Incidence of synchronous and metachronous pancreatic carcinoma in 168 patients with branch duct intraductal papillary mucinous neoplasm.

BACKGROUND/AIMS: Although branch duct intraductal papillary mucinous neoplasms of the pancreas (BD-IPMN) are being diagnosed with increasing frequency, the incidence of concomitant pancreatic carcinoma (PC) is not well known. We investigated the incidence and clinical features of synchronous and metachronous PC in patients with BD-IPMN. METHODS: We studied 168 BD-IPMN patients diagnosed by various imaging modalities, including endoscopic retrograde pancreatography, between 1990 and 2008. We reviewed the medical records and clinical features in both patients developing and not developing PC. The diagnosis of PC was histologically verified in all patients. RESULTS: PC was observed in 9 (5.4%) of 168 patients. Five were synchronously detected at the time of BD-IPMN diagnosis, whereas four were metachronously identified during the follow-up period. All PCs occurred in regions separate from the BD-IPMN lesion. All PCs represented histologically invasive ductal adenocarcinomas, whereas the BD-IPMN lesion was diagnosed as adenoma. Patients developing PC were significantly older than patients not developing PC (p = 0.017). The diameters of the BD-IPMN lesions and main pancreatic ducts were significantly smaller in patients developing PC than patients not developing PC (p = 0.013 and p < 0.001, respectively). CONCLUSIONS: It was not infrequent for PC to occur in the pancreas with BD-IPMN. Particular attention should therefore be paid to the development of PC, even in low-risk BD-IPMN, as well as to changes in BD-IPMN.

Pancreatic ductal adenocarcinomas in long-term follow-up patients with branch duct intraductal papillary mucinous neoplasms.

OBJECTIVE: Although branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) are slow-growing tumors with a favorable prognosis, the synchronous occurrence of pancreatic ductal adenocarcinomas (PDAs) in patients with BD-IPMNs has been reported. This study was aimed to elucidate the development of PDAs in long-term follow-up patients with BD-IPMNs. METHODS: We investigated 89 BD-IPMN patients who had no mural nodules and followed them up conservatively at least 2 years (median follow-up, 64 months; range, 25-158 months). All subjects underwent examinations by imaging modalities including endoscopic retrograde pancreatography. We calculated the standardized incidence ratio (SIR) from the vital statistics compiled by the Ministry of Health, Labor, and Welfare of Japan. RESULTS: Among the 89 patients, 4 cases of PDAs distant from BD-IPMN were observed in 552 patient-years of follow-up (7.2 per 1000 patient-years). The expected number was 0.25, and the SIR of PDAs was 15.8 (95% confidence interval [CI], 4.3-40.4; P = 0.00014). Subgroup analyses showed that the incidence of PDAs was significantly increased in patients 70 years or older (SIR 16.7; 95% CI, 3.4-48.7; P = 0.0008) and in women (SIR 22.5; 95% CI, 2.7-81.1; P = 0.0037). CONCLUSIONS: Patients with BD-IPMNs are at a high risk for PDAs. During the follow-up, careful examination is required to detect the development of PDAs in patients with BD-IPMNs.

Tumor doubling time in two cases of main duct intraductal papillary-mucinous neoplasms of the pancreas.

The present study reports the growth rate in two cases of main duct pancreatic intraductal papillary-mucinous neoplasms (MD-IPMNs) demonstrating significant changes over several years' observation. The first patient was a 74-year-old woman with an incidental finding of diffuse dilatation of the main pancreatic duct (MPD). Endoscopic retrograde pancreatography (ERP) identified a 5 mm filling defect. Three years later computed tomography (CT) revealed a 20 mm mass occupying the MPD. The second patient was a 67-year-old woman who presented with back pain. Abdominal CT revealed a 5 mm mass in the dilated MPD. Five years later, CT and ERP showed a 20 mm mass occupying the markedly dilated MPD. Both patients subsequently underwent pancreatectomy. Histologically, the tumors showed an intraductal papillary growth occupying the dilated MPD and comprised of mucin-containing columnar epithelial cells. The tumor volume doubling time of these MD-IPMNs was 141 and 304 days in patient 1 and 2, respectively, with a mean of 222.5 days. The present reports demonstrate the ability of benign MD-IPMNs to grow at a significant rate, supporting the current consensus guidelines that MD-IPMNs require surgical resection.

