Peutz-Jeghers syndrome: clinicopathology and molecular alterations.

Peutz-Jeghers syndrome (PJS, OMIM 175200) is an unusual inherited intestinal polyposis syndrome associated with distinct peri-oral blue/black freckling. Variable penetrance and clinical heterogeneity make it difficult to determine the exact frequency of PJS. 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, and subsequently a serine/threonine kinase gene defect (LKB1) was noted in a majority of PJS cases. A phenotypically similar syndrome has been produced in an LKB1 mouse knockout model. Several PJS kindred without LKB1 mutations have been described, suggesting other PJS loci. 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.

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.

Apoptosis associated with esophageal adenocarcinoma: influence of photodynamic therapy.

Tumor cell death in vitro by photodynamic therapy (PDT) has been related to the induction of apoptosis. We measured and compared changes in apoptosis and caspase 3 activity, an effector of apoptosis, in normal and neoplastic esophageal tissues during PDT. Apoptosis index, caspase 3 cleavage activity, pro-caspase 3, p53, and bcl-2 levels were measured in normal and neoplastic tissues of patients with esophageal adenocarcinoma before, during, and after PDT with Photofrin. The apoptotic index was greater in carcinoma tissue compared to adjacent normal tissues. In concert, pro-caspase 3 immunoreactivity was absent and caspase 3-like cleavage activity was over 30-fold greater in carcinoma tissue compared to normal esophageal tissues. These parameters were unaffected by PDT. Variable changes in bcl-2 and p53 immunoreactivity were noted in normal and carcinoma tissues during PDT. Greater levels of apoptosis and caspase 3 activity are hallmarks of esophageal adenocarcinoma compared to normal esophageal tissue. These differences were unaffected by PDT. This may be due to the fact that tissues were obtained 72 h post-PDT therapy. Changes in these parameters may have occurred early after PDT therapy. An assessment of apoptosis and caspase 3 activity prior to 72 h post-PDT may provide further insight into the mechanism involved, although no sustained effects on these parameters by PDT were noted.

Outcome of patients with chronic abdominal pain referred to chronic pain clinic.

OBJECTIVE: We determined the outcome of patients with chronic abdominal pain of unknown etiology referred by gastroenterologists to a chronic pain clinic. METHODS: A retrospective chart review of 43 consecutive patients seen by a university-based gastroenterology group was referred to our Chronic Pain Clinic for evaluation and treatment. Pain character and location, the referring diagnosis, and initial Chronic Pain Clinic diagnosis was compared between responders and nonresponders. Early and long-term pain relief was scored by standard questionnaire. RESULTS: Of the 43 patients with chronic abdominal pain of undetermined etiology, 70% reported complete or substantial pain relief by the end of chronic pain management. Pain character and location and the referring diagnosis were not predictors of pain relief. Long-term pain relief was reported by 35% of patients. CONCLUSION: A substantial group of patients with chronic abdominal pain of unknown etiology benefited from Chronic Pain Clinic services.

Giant fundic polyp complicating attenuated familial adenomatous polyposis.

This case details the development of a rapidly growing polypoid mass in the proximal stomach in a patient with known attenuated familial adenomatous polyposis. Surgical resection was required and histology showed hyperplasia with extensive areas of dysplastic adenomatous change. This case illustrates that patients with the attenuated form of familial adenomatous polyposis are at risk for multiple neoplasia distinct from those patients with the classic form of familial adenomatous polyposis.

Somatic mutation screening: identification of individuals harboring K-ras mutations with the use of plasma DNA.

