Gastrointestinal polyposis syndromes

Surgical management of abdominal desmoids: a systematic review and meta-analysis

BACKGROUND

Desmoid tumours are benign fibromatous tumours arising from dysregulated myofibroblast proliferation within musculoaponeurotic structures. They can occur sporadically but more commonly are associated with genetic syndromes such as familial adenomatous polyposis [1] (FAP). Mutations in either the Wnt, β-catenin or APC genes are 'key' triggers for the development of these tumours [5]. Classically, these tumours do not metastasise; however, they are associated with significant morbidity and mortality due to their infiltrative pattern and/or local invasion. Historically, surgical resection was the cornerstone of treatment. There remains paucity of data regarding outcomes following the surgical management of abdominal desmoid tumours in terms of success, recurrence and morbidity.

OBJECTIVES

The aim of this review was to assess the current evidence for surgical management of abdominal desmoid tumours in terms of success, recurrence and morbidity.

METHODS

A systematic search of articles in PubMed, EMBASE and The Cochrane Library databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for the period from January 2000 to November 2020.

RESULTS

Twenty-three studies were included, of which, 749 patients had surgical resection (696 for primary and 53 for recurrent desmoids), 243 patients (18.8%) were medically managed and 353 patients (27.3%) underwent surveillance. Median follow-up was 51.4 months (range 1-372). Six-hundred and ninety-six of the 749 resections (92.9%) underwent primary desmoid resection, with the remaining 53 (7.1%) undergoing resection for recurrence. One-hundred and two surgically managed patients (19%) developed a (re)recurrence, with mesenteric involvement the commonest site for recurrence (55%). When comparing recurrence post-surgery to progression following medical therapy, there was a trend towards better outcomes with surgery, with 25% of surgical patients having a recurrence versus 50.5% having progression with medical therapy [OR 0.40 (95% CI 0.06-2.70), p = 0.35]. Major morbidity following surgery was 4.4% (n = 33) with 2% (n = 14) mortality within 30 days of resection.

CONCLUSION

The management of desmoids has considerable heterogeneity. Surgical resection for abdominal desmoids remains a valid treatment option in highly selective cases where negative margins can be obtained, with low major morbidity and/or mortality.

Progress in surgical treatment of familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominant genetic disease with a high tendency to develop colorectal cancer. The timing and choice of preventive surgical interventions should be based on the number, size and severity of adenomas, combined with a variety of considerations, in order to effectively prevent cancer and make patients easy to accept. Total proctocolectomy and ileal pouch-anal anastomosis (IPAA) procedure, which could minimize the residual rectal mucosa and reduce the risk of adenoma recurrence, has become the first choice for patients with FAP. Besides, laparoscopic IPAA has obvious advantages such as cosmetic appearance, quick recovery, little adhesion and high pregnancy rate. Patients with FAP should be managed by experienced surgeons working in specialized medical centers in order to get the most reasonable treatment at the best time and achieve long-term effective outcomes.

Management of desmoid tumours: A large national database of familial adenomatous patients shows a link to colectomy modalities and low efficacy of medical treatments

BACKGROUND

Desmoid tumours represent a major complication of familial adenomatous polyposis. Our aims were to study the factors associated with the development of desmoid tumours in familial adenomatous polyposis patients, and to describe presentation and management of desmoid tumours.

METHODS AND PATIENTS

We reviewed all patients with familial adenomatous polyposis followed at our institution between 1965-2013, with either identified adenomatous polyposis coli gene mutation, or a personal and family history suggesting adenomatous polyposis coli-related polyposis. Response to treatment of desmoid tumours was assessed by Response Evaluation Criteria In Solid Tumor (RECIST) criteria.

RESULTS

A total of 180 patients with familial adenomatous polyposis were included with a median follow-up of 19 years since diagnosis. Thirty-one (17%) patients developed 58 desmoid tumours, a median (range) 4.7 (0.8-41.6) years after their diagnosis of familial adenomatous polyposis. The only factor significantly associated with occurrence of desmoid tumours was the type of surgery: 12 (12%) desmoid tumours in 104 patients treated by colectomy, versus 19 (25%) desmoid tumours in 76 patients treated by proctocolectomy, p = 0.027. The localisation of desmoid tumours was: mesenteric (n = 25), abdominal wall (n = 30) or extra-abdominal (n = 3). Nineteen patients underwent 36 surgical procedures for desmoid tumours. Recurrence occurred in 26 (72%) cases and the recurrence-free survival was 2.6 (95% confidence interval (CI), 0.2-5.9) years. Thirteen patients received 27 medical treatments over a median 14 months. Objective response was observed in four (15%) patients and the median progression-free survival was nine (95% CI, 1.1-16.9) months.

