND

Faecal immunochemical tests (FITs) for haemoglobin are increasingly used for non-invasive screening for colorectal cancer (CRC) but large scale comparative studies of different FITs for detection of CRC, overall and by stage, are sparse. We aimed to determine and compare performance of different FITs for the detection of CRC, and to assess their stage-specific sensitivities.

MATERIAL AND METHODS

We assessed sensitivity, specificity and their corresponding 95% confidence intervals for six qualitative FITs among 74 CRC cases (59% stage I or II cancers) and 1480 controls free of colorectal neoplasm. Overall and stage-specific receiver operating characteristic curves were derived for three quantitative FITs. The areas under the curves (AUCs) were calculated and compared.

RESULTS

Pairs of overall sensitivity and specificity of the qualitative FITs ranged from 66% and 96% to 92% and 62%, respectively. For the three quantitative tests, AUCs ranged from 0.90 to 0.92, with sensitivities ranging from 80% to 87% at cut-offs yielding 90% specificity. AUCs ranged from 0.85 to 0.92, 0.94 to 0.96, and 0.86 to 0.93 for stage I, stage II and advanced stages (stage III and IV) cancers, respectively. At a specificity of 90%, the tests detected 65%-85% of stage I cancers.

CONCLUSION

The diagnostic performance of FITs regarding detection of CRC is promising, even though the pre-defined cut-offs of some of the qualitative FITs need to be adjusted to limit false-positive rates in screening setting. At cut-off levels yielding 90% specificity, the quantitative tests detected the vast majority of CRCs, even at early stages.

Differences in epidemiologic risk factors for colorectal adenomas and serrated polyps by lesion severity and anatomical site

Using a case-control design, we evaluated differences in risk factors for colorectal polyps according to histological type, anatomical site, and severity. Participants were enrollees in the Group Health Cooperative aged 20-79 years who underwent colonoscopy in Seattle, Washington, between 1998 and 2007 and comprised 628 adenoma cases, 594 serrated polyp cases, 247 cases with both types of polyps, and 1,037 polyp-free controls. Participants completed a structured interview, and polyps were evaluated via standardized pathology review. We used multivariable polytomous logistic regression to compare case groups with controls and with the other case groups. Factors for which the strength of the association varied significantly between adenomas and serrated polyps were sex (P < 0.001), use of estrogen-only postmenopausal hormone therapy (P = 0.01), and smoking status (P < 0.001). For lesion severity, prior endoscopy (P < 0.001) and age (P = 0.05) had significantly stronger associations with advanced adenomas than with nonadvanced adenomas; and higher education was positively correlated with sessile serrated polyps but not with other serrated polyps (P = 0.02). Statistically significant, site-specific associations were observed for current cigarette smoking (P = 0.05 among adenomas and P < 0.001 among serrated polyps), postmenopausal estrogen-only therapy (P = 0.01 among adenomas), and obesity (P = 0.01 among serrated polyps). These findings further illustrate the epidemiologic heterogeneity of colorectal neoplasia and may help elucidate carcinogenic mechanisms for distinct pathways.

Genomic aberrations occurring in subsets of serrated colorectal lesions but not conventional adenomas

A subset of aggressive colorectal cancers exhibit BRAF mutation, MLH1 methylation, and a CpG island methylator phenotype (CIMP), but precursors are poorly established. In this study, we determined the status of these markers in colorectal polyps and evaluated associated risk factors. The study included 771 polyp cases and 1,027 controls who were ages 24 to 80 years, part of a group health program, received a colonoscopy from 1998 to 2007, and completed a structured questionnaire assessing risk factors. Following standard pathology review, polyps were assayed for BRAF mutation (V600E) and tested for MLH1 and CIMP methylation, the latter including the genes, CACNA1G, IGF2, NEUROG1, RUNX3, and SOCS1. Polytomous logistic regression was used to estimate ORs and 95% confidence intervals for the association between molecularly defined subsets of polyps and potential risk factors. There were 580 conventional adenomas and 419 serrated lesions successfully assayed. For adenomas, the prevalence of each marker was ≤1%. In contrast, 55% of serrated lesions harbored mutant BRAF, 26% were CIMP-high, and 5% had methylated MLH1. In these lesions, the highest prevalence of markers was in sessile-serrated polyps (SSP) of ≥10 mm that were in the right-side/cecal regions of the colon. Risk factors for CIMP-high-serrated lesions included Caucasian race, current smoking status, and a history of polyps, whereas for serrated lesions with mutant BRAF, the significant risk factors were male sex, current smoking status, obesity, and a history of polyps. Our results suggest that SSPs and other large, right-sided serrated lesions have a unique molecular profile that is similar to CIMP-high, BRAF-mutated colorectal cancers.

