Extracolonic manifestations of familial polyposis coli

A role for the vitamin D pathway in non-intestinal lesions in genetic and carcinogen models of colorectal cancer and in familial adenomatous polyposis

Vitamin D is implicated in the etiology of cancers of the gastrointestinal tract, usually characterized by alteration in the APC/β-catenin/TCF tumor suppressor pathway. The vitamin D receptor (VDR) is also implicated in cardiovascular and skin diseases as well as in immunity. Activated VDR can indirectly alter β-catenin nuclear localization and directly suppress β-catenin/TCF mediated transcriptional activity. We treated VDR null mice with the carcinogen azoxymethane (AOM) and generated mice bearing a mutated APC (hypomorph) on a VDR null background (Apc^1638N/+Vdr^−/−). VDR null mice do not develop GI or extra-colonic tumors but loss of VDR decreased intestinal tumor latency and increased progression to adenocarcinoma in both models. AOM treatment of VDR null mice also caused squamous cell carcinoma of the anus. Although levels and distribution of total or activated β-catenin in the epithelial component of tumors were unaffected by loss of VDR, β-catenin dependent cyclin D1 expression was affected suggesting a direct VDR effect on β-catenin co-activator activity. Extra-colonic mucosa manifestations in Apc^1638N/+Vdr^−/− animals included increased nuclear β-catenin in submucosal stromal cells, spleno- and cardiomegaly and large epidermoid cysts characteristic of the FAP variant, Gardner's syndrome. Consistent with this, SNPs in the VDR, vitamin D binding protein and CYP24 as well as mutations in APC distal to codon 850 were strongly associated with Gardners syndrome in a cohort of 457 FAP patients, This work suggests that alterations in the vitamin D/VDR axis are important in Gardner's syndrome, as well as in the etiology of anal cancer.

Role of nucleotide excision repair deficiency in intestinal tumorigenesis in multiple intestinal neoplasia (Min) mice

Mice deficient in the Xeroderma pigmentosum group A (Xpa) gene are defective in nucleotide excision repair (NER) and highly susceptible to skin carcinogenesis after dermal exposure to UV light or chemicals. Min (multiple intestinal neoplasia) mice, heterozygous for a germline nonsense mutation in the tumor suppressor gene adenomatous polyposis coli (Apc), develop intestinal tumors spontaneously and show additional intestinal tumors after exposure to the food mutagen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). In this study, we investigated the impact of loss of XPA function on PhIP-induced intestinal tumorigenesis in F1 offspring of Min/+ (Apc(+/-)) mice crossed with Xpa gene-deficient mice. Apc(+/-) mice lacking both alleles of Xpa had higher susceptibility towards toxicity of PhIP, higher levels of PhIP-DNA adducts in the middle and distal small intestines, as well as in liver, and a higher number of small intestinal tumors at 11 weeks, compared with Apc(+/-) mice with one or two intact Xpa alleles. Localization of tumors was not affected, being highest in middle and distal small intestines in all genotypes. At 11 weeks of age, the number of spontaneous intestinal tumors was not significantly increased by homozygous loss of Xpa, but untreated Apc(+/-)/Xpa(-/-) mice had significantly shorter life-spans than their XPA-proficient littermates. Heterozygous loss of Xpa did not affect any of the measured end points. In conclusion, the Xpa gene and the NER pathway are involved in repair of bulky PhIP-DNA adducts in the intestines and the liver, and most probably of DNA lesions leading to spontaneous intestinal tumors. These results confirm a role of the NER pathway also in protection against cancer in internal organs, additional to its well-known importance in protection against skin cancer. An effect of Apc(+/-) on adduct levels, additional to that of Xpa(-/-), indicates that the truncated APC protein may affect a repair pathway other than NER.

Gastrointestinal polyposis in childhood: clinicopathologic and genetic features

Gastrointestinal polyps and certain extraintestinal lesions in children may herald a hereditary polyposis syndrome, with an increased risk of neoplasia and other health problems for both children and their relatives. The availability of molecular/genetic screening tests has increased early diagnosis of younger members of known polyposis families. This article reviews the gross and microscopic features of polyposis syndromes of childhood and summarizes the molecular/genetic advances in this field. Clinical management is also briefly discussed.