CONCLUSION

If confirmed, colectomy (versus proctocolectomy) should be performed in adenomatous polyposis coli-related familial adenomatous polyposis patients to avoid desmoid tumours. We show that there is a high prevalence of post-surgical recurrence and the low efficacy of available medical treatments for desmoid tumours.

Surgical considerations in FAP-related pouch surgery: Could we do better?

The ileoanal pouch has become the standard restorative procedure of choice for patients with the classical phenotype in FAP (familial adenomatous polyposis) and also for ulcerative colitis (UC). Whilst we tend to encounter descriptive analyses comparing functional outcome, fertility and quality of life (QOL) between series in literature, there may be an urgent need to discuss the subtle technical modifications that may be pivotal for improving long-term QOL in FAP patients. Our aim is to review the current literature and discuss the aspects of ileal pouch-anal anastomosis that may require specific reevaluation for FAP. Surgical strategies aimed at minimizing post-interventional desmoid growth is one of the most important aspects. For this study, the following topics of interest were selected: Timing of surgery, IRA or ileoanal pouch for classical FAP, laparoscopic or conventional surgery, TME or mesenteric dissection, preservation of the ileocolic vessels, handsewn or double-staple anastomosis, shape and size of pouch, protective ileostomy, Last and definitely not least: how to manage desmoid plaques or desmoids at the time of prophylactic surgery. For the depicted technicalities of the procedure, a review of recent literature was performed and evaluated. For the topics selected, only sparse reference in literature was identified that was focused on the specific condition situation of FAP. Almost all pouch literature focusses on the procedural aspects, and FAP patients are always a very minor number. Therefore it becomes obvious that the specific entity is not adequately taken into account. This is a serious bias for identification of important steps in the procedure that may be beneficial for patients with either of the diseases. The results of this study demonstrate that several technical differences for construction of ileoanal pouches in FAP patients deserve more attention and prospective evaluation-perhaps even randomized trials. The role, importance and potential benefit or deterioration of outcome in most of the discussed technicalities remains unclear to date. Significant differences between the underlying diseases (UC and FAP) have not been taken into consideration, such as specifically the management of precursor desmoid lesions at the time of prophylactic surgery as well as prevention of desmoid tumors. Several of the aspects discussed in this paper should be prospectively evaluated in larger and exclusive series of FAP patients.

Prophylactic surgery in familial adenomatous polyposis (FAP)--a single surgeon's short- and long-term experience with hand-assisted proctocolectomy and smaller J-pouches

PURPOSE

Prophylactic proctocolectomy with an ileoanal neo-reservoir is the established procedure in non-attenuated familial adenomatous polyposis (FAP). Traditionally, the ileal J-pouch is created by doubling 15 cm of the terminal ileum. Pouch inlet problems are not infrequently encountered in longer pouches. On this rationale, this series reports on the functional outcome and quality of life (QoL) following standardized construction of a shorter J-pouch with a limb of 8-9 cm length.

METHODS

All patients of a single-surgeon series with FAP who underwent hand-assisted laparoscopic proctocolectomy and small ileal pouch-anal anastomosis as the primary procedure between 10/2005 and 04/2010 and responded to the questionnaire were included and retrospectively analyzed.

RESULTS

A total of 46 patients (78 %) out of the consecutive series who underwent operation in this period were included in the study. After a mean follow-up of 38 months, 40/46 patients (87 %) did not report any incontinence and 3 patients (6.5 %) complained about occasional nocturnal incontinence (3 failed to answer this question). The mean stool frequency per 24 h was 6.25. No significant difference was encountered between the QoL outcome of our patients versus the German normative population. Comparable results were achieved in a study analyzing the long-term results in FAP patients with a 15-cm pouch.

CONCLUSIONS

Smaller, 8-9 cm J-pouches show excellent functional results both in short- and in long-term results. The hand-assisted procedure was safe and no conversions were required. QoL is equal to a normative population, as it is in a series of patients with larger J-pouches.

Segmental vs extended colectomy in the management of hereditary nonpolyposis colorectal cancer: a systematic review and meta-analysis

AIM

The optimal surgical approach to the management of colorectal cancer in the setting of hereditary nonpolyposis colorectal cancer (HNPCC) is contentious. While some advocate total colectomy, others perform segmental resection followed by regular endoscopic surveillance. This systematic review evaluates the evidence for segmental colectomy (SC) and total (extended) colectomy (TC) in the management of HNPCC.

