Thomas J. McGarrity

The hamartomatous polyposis syndromes: a clinical and molecular review.

Inherited forms of gastrointestinal cancer have been a major focus of study and advancement over the past decade. Familial adenomatous polyposis and hereditary nonpolyposis colon cancer are the two most common heritable colon cancer syndromes. Inherited polyposis syndromes are characterized by the dominant type of polyp (whether adenomatous or hamartomatous) present and by the polyps location within the gastrointestinal tract. The hamartomatous polyposis syndromes are characterized by an overgrowth of cells native to the area in which they normally occur. They represent a small but appreciable number of the gastrointestinal inherited cancer predisposition syndromes; it is now known that many of these syndromes carry a substantial risk for developing colon cancer as well as other gastrointestinal and pancreatic cancers. Patients afflicted with these syndromes are also at significant risk for extraintestinal malignancies. Seven inherited hamartomatous polyposis syndromes have been described: familial juvenile polyposis syndrome, Cowdens syndrome, Bannayan-Ruvalcaba-Riley syndrome, Peutz-Jeghers syndrome, basal cell nevus syndrome, neurofibromatosis 1, and multiple endocrine neoplasia syndrome 2B. Hereditary mixed polyposis syndrome is a variant of juvenile polyposis characterized by both hamartomatous and adenomatous polyps. The hamartomatous syndromes occur at approximately 1/10th the frequency of the adenomatous syndromes and account for <1% of colorectal cancer in Northern America. While the diagnosis of these inherited syndromes is primarily clinical, genetic testing is now available for all six syndromes. However, there are a significant number of spontaneous mutations seen in each of the syndromes. The management of these patients necessitates a coordinated multidisciplinary approach. The purpose of this review is to characterize the clinical and pathological features of these syndromes and to review the targets of cancer surveillance. The molecular alterations responsible for the inherited hamartomatous polyposis syndromes will also be discussed.

Peutz-Jeghers Syndrome

Peutz-Jeghers syndrome (PJS) is an unusual polyposis syndrome that has enjoyed a rich and somewhat confusing history. Mucocutaneous pigmentation and diffuse gastrointestinal hamartomas are the hallmark features of this autosomal dominant inherited condition. Peutz-Jeghers syndrome is now also recognized as a cancer predisposition syndrome. In this review, we highlight the historical aspects of PJS polyposis with special emphasis on its extraintestinal manifestations, particularly genital tract tumors. A PJS management scheme for clinicians is included.

Peginterferon alfa-2b and Ribavirin: Effective in Patients With Hepatitis C Who Failed Interferon alfa/Ribavirin Therapy

BACKGROUND & AIMS Treatment with peginterferon alfa and ribavirin produces a sustained virologic response (SVR) in approximately 60% of hepatitis C virus (HCV)-infected patients. Alternate options are needed for patients who relapse or do not respond to therapy. METHODS This prospective, international, multicenter, open-label study evaluated efficacy and safety of peginterferon alfa-2b (1.5 microg/kg/wk) plus weight-based ribavirin (800-1400 mg/day) in 2333 chronic HCV-infected patients with significant fibrosis/cirrhosis whose previous interferon alfa/ribavirin therapy failed. Patients with undetectable HCV-RNA at treatment week (TW) 12 received 48 weeks of therapy; patients with detectable HCV-RNA at TW12 could enter maintenance studies at TW18; 188 patients with low/detectable HCV-RNA at TW12 continued therapy at the investigators request. RESULTS Overall, 22% of the patients attained SVR (56% with undetectable HCV-RNA and 12% with low/detectable HCV-RNA at TW12). SVR was better in relapsers (38%) than nonresponders (14%), regardless of previous treatment, and in patients previously treated with interferon-alfa/ribavirin (25%) than peginterferon alfa-ribavirin (17%). Predictors of response in patients with undetectable HCV-RNA at TW12 were genotype (2/3 vs 1, respectively; odds ratio [OR] 2.4; P < .0001), fibrosis score (F2 vs F4; OR, 2.2; F3 vs F4; OR, 1.7; P < .0001), and baseline viral load (< or =600,000 vs >600,000 IU/mL; OR, 1.4; P = .0223). These factors plus previous treatment and response were overall predictors of SVR. Safety was similar among fibrosis groups. CONCLUSIONS Peginterferon alfa-2b plus weight-based ribavirin is effective and safe in patients who failed interferon alfa/ribavirin therapy. Genotype, baseline viral load, and fibrosis stage were predictors of response.