Five-year risk of colorectal neoplasia after normal baseline colonoscopy in asymptomatic Chinese Mongolian over 50 years of age

BACKGROUND

After normal colonoscopy, the 5-year risk of colorectal neoplasia is sufficiently low for asymptomatic people over 50 years of age. In China, the incidence of colorectal carcinoma of Mongolian people is higher than that of Han people. The aim of this study was to assess the 5-year risk of colorectal neoplasia after normal colonoscopy in asymptomatic Chinese Mongolian population.

PATIENTS AND METHODS

A cohort of asymptomatic Chinese Mongolian people (≥50 years old) were recruited and followed up with colonoscopy 5 years after colonoscopy. Baseline colonoscopy and follow-up colonoscopy findings were categorized based on the most advanced lesions: no adenoma, nonadvanced adenoma, and advanced adenoma. Five-year risk of colorectal neoplasia in these people was assessed according to the rates of no baseline adenoma and advanced adenoma at the end of 5 years.

RESULTS

A total of 480 of the 538 recruited people underwent follow-up colonoscopy at the end of 5 years. In people with no baseline adenoma, 27.3 % (82/301) was found to have any adenoma, and 1.7 % had advanced adenoma at follow-up colonoscopy. The risk of an advanced adenoma did not differ significantly between people with no adenoma at baseline and those with nonadvanced adenoma (relative risk (RR), 1.06; 95 % confidence interval (CI), 0.19-6.07). Advanced adenoma at baseline colonoscopy was the independent risk factor for advanced adenoma recurrence, compared with no adenoma at baseline (RR, 8.25; 95 % CI, 1.90-35.77).

CONCLUSION

The risk of advanced adenoma is low 5 years after the normal baseline colonoscopy, even in asymptomatic Chinese Mongolian population over 50 years of age.

Colorectal endoscopy, advanced adenomas, and sessile serrated polyps: implications for proximal colon cancer

OBJECTIVES

Colonoscopy is associated with a decreased risk of colorectal cancer but may be more effective in reducing the risk of distal than proximal malignancies. To gain insight into the differences between proximal and distal colon endoscopic performance, we conducted a case-control study of advanced adenomas, the primary targets of colorectal endoscopy screening, and sessile serrated polyps (SSPs), newly recognized precursor lesions for a colorectal cancer subset that occurs most often in the proximal colon.

METHODS

The Group Health-based study population included 213 advanced adenoma cases, 172 SSP cases, and 1,704 controls aged 50-79 years, who received an index colonoscopy from 1998-2007. All participants completed a structured questionnaire covering endoscopy history. Participants with polyps underwent a standard pathology review to confirm the diagnosis and reclassify a subset as advanced adenomas or SSPs. Logistic regression analyses were conducted to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association between endoscopy and advanced adenomas and SSPs separately; site-specific analyses were completed.

RESULTS

Previous endoscopy was inversely associated with advanced adenomas in both the rectum/distal colon (OR=0.38; 95% CI: 0.26-0.56) and proximal colon (OR=0.31; 95% CI: 0.19-0.52), but there was no statistically significant association between previous endoscopy and SSPs (OR=0.80; 95%CI: 0.56-1.13).

CONCLUSIONS

Our results support the hypothesis that the effect of endoscopy differs between advanced adenomas and SSPs. This may have implications for proximal colon cancer prevention and be due to the failure of endoscopy to detect/remove SSPs, or the hypothesized rapid development of SSPs.

Risk of colorectal cancer after detection and removal of adenomas at colonoscopy: population-based case-control study

PURPOSE

Empirical evidence for recommendations of surveillance intervals after detection and removal of adenomas at colonoscopy is still sparse and mostly based on observations of adenoma recurrence. We aimed to assess risk of colorectal cancer (CRC) according to time since polypectomy and factors that might be relevant for risk stratification.

