Desmoid tumours in familial adenomatous polyposis

Mortality of intra-abdominal desmoid tumors in patients with familial adenomatous polyposis: a single center review of 154 patients

INTRODUCTION

Intra-abdominal desmoid tumors are one of the leading causes of death in patients with familial adenomatous polyposis. Their behavior is unpredictable and their biology is poorly understood, accounting for the lack of a standardized medical and surgical approach. The aim of this study was to evaluate the mortality rate of patients with intra-abdominal desmoid tumors and to identify prognostic factors for the evolution of the disease.

MATERIALS AND METHODS

A total of 154 patients with intra-abdominal desmoid tumors were included in the study. Each tumor was staged and each patient was categorized according to the stage of their most advanced tumor. Mortality was analyzed and the univariate risk factors associated with survival were included in a multivariable Cox regression model. A scoring system was derived from the multivariate analysis to refine outcomes within stages.

RESULTS

Five-year survival of patients with stage I, II, III, and IV intra-abdominal desmoid tumor were 95%, 100%, 89%, and 76% respectively (P < 0.001). Severe pain/narcotic dependency, tumor size larger than 10 cm, and need for total parenteral nutrition were shown to further define survival within stages. Five-year survival rate of stage IV patient with all of the above-mentioned risk factors was only 53%.

CONCLUSIONS

Our study confirmed the validity of the staging system to predict mortality in patients with intra-abdominal desmoid tumors and identified additional risk factors able to better define the risk of death within each stage. Risk stratification is crucial in directing patients with advanced disease and poor prognosis to the most appropriate medical and surgical options.

Diagnosis and management of the intra-abdominal desmoid tumour

Desmoid tumours are a rare entity and are usually detected with a certain delay, as they initially often grow without causing any specific clinical symptoms. Although these tumours grow slowly and do not metastasise, their growth pattern remains aggressive and local tissue displacement or even destruction is common. Surgery remains the only potentially curative treatment option. Here we report on the findings of a 43-year old female patient with a large intra-abdominal desmoid tumour, resulting in the displacement of most intra-abdominal organs to the right of the patient’s abdominal cavity. She successfully underwent surgical removal of the mass and recovered without complications.

Risk factors predicting desmoid occurrence in patients with familial adenomatous polyposis: a meta-analysis

AIM

Desmoid tumours (DT) are myofibroblastic proliferations occurring in 15% of patients with familial adenomatous polyposis (FAP). Several small series have analysed the incidence of DT and predisposing risk factors. Using meta-analytical techniques, this study aimed to identify risk factors for DT development in patients with FAP.

METHOD

Studies of sporadic DT were excluded. The study end-points were the incidence of DT in FAP and DT development by gender, adenomatous polyposis coli (APC) mutation, family history of DT and previous abdominal surgery. A random effect Mantel-Haenszel model was used to calculate odds ratios for each risk factor and age group.

RESULTS

Ten studies of 4625 patients with FAP fulfilled our inclusion criteria. A total of 559 (12%) patients developed DT. Cumulative analysis demonstrated that 80% of DT developed by age 40, the peak incidence rate being in the second and third decades. A positive family history of DT was the most significant risk factor (OR 7.02, 95% CI 4.15-11.9, P < 0.001). An APC mutation 3' to codon 1399 (OR 4.37, 95% CI 2.14-8.91, P < 0.001) and previous abdominal surgery (OR 3.35, 95% CI 1.33-8.41, P = 0.01) were also implicated. Women were more likely to develop DT (OR 1.57, 95% CI 1.13-2.18, P = 0.007).

CONCLUSION

There is consistency amongst polyposis registries in documenting the incidence and risk factors for DT development. Having a positive family history for DT is of greater significance than a 3' mutation, suggesting the existence of modifier genes, independent of the APC genotype-phenotype correlation. Few of these risk factors are modifiable. Delaying prophylactic surgery could be appropriate in female patients with a 3' APC mutation and attenuated polyposis.

Family history, surgery, and APC mutation are risk factors for desmoid tumors in familial adenomatous polyposis: an international cohort study

BACKGROUND

Ability to identify patients with familial adenomatous polyposis who have a high risk of developing desmoid tumors may affect decisions in clinical practice.

OBJECTIVES

Our aim was to assess several risk factors for desmoid tumor development in an international cohort of patients with familial adenomatous polyposis and to evaluate the clinical relevance of risk factors.

DESIGN

This was a retrospective cohort study.

SETTING AND PATIENTS

Polyposis registries in The Netherlands, France, Denmark, Finland, and Italy provided information on familial adenomatous polyposis patients with desmoid tumors.

MAIN OUTCOME MEASURES

We used univariate and multivariable analyses of data from registries in The Netherlands, France, Denmark, and Finland to test whether gender, APC mutation site, previous colorectal surgery, colorectal cancer, and family history for desmoid tumors contribute to risk of developing desmoid tumors at any location, or specifically at an intra-abdominal location. The effect of family history was tested with a generalized linear mixed model.

RESULTS

: Of 2260 patients with familial adenomatous polyposis from 912 families in The Netherlands, France, Denmark, and Finland, 220 patients (10%) had desmoid tumors (101 men). In 387 patients with desmoid tumors (including 167 patients from the Italian registry), the median age at diagnosis of the first desmoid tumor was 31 years (range, 4 months-74 years). Desmoid locations were intra-abdominal (53%), abdominal wall (24%), extremities (9%), and unknown sites or combinations of sites (14%). Multivariable analysis of risk factors for desmoids at any location showed surgery (OR, 2.58; P = .0004), an APC mutation 3' of codon 1444 (OR, 3.0; P < .0001), and a positive family history (P < .0001) to be independently associated with desmoid development. When only intra-abdominal location was analyzed, APC mutation site was not associated with desmoid development.

LIMITATIONS

Selection bias may have occurred.

CONCLUSIONS

A positive family history for desmoid tumors, abdominal surgery, and APC mutation site are significant risk factors for development of desmoid tumors. The results may have implications for determining the optimal management of FAP patients and guide future studies.

