Mutation profile of high-grade appendiceal mucinous neoplasm.

AIMS: High-grade appendiceal mucinous neoplasm (HAMN) was recently proposed as a disease entity histologically analogous to low-grade appendiceal mucinous neoplasm (LAMN), but characterised by high-grade cytological atypia. The pathogenesis and clinical features of HAMN have not been fully elucidated. METHODS AND RESULTS: Nine cases of HAMN, eight LAMN, 10 appendiceal mucinous adenocarcinomas (MACA) and five appendiceal serrated polyps resected between 2008 and 2017 contributed by three medical centres underwent targeted next-generation sequencing of 50 cancer-related genes. The patients in each category had similar profiles with respect to gender, age, tumour stage and follow-up intervals. Both LAMN and HAMN harboured mutations of KRAS [nine of nine and eight of eight (100%), respectively] and GNAS [five of eight (63%) and five of nine (56%), respectively] in significantly higher proportions than MACA [KRAS, seven of 10 (70%, P = 0.04); GNAS: one of 10 (10%, P = 0.02)] and serrated polyps [KRAS, one of five (20%, P = 0.0007); GNAS: none of five (0%, P = 0.04)]. Four cases of HAMN, but none of LAMN, harboured mutations of TP53 [four of nine (44%)] and/or ATM [two of nine (22%)]. Three cases of HAMN (33%) showed extra-appendiceal spread with retention of the same mutational profiles in the intra- and extra-appendiceal components. The 10 cases of MACA harboured a similar prevalence of TP53 mutations (n = 5, 50%) as HAMN but, unlike LAMN and HAMN, some harboured mutations in PIK3CA, APC, FBXW7, PTEN and SMAD4. CONCLUSIONS: HAMN and LAMN share high rates of KRAS and GNAS co-mutations supporting a common histogenesis and distinguishing them from MACA. Acquisition of TP53 or ATM mutations by HAMN may drive its progression to a more advanced phenotype.

Colorectal carcinomas with mucinous differentiation are associated with high frequent mutation of KRAS or BRAF mutations, irrespective of quantity of mucinous component.

BACKGROUND: Mucinous adenocarcinoma (MAC) is a distinct type of colorectal cancer (CRC) associated with poor response to treatment and poorer prognosis. MAC is diagnosed by WHO definition when the extracellular mucin is more than 50% of the lesion. We aimed at assessing the gene expression profiles of the CRCs with any mucinous features (> 5%) in a retrospective study. METHODS: The data of a 50-gene next generation sequencing (NGS) panel of 166 CRCs was analyzed and the gene mutational profile with morphologic features was correlated. RESULTS: We identified the different genetic mutation profiles between CRCs with and without mucinous component, but noticed a similar genetic profile between MACs and CRCs with mucinous component, irrespective of the percentage (if mucinous component more than 5%). The different genetic mutation profile related to MSI status was also identified between two groups of tumors. The most frequent mutations in CRCs with mucinous component are KRAS (28/49, 57.1%) and BRAF (19/49, 38.7%), PIK3CA (16/49, 32.6%), followed by APC (12/49, 24.5%) and TP53 (11/49, 22.5%). The combined mutation frequency of the two key factors in the EGFR signaling pathway, KRAS and BRAF, in the CRCs with and without mucinous component is 95.9 and 52.1%, respectively. CONCLUSIONS: The dysregulation of EGFR pathway plays a critical role in the development of CRCs with mucinous component, irrespective of the percentage. The result suggested that the current cut off of 50% mucin component to define mucinous adenocarcinoma might be challengeable.

Co-expression of XIAP and cyclin D1 complex correlates with a poor prognosis in patients with hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world. Despite improved diagnosis and treatment, the prognosis for HCC patients remains poor. The goal of this study was to identify key regulatory proteins and signaling pathways important for cell apoptosis and proliferation as biomarkers for prognostication and targeted therapy. Protein Pathway Array was applied to screen 38 signaling proteins and phosphoproteins in 12 paired HCC tumors and surrounding benign tissues and found that 20 of them, including XIAP, CDK4, CDK6, and Cyclin D1, were overexpressed in HCC tissues. Immunostaining results of XIAP, CDK4, and Cyclin D1 in an additional 59 HCC tissues showed that the expression of XIAP correlated with the expression of CDK4/Cyclin D1, and that the increased expression of these proteins correlated with poor overall survival in these patients. Further studies using the HCC Huh7 cell line transfected with XIAP siRNA or expression vector demonstrated that XIAP regulated the expression of CDK4, CDK6, and Cyclin D1 via NF-êB and PTEN pathways. Finally, inhibition of XIAP using embelin, a XIAP-specific small molecule, leads to an increased apoptosis and decreased cell proliferation via arrest at G1 phase. Taken together, XIAP is a central modulator regulating cell apoptosis and cell cycle progression. Therefore, XIAP together with cell cycle regulatory proteins can be used as prognostic markers and therapeutic targets.