Genetic predisposition and screening in pediatric cancer

Pediatricians are often the health care providers who first detect the signs and symptoms of childhood cancer. Although pediatric malignancies are rare diseases, early diagnosis is an important factor leading to high cure rates of many types of cancers including retinoblastomara, Wilms' tumor, hepatoblastoma, rhabdomyosarcoma. thyroid carcinoma, and other solid tumors. A number of familial cancer syndromes present with childhood cancers that can be recognized or diagnosed by pediatricians. The genetic origins of several syndromes have been elucidated. Genetic testing is not yet available for all of these inherited cancers. A frequently updated list of genetic tests is available at www.genetests.org. The ordering and interpreting of genetic tests, however, is often best done by trained genetic counselors. The pediatrician will play a vital on-going role in following the at-risk child. In many of syndromes discussed, the cost effectiveness of the tests as well as that of any potential intervention needs further study. The role of the subtle genetic polymorphisms in pediatric tumorigenesis. many more of which will undoubtedly be described in the coming years, has not yet been translated into defined needs for interventions. Perhaps in the future it will be possible to understand the additive effect of multiple genetic polymorphisms and to determine genetic profiles of high cancer risk. Until suitable interventions are established, however, the study of genetic variability and cancer will await practical significance. Undoubtedly other major important cancer genes are yet to be discovered and characterized. An additional challenge is the counseling and management of children and adults who have a strong family history of cancer yet who do not have a recognizable syndrome. The role of the primary pediatrician is to recognize the major cancer genetic syndromes, to make appropriate referrals for genetic counseling and testing when indicated, and to ensure that adequate screening tests are being done.

Familial adenomatous polyposis and benign intracranial tumors: a new variant of Gardner's syndrome

INTRODUCTION

Familial adenomatous polyposis (FAP) is associated with malignant tumors of the central nervous system, predominantly medulloblastomas and glioblastoma multiforme (Turcot's syndrome) and with craniofacial osteomas (Gardner's syndrome). This report details the occurrence of benign, intracranial tumors in two related individuals with Gardner's syndrome, an association not previously described.

PATIENTS AND METHODS

A 57-year-old woman (the propositus), her sister, two of her nieces and one of her grandnephews were previously diagnosed with Gardner's syndrome. The propositus came to neurosurgical attention because of vertigo associated with what proved to be an epidermoid cyst of the cerebellopontine angle. Her unaffected children and her relatives with Gardner's syndrome were examined and underwent computed tomography or magnetic resonance imaging.

RESULTS

A 39-year-old woman with Gardner's syndrome, the niece of the propositus, was found to harbor an asymptomatic left frontal meningioma.

DISCUSSION

Familial adenomatous polyposis, Gardner's syndrome, and that variant of Turcot's syndrome in which medulloblastoma predominate, are associated with a mutation of the adenomatous polyposis coli gene. The demonstration that patients with Gardner's syndrome can also have benign, nonneuroglial, intracranial tumors adds to the previously known extracolonic lesions associated with FAP. The molecular characterization of our patients should reveal if benign intracranial tumors represent a pleiotropic manifestation of the adenomatous polyposis coli gene mutation or if other genes are implicated.

Turcot syndrome with colonic obstruction and small intestinal invagination: report of a case

We report herein the case of a 16-year-old boy diagnosed as having Turcot syndrome, otherwise known as glioma-polyposis syndrome. The patient was transferred from the Department of Neurosurgery where he was undergoing investigation of a brain tumor, to the Department of Medicine for investigation of gastrointestinal symptoms. The patient was diagnosed as having Turcot syndrome, and was then transferred to the Department of Surgery for treatment of an obstruction in the sigmoid colon and small intestinal invagination. A subtotal colectomy with side-to-end ileoproctostomy and release of the invaginations was carried out. Multiple polyps were found in the colon, two of which, including a large polyp that obstructed the colonic lumen, were confirmed histologically to be adenocarcinoma. The remaining polyps were adenomas. A biopsy of the brain tumor confirmed a diagnosis of astrocytoma (WHO grade II). This case report describes the characteristic features of Turcot syndrome presented by this patient.

