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Rats transgenic for HLA-B27 and human beta2microglobulin (B27TR) develop a multi-systemic disease resembling inflammatory bowel disease (IBD) and spondyloarthritis. TNFalpha has a crucial role in chronic inflammation. Our objective was to evaluate the effect of anti-TNFalpha treatment on spontaneous IBD in B27TR. Nine-week-old B27TR received monoclonal anti-TNFalpha or an isotypic IgG2a,k up to age of 18 weeks. A second group was monitored up to 18 weeks and then randomly assigned to anti-TNFalpha or IgG2 a,k treatment. Each rat was monitored for clinical IBD manifestations. After sacrifice, the colon was examined for pathological changes. TNFalpha receptors (TNF-R1, TNF-R2), Fas/Fas-L expression and apoptosis were evaluated. IgG2a,k-treated and untreated B27TR presented signs of IBD at 11 weeks, whereas in anti-TNFalpha-treated B27TR no IBD signs were detected. In the late treatment, IBD signs improved after 1 week. Histopathological analysis of IgG2a,k-treated B27TR colon showed inflammatory signs that were widely prevented by early anti-TNFalpha treatment. Late treatment did not significantly reduce inflammation. TNF-R1 was weakly expressed in intestinal epithelial cells of IgG2a,k-treated B27TR, while it was comparable to controls in anti-TNFalpha-treated animals. TNF-R2 immunopositivity was strongly evident in IgG2a,k-treated B27TR, whereas was absent in anti-TNFalpha-treated rats. RT-PCR confirmed these results. IgG2a,k-treated B27TR showed, at 18 weeks, few Fas-positive cells and an increase of Fas-L-positive cells. At 27 weeks, Fas-/Fas-L-positive cell number was significantly low. Anti-TNFalpha treatment increased Fas-L expression, whereas Fas increased only with the early treatment. TNFalpha blockade is effective in preventing inflammation in early phase of IBD, maintaining the homeostatic balance of apoptosis.

Distinguishing between epithelioid peritoneal mesothelioma and papillary serous carcinomas involving the peritoneum may be very difficult, owing to overlapping morphologic features. Immunohistochemistry may facilitate establishing a correct diagnosis, but, as no single antibody has demonstrated absolute sensitivity and specificity for either mesothelioma or serous carcinoma, the differential diagnosis is based mainly on the combined use of several markers. The purpose of this study was to ascertain the sensitivity and specificity of a series of mesothelial markers [including more recently investigated antigens such as h-caldesmon (h-CD) and D2-40] and, using receiver operating characteristic curve analysis, to identify a selected appropriate panel of antibodies for differentiating between epithelioid peritoneal mesothelioma and serous papillary carcinoma of the ovary. Fifteen cases of epithelioid peritoneal mesothelioma and 40 cases of papillary serous carcinoma of the ovary (25 primary and 15 metastatic to the peritoneum) were immunostained for h-CD, D2-40, calretinin, cytokeratin 5/6, thrombomodulin, estrogen and progesterone receptors (ER and PR), Ber-EP4, B72.3, CA19-9, and CD15. h-CD and calretinin showed the highest sensitivity (100%), followed by D2-40 (93.3%) and cytokeratin 5/6 (93.3%); thrombomodulin had the lowest sensitivity (60%). h-CD and thrombomodulin had the best specificity (95%) for mesothelioma, followed by calretinin (87.5%), D2-40 (80%), and cytokeratin 5/6 (72.5%). Among carcinoma markers, ER and Ber-EP4 demonstrated the highest sensitivity (95%) followed by B72.3 (72.5%), PR (65%), CA19.9 (60%), and CD15 (45%). The specificity of the nonmesothelial markers was 100%, except for Ber-EP4 (93.3%). The relationship between the values of sensitivity and specificity of each marker using receiver operating characteristic analysis permitted the identification of h-CD, calretinin, ER, and Ber-EP4 as the markers with the best performance in differentiating epithelioid peritoneal mesothelioma from serous papillary carcinoma of the ovary.