KRAS mutations are associated with specific morphologic features in colon cancer.

BACKGROUND: Mutations in the KRAS gene occur at an early stage in the development of colorectal carcinoma. Importantly, KRAS mutation predicts resistance to anti-epidermal growth factor receptor therapy in stage IV disease. GOALS: The aim of the current study is to correlate histologic features of colon cancer with the presence of KRAS mutations. STUDY: Tumor tissue from 145 colon cancer resections was tested for KRAS mutations. KRAS mutation status was correlated with demographic and histologic characteristics. Statistical analysis was performed using the Pearson χ2 test and multivariate analysis. RESULTS: KRAS mutations were present in 55/145 cases (37.9%), consistent with reported rates. KRAS mutations were significantly associated with usual adenocarcinoma morphology (multivariate P=0.014), peritumoral lymphocytic response (χ2, P=0.028; multivariate P=0.017), T3-T4 status (χ2, P=0.012; multivariate P=0.015), right-sided location (multivariate P=0.027), absence of lymphovascular invasion (multivariate P=0.008), and metastases at the time of resection (multivariate P=0.034). No association was found between KRAS mutation status and other factors. CONCLUSIONS: Specific morphologic features in colon cancer suggest a higher likelihood of the presence of KRAS mutations. These morphologic features overlap partially with those associated with DNA mismatch repair gene mutations. If confirmed, these results may suggest a paradigm for directed KRAS testing.

Race and the molecular origins of breast cancer in Chinese women: breast cancer in Chinese women.

Although there is considerable controversy regarding the role of race in the etiology of human disease, evidence suggests that breast cancers are racially distinct diseases. Clinical features and genetic alterations are different in Chinese women with breast cancer compared with white women. These differences are significant and may influence clinical care. In this review, we summarize the literature addressing genetic heterogeneity in Chinese women with breast cancer. Data support important variations in genes involved in tumorigenic pathways of DNA repair, steroid synthesis and receptor expression, apoptosis, immunity, inflammation, cell cycle control, cancer growth and metastasis, and growth receptor signaling. These genetic differences contribute to our understanding of the molecular origins of breast cancer and may accelerate the development of personalized disease prevention strategies.

Inverse relationship between cirrhosis and massive tumours in hepatocellular carcinoma.

BACKGROUND: A subset of patients with hepatocellular carcinoma (HCC) present with massive tumours. It is unknown why certain patients develop these massive tumours, and whether this presentation is specific to the underlying viral aetiology or patient demographics such as gender, race and age. METHODS: All patients with HCC at Bellevue Hospital Center, New York from 1998 to 2012 were identified and relevant demographic and clinical information was collected. Computed tomography/magnetic resonance imaging (CT/MRI) images were reviewed and the maximal tumour diameter on axial sections was recorded. Cirrhosis was defined histologically or by radiographical criteria. The two cohorts of massive and non-massive HCC were compared. RESULTS: A total of 361 patients with HCC were identified, of which 58 were categorized as having a massive HCC using a 13 cm size cut-off. Univariate and multivariate analysis demonstrated a significant association of massive HCC with age <40 years; hepatitis B or Asian ethnicity; and a lack of cirrhosis or platelet count >100. DISCUSSION: Massive HCC represents a tumour subtype that is associated with young, chronic hepatitis B carriers with non-cirrhotic livers. The clinical implications of this finding are that patients with massive HCC are typically excellent resection candidates barring the presence of gross vascular invasion or distant metastases.

Distinct function of androgen receptor coactivator ARA70α and ARA70ß in mammary gland development, and in breast cancer.