Extracolonic manifestations of familial adenomatous polyposis: desmoid tumours, and upper gastrointestinal adenomas and carcinomas

It is well known that patients with familial adenomatous polyposis (FAP) are at considerable risk of developing extracolonic manifestations of the disease. Particularly, desmoid tumours of the abdominal cavity, and duodenal adenomas and carcinomas are the most serious ones. It is estimated that some 10% of the FAP patients will develop desmoids, whereas 50-90% of the FAP patients will get duodenal adenomas predominantly concentrated on or around the major papilla. Desmoid tumours and duodenal carcinomas are major causes of death in those patients in whom a prophylactic (procto)colectomy has been performed. Desmoids are histologically benign tumours, composed of mature fibroblasts. They usually grow slowly but they can become quite large and may compress or infiltrate surrounding viscera, which might cause significant morbidity as well as mortality. Successful treatment of these tumours is extremely difficult as surgical therapy often requires the removal of considerable lengths of small bowel. Moreover, surgical therapy may lead to uncontrollable bleeding and is seldom radical. Chemotherapy with cytoxic agents seems promising but so far the data are too few for firm conclusions to be drawn. The same holds true for drug regimens which interfere with the metabolic and hormonal metabolism of the tumour. Although various lines of evidence suggest that the adenoma-carcinoma sequence, which is generally accepted for colorectal adenomas, also applies for the duodenal adenomas in FAP patients, it is not clear whether we should screen these patients for upper gastrointestinal adenomas or not. As these polyps are usually small, sessile, multiple and difficult to remove, the benefit of endoscopic surveillance would be the early detection of cancer rather than eradication of the polyps. In addition, evidence that screening and early treatment leads to improvement of the prognosis is not available. Although the role of (procto)colectomy in the treatment of large-bowel polyps is well established in FAP patients, the treatment of their duodenal counterparts is still open for debate. The risk of the development of periampullary cancer is not high enough to warrant an aggressive prophylactic surgical approach, i.e. a Whipple's procedure, immediately after the discovery of duodenal adenomas. The considerable morbidity and mortality rates of this procedure must be weighted against a putative benefit of screening.

Genetic alterations in a patient with Turcot's syndrome

Turcot's syndrome (TS) is a rare disorder associated with the development of both brain and colon neoplasms. Because of the very low incidence of the disease, its molecular basis remains unclear. Presented is a TS case of a 30-year-old Japanese male with a histopathologically confirmed diagnosis of both brain tumor (glioblastoma multiforme) and colon tumor (well-differentiated adenocarcinoma). Germline mutations of the p53 gene, somatic mutations of the Ki-ras, p53 and APC genes, and microsatellite instability (MSI) was examined using polymerase chain reaction (PCR)-single strand conformation polymorphism analysis, followed by PCR-direct sequencing, and sequencing after subcloning. No germline mutations of the p53 gene were found. Somatic mutations of Ki-ras and APC genes were found in the colon adenocarcinoma but not in the brain tumor. No somatic mutation of the p53 gene was present in either colon or brain tumors. Microsatellite instability of both colon and brain tumors was positive in two of four loci. These results indicate that the colon tumor of the TS patient carries the Ki-ras and APC gene mutations. The finding of MSI in both the brain and the colon tumors may support the hypothesis that alterations of DNA repair genes are involved in the tumor development of the TS patient.

Laparoscopic total abdominal colectomy with ileorectal anastomosis for familial adenomatous polyposis

PURPOSE

This study was undertaken to describe our results in a series of patients undergoing total abdominal colectomy with ileorectal anastomosis (TAC/IRA) using laparoscopic techniques in patients with familial adenomatous polyposis (FAP) and rectal-sparing. Young patients with FAP requiring TAC/IRA may be ideal candidates for minimally invasive surgery, because they are generally thin and have benign disease. They might benefit maximally from the theoretic advantages of these techniques.

