Background/Aims: Defective DNA mismatch repair (MMR) in pancreatic cancer, reported in up to 13% of sporadic pancreatic cancers, may predict a good prognosis. To determine if long-term survival in pancreatic cancer could be attributed to defective DNA MMR, we ascertained its prevalence in 35 pancreatic cancer patients who survived ≥ 3 years after surgery. Methods: We performed immunohistochemistry (IHC) for MMR proteins hMLH1, hMSH2, and hMSH6 in all 35 tumors and microsatellite instability (MSI) studies in 34/35 tumors using 10 microsatellite markers in paired normal and tumor DNA. Defective DNA MMR was defined as absence of protein expression on IHC and/or MSI in ≥30% of markers studied. Results: On IHC, 3/35 (8.6%) tumors had defective DNA MMR. All 3 had absent expression of a DNA MMR protein (hMLH1 in 2 and hMSH2) and 2/3 also had MSI; the third could not be tested. Definitely 2, and probably all 3 patients had hereditary non-polyposis colon cancer as determined by clinical and genetic profiles. Conclusion: Defective DNA MMR is uncommon in long-term survivors of pancreatic cancer and does not account for the survival benefit in those with sporadic pancreatic cancer.

Background & Aims: There is limited data on the spectrum and risk for cancer associated with germline serine/threonine protein kinase 11 (STK11) mutations that cause Peutz-Jeghers syndrome (PJS). Methods : We analyzed the incidence of cancer in 240 individuals with PJS possessing germline mutations in STK11. Results: Fifty-four cancers were found among carriers. Overall, the risk for developing cancer at ages 20, 30, 40, 50, 60, and 70 years was 1%, 3%, 19%, 32%, 63%, and 81%, respectively. Kaplan-Meier analysis showed similar cancer risks between missense and truncating mutation carriers (log-rank chi(2) = 2.48; P = 0.12). There was some evidence that mutations in exon 3 of STK11 were associated with a higher cancer risk than mutations within other regions of the gene. We found no difference in overall cancer risk between male and female carriers (log-rank chi(2) = 1.31; P = 0.25) or between familial and sporadic cases (log-rank chi(2) = 1.16, with 1 df; P = 0.28). The most common cancers represented were gastrointestinal in origin-gastroesophageal, small bowel, colorectal, and pancreatic-and the risk for these cancers at ages 30, 40, 50, and 60 years was 1%, 10%, :18%, and 42%, respectively. In women, the risk for breast cancer was substantially increased, being 32% by age 60 years. Conclusions: These results quantitatively show the spectrum of cancer risk associated with STK11 germline mutations in the context of PJS and provide a valuable reference for defining surveillance regimens.

Frequent BRAF mutations were reported recently in a variety of human malignancies, including colorectal cancer. In this study, we screened 293 colorectal cancers for mutations in exons 11 and 15, two regions containing hotspots for BRAF mutation. Of the 293 cancers, 170 had normal mismatch repair, and 123 had defective mismatch repair (originating from both somatic as well as germ-line mutations in several of the mismatch repair genes). A total of 63 exonic mutations (22%) were detected, 60 of which were V599E, and one each of D593G, G468E, and D586A. Of the tumors with defective mismatch repair, 34% (42 of 123) had a mutation in BRAF, whereas only 12% (21 of 170) of tumors with proficient mismatch repair demonstrated a mutation (P < 0.0001). Interestingly, BRAF mutations were found most often in cases with an hMHL1 abnormality (35 of 60) and rarely in cases with an hMSH2 abnormality (1 of 39; P < 0.0001). More interestingly, of the 31 hMLH1 cases with a BRAF mutation, 30 occurred in tumors known to have hypermethylation of hMLH1 promoter. Only 1 of the 15 cases with a germ-line mutation in hMLH1 had a mutation in BRAF. In this series, BRAF mutations occurred rarely in tumors with defective mismatch repair attributable to the presence of germ-line mutation in either hMLH1 or hMSH2. Furthermore, BRAF mutations were strongly associated with the epigenetic alteration of hMLH1. Overall, these data suggest that BRAF mutations are not a consequence of defective mismatch repair per se.