Steroid receptor coactivators are important in regulating the function of the receptors in endocrine organ development and in cancers, including breast. Androgen receptor (AR) coactivator ARA70, was first identified as a gene fused to the ret oncogene and later characterized as an AR coactivator. We previously reported that the full length ARA70α functions as a tumor suppressor gene and that ARA70ß functions as an oncogene in prostate cancer. Here we show that both ARA70α and ARA70ß function as AR and estrogen receptor (ER) coactivators in breast cancer cells. However, ARA70α and ARA70ß serve different functions in mammary gland development and breast cancer tumorigenesis. We observed hypoplastic development of mammary glands in MMTV driven ARA70α transgenic mice and overgrowth of mammary glands in ARA70ß transgenic mice at virgin and pregnant stages. We determined that ARA70α inhibited cell proliferation, and that ARA70ß promotes proliferation in MCF7 breast cancer cells. These effects were observed in hormone-free media, or in media with androgen or estrogen, though to varying degrees. Additionally, we observed that ARA70ß strongly enhanced the invasive ability of MCF7 breast cancer cells in in vitro Matrigel assays. Significantly, decreased ARA70α expression is associated with increased tendency of breast cancer metastasis. In summary, ARA70α and ARA70ß have distinct effects in mammary gland development and in the progression of breast cancer.

Androgen receptor coactivator p44/Mep50 in breast cancer growth and invasion.

Hormones and their receptors play an important role in the development and progression of breast carcinoma. Although the primary focus has been on oestrogen and oestrogen receptor (ER), androgen, androgen receptor (AR) and its coactivator(s) have been implicated in tumorigenesis of breast carcinoma and warrant further investigation. AR coactivator p44/Mep50 is identified as a subunit of methylosome complex and lately characterized as an AR coactivator that enhances AR mediated transcription activity in a ligand dependent manner. In prostate cancer, p44 is expressed in the nucleus of benign epithelia and translocated into the cytoplasm in cancer cells. Furthermore, nuclear expression of p44 inhibits prostate cancer growth. In this report, we examined the expression and function of p44 in breast cancer. In addition to being an AR coactivator, p44 also functions as an ER coactivator. In contrast to findings in prostate cancer, the expression of p44 shows strong cytoplasmic expression in morphologically normal terminal ductal lobular units, while nuclear p44 is observed in both ductal carcinoma in situ and invasive carcinoma. Further, overexpression of nuclear-localized p44 stimulates proliferation and invasion in MCF7 breast cancer cells in the presence of oestrogen and the process is ERα dependent. These findings strongly suggest that p44 plays a role in mediating the effects of hormones during tumorigenesis in breast.

Toll-like receptor 4 differentially regulates epidermal growth factor-related growth factors in response to intestinal mucosal injury.

Epiregulin (EPI) and amphiregulin (AR) are epidermal growth factor receptor (EGFR) ligands implicated in mucosal repair and tumorigenesis. We have shown that Toll-like receptor 4 (TLR4) induces intestinal epithelial cell (IEC) proliferation by activating EGFR through AR expression. We examined whether TLR4 differentially regulates expression of EGFR ligands in response to mucosal injury. The human IEC line SW480 was examined expression of EGFR ligands, EGFR phosphorylation, and proliferation in response to lipopolysaccharide (LPS). Small-interfering RNA (siRNA) was used to block TLR4. Neutralizing antibodies to EGFR ligands were used to examine inhibition of LPS-dependent EGFR activation. Acute colitis and recovery were examined in the mice given 2.5% dextran sodium sulfate (DSS). Colonic secretion of EPI and AR was analyzed by enzyme-linked immunosorbent assay. LPS selectively induces EPI and AR but not other EGFR ligands. LPS induced early EPI mRNA expression between 30 min and 24 h. The neutralizing antibodies to EPI and AR prevented activation of EGFR by LPS. LPS induces IEC proliferation (200%, P=0.01) in 24 h but blocking EPI and AR significantly decreased proliferation. In vivo, mucosal EPI and AR expression are significantly decreased in TLR4(-/-) mice (P=0.02) compared to wild-type mice during acute colitis. EPI and AR exhibit different kinetics in response to mucosal damage: EPI expression is upregulated acutely at day 7 of DSS, but falls during recovery at day 14. By contrast, a sustained upregulation of AR expression is seen during mucosal injury and repair. We show that TLR4 regulates EPI and AR expression and that both these EGFR ligands are necessary for optimal proliferation of IEC. The diverse kinetics of EPI and AR expression suggest that they function in distinct roles with respect to acute injury vs repair. Our results highlight the role of bacterial sensing for IEC homeostasis and may lead to targeted therapy for mucosal healing and prevention of tumorigenesis.