METHODS

We have performed laparoscopic TAC/IRA in 16 FAP patients (10 females; mean age, 18 years). Procedures were entirely intracorporeal, with a 3-cm to 6-cm specimen extraction incision.

RESULTS

Median operative time was 232 (range, 156-285) minutes, and blood loss 175 (range, 50-675) ml. The only intraoperative complication, a twisted ileorectal anastomosis, was noted intraoperatively and revised. There were no conversions to conventional laparotomy. Median postoperative interval to passage of flatus was three days, and for bowel movements it was three days. Median hospital stay was five days. One case of early postoperative small-bowel obstruction was treated nonoperatively, and one case of brachial plexus neuropraxia resolved spontaneously.

CONCLUSIONS

Based on this preliminary experience, we believe laparoscopic TAC/IRA can be a safe and effective treatment for selected patients with FAP. As techniques and instrumentation for laparoscopic colon surgery are perfected, this procedure will likely become an appealing option in the management of patients with FAP.

Increased incidence of cancer in first degree relatives of women with double primary carcinomas of the breast and colon

Breast and colon cancer are among the most common cancers in the developed world. Several epidemiological studies suggest that the occurrence of one of these two cancers in a woman may predispose to the development of the other. The occurrence of both forms of cancer in the same woman may be because of chance or common susceptibility. In order to determine how frequently double primary cancers have a hereditary basis, we conducted a registry based study at a single Montreal hospital. Cancer rates in first degree relatives of patients with multiple primaries were compared with provincial age standardised incidence rates and relative risks (RRs) were estimated. In first degree relatives under 45 there was a total of 15 cancers observed, compared with 3.70 expected, giving an RR of 4.05 (95% CI: 2.27-6.68). The RR for colon cancer was significantly increased among male relatives. For relatives less than 45 years old at diagnosis, the RR for colon cancer was 66.7 (95% CI: 13.8-195) (three cases observed, 0.045 expected). For all ages the RR was 5.02 (95% CI: 2.04-10.5). The RR for breast cancer was 5.92 (95% CI: 1.91-13.8) for female relatives under 45 (five cases observed, 0.845 expected) and 2.14 (95% CI: 1.07-3.83) for breast cancer at any age. These results suggest that there may be genes that predispose to both breast and colon cancer in certain people.

Changing causes of mortality in patients with familial adenomatous polyposis

Widespread use of prophylactic colectomy has resulted in a reduction in the incidence of colorectal cancer in familial adenomatous polyposis (FAP) patients. A retrospective chart review of families registered at the Steve Atanas Stavro Familial Gastrointestinal Cancer Registry in Toronto was performed to determine whether the decrease in the number of patients developing colorectal cancer implies that causes of mortality in FAP patients are shifting to that of extracolonic manifestations of FAP. Information was available on 140 deaths within 158 families and among 461 individuals with FAP. When stratified by decade, from the 1930s to the 1990s, the ratio of deaths caused by extracolonic manifestations of FAP compared with deaths caused by colorectal cancer was noted to have risen. Even though most deaths in FAP patients are still from colorectal cancer, it appears that screening policies and prophylactic colectomy have resulted in a reduction in the number of FAP patients who develop colorectal cancer. Thus, in recent decades, a greater percentage of deaths in FAP patients appears to be attributable to extracolonic manifestations of the disease.

Papillary thyroid carcinoma in three siblings with familial adenomatous polyposis

The authors report three siblings (two sisters and their aunt, aged 20, 22 and 36, respectively) with familial adenomatous polyposis (FAP) and papillary thyroid carcinoma. After diagnosis of FAP, a single, non palpable nodule was revealed in each patient by routine screening ultrasonography of the gland. The diagnosis of papillary carcinoma was made by fine-needle-aspiration biopsy of the nodules and confirmed by histologic examination of surgical specimens. A review of the literature reveals about 40 reports of such an association, that is considered not fortuitous. Nevertheless, in this family the association seems to be a distinctive, clinical feature of the syndrome, affecting three out of five members intensively screened for extracolonic lesions.

Familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominant condition resulting in the development of more than 100 adenomatous polyps in the large bowel. In addition, a number of extracolonic manifestations of the condition may occur. Recently, increasing knowledge relating to the extracolonic abnormalities, and localization and sequencing of the gene for FAP, have had important implications for screening and long-term follow-up of those affected. In this review the natural history of the disease and the extracolonic manifestations associated with it are considered. Surgical management and advances in understanding at a molecular level are discussed, as well as the problems relating to screening for FAP and the implications of the new knowledge.

Causes of death and postsurgical survival in familial adenomatous polyposis: results from the Italian Registry. Italian Registry of Familial Polyposis Writing Committee

Causes of death were evaluated among 350 deceased patients with familial adenomatous polyposis (FAP) recorded in the Italian Polyposis Registry: 78.1% were due to colorectal cancer, 9.5% to extracolonic cancer (more than half of the upper gastrointestinal tract), 3.6% to desmoid tumors, and 8.8% to other causes. The age at diagnosis among 604 patients was studied in relation to presence of symptoms at presentation and presence of colonic cancer at surgery. In asymptomatic patients younger than 30 years the risk of colonic cancer was 3.3% and in symptomatic patients older than 40 it was 80%. A life-table analysis showed that postsurgical survival among patients without cancer at colectomy was 68% after 30 years, whereas that of patients with cancer was 41% after 10 years. The alternative prophylactic treatments of total colectomy with ileorectal anastomosis versus total proctocolectomy (IRA vs. IAA) were compared in terms of postsurgical survival. Both treatments showed a survival of 83% after 10 years. The risk of cancer in the rectal stump after IRA was 14.5% after 15 years and 25.2% after 25 years; the corresponding risks of dying from it were 4.3% and 9.3%, respectively.

Gastroduodenal polyps in patients with familial adenomatous polyposis

A review of the endoscopy reports and pathology results from esophagogastroduodenoscopy (EGD) of all patients with familial adenomatous polyposis (FAP) undergoing such an examination was performed. Two hundred forty-seven patients were identified, with an overall prevalence of duodenal adenomas of 66 percent and of fundic gland polyps of 61 percent. Analysis of our more recent experience (1986 to 1990) shows the prevalence to be 88 percent and 84 percent, respectively. A normal-appearing papilla was adenomatous in 50 percent of cases. No case of periampullary carcinoma developed in patients under surveillance. Routine EGD is indicated for patients with FAP. Duodenal adenomas and fundic gland polyps will occur in the majority of patients.

Genetic evidence that Turcot syndrome is not allelic to familial adenomatous polyposis

Turcot syndrome (TS) is a rare genetic disease in which brain tumors occur in association with colonic polyposis. Since Turcot's original description in 1959, there have been disagreements about the mode of inheritance as well as the clinical expression of this condition. Some investigators maintain that TS is a phenotypic variant of the autosomal dominant familial adenomatous polyposis (FAP), while others observe that there are clinical differences between TS and FAP, and that the pattern of inheritance of TS is autosomal recessive. The distribution of persons with colonic lesions in a family with a patient of colonic polyposis and a brain tumor, described in this report, favored the recessive hypothesis. In this family, the involvement of the FAP gene on chromosome 5q21-q22 could be excluded by a linkage study using a panel of FAP-linked DNA markers. This finding, which indicates the occurrence of another polyposis gene elsewhere in the genome, will have consequences for the presymptomatic diagnosis of FAP by linked DNA markers. We conclude that TS is a distinct clinical-genetical entity with the triad of atypical polyposis coli, CNS tumors, and a recessive mode of inheritance.