Hereditary colon cancer syndromes

Colon cancer is associated with a family history in up to 25% of cases. As many as 5% are associated with an established hereditary syndrome, demonstrating the profound influence of inheritable genetic mechanisms in the development of this disease. These syndromes confer a diverse spectrum of risk, age of presentation, endoscopic and histological findings, extracolonic manifestations, and modes of inheritance. As the molecular characteristics of these disorders become better described, enhanced genotype-phenotype correlations may offer a more targeted approach to diagnosis, screening, and surveillance. While the strategies for diagnosis and management of familial adenomatous polyposis (FAP) and Lynch syndrome are more established, the approach to newly recognized syndromes such as MUTYH-associated polyposis (MAP) and hyperplastic polyposis syndromes continues to evolve. Effective cancer prevention in affected individuals and at-risk family members first requires timely recognition of these hereditary colon cancer syndromes followed by integration of genetic testing and clinical examinations.

Evaluation of guidelines for management of familial adenomatous polyposis in a multicenter pediatric cohort

OBJECTIVE

To retrospectively assess, in a pediatric multicenter cohort, guidelines for the management of familial adenomatous polyposis (FAP).

METHODS

Ten centers from the French-speaking Pediatric Gastroenterology Hepatology and Nutrition Group provided follow-up data on patients up to 18 years of age. Clinical records, genetic test results, endoscopy with histopathology examination, and therapeutic modalities were reviewed.

RESULTS

A total of 70 children from 47 families were included. When initial consultation resulted from a surveillance program because of an affected family member, 12 of 59 children were already symptomatic. Among 11 patients whose initial consultation was based only on symptoms, families were unaware at the time of a familial FAP history for 7 children, whereas only 4 cases were sporadic. A panel of 27 different pathogenic adenomatous polyposis coli (APC) germ-line mutations and large genomic deletions were identified in 43 families. Extracolonic manifestations were found in half of the patients. As part of the standard practice for initial screening, the entire cohort underwent colonoscopy, which revealed adenoma above an intact rectosigmoid in 8 cases. Prophylactic colectomy was performed in 42 cases; high-grade dysplastic adenoma and 1 invasive carcinoma were detected in 6 children. For timing of surgery, indications were in accordance with recent international guidelines.

CONCLUSIONS

Defining optimal screening and therapeutic modalities in pediatric FAP cohorts is a challenge. Specific advice for genetic screening, endoscopy surveillance, and type of surgery based on recent guidelines is recommended.

Desmoid tumor in patients with familial adenomatous polyposis

CONTEXT

Desmoid tumors constitute one of the most important extraintestinal manifestations of familial adenomatous polyposis. The development of desmoids is responsible for increasing morbidity and mortality rates in cases of familial adenomatous polyposis.

OBJECTIVES

To evaluate the occurrence of desmoid tumors in familial adenomatous polyposis cases following prophylactic colectomy and to present patient outcome.

METHODS

Between 1984 and 2008, 68 patients underwent colectomy for familial adenomatous polyposis at the School of Medical Sciences Teaching Hospital, University of Campinas, SP, Brazil. Desmoid tumors were found in nine (13.2%) of these patients, who were studied retrospectively by consulting their medical charts with respect to clinical and surgical data.

RESULTS

Of nine patients, seven (77.8%) were submitted to laparotomy for tumor resection. Median age at the time of surgery was 33.9 years (range 22-51 years). Desmoid tumors were found in the abdominal wall in 3/9 cases (33.3%) and in an intra-abdominal site in the remaining six cases (66.7%). Median time elapsed between ileal pouch-anal anastomosis and diagnosis of desmoid tumor was 37.5 months (range 14-60 months), while the median time between colectomy with ileorectal anastomosis and diagnosis was 63.7 months (range 25-116 months). In 6/9 (66.7%) patients with desmoid tumors, the disease was either under control or there was no evidence of tumor recurrence at a follow-up visit made a mean of 63.1 months later (range 12-240 months).

CONCLUSIONS

Desmoid tumors were found in 13.2% of cases of familial adenomatous polyposis following colectomy; therefore, familial adenomatous polyposis patients should be followed-up and surveillance should include abdominal examination to detect signs and symptoms. Treatment options include surgery and clinical management with antiestrogens, antiinflammatory drugs or chemotherapy.

Mutation analysis of the APC gene in unrelated Korean patients with FAP: four novel mutations with unusual phenotype

Germline mutations within the adenomatous polyposis coli (APC) gene are responsible for most cases of familial adenomatous polyposis (FAP), an autosomal dominantly inherited predisposition to colorectal cancer. To date more than 900 different APC germline mutations have been characterized worldwide demonstrating allelic heterogeneity. Here, we analyzed the APC gene in 23 DNA samples from unrelated Korean patients with the typical clinical symptoms of FAP by denaturing high-performance liquid chromatography (DHPLC) and direct sequencing. We identified 20 different APC sequence variants, including 9 truncating mutations, 1 missense mutation, 7 polymorphisms, and 3 intronic variants. Nine different truncating mutations, including four novel mutations (p.Leu180TyrfsX5, p.Gly567X, p.Ser1275PhefsX13, p.Leu1280CysfsX8), were detected. The most common mutation was a 5 bp deletion at codon 1,309 (p.Glu1309AspfsX4) as in Western studies. The next most common mutation was p.Ser1275PhefsX13 with a severe form of FAP with many extracolonic manifestations; this was a novel mutation identified in our study and may represent the second hot-spot mutation in a Korean population. Novel mutations are of particular interest because of the unusual phenotypic features shown by patients. In present study, we found new positions associated with thyroid cancer (codon 180) and desmoid tumor (codon 1,280), which have not been previously reported. The results of this molecular study have revealed the existence of novel pathogenic mutations in Korean patients with FAP. In addition to allowing phenotype-genotype correlations to be performed, these results are currently being used in genetic counseling and in patient care.

Mesenteric fibromatosis with intestinal involvement mimicking a gastrointestinal stromal tumour

INTRODUCTION

Mesenteric fibromatosis or intra-abdominal desmoid tumour is a rare proliferative disease affecting the mesentery. It is a locally aggressive tumour that lacks metastatic potential, but the local recurrence is common. Mesenteric fibromatosis with the intestinal involvement can be easily confused with other primary gastrointestinal tumours, especially with that of the mesenchymal origin.

CASE REPORT

We report a case of a 44-year-old female who presented with an abdominal mass that radiologically and pathologically mimicked a gastrointestinal stromal tumour.

CONCLUSIONS

The diagnosis of mesenteric fibromatosis should always be considered in the case of mesenchymal tumours apparently originating from the bowel wall that diffusely infiltrate the mesentery.