Copy number and gene expression differences between African American and Caucasian American prostate cancer.

BACKGROUND: The goal of our study was to investigate the molecular underpinnings associated with the relatively aggressive clinical behavior of prostate cancer (PCa) in African American (AA) compared to Caucasian American (CA) patients using a genome-wide approach. METHODS: AA and CA patients treated with radical prostatectomy (RP) were frequency matched for age at RP, Gleason grade, and tumor stage. Array-CGH (BAC SpectralChip2600) was used to identify genomic regions with significantly different DNA copy number between the groups. Gene expression profiling of the same set of tumors was also evaluated using Affymetrix HG-U133 Plus 2.0 arrays. Concordance between copy number alteration and gene expression was examined. A second aCGH analysis was performed in a larger validation cohort using an oligo-based platform (Agilent 244K). RESULTS: BAC-based array identified 27 chromosomal regions with significantly different copy number changes between the AA and CA tumors in the first cohort (Fisher's exact test, P < 0.05). Copy number alterations in these 27 regions were also significantly associated with gene expression changes. aCGH performed in a larger, independent cohort of AA and CA tumors validated 4 of the 27 (15%) most significantly altered regions from the initial analysis (3q26, 5p15-p14, 14q32, and 16p11). Functional annotation of overlapping genes within the 4 validated regions of AA/CA DNA copy number changes revealed significant enrichment of genes related to immune response. CONCLUSIONS: Our data reveal molecular alterations at the level of gene expression and DNA copy number that are specific to African American and Caucasian prostate cancer and may be related to underlying differences in immune response.

The role of prostaglandin E2 (PGE 2) in toll-like receptor 4 (TLR4)-mediated colitis-associated neoplasia.

BACKGROUND: We have previously found that TLR4-deficient (TLR4-/-) mice demonstrate decreased expression of mucosal PGE 2 and are protected against colitis-associated neoplasia. However, it is still unclear whether PGE 2 is the central factor downstream of TLR4 signaling that promotes intestinal tumorigenesis. To further elucidate critical downstream pathways involving TLR4-mediated intestinal tumorigenesis, we examined the effects of exogenously administered PGE 2 in TLR4-/- mice to see if PGE 2 bypasses the protection from colitis-associated tumorigenesis. METHOD: Mouse colitis-associated neoplasia was induced by azoxymethane (AOM) injection followed by two cycles of dextran sodium sulfate (DSS) treatment. Two different doses of PGE 2 (high dose group, 200 microg, n = 8; and low dose group, 100 microg, n = 6) were administered daily during recovery period of colitis by gavage feeding. Another group was given PGE 2 during DSS treatment (200 microg, n = 5). Inflammation and dysplasia were assessed histologically. Mucosal Cox-2 and amphiregulin (AR) expression, prostanoid synthesis, and EGFR activation were analyzed. RESULTS: In control mice treated with PBS, the average number of tumors was greater in WT mice (n = 13) than in TLR4-/- mice (n = 7). High dose but not low dose PGE 2 treatment caused an increase in epithelial proliferation. 28.6% of PBS-treated TLR4-/- mice developed dysplasia (tumors/animal: 0.4 +/- 0.2). By contrast, 75.0% (tumors/animal: 1.5 +/- 1.2, P < 0.05) of the high dose group and 33.3% (tumors/animal: 0.3 +/- 0.5) of the low dose group developed dysplasia in TLR4-/- mice. Tumor size was also increased by high dose PGE 2 treatment. Endogenous prostanoid synthesis was differentially affected by PGE 2 treatment during acute and recovery phases of colitis. Exogenous administration of PGE 2 increased colitis-associated tumorigenesis but this only occurred during the recovery phase. Lastly, PGE 2 treatment increased mucosal expression of AR and Cox-2, thus inducing EGFR activation and forming a positive feedback mechanism to amplify mucosal Cox-2. CONCLUSIONS: These results highlight the importance of PGE 2 as a central downstream molecule involving TLR4-mediated intestinal tumorigenesis.