METHODS

In a population-based case-control study conducted in Germany, detailed history and results of previous large-bowel endoscopies were obtained by interview and from medical records. Risk of CRC among participants with detection of at least one adenoma at a preceding colonoscopy compared with participants without previous large-bowel endoscopy was assessed according to time since polypectomy among 2,582 cases with CRC and 1,798 matched controls.

RESULTS

Adjusted odds ratios (95% CIs) of CRC for participants with polypectomy less than 3, 3 to 5, and 6 to 10 years ago (using participants without previous endoscopy as reference group) were 0.2 (0.2 to 0.3), 0.4 (0.3 to 0.6), and 0.9 (0.5 to 1.5), respectively. Strong, significant risk reduction within 5 years was consistently seen for women and men, younger and older participants, patients with and without high-risk polyps (three or more polyps, at least one polyp ≥ 1 cm, at least one polyp with villous components), and those with and without polypectomy in the right colon. With adjusted odds ratios of 0.1 (0.1 to 0.2), 0.3 (0.2 to 0.5) and 0.4 (0.2 to 0.8) for patients with polypectomy less than 3, 3 to 5, and 6 to 10 years ago, risk reduction was particularly strong for left-sided CRC.

CONCLUSION

Extension of surveillance intervals to 5 years should be considered, even after detection and removal of high-risk polyps.

Comparison and combination of blood-based inflammatory markers with faecal occult blood tests for non-invasive colorectal cancer screening

Background:

Faecal occult blood tests (FOBTs) are widely used for colorectal cancer (CRC) screening. Blood-based inflammatory markers have been suggested as alternative or supplementary non-invasive CRC screening tests.

Methods:

Among 179 CRC patients, 193 people with advanced adenoma and 225 people free of neoplasm, C-reactive protein (CRP), serum CD26 (sCD26), complement C3a anaphylatoxin and tissue inhibitor of metalloproteinases 1 (TIMP-1) levels in blood were measured by ELISA tests, and an immunochemical FOBT (iFOBT) and a guaiac-based FOBT were performed. Receiver operating characteristic curves were constructed and the areas under the curves (AUCs) were compared.

Results:

The blood levels of CRP, sCD26 and TIMP-1 showed statistically significant differences between CRC patients and neoplasm-free participants, and levels of TIMP-1 were furthermore significantly elevated in advanced adenoma patients. For the four inflammatory markers, AUCs ranged from 0.52 to 0.62 for CRC detection and from 0.50 to 0.58 for advanced adenomas detection, compared with AUCs of 0.90 and 0.68 for the iFOBT. At 97% specificity, blood markers showed much lower sensitivities than FOBTs. Combining inflammatory markers with the iFOBT increased the AUC for advanced adenomas.

Conclusion:

These blood-based markers do not seem to be an alternative to FOBT-based CRC screening. The potential use of these and other blood-based tests in combination with iFOBT might deserve further attention.

Colonoscopy surveillance after polypectomy may be extended beyond five years

OBJECTIVES

Colonoscopy surveillance interval data longer than 5 years are limited. We examined adenoma yield to identify factors that predict appropriate intervals for postpolypectomy surveillance greater than 5 years, including risk of advanced adenoma recurrence.

METHODS

We identified patients with and without adenomas on an index colonoscopy who returned at 5 to 10 years for a follow-up colonoscopy. Multivariate logistic regression was used to identify variables that predict finding an adenoma on follow-up colonoscopy.

RESULTS

Three hundred ninety-nine patients were identified with a follow-up colonoscopy at an interval of >5 years. Irrespective of surveillance interval, adenoma incidence occurred in 116 patients (29.1%) with 25 (6%) having advanced adenomas. Patients with nonadvanced adenomas on index colonoscopy had a similar risk of advanced adenoma on follow-up colonoscopy at 5 years versus 6 to 10 years, 5% versus 6.2% (P=0.39). The risk of advanced adenoma at 5 and 6 to 10 years in patients with a negative index colonoscopy was 7% versus 3.6% (P=0.15). Patients with an advanced adenoma at index colonoscopy had the highest rate of advanced adenoma detection at 5 years at 26%. Proximal polyp location (odds ratio 12.4, confidence interval 2.7-56.7) predicted advanced adenoma occurrence at 5 years.

