Increased incidence of colorectal adenomas in follow-up evaluation of patients with newly diagnosed hyperplastic polyps

Background: Although adenomatous polyps have been established clearly as precursor lesions for most cases of colorectal cancer, the role, if any, of hyperplastic polyps remains uncertain. The aim of the current study was to determine whether a patient with an index finding of hyperplastic polyp on colonoscopy is at increased risk for adenomatous polyps. Methods: We conducted a retrospective cohort study using the records of a single surgeon's colonoscopic experience over a 20-year period (June 1973 to December 1994). Patients found to have hyperplastic lesions on index colonoscopy were compared with those who had "clean" index colonoscopies. The two groups were compared for the subsequent diagnosis of adenomatous polyps on follow-up colonoscopies. Those with cancer or adenomas at index colonoscopy or in their history were excluded. We used Cox proportional hazard modeling with subsequent adenoma or cancer diagnosis at follow-up colonoscopy as the outcome, controlling for age and gender. Results: We identified 42 patients for whom hyperplastic polyps were the only colorectal neoplasms found on the index examination, in contrast to 362 control patients who had a "clean" index examination. In this cohort study, patients found to have only hyperplastic polyps on initial examination had a rate of subsequent adenoma diagnoses (42%) twice that of patients with a clean initial colonoscopy (21%). Mean follow-up time was 4.3 years. The relative rate ratio was 2.0 (95% confidence interval, 1.2-3.4). Conclusions: This study suggests that patients found to have hyperplastic polyps on initial colonoscopic examination may have twice the risk of adenomas on follow-up colonoscopy, as compared with those who have clean initial examinations. If this finding is borne out in larger prospective studies, surveillance strategies may need to be modified accordingly. apd: 14 May 2001     

Intermediate sized adenomas may represent an increased cancer risk

Objective:  The purpose of colonoscopic polypectomy is cancer prevention. Multiple or large adenomas require intensive follow up but solitary or smaller lesions are considered safer and less frequent examinations are necessary. The aim of this study was to test if these principles are supported in practice.
Method:  Individuals with polyps but no family history of colorectal cancer (CRC), where pathology and endoscopy reports could be cross-referenced to confirm size, number and histological classification were included. Cases of colorectal cancer were identified from records of repeat examinations. Follow-up interval and number of subsequent examinations was determined. A control population of individuals with a normal initial colonoscopy were also studied.
Results:  In total 0.05% of individuals with a normal initial colonoscopy developed CRC. The cancer incidence following numerous or large polyps was not significantly higher than the controls although on average more examinations were performed (see table). Individuals with a single small adenoma did not appear to have increased risk of cancer with fewer colonoscopies, but there were significantly higher numbers of cancers where intermediate sized polyps had been identified.
Conclusion:  Risk of cancer is reduced in large or numerous polyps by frequent examinations. Intermediate sized polyps appear to need more intensive follow-up protocols than small single adenomas for effective cancer prevention.
 

     

Intermediate sized adenomas may represent an increased cancer risk

Objective:  The purpose of colonoscopic polypectomy is cancer prevention. Multiple or large adenomas require intensive follow up but solitary or smaller lesions are considered safer and less frequent examinations are necessary. The aim of this study was to test if these principles are supported in practice.
Method:  Individuals with polyps but no family history of CRC, where pathology and endoscopy reports could be cross-referenced to confirm size, number and histological classification were included. Cases of colorectal cancer were identified from records of repeat examinations. Follow up interval and number of subsequent examinations was determined. A control population of individuals with a normal initial colonoscopy were also studied.
Results:  In total 0.05% of individuals with a normal initial colonoscopy developed CRC. The cancer incidence following numerous or large polyps was not significantly higher than the controls although on average more examinations were performed (see table). Individuals with a single small adenoma did not appear to have increased risk of cancer with fewer colonoscopies, but there were significantly higher numbers of cancers where intermediate sized polyps had been identified.
 