Toll-like receptor-4 promotes the development of colitis-associated colorectal tumors.

BACKGROUND & AIMS: Chronic inflammation is a risk factor for colon cancer in patients with ulcerative colitis (UC). The molecular mechanisms linking inflammation and colon carcinogenesis are incompletely understood. We tested the hypothesis that Toll-like receptor 4 (TLR4) is involved in tumorigenesis in the setting of chronic inflammation. METHODS: Tissues from UC patients with cancer were examined for TLR4 expression. Colitis-associated neoplasia was induced using azoxymethane injection followed by dextran sodium sulfate treatment in TLR4-deficient or wild-type mice. Inflammation, polyps, and microscopic dysplasia were scored. Cyclooxygenase (Cox)-2 and prostaglandin E(2) production were analyzed by real-time polymerase chain reaction, immunohistochemistry, or enzyme immunoassay. Epidermal growth factor receptor (EGFR) phosphorylation and amphiregulin production were examined by Western blot analysis and enzyme-linked immunosorbent assay, respectively. RESULTS: We show that TLR4 is overexpressed in human and murine inflammation-associated colorectal neoplasia. TLR4-deficient mice were protected markedly from colon carcinogenesis. Mechanistically, we show that TLR4 is responsible for induction of Cox-2, increased prostaglandin E(2) production, and activation of EGFR signaling in chronic colitis. Amphiregulin, an EGFR ligand, was induced in a TLR4, Cox-2-dependent fashion and contributes to activation of EGFR phosphorylation in colonic epithelial cells. CONCLUSIONS: TLR4 signaling is critical for colon carcinogenesis in chronic colitis. TLR4 activation appears to promote the development of colitis-associated cancer by mechanisms including enhanced Cox-2 expression and increased EGFR signaling. Inhibiting TLR4 signaling may be useful in the prevention or treatment of colitis-associated cancer.

Autophagy proteins suppress protective type I interferon signalling in response to the murine gut microbiota.

As a conserved pathway that lies at the intersection between host defence and cellular homeostasis, autophagy serves as a rheostat for immune reactions. In particular, autophagy suppresses excess type I interferon (IFN-I) production in response to viral nucleic acids. It is unknown how this function of autophagy relates to the intestinal barrier where host-microbe interactions are pervasive and perpetual. Here, we demonstrate that mice deficient in autophagy proteins are protected from the intestinal bacterial pathogen Citrobacter rodentium in a manner dependent on IFN-I signalling and nucleic acid sensing pathways. Enhanced IFN-stimulated gene expression in intestinal tissue of autophagy-deficient mice in the absence of infection was mediated by the gut microbiota. Additionally, monocytes infiltrating into the autophagy-deficient intestinal microenvironment displayed an enhanced inflammatory profile and were necessary for protection against C. rodentium. Finally, we demonstrate that the microbiota-dependent IFN-I production that occurs in the autophagy-deficient host also protects against chemical injury of the intestine. Thus, autophagy proteins prevent a spontaneous IFN-I response to microbiota that is beneficial in the presence of infectious and non-infectious intestinal hazards. These results identify a role for autophagy proteins in controlling the magnitude of IFN-I signalling at the intestinal barrier.

Clinical features, histology, and histogenesis of combined hepatocellular-cholangiocarcinoma.

Combined hepatocellular-cholangiocarcinoma (CHC) is a rare tumor with poor prognosis, with incidence ranging from 1.0%-4.7% of all primary hepatic tumors. This entity will be soon renamed as hepato-cholangiocarcinoma. The known risk factors for hepatocellular carcinoma (HCC) have been implicated for CHC including viral hepatitis and cirrhosis. It is difficult to diagnose this tumor pre-operatively. The predominant histologic component within the tumor largely determines the predominant radiographic features making it a difficult distinction. Heterogeneous and overlapping imaging features of HCC and cholangiocarcinoma should raise the suspicion for CHC and multiple core biopsies (from different areas of tumor) are recommended before administering treatment. Serum tumor markers CA19-9 and alpha-fetoprotein can aid in the diagnosis, but it remains a challenging diagnosis prior to resection. There is sufficient data to support bipotent hepatic progenitor cells as the cell of origin for CHC. The current World Health Organization classification categorizes two main types of CHC based on histo-morphological features: Classical type and CHC with stem cell features. Liver transplant is one of the available treatment modalities with other management options including transarterial chemoembolization, radiofrequency ablation, and percutaneous ethanol injection. We present a review paper on CHC highlighting the risk factors, origin, histological classification and therapeutic modalities.