METHOD

Two major databases (PubMed and Cochrane) were searched using predefined terms. All original articles, published in English, comparing the oncological outcomes of SC and TC in HNPCC patients from January 1950 to July 2013 were included.

RESULTS

Eighty-four studies were identified. After applying exclusion criteria, six studies involving 948 patients were included (mean age 47.4 years, 51.8% male). SC was more commonly performed than TC (n = 780; 82.3%). Mean follow-up was 106.5 months. Metachronous high-risk adenomas were detected more often after SC, although the difference was not statistically significant (23.4% vs 9.6%; OR 2.258, P = 0.057). Metachronous cancers occurred more frequently after SC than after TC (23.5% vs 6.8%; OR 3.679, P < 0.005). However, there was no difference in overall survival (90.7% vs 89.8% for SC and TC, respectively; P = 0.085). Only one study reported operative mortality (0% in each group), there was no report of operative morbidity or functional outcome.

CONCLUSION

The optimal surgical approach in the management of HNPCC remains unclear. More adenomas and cancers occur after SC than after TC but there certainly is no evidence to suggest that more radical surgery leads to improved survival.

ACG clinical guideline: Genetic testing and management of hereditary gastrointestinal cancer syndromes

This guideline presents recommendations for the management of patients with hereditary gastrointestinal cancer syndromes. The initial assessment is the collection of a family history of cancers and premalignant gastrointestinal conditions and should provide enough information to develop a preliminary determination of the risk of a familial predisposition to cancer. Age at diagnosis and lineage (maternal and/or paternal) should be documented for all diagnoses, especially in first- and second-degree relatives. When indicated, genetic testing for a germline mutation should be done on the most informative candidate(s) identified through the family history evaluation and/or tumor analysis to confirm a diagnosis and allow for predictive testing of at-risk relatives. Genetic testing should be conducted in the context of pre- and post-test genetic counseling to ensure the patient's informed decision making. Patients who meet clinical criteria for a syndrome as well as those with identified pathogenic germline mutations should receive appropriate surveillance measures in order to minimize their overall risk of developing syndrome-specific cancers. This guideline specifically discusses genetic testing and management of Lynch syndrome, familial adenomatous polyposis (FAP), attenuated familial adenomatous polyposis (AFAP), MUTYH-associated polyposis (MAP), Peutz-Jeghers syndrome, juvenile polyposis syndrome, Cowden syndrome, serrated (hyperplastic) polyposis syndrome, hereditary pancreatic cancer, and hereditary gastric cancer.

Juvenile polyposis syndrome

Juvenile polyposis syndrome (JPS) is an autosomal dominant predisposition to the occurrence of hamartomatous polyps in the gastrointestinal tract. Diagnosis of JPS is based on the occurrence of numerous colon and rectum polyps or any number of polyps with family history and, in the case of juvenile polyps, their occurrence also outside the large intestine. The JPS is caused by mutations in SMAD4 and BMPR1A. Products of the SMAD4 gene are involved in signal transduction in the transforming growth factor β pathway and BMPR1A protein is a receptor belonging to the family of transmembrane serine/threonine kinases. Both proteins are responsible for processes determining appropriate development of colonic mucosa. The JPS belongs to the group of hamartomatous polyposes. The hamartomatous polyposis syndromes constitute a group of diseases in which manifestations differ slightly and only molecular diagnostics gives the possibility of verifying the clinical diagnosis.

Serrated polyps detected during screening colonoscopies

AIM OF THE STUDY

It is estimated that between 15% and 35% of sporadic colorectal cancers (CRC) developing from adenomas come from serrated polyps. Currently, the most effective method used to prevent CRC is the removal of adenomas, including serrated polyps, during colonoscopy. The aim of this paper is to analyze the changes characterized as serrated polyps and detected during screening colonoscopies performed as part of the Screening Program for Early Colorectal Cancer Detection (SPED).

MATERIAL AND METHODS

In our center, as part of the nationwide SPED between 2000 and 2009, 1,442 screening colonoscopies were performed.

RESULTS

Serrated polyps were found in 11.9% of all patients and in 45.8% of patients who had polyps removed by endoscopy. In screening colonoscopy of the large intestine, the following polyps were found most frequently: hyperplastic, < 1 cm, without a stalk, multiple, located in the distal part of the large intestine, in men and in patients with a first-degree relative with a history of abdominal cancer. Detecting and removing polyps was facilitated by the fact that the cecum was intubated and the bowel preparation had been performed either very well or well. The detection rate of serrated polyps was not influenced by patients' place of residence or their age.