CONCLUSIONS

Postpolypectomy colonoscopy intervals can be extended beyond 5 years in patients with nonadvanced adenomas. Our findings also support a rescreening interval of 5 to 10 years in patients with a negative index colonoscopy. Patients with an index advanced adenoma are at highest risk for recurrent advanced adenoma and should have repeat colonoscopy before a 5 years interval.

[Impact of clinical trials for surgery]

Clinical trials play a key role in patient care, academic education and research in surgery. Without valid studies the practice of evidence-based medicine is limited. Surgery is supported through funding by the German Ministry of Education and Research to establish an infrastructure for clinical trials. So far seven universities have worked together in a network since 2007 and successfully obtained funding for six large randomized trials from a program existing since 2004. Until now 2,249 patients have been randomized within 11 trials and 910 patients have been treated at local hospitals without academic responsibilities. An increase in the interest in clinical trials in daily practice has resulted through the certification of hospitals for special treatment that specifies that at least 5% of all patients are included in clinical trials.

Characteristics of metachronous colorectal adenomas found during long-term follow-up: analysis of four subsequent generations of adenoma recurrence

OBJECTIVE

Because of the high recurrence rates of colorectal adenomas, regular surveillance by colonoscopy has been recommended, but there is still a dearth of information on the long-term results of follow-up colonoscopy after polypectomy. The aims of this study were to determine the differences between initial adenomas and metachronous lesions, to evaluate the effect of long-term surveillance and to describe the hypothetical origin of the colorectal adenoma-carcinoma sequence.

MATERIAL AND METHODS

Between 1978 and 2003 a total of 1091 patients undergoing periodic surveillance examinations were prospectively documented at the Erlangen Registry of Colorectal Polyps. Differences between initial and metachronous lesions found during long-term follow-up were studied. Statistical analysis using chi(2) testing of adenoma characteristics found in four subsequent recurrence periods was carried out, and the relative risk (RR) for the development of metachronous adenomas of advanced pathology was calculated.

RESULTS

In comparison with the initial findings, metachronous adenomas are generally significantly smaller lesions (p<0.00001), usually tubular in shape (p<0.00001) and bearing high-grade dysplasia less often (p<0.00001) and are usually located in the right colon (p<0.00001). These differences are found between the initial and four subsequent generations of metachronous adenomas. The number of synchronous adenomas is reduced only in the first recurrence (p<0.001); in the further generations equal proportions of multiplicity are found, as in the baseline examination. Patients with adenomas of advanced pathology, i.e. large, tubulovillous or villous adenomas at baseline, have a significantly higher risk for large (RR 2.73; 95% CI 1.77-4.20), tubulovillous or villous (RR 1.55; 95% CI 1.06-2.25) or multiple (RR 2.45; 95% CI 1.83-3.29) metachronous adenomas at the first recurrence.

CONCLUSIONS

Metachronous adenomas show the uniform characteristics of being small tubular lesions rarely bearing high-grade dysplasia, usually located in the right colon. Thus regular follow-up colonoscopy can provide sufficient colorectal carcinoma prevention.

Expected reduction of colorectal cancer incidence within 8 years after introduction of the German screening colonoscopy programme: estimates based on 1,875,708 screening colonoscopies

In late 2002, colonoscopy was introduced as a primary screening tool for colorectal cancer (CRC) in Germany. We aimed to estimate the expected reduction in case numbers and incidence of CRC between 2003 and 2010 by detection and removal of advanced adenomas. Data from 1,875,708 women and men included in the national screening colonoscopy database were combined with estimates of transition rates of advanced adenomas and with national population projections. Despite relatively low screening participation, incident CRC cases are expected to be reduced by more than 15,000 between 2003 and 2010. The impact is expected to be largest in age groups 55-59, 60-64 and 65-69 in whom total case numbers in 2010 are expected to be reduced by 13%, 19% and 14% among women, and by 11%, 15% and 12%, respectively, among men. Our results forecast a major rapid reduction of the CRC burden in Germany by screening colonoscopy.

Risk of advanced metachronous colorectal adenoma during long-term follow-up

BACKGROUND

According to the adenoma-carcinoma concept, all colorectal adenomas are to be removed and all patients have to undergo regular surveillance examinations. But there is still shortage on information on the long-term results of follow-up colonoscopy after polypectomy.