BACKGROUND: Many cancers are attributed to somatic mutation of DNA. We investigated whether it is feasible to detect cancer-associated somatic mutations in patients with neoplasms by using plasma DNA. METHODS: Plasma samples were prospectively collected from 240 patients undergoing colonoscopy. Colorectal biopsies were performed as clinically indicated in 135 patients, and risk factor information was available from 232 patients. DNA was extracted from plasma and colorectal tissue and was amplified by use of a polymerase chain reaction method that enriches for mutations in codon 12 of the K-ras oncogene. Molecular, histologic, and clinical data were compared by use of two-sided Fisher's exact test. RESULTS: Mutations in the K-ras gene detected in the plasma of 64 (28%) of 232 patients were statistically significantly associated with colorectal cancer risk factors (P =.0002). Of those patients having tissue available for comparison (n = 135), mutations in the K-ras gene were found in the tissues of 35 patients, and 29 (83%) of these 35 showed mutations in plasma samples. In contrast, the plasma assay was negative in 93 of the 100 patients whose tissue K-ras was wild-type. Among patients without biopsies (n = 105), 28 had mutated K-ras in their plasma DNA, despite the absence of remarkable colonoscopy findings; 24 of these 28 patients had risk factors for colorectal cancer. Overall, 25 (39%) of 64 patients showing mutations in plasma DNA had colorectal neoplasms with K-ras mutations compared with five (3%) of 176 patients without K-ras mutations in plasma DNA. CONCLUSION: Plasma DNA assays for the detection of mutations in K-ras codon 12 may provide a feasible method to screen populations for somatic mutations frequently found in neoplasms. The clinical utility of using this test in screening populations requires further study.

p53 and APC mutations are detectable in the plasma and serum of patients with colorectal cancer (CRC) or adenomas.

BACKGROUND: A variety of tumor-related DNA has been detected in the plasma and serum of cancer patients, including RAS, the BCL2-IgH transgene, and p53. It is not known whether the APC gene, which is frequently mutated in colorectal cancer (CRC), can be identified in the plasma of CRC patients. Similarly, it is unknown whether another tumor suppressor gene altered in CRC, p53, is detectable in people with precursor lesions to CRC. MATERIALS AND METHODS: The plasma of 240 colonoscopy patients was tested for mutations at two frequently altered sites (codons 175 and 248). A restriction enzyme-mediated enrichment assay was used to detect these mutants. We also tested tumor tissue from 8 patients with CRC for mutations in the mutation cluster region of the APC gene using direct DNA sequencing. Corresponding plasma from any positive patient was then similarly sequenced. RESULTS: Three plasma p53 mutations were identified. Two of these patients had adenomas at biopsy, and 1 had a hyperplastic polyp. All were tested for the same p53 mutations, and 1 of the adenomas was positive. One of the 8 CRC patients had a 5-base-pair deletion in the cancer and the same deletion was detectable in that patient's plasma, although at an amount that we estimate at 1-5% of the total APC DNA present. CONCLUSIONS: APC mutations are detectable in the plasma of CRC patients. p53 mutants are detectable in the plasma of colorectal adenoma patients. These may have important implications for cancer screening and diagnosis in the large intestine and suggest that all malignant and premalignant DNA alterations from the colon are identifiable in the blood.

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.

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.

Overexpression of epidermal growth factor receptor in Peutz-Jeghers syndrome.

Peutz-Jeghers syndrome is characterized by gastrointestinal hamartomatous polyposis, mucocutaneous pigmentation, and a predisposition to cancer. The etiology of this syndrome is unknown. We investigated the expression of epidermal growth factor receptor (EGFr), transforming growth factor-alpha (TGF-alpha), transforming growth factor-beta1 (TGF-beta1) and transforming growth factor-beta receptor (TGF-beta RII) between normal and Peutz-Jeghers small bowel tissues. In addition, immunoprecipitation by phosphotyrosine antibodies followed by EGFr western blotting was measured and compared between a Peutz-Jeghers hamartoma and normal duodenal tissue. EGFr expression was increased 2.5-fold in normal and hamartomatous tissue of Peutz-Jeghers patients compared to normal small bowel tissue. In Peutz-Jeghers tissues, the major EGFr immunoreactive band was increased size from 170 to approximately 200 kDa. Using an antibody specific for activated EGFr, this larger size band was predominant in Peutz-Jeghers tissue. Immunoprecipitation of a hamartoma by a phosphotyrosine specific antibody followed by western blotting for EGFr demonstrated this 200-kDa band. Expression of TGF-alpha, TGF-beta1, TGF-beta1 RII was not significantly different between normal and Peutz-Jeghers tissues. In conclusion, EGFr was overexpressed in normal and hamartomatous small bowel tissue of Peutz-Jeghers patients, which suggests that EGFr in Peutz-Jeghers tissue is persistently activated or highly stimulated by endogenous ligands and also suggests a possible role for EGFr in the pathogenesis of Peutz-Jeghers syndrome.