patients per year.Ranson's cdteria were the most frequently employed scoring system, being used by 168 (51%).Prophylactic antibiotics in severe disease were used by 229 (70%) with the most frequent antimicrobial being a third generation cephalosporin or imipanem.Only 168 (51%) of respondents use fine needle aspiration for the diagnosis of infected neorosis and only 99 (59%) of these 168 individuals stated that they would always operate on a patient with a positive result.There was no general consensus as to the optimal timing of surgical intervention with 8-14 days being the most frequently selected time period (45 respondents preferred to operate within 7 days and 70 preferred to defer beyond 21 days).Optimal therapy for treatment of pancreatic abscess was percutaneous drainage 154 (47%)with open surgical drainage 12.8(39%)being the next most popular option.Surgical drainage was the preferred therapeutic option for the treatment of infected pancreatic necrosis in 240 (70%), with 39% of these respondents favoring post-operative closed irrigation.Formal pancreatectomy was favored by 20 (6%) and endoscopic intervention by 4 (1%).Conclusions: This survey highlights wide variation in the surgical management of patients with severe acute pancreatitis by surgeons with a declared interest in the treatment of the condition.Lack of consensus in areas where there is currently available evidence (for example in terms of the use of FNA and the of timing of surgery) suggests that improved outcome may be achieved by wider dissemination and application of current knowledge 505

Twenty percent of colorectal cancers (CRCs) arise in people who have a family history of CRC in at least one other relative. Although a fraction of these CRCs are explained by two well-described autosomal dominant syndromes-5% by hereditary nonpolyposis colorectal cancer (HNPCC) and 1% by familial adenomatous polyposis (FAP)-the cause of the remaining 14% of familial aggregates of CRC is unknown. Many cases of HNPCC are due to germline mutations in DNA mismatch repair genes, leading to the tumor phenotype of microsatellite instability (MSI), and most cases of FAP are caused by germline APC mutations. To date, non-FAP familial CRC aggregates have not been evaluated for germline APC mutations. In this study, we examined the involvement of germline APC mutations in 79 individuals with CRC who had early-age onset of their cancer (age < 50 years) and/or a family history of CRC. Cases with FAP or HNPCC due to defective mismatch repair were excluded from the study. Using conformation-sensitive gel electrophoresis and the protein truncation test as the screening methods, no functionally significant germline mutations were detected for any of the cases. An apparently silent polymorphism resulting in a 1-bp alteration of A --> G (proline --> proline) in exon 4 was observed. Additionally, four intervening sequence (IVS) alterations were detected: IVS2-53t-->c in 3 cases; IVS4-17ins T in 3 cases; IVS5+32t-->c in 16 cases; and IVS5+33g-->a in 1 case. All appeared to be polymorphisms present in similar proportions in an average-risk population. We conclude that germline APC mutations do not account for familial MSS (stable microsatellite) CRC associated with few synchronous polyps. (C) 2001 Wiley-Liss, Inc.

BACKGROUND & AIMS To determine accuracy of endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) for evaluation of Crohn's disease perianal fistulas. METHODS Thirty-four patients with suspected Crohn's disease perianal fistulas were prospectively enrolled in a blinded study comparing EUS, MRI, and examination under anesthesia (EUA). Fistulas were classified according to Parks' criteria, and a consensus gold standard was determined for each patient. Acceptable accuracy was defined as agreement with the consensus gold standard for > or =85% of patients. RESULTS Three patients did not undergo MRI; 1 did not undergo EUS or EUA; and consensus could not be reached for 1. Thirty-two patients had 39 fistulas (20 trans-sphincteric, 5 extra-sphincteric, 6 recto-vaginal, 8 others) and 13 abscesses. The accuracy of all 3 modalities was > or =85%: EUS 29 of 32 (91%, confidence interval [CI] 75%-98%), MRI 26 of 30 (87%, CI 69%-96%), and EUA 29 of 32 (91%, CI 75%-98%). Accuracy was 100% when any 2 tests were combined. CONCLUSIONS EUS, MRI, and EUA are accurate tests for determining fistula anatomy in patients with perianal Crohn's disease. The optimal approach may be combining any 2 of the 3 methods.