CONCLUSIONS

Serrated polyps constitute a frequent, and very frequent among removed polyps, abnormality detected during screening colonoscopy.

Surgical treatment of familial adenomatous polyposis: experience from a single institution in China

AIM

Surgical options for familiar adenomatous polyposis (FAP) have been standardized in developed countries but are still controversial in China. The aim of this study was to retrospectively evaluate the results of patients with FAP treated in a university hospital.

METHODS

In all 42 consecutive patients with FAP were operated on between May 1988 and June 2008. Median follow up was 7.2 years (2.2-20 years). Of these 33 patients were treated by proctocolectomy and ileal pouch anal anastomosis. A total colectomy with ileorectal anastomosis was undertaken in six and a proctocolectomy with ileostomy in three patients who had invasive rectal cancer.

RESULTS

Postoperative morbidity was insignificant. There were five wound infections, one intestinal obstruction, one anastomotic leakage, one anastomotic stenosis and one refractory pouchitis. One patient died from stroke. Five died from FAP-related disorders, namely, abdominal desmoids, liver metastases and advanced rectal cancer. Desmoid tumor occurred in five patients. Periampullary adenoma and carcinoma developed in four patients. In those with pouch procedure the 24-h bowel movement was 7.14 ± 1.28 (range 5-11) and their 10-year overall survival was 87.5%.

CONCLUSION

A proctocolectomy with ileal pouch anal anastomosis maybe the best choice for FAP patients in China. Surgical expertise, good teamwork and careful long-term follow up are mandatory.

Lower gastrointestinal tract cancer predisposition syndromes

Although inherited predisposition to colorectal cancer (CRC) has been suspected for more than 100 years, definitive proof of Mendelian syndromes had to await maturation of molecular genetic technologies. Since the l980s, the genetics of several clinically distinct entities has been revealed. Five disorders that share a hereditary predisposition to CRC are reviewed in this article.

Colonic adenomatous polyposis syndromes: clinical management

Colorectal cancer is one of the major causes of cancer deaths in both men and women. It is estimated that 5 to 10% of patients with colorectal cancer have an inherited germline mutation that predisposes them to cancer. Hereditary colorectal cancer syndromes can be divided into those associated with colonic polyposis - familial adenomatous polyposis (FAP), attenuated familial adenomatous polyposis (aFAP), and MYH associated polyposis (MAP), and those not associated with colonic polyposis - hereditary nonpolyposis colon cancer (HNPCC). The hereditary polyposes are usually easier to diagnose than HNPCC, but their higher penetrance and variable phenotype pose some difficult problems in management and surveillance. The timing and type of surgical intervention, the management of desmoid risk, the treatment of rectal or pouch neoplasia, and the management of duodenal neoplasia are all questions that must be addressed in patients with FAP or MAP.

Surgical management of colorectal cancer: A review of the literature

BACKGROUND

Colon cancer management continues to evolve with significant advances in chemotherapy, surgical technique and palliative interventions. As the options of therapy have improved, so have the challenges of management of primary colon cancer.

REVIEW

A review of historical and up to date literature was undertaken utilising Medline/PubMed to examine relevant topics of interest-related to the surgical management. Enhanced knowledge of genetics associated with colon cancer has improved our care of patients with hereditary colon cancer syndromes. Additionally, traditional approaches to surgical intervention for primary colon cancer have been questioned and will be discussed in this review including the role of laparoscopy, use of mechanical bowel preparation, management of the primary tumour in the face of metastatic disease, as well as the role of palliative intervention in select patients.

CONCLUSION

Colon cancer has seen improvement and expansion of therapeutic approaches to primary colon cancer. Laparoscopy and palliative interventions have become widely accepted with level I evidence to demonstrate good patient outcomes. Traditional dogma with mechanical bowel preparation has been challenged and debunked with regards to the efficacious benefits previously accepted. The management of the primary tumour has now become increasingly complex as it appears to be a reasonable approach to manage the primary tumour non-operatively in select cases of extracolonic disease requiring management.

Article Commentary: Surgical Prophylaxis for Inheritable Malignant Diseases: Colorectal and Gastric Cancer

Despite advances in modern medicine, cancer remains all too common and deadly. At its core, cancer is a disease of our DNA. As such, many cancers are passed from parents to children, making cancer one of the most commonly inherited diseases. Presently, we have no meaningful methods of “preventing” the malignant transformation that occurs as a result of an inherited gene, but investigators have identified several genetic mutations and subsequently developed risk-reduction strategies that sometimes involve surgery.