     

Surveillance of individuals at intermediate risk of colorectal cancer – the impact of new guidelines

Objective Individuals with two first degree relatives, or one diagnosed at age < 45 years, with colorectal cancer are at sufficient risk to merit surveillance. Most undergo colonoscopy four to five yearly, starting 10 years before the youngest case. The aim of this study was to assess the impact of a proposed new surveillance protocol. Subjects and methods We identified individuals with these risk criteria seen in our clinic from 1989 to 2001 and reviewed their notes with respect to colonoscopy. Results Colonoscopy (n = 295) was performed on 186 patients in accordance with current recommendations. Cancer was detected in three and adenoma in 21 individuals. Applying the proposed protocol, 123 (42%) fewer colonoscopies would have been performed. No cancers would have been missed, but in five cases a small adenoma would not have been detected. Conclusions Proposed new guidelines for surveillance of those at intermediate risk reduce the burden of colonoscopy without compromising identification of significant neoplasia.     

Serrated polyps: new classifications highlight clinical importance

Aim Many lesions previously classified as hyperplastic polyps and therefore thought to be innocuous have been reclassified as sessile serrated adenomas/polyps (SSA/Ps), establishing their place in the serrated pathway and underscoring their malignant potential. The clinical relevance of this new nomenclature is incompletely defined. This study examines the incidence and characteristics of colorectal SSA/Ps and describes other associated colorectal neoplasia. Method A single institution pathology database was searched for the diagnosis of SSA/Ps between January 2004 and October 2007. SSA/Ps found by colonoscopy were included. Patient demographics, SSA/P characteristics and associated colonoscopic findings were retrospectively recorded. Results A total of 585 SSA/Ps were removed during 519 colonoscopies in 483 patients performed by 64 different endoscopists. This represented an overall incidence of SSA/Ps per colonoscopy of 2.1% in the 28 054 colonoscopies performed during the study period. The median SSA/P size was 0.8 cm (range 0.2–4.5) and 188 (69%) were ≥ 1.0 cm. Of the 585 SSA/Ps, 366 (63%) were right‐sided, 129 (22%) were in the left colon and 90 (15%) were in the rectum. Also, 439 synchronous polyps of other histology (mainly adenomas and hyperplastic polyps) were found during the same 519 colonoscopies. Conclusion SSA/Ps are rare lesions found during colonoscopy that may coexist with small hyperplastic polyps. Because SSA/Ps are part of the serrated oncogenic pathway, all, even those appearing to be hyperplastic, should be removed or biopsied for diagnosis. Careful review of historical lesions with application of new definitions may redefine risk for malignancy.     

Colonoscopic surveillance after curative colorectal resection: Results of an empirical surveillance programme

Introduction Colonoscopic surveillance after colorectal cancer resection is widely practised despite little evidence that it improves survival. The optimum protocol for colonoscopic follow‐up after colorectal cancer resection has not yet been elucidated. We audited the outcome of an empirical colonoscopic follow‐up programme in a cohort of patients who underwent colorectal resection with a minimum of five years follow‐up to establish patterns of metachronous neoplasia and suitable surveillance intervals. Methods The colonoscopic records, biopsy results and follow‐up details of patients diagnosed with colorectal cancer between June1990 and June1996 were reviewed. The number and type of metachronous neoplastic lesions diagnosed was recorded. Rates of development of new neoplasms were estimated by calculating the time from operation to their first discovery. Factors predictive of further development of polyps or cancer were sought. Results were compared to published reports of intensive follow‐up programmes. Results Seven hundred and ninety‐eight patients underwent colorectal resection with curative intent during the study period. 226 patients had one or more follow‐up colonoscopies (mean time post resection 48.8 months). In total 352 colonoscopies, encompassing 1437 patient years of surveillance, were performed. Nine metachronous cancers in eight patients, five of which were asymptomatic were diagnosed by colonoscopy at a mean of 63 months. Three asymptomatic recurrences were diagnosed but all were inoperable. 70 (31%) patients had adenomatous polyps diagnosed after a mean time from operation of 34 months for simple adenomatous polyps and 21 months for those with advanced features. Patients with multiple polyps or advanced polyps at the initial colonoscopy were more likely to form subsequent polyps. Only 5.8% of patients with a single adenoma or a normal colon formed an advanced adenoma over the next 36 months of surveillance. Conclusion The results of an empirical colonoscopic follow‐up programme compared favourably to the results of the intensive programmes reported in the literature. Most patients are at very low risk of developing significant colonic pathology over the first five years after resection. Colonoscopic surveillance intervals need not be less than five years unless the patient has multiple adenomas or advanced adenomas at the first colonoscopy. Three yearly surveillance intervals are most probably adequate in these individuals.     