The mutation status of KIT or PDGFRA notoriously affects the response of advanced gastrointestinal stromal tumors (GISTs) to tyrosine kinase inhibitors. Conversely, it is currently still unclear whether mutation status impinges on the prognosis of localized, untreated GISTs. Hence, at present, this variable is not included in decision making for adjuvant therapy. A series of 451 primary localized GISTs were analyzed for KIT, PDGFRA, and BRAF mutations. Univariable and multivariable analyses and a backward selection procedure were used to assess the impact of mutation status on overall survival and to identify prognostically homogenous groups. Mutation was a significant prognostic indicator of overall survival in naive, localized GISTs (P

Background Some recent studies have suggested that laparoscopic surgery for colorectal cancer may provide a potential survival advantage when compared with open surgery. This study aimed to compare cancer-related survivals of patients who underwent laparoscopic or open resection of colon cancer in the same, high volume tertiary center. Methods Patients who had undergone elective open or laparoscopic surgery for colon cancer between January 2002 and December 2010 were analyzed. A clinical database was prospectively compiled. Survival analysis was calculated by using the Kaplan-Meier method. Results A total of 460 resections were performed. There were no significant differences between the laparoscopic (n = 227) and the open group (n = 233) apart from tumor stage: stage I tumors were more frequent in the laparoscopic group whereas stage II tumors were more frequent in the open group. The mean number of harvested lymph nodes was significantly higher in the laparoscopic than in the open group (20.0 ± 0.7 vs 14.2 ± 0.5, P

We performed an immunohistochemical study with monoclonal antibodies to Ki67 antigen and p53 protein on 45 cases of thymic epithelial tumors classified according to the recent World Health Organization (WHO) classification system to evaluate whether there is correlation between the expression of these markers and prognosis, histologic subtype, and myasthenia gravis (MG). We also correlated histologic subtype with sex, age, MG, and survival. Ki-67 and p53 labeling indices (LIs) were expressed as a percentage of positive nuclear immunostaining by counting 1,000 epithelial tumor cells. Statistically significant differences were found between Ki-67 LI and survival (p = 0.007), whereas the prognostic implication of p53 could not be demonstrated, although there appeared a trend that patients with tumors of higher LIs had worse survival. Significant correlations were also found between Ki-67 (p < 0.0005) and p53 (p < 0.0005) LIs and histologic subtypes. No correlation was found between these parameters and MG. Histologic subtypes of the WHO classification also correlated with survival (p = 0.01), whereas no correlation was found with sex, age, and MG. In conclusion, our results indicate that the proliferative activity, assessed by Ki-67 LI, and the histologic pattern, according to WHO classification system, seems to represent reliable parameters in the prognosis of thymic epithelial tumors. Int J Surg Pathol 12(4):395‐400, 2004

Purpose: Up-regulation of both inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) enzymes has been reported in colorectal cancer. We aimed at evaluating the possible interaction between the nitric oxide and COX-2 pathways, and its effect on promoting tumor angiogenesis. Experimental Design: Expression of iNOS, COX-2, vascular endothelial growth factor (VEGF), and CD31 was analyzed in tumor samples and corresponding normal mucosa obtained from 46 surgical specimens. We also evaluated iNOS activity, prostaglandin E2 (PGE2), cyclic GMP and cyclic AMP production in the same specimens. Nitrite/nitrate levels, and PGE2 and VEGF production were assessed in HCT116 and HT29 colon cancer cell lines after induction and selective inhibition of the two enzyme pathways. Results: A significant correlation was found between iNOS and COX-2 immunohistochemical expression. PGE2 production significantly correlated with iNOS activity and cGMP levels. A significant correlation was also found among PGE2 production, microvessel density, and VEGF expression. Coinduction of both iNOS and COX-2 activities occurred after lipopolysaccharide (LPS) and epidermal growth factor (EGF) treatment in HCT116 and HT29 cells. Inhibition of iNOS by 1400W significantly reduced both LPS- and EGF-induced PGE2 production. Treatment with LPS, EGF, and arachidonic acid significantly increased VEGF production in the iNOS-negative/COX-2-positive HT29 cells. This effect was completely reversed by treatment with the selective COX-2 inhibitor celecoxib. Conclusions: Our data showed a prominent role of nitric oxide in stimulating COX-2 activity in colorectal cancer. This interaction is likely to produce a cooperative effect in promoting angiogenesis through PGE2-mediated increase in VEGF production.