A nation-wide study comparing sporadic and familial adenomatous polyposis-related desmoid-type fibromatoses

Desmoid-type fibromatoses are neoplasms of fibroblastic origin, occurring sporadically or associated with familial adenomatous polyposis (FAP) coli. By comparing sporadic and FAP-associated desmoid-type fibromatoses, we tried to identify clinical characteristics, which may indicate FAP. Histopathology data of all Dutch patients with desmoid-type fibromatoses diagnosed between 1999 and 2009 were retrieved from PALGA, the nation-wide network and registry of histopathology in the Netherlands. For calculation of incidence rates, person-years from the general matched population were used. Based on polyp counts in pathological records, the cohort was divided into a FAP group and a non-FAP group. Patient- and tumor characteristics were compared between the two groups. A total number of 519 patients older than 10 years with a confirmed diagnosis of desmoid-type fibromatoses were included. Thirty-nine (7.5%) desmoid patients were documented of having FAP. The incidences of sporadic and FAP-related desmoid-type fibromatoses were 3.42 and 2,784 per million person-years, respectively. The majority of FAP patients developed desmoid-type fibromatoses after the diagnosis of FAP. Having FAP was associated with male gender [odds ratio (OR) 2.0, p = 0.034], desmoid diagnosis at an earlier age (mean 36 vs. 42 years, p = 0.031), and desmoid localization intra-abdominally (OR 18.9, p ≤ 0.001) or in the abdominal wall (OR 4.8, p ≤ 0.001), compared to extra-abdominal desmoid localization. In conclusion, patients with desmoid-type fibromatoses are at risk of underlying FAP. Especially cases with desmoid localization intra-abdominal or in the abdominal wall, and all patients younger than 60 years, have a substantial increased risk and should be referred for colonoscopy.

Surgical treatment of familial adenomatous polyposis: ileorectal anastomosis or restorative proctolectomy?

CONTEXT

Controversy regarding the best operative choice for familial adenomatous polyposis lays between the morbidity of restorative proctocolectomy and the supposed mortality due to rectal cancer after ileorectal anastomosis.

OBJECTIVES

To evaluate operative complications and oncological outcome after ileorectal anastomosis and restorative proctocolectomy.

METHODS

Charts from patients treated between 1977 and 2006 were retrospectively analyzed. Clinical and endoscopic data, results of treatment, pathological reports and information regarding early and late outcome were recorded.

RESULTS

Eighty-eight patients - 41 men (46.6%) and 47 women (53.4%) - were assisted. At diagnosis, 53 patients (60.2%) already had associated colorectal cancer. Operative complications occurred in 25 patients (29.0 %), being 17 (19.7%) early and 8 (9.3%) late complications. There were more complications after restorative proctocolectomy (48.1%) compared to proctocolectomy with ileostomy (26.6%) and ileorectal anastomosis (19.0%) (P = 0,03). There was no operative mortality. During the follow-up of 36 ileorectal anastomosis, cancer developed in the rectal cuff in six patients (16,6%). Cumulative cancer risk after ileorectal anastomosis was 17.2% at 5 years, 24.1% at 10 years and 43.1% at 15 years of follow-up. Age-dependent cumulative risk started at 30 years (4.3%), went to 9.6% at 40 years, 20.9% at 40 years and 52% at 60 years. Among the 26 patients followed after restorative proctocolectomy, it was found cancer in the ileal pouch in 1 (3.8%).

CONCLUSIONS

1. Operative complications occurred in about one third of the patients, being more frequently after the confection of ileal reservoir; 2. greater age and previous colonic carcinoma were associated with the development of rectal cancer after ileorectal anastomosis; 3. patients treated by restorative proctocolectomy are not free from the risk of pouch degeneration; 4. the disease complexity and the various risk factors (clinical, endoscopic, genetic) indicate that the best choice for operative treatment should be based on individual features discussed by a specialist; 5. all patients require continuous and long-term surveillance during postoperative follow-up.

Ileal reservoir with ileo-anal anastomosis: long-term complications

Coloproctectomy with ileo-anal anastomosis (CP-IAA) has been in use for 30 years. This intervention is the standard technique when surgery is indicated for familial adenomatous polyposis (FAP) and for ulcerative colitis (UC). Although the surgery is safe with mortality of less than 1%, it is associated with a morbidity of 18-70%. We thought a literature review about long-term complications would be enlightening. Pouchitis is the most common complication; it occurs in 70% of patients over 20 years follow-up; small bowel obstruction affects 25% of patients and pelvic sepsis occurs in 20-30% within 10 years. CP-IAA can impact the patient's sexual life due to erectile and ejaculatory dysfunction, dyspareunia, and incontinence of stool during sexual intercourse. Nevertheless, patients with long-standing UC describe an overall improvement in their sexual function after surgery. The failure rate varies from 3.5 to 15%; major causes of failure are sepsis, unrecognized Crohn's disease, and poor functional results. Cases of dysplasia and cancer have been reported in the reservoir, but more particularly when there is retained colonic glandular mucosa. The transitional zone should be monitored whenever there are risk factors for colon neoplasia. The relatively high morbidity of CP-IAA should not overshadow the good functional results of this technique.

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.

Extracolonic manifestations of hereditary colorectal cancer syndromes

Familial colorectal adenocarcinoma (CRC) accounts for approximately 15 to 20% of CRC. Of these, hereditary nonpolyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP) represent the most common hereditary syndromes associated with CRC, followed by other less common diseases including juvenile polyposis (JP) and Peutz-Jeghers syndrome (PJS). Extracolonic manifestations are common in each of these syndromes having significant implications for surveillance and management in at-risk individuals. The authors review the most common and clinically relevant extracolonic manifestations for each of these syndromes focusing on incidence, presentation, genotype/phenotype correlations, and management (including surveillance) strategies.

[Characteristics of patients with familial adenomatous polyposis in Spain. First results of the Spanish Registry of Familial Adenomatous Polyposis]

BACKGROUND AND OBJECTIVES

Familial adenomatous polyposis is an inherited disorder characterized by the presence of multiple colorectal adenomas (more than 100 in the classic form and between 10 and 100 in the attenuated one), with a high risk of colorectal cancer development. To improve the diagnostic and therapeutic management of these patients, the Spanish Registry of Familial Adenomatous Polyposis was created in 2007.We aimed to evaluate the clinicopathological characteristics of patients with familial adenomatous polyposis in Spain.