Molecular genetics improves the management of hereditary non-polyposis colorectal cancer.

BACKGROUND: The syndrome of hereditary non-polyposis colorectal cancer (HNPCC) can be diagnosed fairly accurately using clinical criteria and a family history. Identifying HNPCC helps to prevent large-bowel cancer, or allows cancer to be treated at an early stage. Once the syndrome has been diagnosed a family member's risk can be judged approximately from a family tree, or it can now be predicted accurately if the causative mutation is known. OBJECTIVE: This study involved attempts to improve the management of a family with HNPCC over a period of 10 years. Clinical diagnostic criteria, colonoscopic surveillance, surgical treatment, genetic counselling, molecular genetic research, and finally predictive genetic testing were applied as they evolved during this time. SUBJECTS AND METHODS: A rural general practitioner first noted inherited large-bowel cancer in the family and began screening subjects as they presented, using rigid sigmoidoscopy at the local hospital. At the time that the disorder was recognised as being HNPCC (1987), screening by means of colonoscopy at our university hospital was aimed primarily at first-degree relatives of affected individuals. After realising how many were at risk, screening was brought closer to the family. A team of clinicians and researchers visited the local hospital to identify and counsel those at risk and to perform screening colonoscopy. Family members were recruited for research to find the gene and its mutation that causes the disease, to develop an accurate predictive test and to reduce the number of subjects undergoing surveillance colonoscopies. RESULTS: There are approximately 500 individuals in this family. In the 10 years of this study the number of subjects who have been counselled for increased genetic risk or who have requested colonoscopic surveillance for HNPCC in this kindred has increased from 20 to 140. After the causative mutation was found in the hMLH1 gene on chromosome 3, a test for it has reduced the number of subjects who need screening colonoscopy by over 70%. A protocol has been devised to inform family members, to acquire material for research in order to provide genetic counselling for (pre-test and post-test) risk, and to test for the mutation. Eventually, identifying those with the mutation should focus surveillance accurately. CONCLUSIONS: The benefits of restricting screening to subjects with the mutation that causes colorectal cancer and of performing operations to prevent cancer are hard to measure accurately. However, it is likely that at least half the family members will be able to avoid colonoscopic screening, some deaths from cancer should be prevented, and the cost of preventing and treating cancer in the family should fall substantially.     

Hyperplastic polyposis: association with colorectal cancer

Hyperplastic polyposis is a loosely defined syndrome initially thought not to confer a clinically important predisposition to colorectal cancer. The aim of the current study was to examine the clinical, histologic, and molecular features of a prospective series of cases meeting a strict definition of the condition. Twelve patients were identified, seven of whom had developed colorectal cancer. Most polyps were hyperplastic, but 11 patients also had polyps containing dysplasia as either serrated adenomas. mixed polyps, or traditional adenomas. The mean percentage of dysplastic polyps in patients with cancer was 35%, and in patients without cancer, 11% (p < 0.05). Microsatellite instability (MSI) was present in 3 of 47 hyperplastic polyps and two of eight serrated adenomas. Kras was mutated in 8 of 47 hyperplastic polyps and two of eight serrated adenomas. No polyps showed loss of heterozygosity of chromosomes 5q, 1p, or 18q. Two of seven cancers showed a high level of MSI. It is concluded that hyperplastic polyposis is associated with a high risk of colorectal cancer. Hyperplastic polyps are the dominant type of polyp, but most cases have some dysplastic epithelium. A higher proportion of dysplastic polyps is associated with increased cancer risk. Clonal genetic changes are observed in some hyperplastic polyps and serrated adenomas.     