Risk of additional pancreatic cancer in patients with branch duct intraductal papillary-mucinous neoplasm.

Branch duct intraductal papillary-mucinous neoplasms of the pancreas (BD-IPMN) are being diagnosed with increasing frequency. Although BD-IPMN outcomes are generally good, pancreatic ductal adenocarcinoma (PDA) is found distant from the original BD-IPMN in about 3.3-9.2% of cases. These reports raise the question of whether a possible association exists between BD-IPMN and PDA. Recent findings from follow-up studies suggest that pancreases with BD-IPMNs have a high risk of developing additional pancreatic cancer, with standardized incidence ratios (SIRs) of 15.8- to 26-fold. These studies suggest that special attention should be paid to BD-IPMN patients who are ≥70 years. Furthermore, molecular evidence supports the hypothesis that field cancerization causing multiple primary neoplastic lesions exists in pancreases harboring IPMNs. Although more extensive studies are required to clarify the magnitude of this increased risk, clinicians should pay close attention to the development of PDA in patients with BD-IPMN, as well as to changes in BD-IPMN lesions.

Reduction of syndecan-1 expression in differentiated type early gastric cancer and background mucosa with gastric cellular phenotype.

BACKGROUND: Syndecan-1 is known to play a role as a cell adhesion molecule, similar to E-cadherin, and is associated with the maintenance of epithelial morphology. The purpose of this study was to elucidate the role and alterations of syndecan-1 expression in comparison with those of E-cadherin in different cellular phenotypes of differentiated-type gastric cancers (DGCs). METHODS: A total of 80 DGCs at an early stage, and their adjacent mucosa, were evaluated by both immunohistochemistry and in situ hybridization. Syndecan-1 and E-cadherin were assessed by immunohistochemical staining with an anti-syndecan-1 and an anti-E-cadherin antibody, respectively. Based on immunohistochemistry, DGCs and their surrounding mucosa were divided into four types: gastric type (G-type), ordinary type (O-type), complete-intestinal type (CI-type), and null type. RESULTS: The expression sites of syndecan-1 mRNA mostly coincided with those of syndecan-1 protein. Syndecan-1 expression was significantly lower in G-type cancers (30%) than in O- (81%) and CI-type cancers (92%) ( P = 0.0001 and P = 0.004, respectively), but E-cadherin did not show this result. In addition, syndecan-1 expression was significantly reduced in DGCs comprised partly of poorly differentiated adenocarcinoma or signet-ring cell carcinoma, compared to DGCs demonstrating papillary and/or tubular adenocarcinoma ( P = 0.02). G-type intestinal metaplasia (IM) surrounding the tumors was observed in 21% of G-type cancers, in 0% of O-, and in 10% of CI-type cancers ( P = 0.01; G-type vs O-type). Reduction of syndecan-1 expression was significant in G-type IM (25%) compared to non-G-type IM (75%; P = 0.02). CONCLUSIONS: Syndecan-1 plays a role in the growth of G-type cancers at an early stage compared with E-cadherin changes, and the reduction of syndecan-1 expression in IM surrounding the tumors may influence the growth of G-type cancer.

Minute findings by magnifying colonoscopy are useful for the evaluation of ulcerative colitis.