PATIENTS AND METHODS

All patients included in the Registry during one year were evaluated with respect to their demographic, clinical, pathological, and genetic characteristics.

RESULTS

243 patients of 156 unrelated families from 15 Spanish centers were included. One hundred thirty patients were male, and the mean age at diagnosis was 40 years. According to the clinical presentation, 127 corresponded to the classic form and 116 to the attenuated one. Colorectal adenoma with high-grade dysplasia was identified in 67 (28%) patients, and colorectal cancer in 42 (17%). Extracolonic manifestations were: duodenal involvement (n=46), gastric involvement (n=44), desmoid tumors (n=24), thyroid cancer (n=8), osteomas (n=6) and brain tumor (n=1). APC and/or MYH gene testing was performed in 140 (90%) families, detecting the causative mutation in 75 (54%) of them (70 in the APC gene and 5 in the MYH gene).

CONCLUSIONS

During its first year of operability, a large number of patients and families were included in the Registry. The reduced prevalence of colorectal cancer as well as the large proportion of families submitted to gene testing demonstrated a high-quality clinical practice in Spain.

Desmoid tumors: need for an individualized approach

Desmoid tumor, also known as aggressive fibromatosis or desmoid-type fibromatosis, is a rare monoclonal, fibroblastic proliferation arising in musculoaponeurotic structures. Although histologically benign, desmoids are often locally invasive and associated with a high local recurrence rate after resection. Since it is a heterogeneous disease, in particular regarding clinical presentation, anatomic location and biological behavior, treatment should be individualized to reduce local tumor control failure with concurrently acceptable morbidity and preservation of quality of life. Many issues regarding optimal treatment of desmoids remain controversial. However, wide surgical excision remains the treatment of choice, except when surgery is mutilating and is associated with considerable function loss or major morbidity. Involvement of surgical margins is probably associated with an increased risk of local recurrence. Postoperative radiotherapy results in a significant reduction of the local recurrence rate, but only in the case of involved surgical margins. Radiotherapy for gross disease is considerably effective, but is associated with a relatively high rate of complications, which are usually mild or moderate and radiation dose dependent. Radiotherapy should only be applied where anatomic constraints preclude complete resection and radiotherapy is not too toxic. Risk factors for local tumor control failure include young age, large size, presentation as recurrent disease, limb/girdle or intra-abdominal location, involved surgical margins, omission of radiotherapy, radiation dose less than 50 Gy and insufficient radiation field size. Increased comprehension of the pathogenesis and biological behavior of desmoids resulted in the emerging applicability of systemic therapies and a wait-and-see policy. Systemic treatment may be indicated in patients that have anatomic barriers to effective surgery or radiotherapy. Considering the significant morbidity of surgery and/or radiotherapy for certain locations, especially mutilation and loss of function, and the tumor's natural history, which is often characterized by prolonged periods of stability or even regression, a period of watchful waiting may compose the most appropriate management in selected asymptomatic patients. Attempts to complete eradication of the disease may be worse than the disease itself.

Rectal and pouch recurrences after surgical treatment for familial adenomatous polyposis

BACKGROUND

Familial adenomatous polyposis (FAP) is a genetic disease characterized by multiple adenomatous colorectal polyps and different extracolonic manifestations (ECM). The present work is aimed to analyze the outcome after surgical treatment regarding complications and cancer recurrence.

METHODS

Charts from patients treated between 1977 and 2006 were retrospectively analyzed. Clinical and endoscopic data, results of treatment, pathological reports and information about recurrence were collected.

RESULTS

Eighty-eight patients (41 men [46.6%] and 47 women [53.4%]) were assisted. At diagnosis, associated colorectal cancer (CRC) was detected in 53 patients (60.2%), whose average age was higher than those without CRC (40.0 vs. 29.5 years). At colonoscopy, polyposis was classified as attenuated in 12 patients (14.3%). Surgical treatment consisted in total proctocolectomy with ileostomy (PCI, 15 [17.4%]), restorative proctocolectomy (RPC, 27 [31.4%]), total colectomy with ileal-rectum anastomosis (IRA, 42 [48.8%]), palliative segmental resection (1 [1.2%]) and internal bypass (1 [1.2%]). Two patients were not operated on due to religious reasons and advanced disease. Complications occurred in 25 patients (29.0%), more commonly after RPC (48.1%). There was no operative mortality. Local or distant metastases were detected in six (11.3%) patients with CRC treated to cure. During the follow-up of 36 IRA, cancer developed in the rectal cuff in six patients (16.6%), whose average age was higher than in patients without rectal recurrence (45.8 vs. 36.6 years). Five of them have had colonic cancer in the resected specimen. Among the 26 patients followed after RPC, cancer in the ileal pouch developed in 1 (3.8%).

CONCLUSIONS

(1) Within the present series, FAP patients presented a high incidence of associated CRC and diagnosis was generally established after the third decade of life; (2) operative complications occurred in about one third of the patients, being more frequent after the confection of an ileal reservoir; (3) rectal cancer after IRA was detected in 16.6% of patients and it was associated with greater age and previous colonic carcinoma; (4) both continuous and long-term surveillance of the rectal stump and ileal pouch are necessary during follow-up.

The pleiotropic phenotype of Apc mutations in the mouse: allele specificity and effects of the genetic background

Familial adenomatous polyposis (FAP) is a human cancer syndrome characterized by the development of hundreds to thousands of colonic polyps and extracolonic lesions including desmoid fibromas, osteomas, epidermoid cysts, and congenital hypertrophy of the pigmented retinal epithelium. Afflicted individuals are heterozygous for mutations in the APC gene. Detailed investigations of mice heterozygous for mutations in the ortholog Apc have shown that other genetic factors strongly influence the phenotype. Here we report qualitative and quantitative modifications of the phenotype of Apc mutants as a function of three genetic variables: Apc allele, p53 allele, and genetic background. We have found major differences between the Apc alleles Min and 1638N in multiplicity and regionality of intestinal tumors, as well as in incidence of extracolonic lesions. By contrast, Min mice homozygous for either of two different knockout alleles of p53 show similar phenotypic effects. These studies illustrate the classic principle that functional genetics is enriched by assessing penetrance and expressivity with allelic series. The mouse permits study of an allelic gene series on multiple genetic backgrounds, thereby leading to a better understanding of gene action in a range of biological processes.