Factors associated with adherence to the recommended postpolypectomy surveillance interval

Background

Appropriate surveillance intervals are important to ensure that the benefits of surveillance are not offset by harm. This study aimed to determine the factors associated with nonadherence to recommended colonoscopic surveillance intervals.

Methods

The study enrolled 296 patients who underwent screening colonoscopy. The colonoscopies were performed by four endoscopists in the first or second year of fellowship. After each procedure, the endoscopists responded to a questionnaire that elicited information on the degree of concern for missed polyps (using a visual analog scale [VAS]), colonoscopic technical factors, and surveillance intervals.

Results

Of the 296 patients, 105 (36%) were adherent and 191 (64%) and were nonadherent to the guidelines. There were no differences in insertion time, withdrawal time, or polyp detection rate between the adherence and nonadherence groups. The endoscopy at cecal intubation was longer in the nonadherence group than in the adherence group (P?=?0.013). The proportion of patients with poor bowel preparation was higher in the nonadherence group than in the adherence group (P?=?0.011). The endoscopist’s concern for missed polyps was greater in the nonadherence group than in the adherence group (P?P?=?0.008). Poor bowel preparation, loop formation, and colonoscopy experience were independent factors associated with a high concern for missed polyps.

Conclusions

Nonadherence to the recommended guidelines was associated with the endoscopist’s concern for missed polyps. Improving colonoscopic skills and bowel preparation may decrease nonadherence to the recommended postpolypectomy surveillance interval.     

Serrated polyposis syndrome: Diagnosis and management

Serrated polyposis syndrome is a clinical diagnosis characterized by a few large right-sided colorectal serrated polyps, multiple small serrated polyps, or a combination of both. Colorectal polyps and cancers develop via the methylator (or serrated) carcinogenic pathway. Patients with SPS have an increased risk of CRC compared to the general population throughout their lifetime and adequate surveillance and intervention are necessary. Cancer develops mainly via serrated polyp intermediates, but adenomas can also be present. The goals of management are to prevent the development of colorectal cancer and death from colorectal cancers. Colonoscopy beginning at age 40 at the latest, with polypectomy is the mainstay of clinical management. Surgery is utilized to treat colorectal cancer or decrease its risk. First-degree family members of patients with SPS are also at increased risk of colorectal cancer compared to the general population and increased colonoscopic screening is indicated.     

The changed histologic paradigm of colorectal polyps

Background: Previous literature has recorded the preponderance of hyperplastic over neoplastic polyps. This study evaluated the histopathologic characteristics of colonic polyps, excised during colonoscopic polypectomy, and further determined their relationship to age, location, and gender. Methods: Of 5132 colonoscopies reviewed between 1976 and 1999, 757 were performed on 582 patients who had polyp removal. Patients with previous colon resection or incomplete cecal intubation were excluded. Results: The mean age was 67 ± 11 years for men and 66 ± 11 years for women. Of the 1050 lesions histologically analyzed, 871 (83.0%) were neoplastic, 129 (12.3%) were hyperplastic, and 50 (4.8%) were miscellaneous lesions (29 inflammatory polyps, 14 lipomas, 2 leiomyomas, 1 juvenile polyp, and 4 no pathology identified). Hyperplastic polyps were always less than 1 cm (with one exception) and were located predominantly in the left colon, the majority residing in the sigmoid colon. Peak prevalence of hyperplastic polyps occurred in the 50–70 years old age group. Of the neoplastic polyps, 566 (65.0%) were tubular, 225 (25.8%) villotubular, 63 (7.2%) villous adenomas, 4 (0.5%) mixed adenomatous hyperplastic polyps, and 12 (1.4%) invasive carcinomas. The peak prevalence of neoplastic polyps occurred in the same age group as did hyperplastic polyps. Even though adenomatous polyps outnumbered hyperplastic polyps throughout the colon and within each age group, a greater percentage of hyperplastic polyps were found distally and in younger patients compared to location and age groups for neoplastic polyps. Conclusion: Adenomatous polyps outnumber hyperplastic polyps 7:1, even in the distal colon. Even small polyps seen during colonoscopy should be removed and subjected to histologic analysis because of the advisability of follow-up examinations of patients with neoplastic polyps. The increase in the incidence of neoplastic polyps beginning at the age of 50 years supports the need for colonoscopy in these individuals.     