Cost effectiveness of peginterferon α-2b plus ribavirin versus interferon α-2b plus ribavirin for initial treatment of chronic hepatitis C

Background: Peginterferon α-2b plus ribavirin therapy in previously untreated patients with chronic hepatitis C yields the highest sustained virological response rates of any treatment strategy but is expensive. Aims: To estimate the cost effectiveness of treatment with peginterferon α-2b plus ribavirin compared with interferon α-2b plus ribavirin for initial treatment of patients with chronic hepatitis C. Methods: Individual patient level data from a randomised clinical trial with peginterferon plus ribavirin were applied to a previously published and validated Markov model to project lifelong clinical outcomes. Quality of life and economic estimates were based on German patient data. We used a societal perspective and applied a 3% annual discount rate. Results: Compared with no antiviral therapy, peginterferon plus fixed or weight based dosing of ribavirin increased life expectancy by 4.2 and 4.7 years, respectively. Compared with standard interferon α-2b plus ribavirin, peginterferon plus fixed or weight based dosing of ribavirin increased life expectancy by 0.5 and by 1.0 years with incremental cost effectiveness ratios of 11 800 and 6600 per quality adjusted life year (QALY), respectively. Subgroup analyses by genotype, viral load, sex, and histology showed that peginterferon plus weight based ribavirin remained cost effective compared with other well accepted medical treatments. Conclusions: Peginterferon α-2b plus ribavirin should reduce the incidence of liver complications, prolong life, improve quality of life, and be cost effective for the initial treatment of chronic hepatitis C.

The epidermal growth factor receptor (EGF-R) is present on the basolateral, but not the apical, surface of enterocytes in the human gastrointestinal tract.

BACKGROUND: While it is clear that luminal epidermal growth factor (EGF) stimulates repair of the damaged bowel, its significance in maintaining normal gut growth remains uncertain. If EGF is important in maintaining normal gut growth, the EGF receptor (EGF-R) should be present on the apical (luminal) surface in addition to the basolateral surface. AIMS/SUBJECTS/METHODS: This study examined the distribution of the EGF-R in the epithelium throughout the human gastro-intestinal tract using immunohistochemistry, electron microscopy, and western blotting of brush border preparations. RESULTS: Immunostaining of the oesophagus showed circumferential EGF-R positivity in the cells of the basal portions of the stratified squamous epithelium but surface cells were EGF-R negative. In the normal stomach, small intestine, and colon, immunostaining localised the receptor to the basolateral surface with the apical membranes being consistently negative. EGF-R positivity within the small intestine appeared to be almost entirely restricted to the proliferative (crypt) region. Western blotting demonstrated a 170 kDa protein in whole tissue homogenates but not in the brush border vesicle preparations. CONCLUSIONS: As the EGF-R is located only on the basolateral surfaces in the normal adult gastrointestinal tract, the major role of luminal EGF is probably to stimulate repair rather than to maintain normal gut growth.

Genotype–phenotype correlations in Peutz-Jeghers syndrome

Background and aims: Peutz-Jeghers syndrome (PJS) is a dominantly inherited disorder often caused by mutations in STK11. Time to onset of symptoms was characterised for a large collection of individuals with PJS who had been tested for STK11 mutations and genotype–phenotype correlations were evaluated. Methods: We characterised mutations in 42 independent probands and also used a historical cohort design to study 51 individuals with Peutz-Jeghers syndrome who had completed self-administered questionnaires. Results: Mutations were detected in 22/32 (69%) probands with PJS and 0/10 probands referred to rule out PJS. Real-time PCR analysis to quantitate DNA failed to detect any large deletions in PJS participants without STK11 mutations. The median time to onset for gastrointestinal symptoms or polypectomy was 13 years of age but showed a wide variability. Gastric polyps were frequent in PJS participants, with a median age at onset of 16 years. Individuals with missense mutations had a significantly later time to onset of first polypectomy (p = 0.04) and of other symptoms compared with those participants either with truncating mutations or no detectable mutation. Conclusion: STK11 mutation analysis should be restricted to individuals who meet PJS criteria or their close relatives. Direct sequencing of STK11 yields a high rate of point mutations in individuals who meet phenotypic PJS criteria. Individuals with missense mutations of STK11 typically had a later time to onset for PJS symptoms. The common occurrence of gastric polyps may facilitate chemopreventive studies for this disorder.