The role of APC and beta-catenin in the aetiology of aggressive fibromatosis (desmoid tumors)

BACKGROUND

Aggressive fibromatosis (syn. desmoid tumor) is a sporadically occurring neoplastic proliferation of fibroblasts originating from musculoaponeurotic planes, forming invasively growing masses without the capability to metastasize. The choice of treatment remains surgical resection with or without radiotherapy, and is characterized by high recurrence rates. Better understanding of the aetiology of aggressive fibromatosis is needed to be able to develop new treatment strategies to cope with the high recurrence rates.

METHODS

Relevant studies were identified through a search of the electronic databases PubMed/ Medline. The following search terms were used: 'aggressive fibromatosis', 'desmoid tumor', 'adenomatous polyposis coli', 'APC', 'beta-catenin', 'Wnt', 'Wingless' and 'Wnt/Wingless'. Studies were selected for review on the basis of abstract reading. A hand search was performed by checking reference lists in selected articles.

RESULTS

The neoplastic nature of aggressive fibromatosis and the role of the adenomatous polyposis coli (APC) and beta-catenin signaling cascade in driving the onset and progression of this disease are discussed.

CONCLUSION

Mutations in either the APC or beta-catenin genes are likely to be a major driving force in the formation of these desmoid tumors. More research is needed to develop new treatment strategies.

Extra-intestinal manifestations of familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominantly inherited disorder, which results from a germ line mutation in the APC (adenomatous polyposis coli) gene. FAP is characterized by the formation of hundreds to thousands of colorectal adenomatous polyps. Although the development of colorectal cancer stands out as the most prevalent complication, FAP is a multisystem disorder of growth. This means, it is comparable to other diseases such as the MEN syndromes, Von Hippel-Lindau disease and neurofibromatosis. However, the incidence of many of its clinical features is much lower. Therefore, a specialized multidisciplinary approach to optimize health care-common for other disorders-is not usually taken for FAP patients. Thus, clinicians that care for and counsel members of high-risk families should have familiarity with all the extra-intestinal manifestations of this syndrome. FAP-related complications, for which medical attention is essential, are not rare and their estimated lifetime risk presumably exceeds 30%. Affected individuals can develop thyroid and pancreatic cancer, hepatoblastomas, CNS tumors (especially medulloblastomas), and various benign tumors such as adrenal adenomas, osteomas, desmoid tumors and dental abnormalities. Due to improved longevity, as a result of better prevention of colorectal cancer, the risk of these clinical problems will further increase. We present a clinical overview of extra-intestinal manifestations, including management and treatment options for the FAP syndrome. Furthermore, we provide recommendations for surveillance of FAP complications based on available literature.

Updates on abdominal desmoid tumors

Desmoid tumor is a monoclonal, fibroblastic proliferation arising in musculoaponeurotic structures. This connective tissue hyperplasia infiltrates locally, recurs frequently after resection but does not metastasize. Abdominal desmoid occurs sporadically, in association with some familial syndromes and often represents a clinical dilemma for surgeons. The enigmatic biology and anatomical location of abdominal desmoids make treatment recommendations difficult. This distinct pathological entity is reviewed with a specific focus on aetiology and management.

Updates on abdominal desmoid tumors

Desmoid tumor is a monoclonal, fibroblastic proliferation arising in musculoaponeurotic structures. This connective tissue hyperplasia infiltrates locally, recurs frequently after resection but does not metastasize. Abdominal desmoid occurs sporadically, in association with some familial syndromes and often represents a clinical dilemma for surgeons. The enigmatic biology and anatomical location of abdominal desmoids make treatment recommendations difficult. This distinct pathological entity is reviewed with a specific focus on aetiology and management.

Post-traumatic soft tissue tumors: case report and review of the literature a propos a post-traumatic paraspinal desmoid tumor

Background

Antecedent trauma has been implicated in the causation of soft tissue tumors. Several criteria have been established to define a cause-and-effect relationship. We postulate possible mechanisms in the genesis of soft tissue tumors following antecedent traumatic injury.

Case presentation

We present a 27-year-old woman with a paraspinal desmoid tumor, diagnosed 3-years following a motor vehicle accident. Literature is reviewed.

Conclusion

Soft tissue tumors arising at the site of previous trauma may be desmoids, pseudolipomas or rarely, other soft tissue growths. The cause-and-effect issue of desmoid or other soft tissue tumors goes beyond their diagnosis and treatment. Surgeons should be acquainted with this diagnostic entity as it may also involve questions of longer follow-up and compensation and disability privileges.

A case report of synchronous osteoblastoma and fibromatosis

Osteoblastoma is a rare bone tumour that accounts for 1% of all primary bone tumours and 3% of all benign bone tumours. Osteoblastoma occurring in long bones has a predilection for the meta-diaphysis. It bears a close histological resemblance to osteoid osteoma, but it is not growth limited - usually 2 cm or greater at diagnosis. The term "fibromatosis" covers a broad spectrum of benign fibrous tissue proliferations. It is characterized by infiltrative growth and a tendency for recurrence; however, unlike sarcoma, it never metastasizes. To our knowledge, this is the first case report in the English literature of a patient with synchronous presentation of an osteoblastoma and fibromatosis.

Desmoid tumors in a dutch cohort of patients with familial adenomatous polyposis

BACKGROUND & AIMS

Desmoid tumors are a severe extracolonic manifestation in familial adenomatous polyposis (FAP). Identification of risk factors might be helpful in the management of FAP patients with such tumors. The aim of this study was to assess potential risk factors for the development of desmoids in a cohort of Dutch FAP patients.

METHODS

The medical records of 735 FAP patients were analyzed for the occurrence of desmoids. Relative risks and survival times were calculated to assess the influence of potential risk factors (female sex, family history, mutation site, abdominal surgery, and pregnancy) on desmoid development.

RESULTS

Desmoid tumors were identified in 66 of the 735 patients (9%). The cumulative risk of developing desmoids was 14%. No correlation was found between specific adenomatous polyposis coli mutation sites and desmoid development. Patients with a positive family history for desmoids had a significant increased risk to develop this tumor (30% vs 6.7%, P < .001). No association was found between female sex or pregnancy and desmoid development. Most desmoid patients (95%) had undergone previous abdominal surgery. In a substantial proportion of patients with an ileorectal anastomosis, it was impossible to convert the ileorectal anastomosis to an ileal pouch-anal anastomosis as a result of desmoid development.