Overview of screening and management of familial adenomatous polyposis

The rarity of familial adenomatous polyposis (FAP) means that many clinicians may be unaware of the major advances that have taken place in screening for the condition over the past five years. This review is not only to document the current scene but also to give details of those involved in establishing registries throughout the country. FAP is a hereditary disorder which carries with it almost a 100% risk of colorectal cancer. The aim of screening is to detect gene carriers before they present with symptoms attributable to colonic polyps. In this way the incidence of colorectal cancer can be greatly reduced. The use of gene probes to identify patients with FAP is in its infancy but in selected pedigrees gene carriers can be identified using a venous blood sample. The recognition that congenital hypertrophy of the retinal pigment epithelium is an extracolonic manifestation of FAP in most pedigrees allows non-invasive ophthalmological screening of relatives at risk. The combination of these new screening methods with an effective regional registry for FAP can increase the number of patients detected by screening rather than by symptoms. This facilitates appropriate prophylactic surgery and reduces mortality related to colorectal cancer.

Skin and bones. I

Skin disorders in which a radiograph may detect associated bony changes or abnormalities of calcification are discussed. They are grouped into eight categories: (1) inherited diseases (e.g., alkaptonuria, neurofibromatosis); (2) congenital disorders (e.g., Sturge-Weber and Proteus syndromes); (3) inflammatory conditions (e.g., dermatomyositis, sarcoidosis); (4) infections (e.g., dental sinus, syphilis); (5) neoplasias (e.g., histiocytosis, mastocytosis); (6) drug- and environment-induced (e.g., acroosteolysis, retinoid toxicity); (7) calcinosis cutis; and (8) osteoma cutis. Part I of our review discusses the first two categories.

Predictive value of congenital hypertrophy of the retinal pigment epithelium as a clinical marker for familial adenomatous polyposis

One hundred forty-eight members of 53 kindreds with familial adenomatous polyposis (FAP) were examined for congenital hypertrophy of the retinal pigment epithelium (CHRPE) and extracolonic manifestations (ECM) to assess the value of CHRPE as a predictive marker for FAP. Based on eye examination results, the families were divided into 2 groups. In a first group of 34 families, all 61 members diagnosed as having polyps and 13 of the 33 patients at risk had 4 or more lesions distributed in both eyes. By contrast, in a second group of 18 families, all 32 polyposis patients and all 18 members at risk had less than 4 lesions. Extra-colonic manifestations were present in 26 of 34 families in the first group and in 11 of 18 families in the second group. Data on one family with ambiguous ancestry were reviewed separately. The existence of 4 or more CHRPE lesions distributed in both eyes seems to be a congenital marker for FAP, present in 65.4 percent of families. When present in a family: 1) it is found in all diagnosed patients in that family, 2) can therefore be considered predictive for the development of polyps in other family members who carry the trait, and 3) if confirmed by longer follow-up, may possibly preclude members without the trait from further evaluation and surveillance.

A case of adenomatosis coli complicated with malignant lymphoma of the spleen

A case of adenomatosis coli complicated with malignant lymphoma of the spleen is described herein. An increase in the serum lactic dehydrogenase level of a 50 year old female was noted 9 years after she underwent a total colorectal resection for adenomatosis coli complicated by cancer. A tumor was observed in the spleen on CT and ultrasonography, and a diagnosis of malignant lymphoma was subsequently made by biopsy. At the time of splenectomy, no extension of the tumor was observed in any other organs and it was found histologically to be large cell type follicular lymphoma. A review of the 903 patients with adenomatosis coli documented in Japan revealed the occurrence of mesodermal malignant tumors to be considerably high. Hence, adenomatosis coli appears likely to be a causative factor in malignant lymphoma of mesodermal origin.

Mesenteric desmoid tumours in Gardner's syndrome--review of medical treatments

Gardner's syndrome comprises a triad of polyposis coli, osteomata and soft tissue tumours including desmoid tumours which can often present difficult problems in management. We report a patient with Gardner's syndrome treated with tamoxifen and medroxyprogesterone acetate. The literature on this rare syndrome and its management is reviewed.