First observation of microadenomas in the ileal mucosa of patients with familial adenomatous polyposis and colectomies

Risk of ileal pouch neoplasms in patients with familial adenomatous polyposis

Restorative proctocolectomy is the most common surgical option for patients with familial adenomatous polyposis (FAP). However, adenomas may develop in the ileal pouch mucosa over time, and even carcinoma in the pouch has been reported. We therefore reviewed the prevalence, nature, and treatment of adenomas and carcinoma that develop after proctocolectomy in the ileal pouch mucosa in patients with FAP. In 25 reports that were reviewed, the incidence of adenomas in the ileal pouch varied from 6.7% to 73.9%. Several potential factors that favor the development of pouch polyposis have been investigated, but many remain controversial. Nevertheless, it seems certain that the age of the pouch is important. The risk appears to be 7% to 16% after 5 years, 35% to 42% after 10 years, and 75% after 15 years. On the other hand, only 21 cases of ileal pouch carcinoma have been recorded in the literature to date. The diagnosis of pouch carcinoma was made between 3 to 20 years (median, 10 years) after pouch construction. Although the risk of malignant transformation in ileal pouches is probably low, it is not negligible, and the long-term risk cannot presently be well quantified. Regular endoscopic surveillance, especially using chromoendoscopy, is recommended.

Prevalence and risk factors for adenomas in the ileal pouch and the afferent loop after restorative proctocolectomy for patients with familial adenomatous polyposis

BACKGROUND

Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) has become the treatment of choice in familial adenomatous polyposis (FAP) to prevent the risk of colorectal cancer. However, it currently is recognized that adenomas may develop in the ileal pouch. The risk of adenoma occurring in the afferent ileal loop above the pouch is less clearly identified. This study aimed to evaluate the difference in prevalence of adenomas between the ileal pouch and the afferent ileum after IPAA in FAP.

METHODS

The study analyzed 442 endoscopies performed between 2003 and 2008 for 139 FAP patients. The patients had undergone an IPAA in 118 cases, an ileorectal anastomosis in 13 cases, or an ileostomy in 8 cases.

RESULTS

Among the 118 IPAA patients, 57 (48.3 %) had pouch adenomas a median of 15 years after surgery. The risk factors for pouch adenomas were delay since pouch construction [odds ratio (OR), 1.11; p = 0.016] and presence of advanced duodenal adenomas (OR, 4.35; p = 0.011). Seven patients had pouch adenomas with high-grade dysplasia. Only nine patients had afferent ileal loop adenomas (6.5 %). The only significant risk factor for ileal adenomas was the presence of pouch adenomas (OR, 2.16; p = 0.007).

CONCLUSION

After restorative proctocolectomy in FAP, adenoma recurrence is frequent in the pouch, with a higher risk for patients with advanced duodenal adenomas and an increasing risk over time, whereas adenomas are rarely found in the afferent ileal loop. This finding may help to propose redo ileal pouch anal anastomosis if required.

[Hereditary colorectal cancer]

One of the main challenges in the clinical management of familial colorectal cancer (CRC) remains the overlap of syndromes with different underlying genetic causes and the differentiated risk management of colorectal and associated malignancies. The Lynch syndrome (hereditary non-polyposis colorectal cancer, HNPCC) is characterized by the development of colorectal, endometrial, gastric and other cancers and is caused by a mutation in one of the mismatch repair (MMR) genes. Microsatellite instability (MSI) and/or immunohistochemistry (IHC) are important prognostic factors and may predict the response to chemotherapy. Familial adenomatous polyposis (FAP) may be seen as a counterpart to Lynch syndrome, responsible for <1% of all CRC cases. Recently the MUTYH gene has been identified as a further polyposis gene. The associated disorder has been termed MYH-associated polyposis (MAP) and displays an autosomal recessive pattern of inheritance. For clinical management, distinguishing between Lynch syndrome, attenuated FAP and MAP is important for risk assessment, surveillance recommendations and indication for prophylactic surgery.

Role of aberrant crypt foci detected using high-magnification-chromoscopic colonoscopy in human colorectal carcinogenesis

Abstract Liaison between gastrointestinal endoscopists and histopathologists is essential to provide the highest standards of diagnostic accuracy and patient management. The histopathologist needs to be aware of the endoscopic findings when interpreting endoscopic biopsies. High-magnification-chromoscopic-colonoscopy (HMCC) is a new technology that provides the endoscopists with much greater resolution and functional staining of the gastrointestinal tract. Using HMCC, the endoscopist is now able to identify subtle changes in the colorectal luminal openings or crypts. Changes in crypt appearances now allow detection of aberrant crypt foci (ACF) in the colon, which might themselves be precancerous lesions but additionally might serve as a valid biomarker of subsequent adenoma and colorectal cancer formation. This article describes the role of the aberrant crypt focus in colorectal carcinogenesis and discusses the clinical impact of HMCC techniques as applicable to ACF.