CONCLUSIONS

A positive family history of desmoids is an evident risk factor for developing desmoids. Most desmoids develop after colectomy. No correlation was found between desmoids and the adenomatous polyposis coli gene mutation site, female sex, and pregnancy. Ileal pouch-anal anastomosis is the appropriate type of surgery in FAP patients with a positive family history for desmoids.

Genetic alteration in hereditary colorectal cancer

Colorectal cancer is a major cause of morbidity and mortality. Both genetic and environmental factors contribute to cancer aetiology. About 15-20% of all colorectal cancers are familial. Approximately 6% of colorectal cancers can be attributed to recognizable heritable germline mutations. The discovery of genes responsible for inherited forms of colorectal cancer have the potential to improve cancer risk assessment and counselling. Genetic testing for hereditary forms of colorectal cancer can confirm or reject diagnoses at the molecular level, determine surveillance intervals for at-risk persons, decrease the cost of surveillance by risk stratification, aid in surgical and chemoprevention decision-making, and help patients in family and career planning. This paper reviews the genetics behind genes and molecular study of the hereditary colorectal cancer. This may help the medical professionals especially internists, gastroenterologists, and oncologists to update their knowledge in this field.

Assessment of endostatin gene therapy for familial adenomatous polyposis-related desmoid tumors

Constitutive activation of the Wnt signaling pathway is a hallmark of many cancers, including familial adenomatous polyposis (FAP)-related desmoid tumors. Endostatin is a well-known antiangiogenic protein that has been described recently as a potential inhibitor of this signaling pathway. Here, we show that endostatin directly induces apoptosis and inhibits the Wnt signaling pathway in colorectal cancer cell lines bearing mutations on the adenomatous polyposis coli (APC) gene as a model of FAP-related malignant cells. We then explore the relationship between apoptosis and inhibition of this pathway and show that they are not correlated. These results seem to contradict a well-recognized study, showing that reintroduction of the APC cDNA in APC-deficient cells leads to apoptosis. To reconcile our conclusions with the literature, we further show that a truncated fragment of APC capable of inhibiting the Wnt signaling pathway in SW480 cells is incapable of inducing apoptosis in these cells, confirming that APC-mediated apoptosis is uncoupled to the inhibition of the Wnt signaling pathway. Finally, we show that endostatin directly induces cell death on primary FAP-related desmoid tumor cells in culture. This phenomenon is also independent of the inhibition of the Wnt signaling pathway. Considering the current lack of effective treatment against desmoid tumors, we advocate that endostatin gene therapy represents an attractive new therapeutic approach for this disease.

Does early colectomy increase desmoid risk in familial adenomatous polyposis?

BACKGROUND & AIMS

Desmoid tumors are non-metastasizing fibromatoses that occur in 10%-20% of subjects with familial adenomatous polyposis (FAP). Intra-abdominal desmoid tumors are a major cause of mortality in FAP. FAP-associated desmoid tumors are linked to trauma, particularly abdominal surgery, family history of desmoids, hormonal factors, and the location of the APC mutation. We hypothesized that prophylactic colectomy at an early age might increase the risk of developing desmoids. The aim of this study was to determine whether colectomy earlier in life is a risk factor for the development of desmoid tumors.

METHODS

An analysis was made of the association between development of desmoid and age at colectomy, family history of desmoids, gender, and APC mutation in FAP patients in the Registry (1980-2005) at Mount Sinai Hospital, Toronto, Ontario, Canada.

RESULTS

FAP patients (n = 930) from 365 kindreds were identified. Desmoid prevalence was 14% (n = 121). Female patients were more likely to develop desmoids than male patients (17% vs 11%, P = .03). Female patients who had an early colectomy were more than 2 times more likely to develop a desmoid, compared with women who had a colectomy at >18 years (P = .01). Early colectomy did not increase risk of developing a desmoid in male patients (P = .42). Female patients who had an early colectomy (</=18 years) were 2.5 times more likely to develop desmoids, compared with male patients who had a late colectomy (P = .05). The prevalence of desmoids in the 5' and 3' groups was 13% and 38%, respectively (P = .0005). Patients with a mutation after codon 1399 were found to have 4 times greater chance of developing a desmoid.

CONCLUSIONS

Female patients with FAP are more likely to develop desmoids than male patients. Female patients who had an early colectomy are at significantly greater risk of developing a desmoid compared with female patients who had a colectomy in adulthood. Patients with APC mutations beyond codon 1399 are more likely to develop desmoids. These results suggest that delayed colectomy might be considered in young female patients with FAP to decrease the chances of developing desmoids.

IFN-{beta} signaling positively regulates tumorigenesis in aggressive fibromatosis, potentially by modulating mesenchymal progenitors

Aggressive fibromatosis (also called desmoid tumor) is a benign, locally invasive, soft tissue tumor composed of cells with mesenchymal characteristics. These tumors are characterized by increased levels of beta-catenin-mediated T-cell factor (TCF)-dependent transcriptional activation. We found that type 1 IFN signaling is activated in human and murine aggressive fibromatosis tumors and that the expression of associated response genes is regulated by beta-catenin. When mice deficient for the type 1 IFN receptor (Ifnar1-/-) were crossed with mice predisposed to developing aggressive fibromatosis tumors (Apc/Apc1638N), a significant decrease in aggressive fibromatosis tumor formation was observed compared with littermate controls, showing a novel role for type 1 IFN signaling in promoting tumor formation. Type 1 IFN activation inhibits cell proliferation but does not alter cell apoptosis or the level of beta-catenin-mediated TCF-dependent transcriptional activation in aggressive fibromatosis cell cultures. Thus, these changes cannot explain our in vivo results. Intriguingly, Ifnar1-/- mice have smaller numbers of mesenchymal progenitor cells compared with littermate controls, and treatment of aggressive fibromatosis cell cultures with IFN increases the proportion of cells that exclude Hoechst dye and sort to the side population, raising the possibility that type 1 IFN signaling regulates the number of precursor cells present that drive aggressive fibromatosis tumor formation and maintenance. This study identified a novel role for IFN type 1 signaling as a positive regulator of neoplasia and suggests that IFN treatment is a less than optimal therapy for this tumor type.

[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.