The acquisition of the capacity to invade surrounding tissues confers a more malignant phenotype to tumor cells and is necessary for the establishment of metastases. The understanding of the molecular mechanisms underlying cell invasion in human solid tumors such as colorectal cancers could provide not only more sensitive prognostic analyses but also novel molecular targets for cancer therapy. We report in this article that K+ ion channels belonging to the HERG family are important determinants for the acquisition of an invasive phenotype in colorectal cancers. The herg1 gene and HERG1 protein are expressed in many colon cancer cell lines, and the activity of HERG channels modulates colon cancer cell invasiveness. Moreover, the amount of HERG1 protein expressed on the plasma membrane is directly related to the invasive phenotype of colon cancer cells. Finally, both the herg1 gene and HERG1 protein were expressed in a high percentage of primary human colorectal cancers, with the highest incidence occurring in metastatic cancers, whereas no expression could be detected either in normal colonic mucosa or in adenomas.

To investigate the potential involvement of the nitric oxide (NO) pathway in colorectal carcinogenesis, we correlated the expression and the activity of inducible nitric oxide synthase (iNOS) with the degree of tumor angiogenesis in human colorectal cancer. Tumor samples and adjacent normal mucosa were obtained from 46 surgical specimens. Immunohistochemical expression of iNOS, vascular endothelial growth factor (VEGF), and CD31 was analyzed on paraffin-embedded tissue sections. iNOS activity and cyclic GMP levels were assessed by specific biochemical assays. iNOS protein expression was determined by Western blot analysis. iNOS and VEGF mRNA levels were evaluated using Northern blot analysis. Both iNOS and VEGF expressions correlated significantly with intratumor microvessel density (rs = 0.31, P = 0.02 and rs = 0.67, P < 0.0001, respectively). A significant correlation was also found between iNOS and VEGF expression (P = 0.001). iNOS activity and cyclic GMP production were significantly higher in the cancer specimens than in the normal mucosa (P < 0.0001 and P < 0.0001, respectively), as well as in metastatic tumors than in nonmetastatic ones (P = 0.002 and P = 0.04, respectively). Western and Northern blot analyses confirmed the up-regulation of the iNOS protein and gene in the tumor specimens as compared with normal mucosa. NO seems to play a role in colorectal cancer growth by promoting tumor angiogenesis.

We describe two cases of solitary necrotic nodule of the liver, an uncommon nonmalignant lesion that can mimic a metastasis. The nodule appeared hypoechoic, or targetlike, on sonography, hypodense without contrast enhancement on computed tomography, and hypointense on magnetic resonance imaging, including diffusion-weighted images. These features, peculiar when considered together, are explained by the coagulative type of necrosis.