METHODS

Between 1978 and 2003, more than 20,000 polyps were prospectively documented at the Erlangen Registry of Colorectal Polyps. A total of 1,091 patients undergoing periodic surveillance examinations are studied for differences between initial and metachronous lesions of the colorectum. Statistical analysis using chi (2)-testing of adenoma characteristics found in four subsequent recurrence periods and calculation of the relative risk (RR) for the development of metachronous adenomas of advanced pathology was performed.

RESULTS

In comparison with the initial findings, metachronous adenomas are, in general, significantly smaller ones (p < 0.00001), more frequently tubular lesions (p < 0.00001) and bearing less often high-grade dysplasia (p < 0.00001). Adenomas of advanced pathology were significantly less often found during follow-up than at baseline examination (p < 0.0001). These differences are found between the initial and four subsequent generations of metachronous adenomas. Patients with adenomas of advanced pathology at baseline have a significantly higher risk for metachronous adenomas of advanced pathology (RR 1.51; 95%CI 1.04-1.93) at the first recurrence.

CONCLUSIONS

Metachronous adenomas show uniform characteristics of being small tubular lesions rarely bearing high-grade dysplasia. Thus, regular surveillance examinations can provide sufficient colorectal carcinoma prevention.

Importance of postpolypectomy surveillance and postpolypectomy compliance to follow-up screening--review of literature

INTRODUCTION

Approximately 150,000 people are diagnosed with colorectal cancer each year and 56,000 may die from it annually in the United States. Colorectal cancer is the second leading cause of cancer deaths in the USA and yet, when diagnosed at an early stage, it is one of the most preventable cancers. According to the US Preventive Services Task Force, initial screening for colorectal cancer is recommended in people above 50 years of age with average risk and earlier in people with a strong family history and other risk factors. Adenomatous polyps are considered as precursors of colorectal cancer. Removal of polyps and postpolypectomy surveillance reduces the overall mortality from colorectal cancer.

DISCUSSION

According to updated guidelines in 2006, a 3-year-follow-up colonoscopy is recommended in patients with adenomatous polyps>or=1 cm. An important factor in the surveillance and prevention of colorectal cancer in postpolypectomy patients is compliance with follow-up colonoscopy. In the present article, we provide an overview of the importance of postpolypectomy surveillance and summarize the compliance data for postpolypectomy surveillance. Compliance to postpolypectomy surveillance varies from one study to another and it should be expected that the compliance with follow-up would be low outside of clinical trials. Some measures that can improve patient compliance include patient education regarding a need of follow-up screening, reminder letters, and alerts in patient's charts.

CONCLUSION

In conclusion, effective surveillance screening with good patient compliance in postpolypectomy patients will contribute significantly in reducing colon cancer morbidity and mortality.

Hormone replacement therapy, body mass, and the risk of colorectal cancer among postmenopausal women from Germany

Previous studies have reported inconsistent results regarding the modifying effect of hormone replacement therapy (HRT) on the association of body mass index (BMI) and the risk of colorectal cancer (CRC) among postmenopausal women. We assessed the use of HRT and BMI in 208 postmenopausal women with histologically confirmed incident CRC and 246 controls in a population-based case–control study in Germany (DACHS study). Ever use of HRT was strongly associated with reduction of CRC risk (adjusted odds ratio 0.41, 95% confidence interval 0.25–0.67). Among nonusers of HRT, risk of CRC was strongly increased in women with BMI 27 to <30 kg m⁻² (2.76, 1.07–7.12) and obese women (3.30, 1.25–8.72), when compared with women with BMI <23 kg m⁻² (P for trend <0.01). BMI was not associated with risk of CRC among HRT users (P for interaction <0.01). In contrast to most other studies, a positive association of BMI and CRC risk was found among nonusers of HRT, but not among users of HRT. The reasons for the inconsistency of results regarding the potential risk modifying effect of postmenopausal hormones in the association of BMI with CRC remain inconclusive and require further study.

Dealing with uncertainty: surveillance colonoscopy after polypectomy

Post-polypectomy surveillance is often done sooner than guideline recommendations. This practice is driven by physician intolerance of uncertainty. The accompanying article by Brenner et al. supports the recommendation to wait 5 years or longer following adenoma removal before performing surveillance colonoscopy. This is particularly true for patients with 1 or 2 small adenomas. Unnecessarily aggressive post-polypectomy surveillance exposes patients to excessive risk of colonoscopy complications without clinical benefit. It also diverts colonoscopy resources away from the more valuable practice of primary screening.