Abdominal desmoid tumors

Desmoid tumors are rare, benign, fibromatous lesions that are the result of abnormal proliferation of myofibroblasts. Desmoid tumors can be classified as extra-abdominal and abdominal. Abdominal desmoid tumors are either superficial or intraabdominal. These tumors are associated with a high recurrence rates, even if their microscopic characters indicate a benign disease; their biologic behavior often indicates rather a "malignant" disease, which can cause even the death. Intraabdominal desmoid tumors can engulf surrounding viscera and vessels, thereby greatly complicating their surgical treatment. Management is multidisciplinary. Simple observation is a reasonable management option for asymptomatic patients; spontaneous regression of these tumors may be observed. Complete excision is the treatment of choice for tumors causing symptoms or complications. Surgery should be minimized as much as feasible, while at the same time achieving free margins. Adjuvant therapy should be considered in selected cases; the role of other management options (including gene transfer therapy) is currently under intensive investigation.

Self-Surveillance for Genetic Predisposition to Cancer: Behaviors and Emotions

PURPOSE/OBJECTIVES

To describe the kinds of self-monitoring activities and the emotional responses associated with those activities in patients with a genetic predisposition to multiple endocrine neoplasia type 2a (MEN2a) or familial adenomatous polyposis (FAP).

RESEARCH APPROACH

Thematic analysis of the transcripts of patient interviews conducted for two previous grounded theory investigations of participation in lifelong surveillance for patients with cancer predisposition syndromes and their family members.

SETTING

In the original studies, participants were recruited through a high-risk gastrointestinal cancer clinic (for FAP) and pediatric and adult endocrinology clinics (for MEN2a) at two eastern U.S. medical centers and by patient referral.

PARTICIPANTS

58 transcripts of interviews with 29 patients; 17 diagnosed with FAP or the variants of Gardner syndrome and attenuated FAP and 12 patients diagnosed with MEN2a.

METHODOLOGIC APPROACH

Informants participated in two hour-long, in-depth interviews and completed a self-administered sociodemographic questionnaire.

MAIN RESEARCH VARIABLES

Types of self-surveillance activities.

FINDINGS

Patients engage in an elaborate set of self-surveillance activities that are grouped into five categories of behavior: Medication Appraisal, Phenotype Tracking, Intake and Output Monitoring, Laboratory and Treatment Recording, and Tracking of Visits. Self-surveillance behaviors are grouped independent of type of syndrome, penetrance, age, or gender of the patient. Each category comprises a variety of behaviors that correspond with treatment recommendations and understanding of the disorder.

CONCLUSIONS

Self-surveillance may be driven by a combination of anticipation and the need for control and understanding.

INTERPRETATION

Findings from the study could be used to create an assessment tool to evaluate the extent to which patients are involved in day-to-day self-monitoring. Clinicians may use the categories to better understand patients' knowledge deficits and the emotional impact of enhanced vigilance. Self-surveillance activities performed by patients with MEN2a and FAP also may be performed by patients with other cancer predisposition syndromes.

Mesenteric desmoid tumors in Singapore familial adenomatous polyposis patients: clinical course and genetic profile in a predominantly Chinese population

PURPOSE

This study examined the mutational profile of the adenomatous polyposis coli gene in relation to the development of desmoid tumors in familial adenomatous polyposis patients from a predominantly Chinese population.

METHODS

This is a retrospective review of all patients with familial adenomatous polyposis coli from the Singapore Polyposis Registry. Identification of specific adenomatous polyposis coli gene mutation was performed and clinical course of associated desmoid disease obtained from case records and a computerized database.

RESULTS

Two hundred five patients from 75 families afflicted with familial adenomatous polyposis coli were reviewed, with gene mutations identified in 107 patients. Of these, 23 (11.2 percent) developed desmoids. The male-to-female ratio was 1:1.3 and the ethnic distribution was Chinese (n=17) and Malay (n=6). Of the 92 patients with mutations 5' to codon 1444, 11 patients (12 percent) developed desmoids compared with 6 of 15 (40 percent) patients with adenomatous polyposis coli gene mutations 3' to codon 1444 (P<0.01). The clinical course of desmoid tumors can be divided into stable (n=11), variable (n=3), progressive (n=6), and aggressive growth (n=3). Only 3 (13 percent) patients with aggressive tumor growth required chemotherapy. There was no correlation between the site of mutation and the clinical progression of the desmoids. Seventy-four percent of these desmoids (17/23) developed at a mean interval of 2.98 years after restorative proctocolectomy, while only 30 percent (7/23) were diagnosed preoperatively or discovered during the initial surgery. The most common complications related to the mesenteric desmoids were intestinal obstruction (21.7 percent), ureteric obstruction (17.4 percent), and encasement of superior mesenteric vessels (13 percent).

CONCLUSION

The clinical course of desmoids in an individual familial adenomatous polyposis patient remains unpredictable and no reliable genetic marker is available for prognostication in desmoid disease.

Current ideas in desmoid tumours

Desmoid tumours are rare neoplasms of fibroblastic origin which arise with disproportionate frequency in patients with familial adenomatous polyposis (FAP). They are thought to develop in about 10-25% of FAP patients and may be the leading cause of death amongst those who have undergone colectomy. Risk factors include trauma, having a distal germline APC mutation, having a family history of desmoids, and probably oestrogens. In very high-risk individuals there may be a case for delay of colectomy or chemoprophylaxis at the time of surgery. Desmoids are now known to be true neoplasms but with normal telomere length and telomerase activity. FAP-associated tumours seem to carry biallelic APC mutations, one of which lies in the distal part of the gene. Such loss of wild-type APC seems to occur relatively late in tumour development. It is likely that beta-catenin plays an important role in tumourigenesis. FAP-associated desmoids tend to arise in the abdomen or abdominal wall. CT scanning gives the best information on tumour anatomy whilst T2-weighted MRI indicates likely behaviour. Treatment may simply consist of observation. Otherwise, usual first-line therapy is with sulindac with or without an anti-oestrogen. Cytotoxic chemotherapy is an option in unresectable tumours. Surgery is a reasonable first-line treatment in abdominal wall tumours but is risky for intra-abdominal tumours and may necessitate massive small bowel resection. Desmoids are the greatest remaining challenge in the management of FAP and further research into their aetiology needs to be combined with multicentre clinical trials of new treatments in order to improve management of the disease.