Do guidelines improve clinical practice? – a national survey on surveillance colonoscopies

Background Colonoscopic services are increasingly being utilized in surveillance of conditions predisposing to colorectal cancers (CRC). The ACPGBI/BSG guidelines are the most commonly followed recommendations. Numerous retrospective studies have shown poor compliance with them. We conducted a national survey of colonoscopic practitioners investigating attitudes, awareness and implementation of surveillance guidelines. Method A postal questionnaire was sent to a random population of 250 ACPGBI and 200 BSG members. Questions assessed practice as regards colorectal polyp surveillance, family screening and surveillance for past history of CRC. Results The ACPGBI/BSG guidelines were the most commonly followed recommendations. Only 17.2% of practitioners used the criteria that would ensure accurate implementation of guidelines for colorectal adenoma surveillance. With regards to familial surveillance for CRC, 53.5% respondents assessed familial risk accurately, while 69.3% recommended surveillance incorrectly. A total of 48.8% of ACPGBI members recommended five yearly colonoscopies following curative treatment for CRC. Conclusion This study has revealed the widespread ignorance of guidelines, which will potentially translate into the gross over utilization of colonoscopic resources. Strategies to improve and audit guideline implementation must be integral to guideline formation. Methods to improve accurate guideline implementation need to be explored.     

Endoscopic treatment of colorectal polyps in a digestive endoscopy outpatient department

The aim of this report was to evaluate the effectiveness of the endoscopic treatment of colonic polyps to allow secondary prophylaxis in order to prevent the onset of cancer arising from adenomas. From October 2002 to January 2004 we performed 487 colonoscopies on a patient group with the following indications: screening prior to kidney transplant; screening for colorectal cancer (patients positive at faecal occult blood testing); follow-up of patients who had undergone colonic resections for colorectal cancer; patients with other diseases. Colorectal polyps were diagnosed in 15 males and 15 females, with a mean age of 63 years. All the neoplasms were resected during colonoscopy and specimens sent for histological study. The histological examinations yielded the following results: 4 hyperplastic polyps; 9 tubular adenomas (6 with mild, 2 with mild-to-moderate, and 1 with severe dysplasia); 8 tubulo-villous adenomas (3 with mild, 1 with mild-to-moderate, and 4 with moderate dysplasia); 4 villous adenomas (3 with mild and 1 with severe dysplasia); 1 adenocarcinoma; 1 inflammatory polyp; in 3 cases we were unable to retrieve the polyps after polypectomy. Colonoscopic detection of a neoplasm allows us to remove it and send to the pathology laboratory for definitive histological diagnosis. Moreover, snare polypectomy can be a radical treatment for dysplastic polyps without stromal axis and basal membrane infiltration. We therefore conclude that colonoscopy allows not only early diagnosis of colonic neoplasms, but also radical curative treatment in the early stages.     

22-year longitudinal study of repetitive colonoscopy in patients with a family history of colorectal cancer

Introduction

We report the outcomes of a long-term surveillance programme for individuals with a family history of colorectal cancer.

Methods

The details of patients undergoing a colonoscopy having been referred on the basis of family history of colorectal cancer were entered prospectively into a database. Further colonoscopy was arranged on the basis of the findings. The outcomes assessed included incidence of cancer and adenoma identification at initial and subsequent colonoscopy.

Results

The records of 2,293 patients (917 men; median patient age: 51 years) were entered over 22 years, giving data on 3,982 colonoscopies. Eight adverse events (0.2%) were recorded. Twenty-seven cancers were found at first colonoscopy and thirteen developed during the follow-up period. There were significantly more cancers identified in those with more than one first-degree relative with cancer than in other groups (p=0.01). The number of adenomas identified at subsequent surveillance colonoscopies remained constant with between 9.3% and 12.0% of patients having adenomas that were removed. Two-thirds (68%) of patients with cancer and three-quarters (77%) with adenomas fell outside the British Society of Gastroenterology (BSG) 2006 guidelines.