BACKGROUND: Colonoscopy has an important role in the diagnosis of ulcerative colitis. However, colonoscopic findings are inadequate for the prediction of relapse without histologic examination. In this study, the role of magnifying colonoscopy in ulcerative colitis was evaluated. METHODS: One hundred sixteen magnifying colonoscopy observations were made in 61 patients with ulcerative colitis between January 1994 and October 1998. A simple classification of magnifying colonoscopic findings into 5 categories was devised as follows: regularly arranged crypt openings, villous-like, minute defects of epithelium, small yellowish spots, and coral reef-like appearance. The colonoscopic findings by classification were compared with histopathologic findings, and the usefulness of the classification for predicting relapse was prospectively analyzed in 18 patients. RESULTS: Compared with grade as determined by conventional colonoscopy, there was a better correlation between the classification of findings by magnifying colonoscopy and histopathologic findings (r(2) = 0.665, 0.807, respectively). Of 18 patients studied prospectively, 7 of 9 with minute defects of epithelium relapsed within 6 months, and the cumulative nonrelapsing rate was significantly lower in patients with minute defects of epithelium compared with those without minute defects of epithelium (p = 0.0059). Moreover, minute defects of epithelium was found to be a significant independent predictive factor for relapse (multivariate analysis, Cox proportional hazards model; p = 0.0203). CONCLUSIONS: Our proposed classification of magnifying colonoscopic findings in patients with ulcerative colitis is useful for the evaluation of disease activity and for the prediction of periods of remission.

Natural history of colorectal nonpolypoid adenomas: a prospective colonoscopic study and relation with cell kinetics and K-ras mutations.

OBJECTIVE: Serial colonoscopic observations were prospectively conducted to elucidate the natural history of nonpolypoid tumors. Furthermore, to clarify whether cell kinetic status affects the tumor development, proliferative indices, apoptotic indices, and K-ras codon 12 point mutations on biopsy specimens were investigated. METHODS: Seventy-five colorectal tumors, 13 polypoid and 62 nonpolypoid type (56 flat elevated and six depressed type) were studied. Proliferating and apoptotic cells were detected with anti-Ki-67 antibody and the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling method, respectively. Point mutations at K-ras codon 12 were examined by enriched polymerase chain reaction-based restriction fragment length polymorphism assay. RESULTS: The average follow-up period was 22 months (range 1-50). The lesions of subsequent exophytic growth, unchanged shape, depressed growth, and disappearance were observed in 0%, 92%, 0%, and 8% of polypoid type, in 39%, 39%, 13%, and 9% of flat elevated type, and in 33%, 67%, 0%, and 0% of depressed type, respectively. There was no significant difference in tumor size between initial and follow-up colonoscopy. Nonpolypoid tumors apparently changed to the exophytic growth during 2 yr or more. The tumors with exophytic growth had significantly higher proliferative indices/apoptotic indices ratios than those with unchanged morphology and disappearance/depressed growth (p < 0.05, respectively). K-ras codon 12 point mutations did not correlate with tumor development. CONCLUSIONS: Cell kinetic status plays an important role in determining minute colorectal tumor development, but not K-ras codon 12 mutations. Minute nonpolypoid adenomas frequently tend to grow slowly, and nearly 40% of those become the exophytic growth with time. Most of minute nonpolypoid tumors seem to follow the adenoma-carcinoma sequence.

Prognostic Significance of the Labeling of Adnab-9 in Pancreatic Intraductal Papillary Mucinous Neoplasms.

First described as a distinct entity in the early1980s (1), pancreatic ductal neoplasms with mucinhypersecretion have been increasingly recognized.This motivated the World Health Organization(WHO) reclassification proposal in 1996 (2), which separated them from mucinous cystic neoplasms.These tumors are now (3) termed intraductal papillarymucinous neoplasms (IPMN). Despite a burgeoningvolume of recent literature devoted to thiscondition, little is known of the pathogenesis ofIPMN,which is believed to constitute 10% of mucinproducingpancreatic tumors and 1% of pancreaticcancers (4). IPMN presents diagnostic and therapeuticchallenges to the clinician because it representsa histologic spectrum of morphology, from thebenign adenoma to invasive carcinoma. The initialhistological and morphological features of IPMN oftenunderestimate its invasive potential (5), and may notaccurately predict survival. Conversely, it may oftenbe difficult to differentiate benign from malignantlesions (5-7). In the most advanced stages, when aninvasive carcinoma is present, IPMN can be indistinguishablefrom common pancreatic ductal cancer(PC), yet with aggressive surgical management, theprognosis for patients with IPMN is far better (6,7).The availability of a prognostic indicator, independentfrom the pathological stage, may help to directtherapy.