Restorative proctocolectomy and ileal pouch-anal anastomosis for familial adenomatous polyposis revisited

Since restorative proctocolectomy (RPC) with ileal-pouch anal anastomosis (IPAA) removes the entire diseased mucosa, it has become firmly established as the standard operative procedure of choice for familial adenomatous polyposis (FAP). Many technical controversies still persist, such as mesenteric lengthening techniques, close rectal wall proctectomy, endoanal mucosectomy vs. double stapled anastomosis, loop ileostomy omission and a laparoscopic approach. Despite the complexity of the operation, IPAA is safe (mortality: 0.5-1%), it carries an acceptable risk of non-life-threatening complications (10-25%), and it achieves good long-term functional outcome with excellent patient satisfaction (over 95%). In contrast to the high incidence in patients operated for ulcerative colitis (UC) (15-20%), the occurrence of pouchitis after IPAA seems to be rare in FAP patients (0-11%). Even after IPAA, FAP patients are still at risk of developing adenomas (and occasional adenocarcinomas), either in the anal canal (10-31%) or in the ileal pouch itself (8-62%), thus requiring lifelong endoscopic monitoring. IPAA operation does not jeopardise pregnancy and childbirth, but it does impair female fecundity and has a low risk of impairment of erection and ejaculation in young males. The latter can almost completely be avoided by a careful "close rectal wall" proctectomy technique. Some argue that low risk patients (e.g. <5 rectal polyps) can be identified where ileorectal anastomosis (IRA) might be reasonable. We feel that the risk of rectal cancer after IRA means that IPAA should be recommended for the vast majority of FAP patients. We accept that in some very selected cases, based on clinical and genetics data (and perhaps influenced by patient choice regarding female fecundity), a stepwise surgical strategy with a primary IPA followed at a later age by a secondary proctectomy with IPAA could be proposed.

A 10-year review of surgery for desmoid disease associated with familial adenomatous polyposis

BACKGROUND

Desmoid tumours affect 10-25 per cent of patients with familial adenomatous polyposis and represent a major cause of morbidity and mortality. Surgery for intra-abdominal desmoids has traditionally been used as a last resort or to manage obstructive complications. The aim was to review 10 years of desmoid surgery in patients with familial adenomatous polyposis from a single centre.

METHODS

Patients who had surgery for desmoid disease between 1994 and 2004 were identified from the Polyposis Registry database and their hospital notes reviewed.

RESULTS

Twenty patients had surgery to remove 32 desmoid tumours (16 intra-abdominal, 12 abdominal wall, four extra-abdominal). Complete clearance was achieved in 19 tumours and, of these, clinically significant recurrence occurred in eight. There was no difference in recurrence rates for site or sex. There was no operative mortality. Intra-abdominal desmoid resection was associated with a mean resection of 45.55 (range 10-200) cm of small bowel. One patient required long-term parenteral feeding. Median follow-up was 5 (range 0.6-10) years. During this period, one patient died (metastatic duodenal cancer); there was no mortality from desmoid disease.

CONCLUSION

Surgery for intra-abdominal desmoids in selected patients is less hazardous than previously reported. Surgery for abdominal wall and extra-abdominal tumours is safe. However, disease recurrence remains a major problem.

Large mesenteric gastrointestinal stromal tumor in a patient with familial adenomatous polyposis syndrome

We report a case of a 30-year-old man who presented with severe debilitation, anemia and diarrhea over two months. Colonoscopy revealed many (>100) polyps (familial adenomatous polyposis syndrome). Abdominal CT scan showed a large mass at the left upper abdomen in conjunction with the splenic flexure. Total colectomy with mesenteric mass and adjacent small bowel removal and ileoanal pouch was performed. Examination of the resected mesenteric mass showed a gastrointestinal stromal tumor (GIST) with scarce mitosis and infiltration of the adjacent small bowel. We describe for the first time in medical literature the coexistence of familial adenomatous polyposis syndrome and GIST in a 30-year-old man.

Genetic predisposition to colorectal cancer: new pieces in the pediatric puzzle

Colorectal cancer is rare in childhood. The 2 best characterized familial syndromes, hereditary nonpolyposis colorectal cancer (HNPCC, Lynch syndrome) and familial adenomatous polyposis (FAP), are autosomal dominant inherited disorders. HNPCC is relevant to pediatric gastroenterology practice because children and adolescents with underlying colorectal cancer can have germ-line mutations of mismatch repair genes. Recent attention has focused on characterizing genetic predisposition to attenuated FAP in individuals who do not have germ-line mutations in the APC gene. The identification of a second mechanistic explanation called MYH-associated polyposis (MAP), which is an autosomal-recessive condition, has important implications for both screening and management strategies. Hereditary colorectal cancer including HNPCC, FAP, attenuated FAP and MYH-associated polyposis in children are the subject of this review.

Desmoid Tumors – a Characterization of Patients Seen at Mayo Clinic 1976–1999

Desmoid tumors occur with high frequency in individuals with Familial Adenomatous Polyposis (FAP). Because of this, individuals developing desmoid tumors may be referred for genetic risk assessment. Determining whether a person has a FAP-related desmoid tumor or a sporadic desmoid can be challenging. We sought to characterize the patients who were seen at our institution to determine if there were clinical differences in presentation between FAP-associated and sporadic desmoid tumors. We searched the Mayo Clinic-modified H-ICDA (Hospital adaptation of the International Classification of Diseases) diagnostic codes for all diagnoses of desmoid tumors in patients seen between 1976 and 1999. Charts were reviewed to determine accuracy of diagnosis, age when seen, gender, site of tumor, and presence of polyposis. A total of 454 patients (174 males and 280 females) met the search criterion. Of the 447 patients on whom all data was obtained, 70 had FAP and 377 had no evidence of FAP. The female/male ratio for FAP cases was 1.12 compared to female/male ratio of 1.71 for non-FAP cases. (P=0.17). Location of development of desmoid tumors was correlated with but not specific for distinguishing FAP from non-FAP desmoids. Abdominal desmoids comprised the majority of FAP desmoids and extra-abdominal desmoids comprised the majority of non-FAP desmoids (P<0.001) but age was not a discriminating factor. Using Bayesian analysis, we demonstrate how these findings can assist genetic professionals in their evaluation of patients with desmoid tumors by providing prior probabilities of FAP based upon clinical presentation.