Conclusions

Repeated colonoscopy continues to yield significant pathology including new cancers. These continue to occur despite removal of adenomas at prior colonoscopies. The majority of patients with cancers and adenomas fell outside the BSG 2006 guidelines; more would have fallen outside the 2010 guidelines.     

Diagnostic yield of screening colonoscopies in lung transplant candidates

BACKGROUND: Colonoscopy has been used to screen lung transplant candidates for colorectal diseases that would preclude transplantation. The diagnostic yield of this procedure is unknown. METHODS: This is a retrospective cohort study of patients 50 years of age and over who underwent lung transplant evaluations from 1996 to 1999. We assessed the prevalence and location of colonoscopic abnormalities, the predictive value of risk factors for colonic neoplasms, and the impact of colonoscopic findings on management. RESULTS: Thirty-one patients were evaluated. Twenty-four patients had at least one abnormal endoscopic finding. Six patients (19%) had adenomatous polyps; no carcinomas were detected. The 13 patients with risk factors were more likely to have adenomas (relative risk=2.8, P=0.2). The negative predictive value of risk factors for adenomas was 89%. One patient's management was altered and none were denied transplant listing because of the colonoscopic findings. CONCLUSIONS: Screening colonoscopy did not substantively alter the management of lung transplant candidates. More selective screening strategies may be warranted.     

Screening colonoscopy in the asymptomatic 50- to 59-year-old population

Background: In an effort to decrease the death rate from colorectal cancer, a multitude of medical societies and task forces recommend routine screening for colorectal cancer beginning at age 50. Yet, there is no consensus as to the best and most cost-effective screening method. Medicare now pays for screening colonoscopies for its average risk beneficiaries [3]. Many insurance companies, however, will not cover this test in younger patients. We therefore reviewed our institutions colonoscopy experience with asymptomatic 50- to 59-year-olds, with negative fecal occult blood tests and negative family histories. Methods: Between January 1999 and January 2002, 4779 colonoscopies were performed at our institution. The charts for 619 persons 50–59 years of age were retrospectively reviewed, with 91 patients meeting the strict requirements of this study. We defined polyps with high-grade neoplasias as those with villous or tubulovillous components, and cancerous lesions included those with carcinoma in situ. The distal colon was defined as the rectum and sigmoid colon. Results: There was a 58% incidence of neoplastic polyps in this younger asymptomatic population. More than 4% of our subjects had high-grade neoplasias or cancerous lesions. In the absence of any distal findings, flexible sigmoidoscopy would have missed up to 38% of these polyps. Conclusions: The findings generally support the recommendations by the American College of Gastroenterology for average-risk patients to preferentially undergo a screening colonoscopy at age 50 in lieu of other methods.     

Surveillance colonoscopies for colorectal polyps – too often,too many! An Audit at a Large District General Hospital

Introduction The British society of Gastroenterologists (BSG) have laid down guidelines for surveillance colonoscopies in patients with large bowel adenomatous polyps. However, numerous studies have shown the gross over‐utilization of colonoscopic services in their management. We audited our practice of polyp management and looked at guideline compliance amongst patients on our colonoscopic surveillance list. Method All patients undergoing adenoma surveillance and those with newly detected adenomas over a 2‐month period were included in the first loop of the audit. Data on the colonoscopic findings, histology and management were retrieved from paper and on‐line records. The BSG guidelines were printed, laminated and displayed in the colorectal clinics. Following this, we re‐audited (second loop) our practice. In the second part of the study, we randomly retrieved 533/1800 case notes from our colonoscopic waiting list. Amongst those on surveillance for polyps, compliance was ascertained as regards need for procedure and appropriateness of surveillance interval. Findings Fifty‐four patients were included in the first loop and 59 during the second loop of the audit. Guidelines were followed in 16% (4/25, 95% CI: 0.054–0.33) of patients in the first loop and 46.5% (13/28, 95% CI: 0.293–0.642) in the second loop (P = 0.017). Of the patients on our colonoscopic waiting list for adenomatous polyps, 17.7% satisfied guidelines, 23.4% did not require any further surveillance and 58.9% were booked for a procedure earlier than recommended. Conclusion The mere framing of guidelines is insufficient to improve clinical practice. Strategies to improve implementation need to be explored. Audit of individual practice is recommended.     