Long-term outcome of familial adenomatous polyposis patients after restorative coloproctectomy

BACKGROUND

Restorative proctocolectomy (RPC) eliminates the risk of colorectal adenocarcinoma in familial adenomatous polyposis (FAP) patients, but desmoid tumors, duodenal, and ileal adenomas can still develop. Our aim was to assess the long-term outcome of FAP patients after RPC.

PATIENTS AND METHODS

FAP patients who had RPC between 1983 and 1990 were contacted for interview and upper gastrointestinal (GI) and ileal pouch endoscopy.

RESULTS

Sixty-two males and 48 females had undergone hand-sewn RPC during this period. One patient died postoperatively (0.9%). Among 96 patients available for a minimal follow-up of 11 years, 7 patients died: 3 from causes unrelated to FAP, 2 from metastatic colorectal cancer, and 2 from mesenteric desmoid tumor (MDT). Thirteen patients had a symptomatic MDT (13.5%). Of 73 patients who had an upper GI endoscopy, 52 developed duodenal and/or ampullary adenomas. Four patients required surgical treatment of their duodenal lesions. Among 54 patients who underwent ileal pouch endoscopy, pouch adenomas were noted in 29. No invasive duodenal or ileal pouch carcinoma were detected. Functional results of RPC were significantly worse in MDT patients.

CONCLUSIONS

RPC eliminates the risk of colorectal cancer, and close upper GI surveillance may help prevent duodenal malignancy. MDTs are the principal cause of death, once colorectal cancer has been prevented, and the main reason for worsening functional results.

Familial adenomatous polyposis at the Tel Aviv Medical Center: demographic and clinical features

Familial adenomatous polyposis (FAP) is an uncommon, but widespread genetic disorder that develops multiple colonic adenomatous polyps and, if untreated, can lead to large bowel cancer. Little is known about its occurrence and characteristics in the Israeli population.

AIMS

To evaluate FAP prevalence, phenotypic manifestations and compliance for diagnosis and follow-up in our registry.

METHODS

Since 1993 approximately one-half of FAP patients in Israel have been seen and followed-up by us before and/or after colectomy. They and their families were encouraged to have mutation analysis, genetic and/or endoscopic screening.

RESULTS

37 pedigrees were identified, including 2 non-Jewish. The Jewish ethnic distribution was similar to that of the general population and the point prevalence rate estimated as 28.4/one million Jewish inhabitants. There were 461 first-degree relatives at-risk for FAP. Genetic screening was completed and successful in 28 pedigrees (87.5%), and 73 FAP patients entered the registry. Marked intra- familial phenotypic variations with minimal disease manifestation were noted in 11 patients belonging to 4 pedigrees. Cancer occurred in 15.1% (11 patients), in 10 before FAP diagnosis or during follow- up elsewhere, but one non-compliant patient developed duodenal cancer. One other patient died from a massive, neglected, intra- abdominal desmoid. Compliance for evaluation and follow-up of pedigree members and individual FAP patients was inadequate in 29% and 27%, respectively.

CONCLUSIONS

FAP occurs in the Israeli Jewish population at the expected rate, but is inadequately recognized in non-Jews. The inadequate compliance for screening and post-surgical follow-up needs to be addressed by educating the public, health care workers and Health Insurers.

Preventive surgery for colon cancer in familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer syndrome

BACKGROUND

A better understanding of the molecular basis of hereditary colorectal cancer syndromes such as hereditary nonpolyposis colorectal cancer syndrome (HNPCC) and familial adenomatous polyposis (FAP) has profound consequences for both the diagnosis and (prophylactic) treatment of (pre)malignant neoplastic lesions.

DISCUSSION

Sequence analysis of the underlying genes for these conditions and the detection of disease-causing genetic alterations in an index patient enable predictive testing for individuals at risk within an affected family. However, the clinical implications of predictive molecular testing depend on the overall penetrance and variability in the expression of pathogenic mutations. The extent of these parameters differs considerably among the various known hereditary colorectal cancer syndromes. Hence the integration of genetic information into the daily surgical practice remains challenging.

CONCLUSIONS

This review provides an update on the indications for family assessment, purpose and limitations of the genetic testing and resulting recommendations for prophylactic surgery in FAP and HNPCC.