Hereditary nonpolyposis colorectal cancer (HNPCC) is widely considered to be a syndrome of defective mismatch repair (MMR). A major concern with genetic diagnosis of HNPCC is the variable, often low, percentage of pathogenic germline mutations that can be detected in MMR genes using common screening methods. The variable percentage of mutation detected is in part related to the sensitivity of conventional screening methods and may also depend on the heterogeneous genetics of HNPCC. Thus, identification of phenotypic criteria predictive of germline mutations in MMR genes may be helpful in efficient HNPCC genetic testing. Clinical diagnostic criteria, initially developed for HNPCC (e.g., Amsterdam I and II, or Bethesda criteria), can be used to clinically select patient candidates that carry germline mutations in MMR genes. More useful criteria were previously developed by analyzing families with germline MMR mutations. Using a complementary approach based on tumor microsatellite instability analysis, we confirm that the Amsterdam criteria are significantly better than the Bethesda criteria in predicting families with MSI-H tumors (P= 0.0227). Our results also suggest that a cutoff at < 50 years' mean age at diagnosis of HNPCC-related cancers (especially colorectal and endometrial cancer) may be an additional tool for the identification of families with defective MMR. Recent advances in MMR mutation screening are expected to improve detection of pathogenic MMR mutations in these families. Conversely, the high proportion of MSS tumors observed in our series of families with advanced age at cancer diagnosis is consistent with the low percentage of MMR mutations detected by previous studies in families with this phenotype. These families probably carry mutations in other genes that may or may not be related to MMR. Additional studies are necessary to clarify the molecular basis for HNPCC in families with MSS tumors.

Background: Intratumoral microvessel density (MVD) could be used as a prognostic factor in colorectal cancer. We retrospectively analyzed the value of microvessel count in predicting the clinical outcome of stage I and II (Dukes A and B) rectal cancer patients. Methods: Eighty-four patients who had undergone curative resection of lymph node-negative rectal cancer were included. Tumor type and differentiation, the depth of local invasion, venous invasion, the character of the invasive margin, and the degree of lymphocytic infiltration were evaluated for each tumor specimen. Immunohistochemical staining for the CD31 endothelial antigen was performed to highlight the microvessels. Results: The median value of MVD was 45 microvessels. Low MVD (microvessels ≤45) was observed in 41 patients (48.8%), and high MVD (>45) was found in 43 (51.2%). The presence of conspicuous lymphocytic infiltration was significantly associated with increased vessel density. With uni- and multivariate survival analysis MVD did not show any prognostic significance. The character of the invasive margin was the only parameter with independent prognostic value. Conclusions: MVD does not seem to provide any additional prognostic information when compared with standard histopathological parameters in lymph node-negative rectal cancer. It is likely that the strong association between MVD and the presence of conspicuous lymphocytic infiltration may interfere with its predictive value.

AIM To test the fujinon intelligent color enhancement (FICE) in identifying dysplastic or adenomatous polyps in familial adenomatous polyposis (FAP) patients. METHODS Seventy-six consecutive FAP patients, already treated by colectomy and members of sixty-five families, were enrolled. A FICE system for the upper gastro-intestinal tract with an electronic endoscope system and a standard duodenoscope (for side-viewing examination) were used by two expert examiners. Endoscopic resection was performed with diathermic loop for polyps ≥ 6 mm and with forceps for polyps < 6 mm. Formalin-fixed biopsy specimens were analyzed by two expert gastrointestinal pathologists blinded to size, location and number of FAP-associated fundic gland polyps. RESULTS Sixty-nine (90.8%) patients had gastric polyps (34 only in the corpus-fundus, 7 only in the antrum and 28 in the whole stomach) and 52 (68.4%) in duodenum (7 in the bulb, 35 in second/third duodenal portion, 10 both in the bulb and the second portion of duodenum). In the stomach fundus after FICE evaluation, 10 more polyps were removed from 10 patients for suspicious features of dysplasia or adenomas, but they were classified as cystic fundic gland after histology. In the antrum FICE identified more polyps than traditional endoscopy, showing a better tendency to identify adenomas and displastic areas. In the duodenum FICE added a significant advantage in identifying adenomas in the bulb and identified more polyps in the II/III portion. CONCLUSION FICE significantly increases adenoma detection rate in FAP patients but does not change any Spigelman stage and thus does not modify patient’s prognosis and treatment strategies.