Differential effects of deoxycholic acid on proliferation of neoplastic and differentiated colonocytes in vitro.

The secondary bile acid deoxycholic acid is believed to be a promoter of large bowel cancer, in part by inducing colonic epithelial proliferation. The effects of deoxycholic acid on [3H]thymidine incorporation by the human colon cancer cell line HT29 and two differentiated subclones were measured and compared. The subclone HT29-C1 has features of mature absorptive cells and HT29-N2 cells secrete mucus under cholinergic control. The three cell lines were treated with deoxycholic acid (DCA) at concentrations of 0, 5, 10, 50, 100, 150, and 300 microM for 3, 6, 9, 15, 24, and 48 hr. A significant increase in proliferation was noted in HT29 cells only at 6 hr with 5 and 10 microM deoxycholic acid. Neither the subclone HT29-C1, nor HT29-N2 cells exhibited significant change in [3H]thymidine incorporation with DCA at these concentrations or time points. Higher doses of deoxycholic acid above 50 microM and duration of exposure greater than 24 hr were cytotoxic to all three cell lines. The proliferative effects of DCA in HT29 cells were not paralleled by changes in protein kinase C activity or protein kinase C isoform expression. Quantitative and qualitative differences in PKC isoform expression were not noted in the three cell lines used in this study. The proliferative effects of DCA on HT29 cells appear to be independent of the PKC signal transduction pathway.

Fine mapping of a genetic locus for Peutz-Jeghers syndrome on chromosome 19p.

Peutz-Jeghers syndrome (PJS) was recently mapped in a single report to the telomeric region of chromosome 19p (A. Hemminki et al., Nat. Genet., 15: 87-90, 1997). Our studies confirm this location and provide further localization of the PJS locus. In the five families examined, there were no recombinants with the marker D19S886. The multipoint log odds score at D19S886 is 7.52, and we found no evidence for genetic heterogeneity. We also found that all carriers expressed the PJS phenotype and no noncarriers displayed PJS sequellae, indicating complete penetrance with no sporadic cases.

Treatment strategies for Helicobacter pylori infection.

Peptic ulcer disease is strongly associated with infection by Helicobacter pylori, a spiral-shaped, flagellated organism found predominantly in the gastric antrum. More than 90 percent of duodenal ulcers and adenocarcinomas of the distal stomach are associated with H. pylori infection. Eradication of the organism effectively prevents relapses of gastroduodenal ulcers associated with H. pylori. In patients undergoing endoscopy, the rapid urease test is highly sensitive and specific in diagnosing H. pylori infection. Noninvasive diagnostic methods include serologic antibody measurements and urea breath testing. Empiric therapy may be tried if the diagnosis is suspected on a clinical basis. Traditional 14-day "triple therapy" with bismuth, metronidazole and either amoxicillin or tetracycline has consistently produced eradication rates of approximately 90 percent. Newer combination regimens have shown promise in a smaller number of studies. No single agent given as monotherapy has proved to be acceptably effective in clinical studies.

Opioid growth factor ([Met5]enkephalin) prevents the incidence and retards the growth of human colon cancer.

Endogenous opioid peptides serve as growth factors in normal and neoplastic cells and tissues, and both opioids and their receptors have been identified in human colon cancer. This study examined the hypothesis that opioids serve to modulate the growth of human colon cancer. Daily administration of the native opioid growth factor (OGF), [Met5]enkephalin, at dosages of 0.5, 5, or 25 mg/kg prevented the occurrence of human colon cancer HT-29 xenografts in nude mice. More than 80% of the mice receiving OGF beginning at the time of tumor cell inoculation did not exhibit neoplasias within 3 wk, in comparison with a tumor incidence of 93% in control subjects. Even 7 wk after cancer cell inoculation, 57% of the mice given OGF did not display a tumor. OGF delayed tumor appearance and growth in animals developing colon cancer with respect to the control group. The suppressive effects of OGF on oncogenicity were opioid receptor mediated. OGF and its receptor, zeta (zeta), were detected in transplanted human HT-29 colon tumors. Surgical specimens of human colon cancers also contained OGF. These results show that a naturally occurring opioid peptide acts as a potent negative regulator of human gastrointestinal cancer and may suggest pathways for tumor etiology, progression, treatment, and prophylaxis.