Pancreaticoduodenectomy for Dysplastic Duodenal Adenoma in a Patient with Familial Adenomatous Polyposis

Colorectal polyposis is the main feature of familial adenomatous polyposis (FAP), but benign and malignant lesions have also been described in the stomach, duodenum, small bowel, biliary tract and pancreas. There are few reports on FAP patients with duodenal polyps that developed at a younger age and even fewer on cases with dysplastic degeneration. The progression to carcinoma usually presents quite late in the clinical history of FAP patients, typically at least 20 to 25 years after proctocolectomy. This report described the rare case of a patient presenting with duodenal adenomas with dysplastic changes and tumor infiltration as the first sign of FAP, who was treated by pancreaticoduodenectomy followed by proctocolectomy for subsequent dysplastic changes in colonic polyps.

Câncer ano-reto-cólico: aspectos atuais II - câncer colorretal - fatores de riscos e prevenção

O câncer colorretal é curável e passível de prevenção. A chave para o alcance desses objetivos é relativamente simples e pode ser aplicada em escala populacional. Basta, para tanto, que sejamos capazes de conscientizar os médicos, independente da sua área especial de atuação, e proporcionar às pessoas o mais fácil alcance às informações médicas expressas em termos simples sobre a profilaxia e o diagnóstico precoce dessa neoplasia maligna, sobretudo, destacando os fatores protetores e os de riscos, principalmente os que são suscetíveis de ser modificados.

[Intestinal and extraintestinal manifestations in familial adenomatous polyposis]

<zakljucak> U radu su opisane intestinalne i ekstraintestinalne manifestacije familijarne adenomatozne polipoze koje mogu imati dijagnosticki i prognosticki znacaj. Pojava tumora izvan kolona znacajna je za razvoj ozbiljnih simptoma bolesti (opstrukcija, krvarenje), ali i za malignu alteraciju i razvoj karcinoma, posebno u duodenumu (karcinom duodenuma i dezmoidni tumori su najcesci uzrok smrti kod bolesnika sa familijarnom adenomatoznom polipozom nakon kolekotmije). Poseban znacaj imaju dezmoidni tumori, koji su benigni po svojoj prirodi, ali koji lokalnom invazijom mogu dovesti do smrtnog ishoda, a najcesce ispoljavaju tendenciju rasta nakon hirurske resekcije creva. Kongenitalna hipertrofija pigmentnog epitela retine je prediktivni marker koji omogucava postavljanje dijagnoze familijarne adenomatozne polipoze i pre otkrivanja adenoma debelog creva.

Single-amplicon MSH2 A636P mutation testing in Ashkenazi Jewish patients with colorectal cancer: role in presurgical management

OBJECTIVE

This study summarizes our initial experience with prospective, single-amplicon (mutation-specific) A636P testing in Ashkenazi Jewish patients at risk for Hereditary Nonpolyposis Colorectal Cancer (HNPCC).

SUMMARY BACKGROUND DATA

We previously described a founder mutation, MSH2*1906G >C (A636P) that causes HNPCC in 8/1345 (0.59%) of Ashkenazim with colorectal cancer. The mutation was more common in Ashkenazim diagnosed at <or=40 years (7%).

METHODS

Twenty-seven Ashkenazi probands at risk for HNPCC were ascertained. Single-amplicon A636P testing was performed on 21 by polymerase chain reaction of exon 12 of MSH2, followed by direct DNA sequencing. Mutational analysis of the entire open reading frame of MLH1 and MSH2 was performed on 7 by PCR of each exon, followed by heteroduplex analysis using denaturing high-performance liquid chromatography and direct sequencing of exons with variant chromatographs. One patient received both studies,

RESULTS

The A636P mutation was detected in 3/21 (14%) prospectively evaluated patients using single amplicon testing. In 6 patients, the entire open reading frame of MLH1 and MSH2 was analyzed, and 1 additional A636P carrier and 2 carriers of previously unrecognized mutations were identified. The A636P mutation was present in 2 patients who met Amsterdam criteria and in 2 patients who did not.

CONCLUSIONS

Although rare in the general population, A636P mutations are found at increased frequency in Ashkenazim with a personal or family history of colorectal or other HNPCC-associated cancers. This inexpensive and rapid approach may be useful preoperatively in helping determine the extent of colon resection for a subset of patients.