A number of immunohistochemical markers have been suggested as useful in the positive diagnosis of epithelioid mesothelioma. The most widely used mesothelioma markers are thrombomodulin, calretinin, cytokeratin 5/6, D2-40 and WT-1. Numerous investigations have demonstrated their variable sensitivity and specificity in differentiating epithelioid mesothelioma from lung adenocarcinoma. However, data on the expression of these markers in other types of lung carcinomas are very limited. We evaluated the expression of these markers in a series of 172 primary carcinomas of the lung and in 75 epithelioid pleural mesotheliomas.Thrombomodulin expression was found in squamous cell carcinomas (71%), small cell lung carcinomas (11%), adenocarcinomas (4%), large cell carcinomas (50%), large cell neuroendocrine carcinomas (25%) and in sarcomatoid carcinomas (10%). Calretinin expression was common in small cell lung carcinomas (44%) and large cell neuroendocrine carcinomas (25%), less common in squamous cell carcinomas (20%), rare and focal in adenocarcinomas (4%) and sarcomatoid carcinomas (10%). Cytokeratin 5/6 was expressed in most of the squamous cell carcinomas (94.5%). Immunoreactivity was also found in large cell carcinomas (50%), sarcomatoid carcinomas (30%) and rarely in adenocarcinomas (4%). D2-40 was consistently expressed in squamous cell carcinomas (42%). Focal immunoreactivity was found in adenocarcinomas (3%). WT-1 was focally present in one (2%) squamous cell carcinoma.These results indicate that some of the most commonly used mesothelioma markers may react with different types of primary lung carcinomas. These data should be taken into consideration especially when dealing with small biopsy fragments and poorly differentiated tumors.

Gallbladder neuroendocrine neoplasms (GB-NENs) are rare. The majority of GB-NENs are poorly differentiated, with increased mitotic activity and clinically aggressive course. Surgery is the only curative approach and the optimal medical treatment is uncertain. In this report we describe the case of a woman affected by metastatic well differentiated GB-NEN with increased Ki 67. The patient underwent surgical removal of the gallbladder neoplasm and showed disease recurrence with pulmonary and liver metastases. After achieving a partial chemotherapy response, the patient rapidly died due to progressive disease. This case raises important issues. Well differentiated NENs with a high proliferative index are not included as a specific entity in any of the most widely used nomenclature systems. Moreover considering the proliferative index of the disease, it is reasonable to consider the patient a candidate for chemotherapy. Nevertheless, recently published papers raise the possibility that well differentiated NENs and specific proliferative index cutoff can predict low chemosensitivity in patients with highly proliferative neuroendocrine carcinoma.

The conversion of levamisole to aminorex in horses was first described in 2009 and, for the first time, confirmed in humans two years later by our laboratory. Aminorex and levamisole interfere with serotonin metabolism and both are proven cause of potentially fatal idiopathic pulmonary hypertension (IPH). Because most of the world's seizures of illicit cocaine is now contaminated with levamisole, this raises the possibility that users of levamisole adulterated cocaine users may be at risk for IPH. Here we describe the first case of IPH in a user of levamisole-contaminated cocaine. Levamisole and aminorex were both identified and quantified in hair and other biological specimens by means gas chromatography/mass spectrometry system (levamisole: urine, 75.05ng/mL; blood, 15.05ng/mL; brain, >0.15ng/g; liver, >0.15ng/g; hair, 12.15ngmg; aminorex: urine, 38.62ng/mL; blood, 8.92ng/mL, brain >0.15ng/g; liver, 0.15ng/g; hair 7.35ng/mg; cocaine, benzoylecgonine, morphine, 6-acetylmorphine, methadone, 2-ethylidine-1, 5-dimetil-3, 3 diphenylpyrrolidine were also detected). Moreover histological changes associated with IPH were observed in the lung. As IPH produces relatively non-specific symptoms in its early stages, this index case may serve as a harbinger of many more cases to come. It should also alert clinicians to the possibility that their patient may be suffering from this relatively rare disorder.