Peutz-Jeghers syndrome: clinicopathology and molecular alterations

Abstract.Peutz-Jeghers syndrome (PJS, OMIM 175200) is an unusual inherited intestinal polyposis syndrome associated with distinct peri-oral blue/black freckling [1–9]. Variable penetrance and clinical heterogeneity make it difficult to determine the exact frequency of PJS [4]. PJS is a cancer predisposition syndrome. Affected individuals are at high risk for intestinal and extra-intestinal cancers. In 1997, linkage studies mapped PJS to chromosome 19p [10, 11], and subsequently a serine/threonine kinase gene defect (LKB1) was noted in a majority of PJS cases [12, 13]. A phenotypically similar syndrome has been produced in an LKB1 mouse knockout model [14–18]. Several PJS kindred without LKB1 mutations have been described, suggesting other PJS loci [19–22]. The management of PJS is complex and evolving. New endoscopic technologies may improve management of intestinal polyposis. Identification of specific genetic mutations and their targets will more accurately assess the clinical course, and help gage the magnitude of cancer risk for affected individuals.

The watermelon stomach: Long-term outcome in patients treated with ND:YAG laser therapy

Watermelon stomach is an unusual cause of gastrointestinal bleeding and iron deficiency anemia. Its etiology is unknown, but it has been reported to be associated with a variety of diseases, including autoimmune disorders and cirrhosis. We report on the long-term outcome of 15 patients (13 women, 2 men) treated with neodymium-yttrium-aluminum-garnet (Nd:YAG) laser therapy. The mean age of patients at presentation was 71.6 years (range, 59 to 85 years). Fourteen patients were transfusion-dependent, requiring an average of 9.6 units of blood in the 12 months preceding diagnosis and treatment. Associated diseases included scleroderma (3 patients), mixed connective tissue disease (1 patient), history of cancer (3 patients), cryptogenic cirrhosis (3 patients), and chronic renal failure (3 patients). In 7 of 9 patients who had an antinuclear antibody test, an elevated titer greater than 1:160 in a speckled pattern was noted. Nd:YAG laser coagulation therapy was administered to all patients without complications and was successful in reducing bleeding in every case. Five patients died during the course of follow-up without signs of recurrent gastrointestinal bleeding. The remaining 10 patients have had both endoscopic and hematologic improvement during a mean follow-up period of 4.4 years from the time of initial diagnosis (range, 2 to 8 years). The 10 survivors are no longer transfusion-dependent and have stable hematocrits.

Herpes simplex-induced fulminant hepatitis in adults: a call for empiric therapy.

Herpes simplex-induced fulminant hepatitis is an infrequently reported cause of hepatitis in adults. Pregnant females and patients with impaired cellular immunity may be at increased risk, although healthy adults have been affected. The diagnosis may be underrecognized due to nonspecific presenting symptoms and lack of typical cutaneous herpes lesions. We present three cases of fatal herpes simplex fulminant hepatitis. Our review of case reports of herpes simplex hepatitis in adults demonstrates improved survival with intravenous acyclovir therapy. We believe that empiric use of acyclovir should be considered while the diagnostic evaluation of non-acetaminophen-induced fulminant hepatitis is underway. Recognition of characteristic liver function abnormalities seen with fulminant herpes simplex hepatitis include marked elevation of transaminases with AST > ALT and a mild hyperbilirubinemia (anicteric hepatitis), and they should prompt acyclovir therapy. This is especially true when there are no obvious risk factors for other forms of hepatitis.

GI Polyposis and Glycogenic Acanthosis of the Esophagus Associated With PTEN Mutation Positive Cowden Syndrome in the Absence of Cutaneous Manifestations

A 62-yr-old man was referred for management of GI polyposis. Large bowel polyps were initially diagnosed >25 yr ago, and the patient had undergone multiple colonoscopies and polypectomies. Personal and family history were notable for thyroid goiter and hypothyroidism. Physical examination was notable for lingular papillomatosis. No cutaneous lesions were seen. Upper endoscopy revealed esophageal glycogen acanthosis. There were multiple polyps throughout the stomach and the small and large intestines. Histology of these polyps showed multiple cell types including juvenile polyps, inflammatory polyps with fibromuscular proliferation and lamina propria ganglion cells, and focal adenomatous change. A clinical diagnosis of Cowden syndrome was made. Mutation analysis revealed a variant in exon 8 of the PTEN gene. Direct sequencing revealed a germline heterozygous C.892–895InsA, which is predicted to result in a truncated PTEN protein. Cowden syndrome is an underdiagnosed, underrecognized, autosomal dominant, inherited syndrome. For the gastroenterologist, esophageal acanthosis and multiple hamartomatous polyps should suggest the diagnosis. Sensitive molecular diagnostic tests looking for mutations in the appropriate genes are clinically available. Together with genetic counseling, molecular diagnostic testing will allow more accurate risk assessment and surveillance for cancer for both the patient and family members.