Survival of patients diagnosed with colorectal cancer through a television-advertised screening program.

OBJECTIVES: Although controversial, fecal occult blood testing (FOBT) is advocated to reduce mortality due to colorectal cancer. Our aim was to determine whether a television-advertised screening program for colorectal cancer using fecal occult blood tests improved survival of patients diagnosed with colorectal cancer. METHODS: A retrospective analysis of the stage and survival of patients diagnosed with colorectal cancer in our 1986 and 1987 screening programs was conducted. The 5-yr survival rate of patients diagnosed with colorectal cancer was determined in our screened population and compared with national survival data from the National Cancer Institute Surveillance, Epidemiology, End Results (SEER) program. RESULTS: In our screening programs, 75,633 FOBT were distributed and returned for analysis. Test slides were positive in 3.3%. Follow-up was available in 121 of 131 patients diagnosed with colorectal cancer. In our screened population, significantly more colorectal cancers were identified in a localized stage compared with the national average (76 vs 37%). Consequently, the percentage of our patients with regional and distant disease was decreased compared with SEER data. The overall 5-yr survival rate of patients with colorectal cancer who participated in our screening program was significantly higher than the national survival rate (75 vs 59%). Survival of patients older than 75 yr of age with colorectal cancer in our screening program was not improved. CONCLUSIONS: Television-advertised screening for colorectal cancer using FOBT was effective in recruiting a large number of participants. Patients diagnosed with colorectal cancer in our program tended to have early stage disease with improved 5-yr survival. The results of this study support FOBT as an effective means to reduce the mortality of colorectal cancer.

Localization of protein kinase C alpha isoform expression in the human gastrointestinal tract.

Protein kinase C (PKC) includes a family of related proteins which constitutes a major signal transduction pathway. The aim of this study was to determine the localization of the PKC-alpha isoform throughout the human gastrointestinal tract. PKC-alpha expression was also measured and compared between normal and neoplastic colorectal tissue. PKC-alpha mRNA expression was detected in normal human gastrointestinal tract tissue using Northern blot analyses and in situ hybridization. PKC-alpha protein expression was detected in normal gastrointestinal tissue and colorectal neoplasia using Western blot and immunohistochemical analyses. PKC-alpha was expressed throughout the human gastrointestinal tract. Distinct organ and cellular localization was characterized. PKC-alpha mRNA and protein localization were most prevalent in the deep basal layer of the esophageal mucosa. In the stomach, PKC-alpha expression was detected predominately in the cells of the deep glands and surface epithelial cells but less in the mucous neck cells of the gastric pits. In the duodenum and ileum, PKC-alpha mRNA expression was greater in the deeper crypt cells than in the differentiated cells that line the villi. However, immunohistochemistry showed greater expression in the cells of the villi compared to crypt cells. In normal colonic tissue, PKC-alpha mRNA and protein predominated in the cells of the upper crypt and surface epithelial cells. PKC-alpha protein was also prominently expressed in the glands of colorectal adenocarcinoma. There was no quantitative difference in the level of PKC-alpha protein expression between normal and neoplastic colorectal tissue. The specific organ and cellular expression of PKC-alpha suggests separate and distinct functional roles for this PKC isoform throughout the gastrointestinal tissues.

Identification and characterization of zeta-opioid receptor in human colon cancer.

Opioid growth factor (OGF, [Met5]enkephalin) inhibits the growth of human colon cancer in nude mice in a receptor-mediated fashion. Ligand binding assays using HT-29 human colon cancer tissue and [3H][Met5]enkephalin were performed to characterize the receptor responsible for the growth-regulatory effects of OGF in colon cancer. Specific and saturable binding was detected, and Scatchard analysis revealed that the data were consistent for a single binding site with a binding affinity of 15.4 +/- 2.0 nM and a binding capacity of 364.8 +/- 25.7 fmol/mg protein. Subcellular fractionation studies revealed that binding was restricted to the nuclear fraction. Competition experiments showed that cold [Met5]enkephalin was the most effective ligand at displacing [3H][Met5]enkephalin. Binding to radiolabeled [Met5]enkephalin also was detected in colon cancers obtained from surgical resections. The function, pharmacological and biochemical characteristics, distribution, and subcellular location of this OGF receptor in human colon cancer are consistent with the zeta-opioid receptor.

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.