Outcome of primary and secondary ileal pouch-anal anastomosis and ileorectal anastomosis in patients with familial adenomatous polyposis

PURPOSE

The aim of this study was to present Swedish experiences of the ileal pouch-anal anastomosis in patients with familial adenomatous polyposis from the introduction in 1984. The study also compared the surgical and functional outcome of different anal continence preserving procedures: ileal pouch-anal anastomosis as primary surgery, ileal pouch-anal anastomosis as secondary surgery after colectomy and ileorectal anastomosis, and ileorectal anastomosis alone.

METHODS

The material comprises all 120 patients with familial adenomatous polyposis reported to the Swedish Polyposis Registry who had undergone prophylactic colorectal surgery, including those operated on because of colorectal cancer from 1984 until the end of 1996. Anal continence preserving surgery was performed on 102 patients: 20 had ileal pouch-anal anastomosis as primary surgery at a median age of 24.5 years, 39 had ileal pouch-anal anastomosis as secondary surgery at a median age of 34 years, and 43 had ileorectal anastomosis alone, at a median age of 26 years, because 6 of the initially ileorectal anastomosis-operated patients were converted to ileal pouch-anal anastomosis as secondary surgery. Surgical outcome was assessed on the basis of hospital records. A questionnaire was used to evaluate the functional outcome. Fisher's exact probability test was used for statistical analysis.

RESULTS

Complications occurred in 51 percent of the patients after ileal pouch-anal anastomosis: 40 percent after ileal pouch-anal anastomosis as primary surgery and 56 percent after ileal pouch-anal anastomosis as secondary surgery. When the previous ileorectal anastomosis was taken into account 67 percent of the patients suffered complications which was significantly more compared with ileal pouch-anal anastomosis as primary surgery. After ileorectal anastomosis, 26 percent had complications which was significantly less compared with all other procedures but ileal pouch-anal anastomosis as primary surgery. No cancer occurred after ileal pouch-anal anastomosis, either in the ileal pouch or in retained rectal mucosa, but two of the patients who had an ileorectal anastomosis developed rectal cancer. One pouch excision was performed compared with ten rectal excisions. Functional outcome did not differ between ileal pouch-anal anastomosis as primary surgery and ileal pouch-anal anastomosis as secondary surgery. However, ileorectal anastomosis-operated patients had significantly better bowel function with regard to nighttime stool frequency, continence and perianal soreness.

CONCLUSION

These findings indicate that major advantages of ileal pouch-anal anastomosis are the low excision rate and, so far, no cancer in the ileal pouch. Moreover, the surgical outcome of ileal pouch-anal anastomosis as primary surgery is not significantly different from that of ileorectal anastomosis. However, the good surgical and functional outcome of ileorectal anastomosis, despite the long-range prognosis including rectal cancer and excision risks, has to be taken into consideration when selecting patients with familial adenomatous polyposis for primary surgery.

Adenomatous polyps develop commonly in the ileal pouch of patients with familial adenomatous polyposis

PURPOSE

The aim of this study was to establish the prevalence of adenomatous polyps in the ileal pouch of patients with familial adenomatous polyposis.

METHOD

Forty-three patients who had an ileal pouch for familial adenomatous polyposis were invited to have a careful endoscopic examination of their pouch, including dye spraying. The number of polyps was recorded, and up to ten were biopsied. In addition, four random biopsy specimens were taken from the proximal and four from the distal pouch.

RESULTS

Thirty-three patients with a median age of 36 (range, 14-63) years who had a pouch (5 Kock and 28 pelvic) for a median of 7 (range, 1-19) years accepted the invitation. Twenty-one patients (64 percent) had endoscopically identified polyps, the number of polyps ranging from 1 to 100 (median, 10) and varying in size from 1 to 3 mm. Fourteen patients (42 percent) had adenomatous polyps and 4 of these also had microadenomas on random biopsies. Nine of the 14 patients with adenomas also had lymphoid polyps. Seven patients had lymphoid polyps only and two of these patients had a microadenoma on random biopsy. Four of 12 patients with no visible polyps had microadenomas in their random biopsies. The presence of adenomatous polyps (Pearson's correlation; P < 0.01) increased with the age of the pouch. In total, 20 of 33 (60 percent) patients had adenomas and or microadenomas.

CONCLUSION

Adenomatous polyps occur frequently in ileal pouches. These findings are of concern, and therefore, regular surveillance seems warranted until the natural history of these adenomatous polyps is determined.

Familial adenomatous polyposis: prevalence of adenomas in the ileal pouch after restorative proctocolectomy

OBJECTIVES

To determine the prevalence of adenomas in ileal pouches from patients with familial adenomatous polyposis (FAP) and to determine whether a correlation exists between the presence of pouch adenomas and duodenal adenomas and the site of the adenomatous polyposis coli gene mutation.