Colchicine-Induced Hepatotoxicity.

Drug-induced injury (DILI) is a frequent cause of abnormal liver tests and a leading cause of liver failure in the United States. Colchicine has long been used as a systemic anti-inflammatory agent for treatment of gout by inhibiting mitotic activity and neutrophil function. We present the first case of colchicine-induced hepatoxicity, supported by histopathologic findings characteristic of colchicine-induced injury and resolution of liver enzyme abnormalities after its discontinuation. Colchicine-associated DILI has implications for the evaluation of patients with abnormal liver tests and gout, especially for patients with alcoholism and non-alcoholic fatty liver disease, in whom there is an increased incidence of gout.

The TGF-ß/Smad4 Signaling Pathway in Pancreatic Carcinogenesis and Its Clinical Significance.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal human cancers due to its complicated genomic instability. PDAC frequently presents at an advanced stage with extensive metastasis, which portends a poor prognosis. The known risk factors associated with PDAC include advanced age, smoking, long-standing chronic pancreatitis, obesity, and diabetes. Its association with genomic and somatic mutations is the most important factor for its aggressiveness. The most common gene mutations associated with PDAC include KRas2, p16, TP53, and Smad4. Among these, Smad4 mutation is relatively specific and its inactivation is found in more than 50% of invasive pancreatic adenocarcinomas. Smad4 is a member of the Smad family of signal transducers and acts as a central mediator of transforming growth factor beta (TGF-ß) signaling pathways. The TGF-ß signaling pathway promotes many physiological processes, including cell growth, differentiation, proliferation, fibrosis, and scar formation. It also plays a major role in the development of tumors through induction of angiogenesis and immune suppression. In this review, we will discuss the molecular mechanism of TGF-ß/Smad4 signaling in the pathogenesis of pancreatic adenocarcinoma and its clinical implication, particularly potential as a prognostic factor and a therapeutic target.

Frequency and pathological characteristics of drug-induced liver injury in a tertiary medical center.

Drug-induced liver injury (DILI) accounts for approximately 10% of acute hepatitis cases. DILI can arise as idiosyncratic or intrinsic injury from hundreds of drugs, herbals, and nutritional supplements and is essential to recognize as one of the differential diagnoses of hepatitis in a liver biopsy. The purpose of this study is to investigate the frequency and pathological characteristics of DILI related to the variety of hepatotoxic agents. We searched our pathology database for all patients with hepatitis diagnosed on liver biopsy from January 2012 to May 2016, and selected patients with a diagnosis of DILI. Electronic medical records were reviewed for patient medication list, history of herbal medicine or supplement use, and pre-biopsy liver function test (LFT) results. Clinical and pathologic correlation was used to determine the causative or related agents for DILI. We then assessed histopathologic features of liver injury and categorized biopsy findings as primarily bile duct injury, lobular/portal hepatitis, or mixed changes. Six hundred four total liver biopsies for hepatitis or liver injury were identified, of which 70 cases (11.6%) carried the diagnosis of DILI confirmed by clinical correlation. The most common etiologies associated with DILI were supplements and herbal products (31.4%), antimicrobials (14.3%), chemotherapeutics (11.4%), antilipidemics (7.1%) and immunomodulatory agents (7.1%). LFT results positively correlated with histological findings. Nutritional/herbal supplements have emerged as one of the major hepatotoxicity agents. DILI can manifest as predominantly hepatitis, bile duct injury or combination. Histological pattern recognition in the liver biopsy may help identify specific hepatotoxic agents causing DILI.

Microcarcinoids in large intestinal adenomas.