ASCO/SSO review of current role of risk-reducing surgery in common hereditary cancer syndromes

BACKGROUND

A significant portion of cancers are accounted for by a heritable component, which has increasingly been linked to mutations in specific genes. Clinical interventions have been formulated for mutation carriers within affected families. The primary interventions for mutation carriers of highly penetrant syndromes are surgical.

METHODS

The American Society of Clinical Oncology and the Society of Surgical Oncology formed a task force charged with presenting an educational symposium on surgical management of hereditary cancer syndromes at annual society meetings, and this resulted in a position paper on this topic. The content of both the symposium and the position paper was developed as a consensus statement.

RESULTS

This article addresses hereditary breast, colorectal, ovarian/endometrial, and multiple endocrine neoplasias. A brief introduction on the genetics and natural history of each disease is provided, followed by detailed descriptions of modern surgical approaches, clinical and genetic indications, timing of prophylactic surgery, and the efficacy of surgery (when known). Although several recent reviews have addressed the role of genetic testing for cancer susceptibility, this article focuses on the issues surrounding surgical technique, timing, and indications for surgical prophylaxis.

CONCLUSIONS

Risk-reducing surgical treatment of hereditary cancer is a complex undertaking. It requires a clear understanding of the natural history of the disease, realistic appreciation of the potential benefits and risks of these procedures in potentially otherwise healthy individuals, and the long-term sequelae of such interventions, as well as the individual patient's and family's perceptions of surgical risk and anticipated benefit.

ASCO/SSO review of current role of risk-reducing surgery in common hereditary cancer syndromes

Although the etiology of solid cancers is multifactorial, with environmental and genetic factors playing a variable role, a significant portion of the burden of cancer is accounted for by a heritable component. Increasingly, the heritable component of cancer predispositions has been linked to mutations in specific genes, and clinical interventions have been formulated for mutation carriers within affected families. The primary interventions for mutations carriers for highly penetrant syndromes such as multiple endocrine neoplasias, familial adenomatous polyposis, hereditary nonpolyposis colon cancer, and hereditary breast and ovarian cancer syndromes are primarily surgical. For that reason, the American Society of Clinical Oncology (ASCO) and the Society of Surgical Oncology (SSO) have undertaken an educational effort within the oncology community. A joint ASCO/SSO Task Force was charged with presenting an educational symposium on the surgical management of hereditary cancer syndromes at the annual ASCO and SSO meetings, resulting in an educational position article on this topic. Both the content of the symposium and the article were developed as a consensus statement by the Task Force, with the intent of summarizing the current standard of care. This article is divided into four sections addressing breast, colorectal, ovarian and endometrial cancers, and multiple endocrine neoplasia. For each, a brief introduction on the genetics and natural history of the disease is provided, followed by a detailed description of modern surgical approaches, including a description of the clinical and genetic indications and timing of prophylactic surgery, and the efficacy of prophylactic surgery when known. Although a number of recent reviews have addressed the role of genetic testing for cancer susceptibility, including the richly illustrated Cancer Genetics and Cancer Predisposition Testing curriculum by the ASCO Cancer Genetics Working Group (available through http://www.asco.org), this article focuses on the issues surrounding the why, how, and when of surgical prophylaxis for inherited forms of cancer. This is a complex process, which requires a clear understanding of the natural history of the disease and variance of penetrance, a realistic appreciation of the potential benefit and risk of a risk-reducing procedure in a potentially otherwise healthy individual, the long-term sequelae of such surgical intervention, as well as the individual patient and family's perception of surgical risk and anticipated benefit.

Familial adenomatous polyposis and mental retardation caused by a de novo chromosomal deletion at 5q15-q22: report of a case

Familial adenomatous polyposis, caused by mutations in the adenomatous polyposis coli gene located at chromosome 5q21, is an autosomal dominant syndrome characterized by polyposis of the colon and rectum and nearly 100 percent progression to colorectal cancer. We report a case of familial adenomatous polyposis and mental retardation caused by a chromosomal deletion at 5q15-q22. Chromosomal analysis is considered part of the evaluation of children with mental retardation and developmental delay. The resulting karyotypes from high-resolution chromosomal analysis can help characterize large deletions, some of which involve known tumor suppressor genes. Because familial adenomatous polyposis may arise from de novo chromosomal deletions involving the adenomatous polyposis coli gene locus, individuals with chromosomal deletions involving 5q21 should be considered at-risk for familial adenomatous polyposis and offered standard screening with flexible sigmoidoscopy by 10 to 12 years of age.