SUMMARY BACKGROUND DATA

Restorative proctocolectomy can markedly reduce the risk of colorectal adenocarcinoma in FAP patients. However, adenomas with the potential to progress to adenocarcinoma can develop in the duodenum, ileum, and continent ileostomy after restorative proctocolectomy. More recently, adenomas have been described in the ileal pouch after ileoanal anastomosis.

METHODS

Pouch endoscopy was offered to 167 patients with FAP who had undergone restorative proctocolectomy between January 1984 and December 1996.

RESULTS

Adenomas were found in 35% of the 85 ileal pouches examined. No invasive carcinomas were noted. The risk of developing one or more adenomas at 5, 10, and 15 years was 7%, 35%, and 75%, respectively. Patients with adenomas were more likely to have duodenal and ampullary adenomas. No correlation was detected between adenoma development and the site of the adenomatous polyposis coli mutation.

CONCLUSIONS

Adenomas are frequently found in the ileal pouch of patients after restorative proctocolectomy for FAP. Regular endoscopic surveillance of the pouch is recommended at a frequency similar to that of upper gastrointestinal endoscopy.

Risk factors for rectal cancer morbidity and mortality in patients with familial adenomatous polyposis after colectomy and ileorectal anastomosis

PURPOSE

The aims of the study were to investigate the effects of ileorectal anastomosis and the follow-up program on rectal cancer morbidity and mortality and to identify risk factors that predict the fate of the rectal stump.

METHODS

One hundred ninety-five patients with familial adenomatous polyposis on whom an ileorectal anastomosis was performed between 1957 and the end of 1995 were included. Median follow-up time was 14 (range, 1-39) years. The cumulative risks of rectal cancer and rectal excision were estimated using survival analysis.

RESULTS

Eighteen patients (9.2 percent) developed cancer, 17 in the retained colorectal segment and one on the ileal side of the anastomosis, and nine died of their cancer during the study period. The cumulative rectal cancer morbidity and mortality 20 years after ileorectal anastomosis was 12.1 percent (95 percent confidence interval = 5.7-18.5) and 7 percent (95 percent confidence interval = 2-12), respectively. The cumulative age-dependent risk of rectal cancer was 22.9 percent (95 percent confidence interval = 11.4-34.5) and 25.7 percent (95 percent confidence interval = 13.2-38.2) at the ages of 60 and 70 years, respectively. The corresponding cumulative mortality was 11.1 percent (95 percent confidence interval = 2.9-19.3) at the age of 70 years. Patients with dense polyposis at colectomy had an increased risk for cancer in the retained colorectal segment compared with patients with intermediate or sparse polyposis (P = 0.04). Sixty-six patients (34 percent) had their rectum removed, and the cumulative rectal excision rate 35 years after ileorectal anastomosis was 65.5 percent (95 percent confidence interval = 53-78).

CONCLUSION

Patients on whom ileorectal anastomosis was performed had, despite the high rectal excision rate, a substantial risk of developing cancer in the retained colorectal segment, with an ensuing high mortality. Our results indicate that patients with dense polyposis should undergo restorative proctocolectomy as primary operation for familial adenomatous polyposis. In younger patients with intermediate or sparse polyposis and good expected follow-up compliance, ileorectal anastomosis still is an alternative.

Aberrant crypt foci in colorectal carcinogenesis. Cell and crypt dynamics

Aberrant crypt foci (ACF) have been identified on the colonic mucosal surface of rodents treated with colon carcinogens and of humans after methylene-blue staining and observation under a light microscope. Several lines of evidence strongly suggest that ACF with certain morphological, histological, cell kinetics, and genetic features are precursor lesions of colon cancer both in rodents and in humans. Thus, ACF represent the earliest step in colorectal carcinogenesis. This paper has the main purpose of reviewing the evidence supporting this view, with particular emphasis on cell and crypt dynamics in ACF. ACF have been used as intermediate biomarkers of cancer development in animal studies aimed at the identification of colon carcinogens and chemopreventive agents. Recently, evidence has also shown that ACF can be effectively employed in chemopreventive studies also in humans.

In vivo observation of the ileal microadenoma in familial adenomatous polyposis

Microadenomas or aberrant crypt foci (ACFs) are regarded as early neoplastic lesions that precede the development of macroscopic adenomas. The aim of this study was to characterize surface features of ileal microadenomas in patients with familial adenomatous polyposis (FAP). Magnifying ileoscopy was performed in 19 patients with FAP. A histologically verified adenomatous tubule, the existence of which was suggested by magnified observation, was regarded as a microadenoma. Magnifying ileoscopy detected microadenoma in five patients. In four of the five cases, the ileal microadenomas were identified as areas with tiny crypt openings or serrated surfaces, which were distinctive of nonneoplastic, diminutive protrusions. Magnifying ileoscopy seems to be useful in the detection of ileal microadenomas.