Composite adenoma-carcinoid tumors are rare colorectal lesions consisting of intermingled adenomatous and carcinoid components. Unlike other mixed endocrine-glandular colorectal neoplasms, which are generally malignant, their glandular component is histologically benign and their natural history is favorable. We present 4 cases of colonic adenomas containing microcarcinoids, a hitherto undescribed lesion that is either a precursor of composite adenoma-carcinoids or a related but independent entity. The cases, identified among our surgical and consultation files, were endoscopically routine sessile polyps removed from 4 otherwise normal individuals, 3 from the cecum and 1 from the distal colon. The microcarcinoids were 0.5 to 1.5 mm in size and situated within the basal lamina propria, where they interposed between the crypts and muscularis mucosae without disturbing the overall polyp architecture. Histologically, they consisted of collections of low-grade epithelial cells arranged in nests, cords, tubules, and irregular clusters and characterized by eosinophilic, granular, or clear cytoplasm and by round central nuclei with stippled or dusty chromatin. Endocrine differentiation of the microcarcinoids was confirmed by the expression of 3 or more of the following: Grimelius argyrophil, chromogranin, synaptophysin, neuron-specific enolase and somatostatin. No mitotic figures or MIB-1 or p53 positivity were observed. The glandular component of the polyps was unremarkable in 3 cases, but 1 polyp, in addition to a microcarcinoid, showed a diffuse pattern of mixed adenomatous-endocrine differentiation. The patients' clinical course was benign on the basis of 2 years' median follow-up (range, 6 mo to 10 y). Two patients with incomplete polypectomies underwent hemicolectomy revealing no residual endocrine neoplasia. Awareness of microcarcinoids in colonic adenomas should help avert potential diagnostic pitfalls posed by their pleomorphism, basal location, and infiltrative patterns, and may help clarify their natural history and possible relationship to composite glandular-carcinoid tumors.

Clinical and biological significance of precursor lesions of intrahepatic cholangiocarcinoma.

Cholangiocarcinoma (CC) is primarily a malignant tumor of older adults most prevalent in Southeast Asia, where liver fluke infestation is high. However the etiology in western countries is unknown. Although the incidence of extrahepatic cholangiocarcinoma has remained constant, incidence of intrahepatic CC (ICC) which differs in morphology, pathogenesis, risk factors, treatment and prognosis is increasing. While this increase is associated with hepatitis C virus infection, chronic nonalcoholic liver disease, obesity, and smoking, the pathogenesis of ICC and molecular alterations underlying the carcinogenesis are not completely elucidated. Benign biliary lesions such as biliary intraepithelial neoplasia, intraductal papillary neoplasm of the bile duct, von Meyenburg complex or bile duct hamartoma, and bile duct adenoma have been associated with ICC. For each of these entities, evidence suggests or supports a role as premalignant lesions. This article summarized the important biological significance of the precursor lesions of ICC and the molecular mechanisms that may be involved in intrahepatic cholangiocarcinogenesis.

Warfarin dosing and cytochrome P450 2C9 polymorphisms.

Two cytochrome P450 2C9 (CYP2C9) polymorphisms, CYP2C9*2 and *3, metabolize warfarin inefficiently. We assessed the extent to which these polymorphisms explain very low warfarin dose requirements and hemorrhagic complications after excluding non-genetic determinants of warfarin dosing. In this retrospective observational study, 73 patients with stable warfarin doses for > or =1 month and International Normalized Ratios (INR) of 2.0-3.0 were enrolled from our Anticoagulation Clinic. Seventeen patients required < or =2 mg (low-dose), 41 required 4-6 mg (moderate-dose), and 15 required > or =10 mg (high-dose) of daily warfarin. CYP2C9 genotyping was assessed by PCR amplification and restriction enzyme digestion analysis of DNA isolated from circulating leukocytes. The CYP2C9 polymorphisms independently predicted low warfarin requirements after adjusting for Body Mass Index, age, acetaminophen use, and race (OR 24.80; 95% CI 3.83-160.78). At least one polymorphism was present in every patient requiring < or =1.5 mg of daily warfarin, and 88%, 37%, and 7% of the low-, moderate-, and high-dose groups, respectively. All homozygotes and compound-heterozygotes for the variant alleles were in the low-dose group. Rates of excessive (INR>6.0) anticoagulation (and bleeding) were 4.5 (6.0), 7.9 (7.9), and 14.7 (0) per 100 patient-years in the wild-types, heterozygotes, and compound heterozygotes/homozygotes, respectively. In conclusion, CYP2C9*2 or *3 compound heterozygotes and homozygotes have low warfarin requirements even after excluding liver disease, excessive alcohol or acetaminophen consumption, low body weight, advancing age, and drug interactions. These polymorphisms increase the rate of excessive anticoagulation, but this risk does not appear to be associated with higher bleeding rates when anticoagulation status is closely monitored.