A636P testing in Ashkenazi Jews

Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominantly inherited colorectal cancer syndrome attributable to mutations in one of several DNA mismatch repair genes, most commonly MLH1 and MSH2 . In certain populations, founder mutations account for a substantial portion of HNPCC. In this report we summarize the literature and our personal experience testing for a specific founder mutation in the Ashkenazi Jewish population, MSH2*1906G > C , also known as A636P. Although rare in the general population, the A636P mutation is detected in up to 7% of Ashkenazi Jewish patients with early age-of-onset colorectal cancer, and may account for up to one third of HNPCC in the Ashkenazi Jewish population. In addition, we summarize our initial experience with a prospective A636P testing protocol aimed at Ashkenazi Jewish patients at high or intermediate risk for harboring the A636P mutation.

Highly penetrant hereditary cancer syndromes

The past two decades have brought many important advances in our understanding of the hereditary susceptibility to cancer. Approximately 5-10% of all cancers are inherited, the majority in an autosomal dominant manner with incomplete penetrance. While this is a small fraction of the overall cancer burden worldwide, the molecular genetic discoveries that have resulted from the study of families with heritable cancer have not only changed the way these families are counselled and managed, but have shed light on molecular regulatory pathways important in sporadic tumour development as well. In this review, we consider 10 of the more highly penetrant cancer syndromes, with emphasis on those predisposing to breast, colon, and/or endocrine neoplasia. We discuss the prevalence, penetrance, and tumour spectrum associated with these syndromes, as well as their underlying genetic defects.

A636P is associated with early-onset colon cancer in Ashkenazi Jews

BACKGROUND

Hereditary predisposition to colorectal cancer most often manifests itself as familial adenomatous polyposis from mutations of APC, or hereditary nonpolyposis colorectal cancer, resulting from mutations of MSH2, MLH1, MSH6, or other genes. Previously, we described a rare founder mutation MSH2*1906C > G in Ashkenazi Jews that was found in 8 of 1,345 individuals (0.6%) of Ashkenazi descent with colorectal cancer. This study seeks to characterize the proportion of individuals of Ashkenazi heritage with very early-onset colon cancer (diagnosed at age 40 or younger) that could be attributed to MSH2*1906C>G.

STUDY DESIGN

We analyzed the carrier frequency of MSH2*1906C>G in paraffin samples from 31 Jewish patients age 40 or less, diagnosed with colorectal cancer at Memorial Sloan-Kettering and lymphocyte-derived DNA from 10 patients. We did not select for family history. Genotyping for MSH2*1906C>G was performed by polymerase chain reaction and restriction enzyme digestion methods.

RESULTS

We detected the MSH2*1906G>C mutation in 3 of the 41 samples (7.14%) of patients who had colorectal cancer diagnosed at age 40 or younger. This incidence is significantly greater than the 8 in 1,345 (0.6%) we observed for cases of colorectal cancer in Ashkenazi Jews not selected for age (p = 0.004).

CONCLUSION

Although very rare in the population, MSH2*1906G>C is found at an increased frequency in young Jewish patients with colorectal cancer. These results suggest that testing for the MSH2*1906G>C mutation should be included in the evaluation of Ashkenazi Jewish individuals diagnosed with early-onset colon cancer.

Colorectal cancer screening

During the past decade we have seen dramatic advances in colon cancer screening. Reduction in mortality in average risk screening for colorectal cancer has now been shown in multiple trials. Efforts to increase public awareness and compliance with evidence-based screening guidelines are underway. Recent guidelines have incorporated family history, as it has been identified as a common risk factor. The genes responsible for the inherited syndromes of colon cancer have been identified and genetic testing is available. Currently, screening the average risk population over the age of 50 would reduce mortality from colon cancer by 50%. Future advances will likely include improved screening tests, and the development of familial genetic testing.

Long-term follow-up of patients with familial adenomatous polyposis undergoing pancreaticoduodenal surgery