Purpose: hERG1 channels are aberrantly expressed in several types of human cancers, where they affect different aspects of cancer cell behavior. A thorough analysis of the functional role and clinical significance of hERG1 channels in gastric cancer is still lacking. Experimental Design: hERG1 expression was tested in a wide (508 samples) Italian cohort of surgically resected patients with gastric cancer, by immunohistochemistry and real-time quantitative PCR. The functional link between hERG1 and the VEGF-A was studied in different gastric cancer cell lines. The effects of hERG1 and VEGF-A inhibition were evaluated in vivo in xenograft mouse models. Results: hERG1 was positive in 69% of the patients and positivity correlated with Lauren's intestinal type, fundus localization of the tumor, G1–G2 grading, I and II tumor—node—metastasis stage, and VEGF-A expression. hERG1 activity modulated VEGF-A secretion, through an AKT-dependent regulation of the transcriptional activity of the hypoxia inducible factor. Treatment of immunodeficient mice xenografted with human gastric cancer cells, with a combination of hERG1 blockers and anti-VEGF-A antibodies, impaired tumor growth more than single-drug treatments. Conclusion: Our results show that hERG1 (i) is aberrantly expressed in human gastric cancer since its early stages; (ii) drives an intracellular pathway leading to VEGF-A secretion; (iii) can be exploited to identify a gastric cancer patients' group where a combined treatment with antiangiogenic drugs and noncardiotoxic hERG1 inhibitors could be proposed. Clin Cancer Res; 20(6); 1502–12. ©2014 AACR.

Background and Objectives: Ileorectal anastomosis (IRA) is still used in the treatment of familial adenomatous polyposis (FAP). Sulindac appears to induce regression of colorectal adenomas; however, its effects in long-term therapy and in preventing carcinoma remain unclear. Methods: Fifteen FAP patients treated by IRA received sulindac (200 mg/day) for a mean period of 48.6 ± 28.7 (range 12-124) months. Number, size, and type of rectal polyps were assessed by endoscopic and histological evaluation every 6 months. Results: Significant regression of polyps was observed in all patients after 6 months (P < 0.02). However, after a mean of 48.6 ± 28.7 months, both number and size of polyps increased again, showing no statistical difference with baseline values. Minute polyps appeared reddish, while the largest lesions were flat or slightly elevated. Endoscopic polypectomy was necessary in 9 patients and transanal surgical excision in 3. Two patients were submitted to restorative proctectomy because of a large polyp with severe dysplasia and a rectal cancer, respectively. Conclusions: Sulindac appears to influence the morphological appearence of polyps in FAP patients, inducing apparent regression. However, at a dose of 200 mg, it does not influence the progression of polyps toward a malignant pattern.

We investigated the prognostic significance of microsatellite instability (MI) in 50 consecutive patients with sporadic mucinous colorectal cancer who had undergone only surgery. We evaluated MI and the pathological features with a possible prognostic value for each tumor, and the effect of the examined parameters on patients' outcome was statistically analyzed (univariate and multivariate analysis). All patients were followed-up for a minimum of 72 months or until death; in evaluating survival, only deaths of colorectal cancer were considered. DNA extracted from tumor sections and the corresponding normal tissue was analyzed by polymerase chain reaction at six microsatellite loci: D2S123, D3S1611, D3S49, D5S107, BAT26, BAT40. Alterations at two or more loci were detected in 36% of cases (MI+ tumors). MI+ and MI- cancers differed significantly in the pattern of growth, and most MI+ tumors showed an expanding type of growth (72.2%, P = .005). At univariate analysis, improved survival rate was significantly associated with MI, as well as with the following parameters: expanding cancer growth, Dukes stage, and absence of venous invasion. Nevertheless, at multivariate analysis, only the pattern of cancer growth and Dukes stage were independent prognostic factors, whereas the effect on survival of MI and venous invasion was found to be negligible. In our study, MI+ and MI- cancers differ only on the pattern of growth; therefore, our data suggest that the better survival rate in mucinous cancers with genomic instability is strictly related to their less aggressive type of growth.