and histological types.Contrary to that stage distribution was statistically different between groups, namely due to lack of pts with stage I and 3 times higher incidence of pts with stage IV (38.7% vs. 12.1%;p<0.05) in the study group.As a result curative procedures were performed in 52% of the study group and 88% in the control group (p=0.001),Patients in the POCRC group were followed for an average of 29 months, while controls -for 32 months.Kaplan-Meir analysis at 5 years demonstrated overall survival of 32% in the POCRC and 59% in the NCCRC groups (p=O.OOl).When survival was analyzed by stage it appeared not different between the groups of pts with stage II and IV.For pts with stage III survival was statistically different at 5 years but difference disappeared at 6 years.Perforations were detected in 32 of 75 pts with 26 of them (81%) occurring at the tumor site.In the POCRC group diverting ostomy was utilized in 51 pts (68%) and bypass procedure in 3 (4%).Curative resection was done in 39 pts (52% of all pts).Anastomosis after resection was performed in 21 pts (28% of all or 58.8% of curative resections), in the POCRC group morbidity was 37% and mortality was 5.3%.It can be concluded that decreased 5-year survival in pts with POCRC was attributable to the higher proportion of pts with stage IV compared to the NCCRC group.Stage for stage comparison of survival demonstrates no difference between groups.Though risk of morbiiity and mortality is increased in pts with POCRC, curative resection of the primary cancer must be the goal of surgery when possible.

LKB1, the human gene encoding a serine threonine kinase, was recently identified as a susceptibility gene for Peutz-Jeghers syndrome (PJS), a disease characterized by the constellation of intestinal hamartomata, oral mucocutaneous hyperpigmentation, and an increased risk for gastrointestinal as well as extraintestinal malignancies. To date, the majority of individuals with PJS have been found to have genetic alterations in LKB1, most of which result in protein truncation. Additionally, linkage analyses have suggested a modicum of genetic heterogeneity, with the majority of PJS families showing linkage to the LKB1 locus. In this study, we evaluated five kindreds with greater than two affected family members, five PJS probands with only one other affected family member, as well as 23 individuals with sporadic PJS for mutations within the LKB1 gene. Conformation sensitive gel electrophoresis was utilized for the initial screen, followed by direct sequence analysis for characterization. Long-range PCR was used for the detection of larger genetic insertions or deletions. Mutation analysis revealed genetic alterations in LKB1 in two probands who had a family history of PJS. LKB1 mutations were detected in only four of the remaining 23 cases of sporadic PJS. These data suggest the presence of significant genetic heterogeneity for PJS and the involvement of other loci in this syndrome.

Most reports describe an increased risk of malignancy in Peutz-Jeghers syndrome (PJS). We identified individuals with PJS-like pigmentation but no polyposis, designated as isolated mucocutaneous melanotic pigmentation (IMMP), and 1) characterized their clinical features, 2) assessed them for cancer events, and 3) screened a sample of these subjects for mutations in LKB1, a gene responsible for a portion of PJS cases. Review of Mayo Clinic records from 1945 to 1996 identified 26 patients with IMMP. All were then interviewed or their medical records reviewed to determine if cancer had developed. Conformation-sensitive gel electrophoresis (CSGE) screening for LKB1 mutations was followed by direct sequencing. Ten of these 26 individuals (38%) developed 12 malignancies that arose in the cervix (n = 3), endometrium (n = 3), breast (n = 1), kidney (n = 1), lung (n = 2), colon (n = 1), and lymphatic tissue (n = 1). In females with IMMP, the relative risk for cancer was 3.2 (95% CI, 1.2-6.9), while that for males was not increased. The relative risk for breast and gynecologic cancers was 7.8 (95% CI, 2.5-18.1) in affected females. Of 9 individuals tested, no LKB1 mutations were detected. Classical PJS is associated with an increased cancer risk. Our results indicate that IMMP is another lentiginosis with cancer predisposition. In particular, the relative risk for cancer in females with IMMP was significantly increased, as is true in females with PJS. However, LKB1 mutations did not contribute to the development of IMMP in the patients tested.

An increasing interest in gene expression profiles in human diseases has led to the use of microdissected tumors and biopsies in gene discovery approaches. Since many of these clinical samples yield extremely small amounts of RNA, reproducible methods are needed to amplify this RNA while maintaining the original message profile. Using the SMART cDNA Synthesis Method, we show that high-, medium- and low-abundance transcripts can be amplified in a representative fashion and that the resulting cDNA can also be used as a complex probe to confirm gene expression differences identified by other techniques.