DOES COLONOSCOPIC POLYPECTOMY REDUCE THE INCIDENCE OF COLORECTAL CARCINOMA?

The study's objective was to examine whether there is evidence that colonoscopic polypectomy reduces the incidence of colorectal cancer. The records of all patients who underwent colonoscopic polypectomy by a single surgeon between 1974 and 1991 were reviewed. Patients with colorectal cancer diagnosed at the initial colonoscopy, with a history of colorectal cancer, inflammatory bowel disease or familial adenomatous polyposis or with only hyperplastic polyps were excluded. There were 1008 remaining patients, of whom 645 have attended at least one follow-up colonoscopic examination, and these 645 patients form the basis of the study, because the incidence of cancer is known exactly in this group. The mean period of follow up was 4.4 years and the mean number of follow-up colonoscopic examinations was 2.2. There was a total of 2847 person-years of colonoscopic follow up. The expected incidence of cancer, age and sex adjusted, is calculated using Australian epidemiological figures. The observed incidence of cancer was 3 cases (all asymptomatic) per 2847 person-years, which is indistinguishable from the general population's risk of 3.75 cases per 2847 person-years. Analysis of previous publications suggests that patients with adenomas are at an increased risk of developing colorectal cancer of about 2.5 times the general population's risk. If correct, then the observed incidence of 3 cases per 2847 person-years is less than the expected incidence of 9.4 cases per 2847 person-years. This analysis suggests colonoscopic polypectomy does reduce the incidence of colorectal cancer.     

Colorectal cancer surveillance after age 65 years

BACKGROUND: It would be valuable to determine whether or not asymptomatic patients 60 to 65 years of age with normal colonoscopies should continue to undergo serial colorectal cancer surveillance examinations. METHODS: Data were obtained from retrospective review of our existing database. Additional data were obtained from patients' medical records, office charts, and pathology reports. In situ endoscopic measurements were performed using a biopsy forceps that was 7 mm when fully extended. RESULTS: Over the past 25 years, 699 asymptomatic patients between 60 and 65 years of age underwent colonoscopies which revealed no pathology. As part of their routine continuing colorectal surveillance and without any prior abnormal endoscopic findings, 56 of these patients underwent a total of 123 colonoscopies after age 65. Thirty-seven patients (66%) had surveillance colonoscopies that continued to be normal while 13 patients (23%) were diagnosed with colorectal adenomas and 6 patients (11%) were found to have hyperplastic polyps. No cancers were discovered. CONCLUSIONS: Patients over the age of 65 should continue to undergo colorectal surveillance even if prior examinations have been negative.     

Evaluation of the occult blood test in screening for colorectal neoplasms. A prospective study using flexible endoscopy

Survival rates from colorectal cancer will rise only when polyps and cancers are found at an earlier, curable stage. Consequently, the purpose of the present study was to compare the yield of colonic neoplasms from flexible sigmoidoscopy and colonoscopy with that from occult blood testing. Results from 474 flexible sigmoidoscopies and 1,115 colonoscopies were prospectively recorded during a four-year study period. Colorectal polyps were found in 111 (23.4%) patients undergoing flexible sigmoidoscopy and 325 (29.1%) patients undergoing colonoscopy. Among the 436 patients with polyps, the occult blood test was negative in 282 (64.7%). Among the 51 patients with colorectal cancers, the occult blood test was negative in 20 (39.1%). Thus, testing for occult blood missed the majority of polyps and a large percentage of the carcinomas. These data indicate that lower gastrointestinal endoscopy is superior to occult blood testing as a screening test for detecting colorectal polyps or cancers. Furthermore, given the high incidence of neoplasia in this patient population, the authors suggest that colonoscopy become the screening test of choice for colorectal cancer.