Adenomatous polyps and adenocarcinomas of the periampullary region are the most common upper gastrointestinal neoplasms encountered in familial adenomatous polyposis (FAP) patients. Tumors arising from the liver, biliary tract, and pancreas have also been reported. The purpose of this study was to review the clinical outcome of FAP patients after pancreaticoduodenal surgery for periampullary neoplasms. Of the 61 individuals participating in our prospective FAP registry, 8 underwent surgical resection of periampullary neoplasms between 1987 and 1998. The charts of these individuals were reviewed for clinical indications, type of pancreaticoduodenal surgery, postoperative complications, and outcome. Of the 8 patients identified, 7 had pancreaticoduodenectomy and 1 had duodenotomy with ampullectomy. The indications for surgery were periampullary cancer (3), severe dysplasia within a duodenal villous tumor (4), and solid-pseudopapillary tumor of the pancreas (1). At the time of pancreaticoduodenal surgery, patients ranged in age from 29-65 years, and all but one had undergone colorectal surgery, on average 16 years beforehand. Pancreatic ascites after a pylorus-sparing pancreaticoduodenectomy was the only surgical complication. At a median follow-up of 70.5 months (range 37-162), 2 patients had died, neither from their periampullary neoplasm. The patient treated by local excision subsequently developed gastric cancer arising from a polyp and went on to gastrectomy. Another patient developed confluent benign jejunal adenomas just beyond the gastroenteric anastomosis almost 12 years after pancreaticoduodenectomy for severe dysplasia of a duodenal villous adenoma. Pancreaticoduodenectomy is a safe and appropriate surgical option for FAP patients with duodenal villous tumors containing severe dysplasia or carcinoma. Postoperative morbidity was minimal and there was no perioperative mortality. Good long-term prognosis can be expected in completely resected patients although subsequent proliferative and/or neoplastic lesions may still be detected in the gastrointestinal tract with prolonged follow-up.

Secondary prevention: screening and surveillance of persons at average and high risk for colorectal cancer

Secondary prevention of colorectal cancer with FOBT and endoscopy with polypectomy decreases cancer deaths. Other available modalities include genetic tests and imaging studies, but outcomes data are not yet available. Issues remain concerning the most appropriate test, the optimal intervals, and cost-efficacy. Patients may be stratified by personal and family risk, and specific strategies may be used. Newer developments in genetic tests and imaging, including virtual colonoscopy, hold promise for the future. The most important issue at present is to have people screened or surveilled by any of the recommended modalities.

Genetic insights into familial cancers-- update and recent discoveries

While the vast majority of cancers are believed to occur sporadically, most forms of cancer, both adult and paediatric, have a hereditary equivalent. In the case of adult malignancies, these include hereditary breast and ovarian cancer and syndromes such as the multiple endocrine neoplasias types 1 and 2 characterised by specific tumours of the endocrine gland system. In the case of paediatric malignancies, these include syndromes such as retinoblastoma and Wilms tumour. In a little over a single decade, we have seen a tremendous increase in the knowledge of the primary genetic basis of many of the familial cancer syndromes. The majority of familial syndromes are inherited as autosomal dominant traits including hereditary colon cancer and familial malignant melanoma, however, the genetics behind autosomal recessive disorders such as Bloom syndrome and Fanconi anaemia are also being elucidated. A third mode of inheritance less well understood in the setting of familial cancer is that of imprinting recently observed in a subset of families with inherited paraganglioma. In this review, we discuss 31 genes inherited in an autosomal dominant manner associated with 20 familial cancer syndromes. Genes inherited in an autosomal recessive manner linked to familial cancer syndromes are also discussed. The identification of genes associated with familial cancer syndromes has in some families enabled a 'molecular diagnosis' that complements clinical assessment and allows directed cancer surveillance for those individuals determined to be at-risk of disease.

Surgical management of intra-abdominal desmoid tumours

BACKGROUND

Intra-abdominal desmoids are uncommon neoplasms. The aggressive nature of these tumours and the potential for major morbidity secondary to resection can present a difficult surgical dilemma.

METHODS

Patients with histologically confirmed intra-abdominal desmoid tumours undergoing laparotomy were identified from a prospective database. Clinical features and outcomes in this group were evaluated.

RESULTS

The study group comprised 24 patients. Sixteen patients underwent complete resection of the tumour while eight had biopsy only, with or without intestinal bypass. Small intestinal resection was performed in 12 patients, including three who had a near-total enterectomy. Median follow-up was 62 months, with an actuarial overall survival rate of 73 per cent at 10 years. There was no difference in survival rate between completely resected and unresected patients (P = 0.73). There were seven deaths in the entire group, of which four were in those undergoing complete resection.

CONCLUSION

Operation can cure patients with intra-abdominal desmoid tumours, but may result in significant morbidity, especially from loss of small intestine. No other therapy is a predictably good alternative to operation but the natural history of desmoids is often characterized by prolonged periods of stability or even regression. A period of watchful waiting, until significant symptoms develop, may be the most appropriate course in patients who risk mesenteric vascular injury or substantial enterectomy with attempts at resection.