PURPOSE: The possible existence of an anatomic and functional separation between the external sphincter and the puborectalis muscle has been reported in the medical literature. In this article we confirm, by means of anatomic and clinical observations, the presence of such a separation, focusing on its importance in understanding the pathway of diffusion for some suppurative anal lesions and to plan advanced sphincter-sparing procedures. METHODS: Twenty adult anatomic specimens of the anal region (12 from women) were cut in the sagittal, coronal, and paracoronal planes, stained with hematoxylin and eosin, and examined. The pelvic floor musculature was examined in three patients undergoing postanal repair operations. Thirty primary posterior and posterolateral anal fistulas, preoperatively classified as transsphincteric (22) or suprasphincteric (8) were carefully traced during and after staged fistulotomy in 30 (11 female) patients, and their relationship with puborectalis muscle and external sphincter was evaluated. An attempt was made peranally to separate the external sphincter from the puborectalis muscle in four patients (3 females) aged 56 to 65 years with rectal cancers 4 to 5 cm from the anal verge so as to perform a sphincter-sparing procedure. RESULTS: A connective plane of separation between puborectalis muscle and external sphincter was clearly identified in 14 (70 percent) anatomic specimens. In three (21 percent) cases the two muscles presented a pronounced overlapping arrangement. An anatomicofunctional separation between puborectalis muscle and external sphincter was easily demonstrated during postanal repair operations. All fistulous tracks ran between the external sphincter and puborectalis muscle, despite the pronounced upward direction of the ones preoperatively classified as suprasphincteric. A plane of separation between puborectalis muscle and external sphincter was identified and developed in four patients with very low rectal cancers. An abdominoperanal rectolevatorial excision was performed. A coloanal anastomosis was performed on the residual lower anal canal. CONCLUSION: An anatomic plane of separation is present between the puborectalis muscle and the external sphincter. The presence of this plane is important to help understand the diffusion of some suppurative anal lesions and to plan advanced sphincter-sparing procedures.

Germline mutations of the hMLH1 gene are estimated to account for a large fraction of kindreds affected by hereditary non-polyposis colorectal cancer (HNPCC). In a significant number of cases, hMLH1 mutations result in the expression of truncated proteins. We report here two novel alternatively spliced forms of hMLH1 mRNA in normal lymphocytes. One of these novel isoforms lacks the coding region of the gene between codons 557 and 578, corresponding to the entire exon 15. The deletion introduces a frameshift that results in a premature stop signal. The other isoform is characterised by an in-frame deletion spanning codons 578-632, corresponding to loss of the entire exon 16. Further studies are necessary to establish the biological significance of these alternative splicings. The presence of alternatively spliced hMLH1 transcripts that mimic pathogenic mutations should be taken into account in the mutational screening of the hMLH1 gene by reverse transcription-polymerase chain reaction methodologies.

The purpose of this study was to correlate p53 gene alterations and their expression in 85 head and neck squamous cell carcinomas. Genomic p53 was amplified with the polymerase chain reaction (PCR) from formalin-fixed, paraffin-embedded tissues. Exons 5 through 8 were screened for mutations by means of non-isotopic single-strand conformation polymorphism (SSCP) analysis. p53 expression was detected by means of immunohistochemistry (IHC) with the p53 monoclonal antibody DO-7. Twenty-three lesions (27%) showed both SSCP variants and DO-7 immunostaining, whereas 37 (44%) demonstrated both SSCP normal patterns and negative staining. Twenty-five lesions (29%) were discordant, including 12 IHC-positive (14%) and 13 SSCP-positive (15%) lesions. However, discordant IHC-negative, SSCP-positive lesions could have been easily interpreted after sequencing of the abnormal samples. Had these been screened with IHC only, all nonsense or frameshift p53 mutations would have been missed. IHC-positive, SSCP-negative lesions were interpreted in light of current models of p53 immunodetection. Had these been screened with SSCP or sequencing only, a sizeable number of tumors expressing p53 protein abnormalities would have been undetected. Therefore, simultaneous use of both methods increases the number of p53 abnormalities detected, and is warranted.

Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections lead to cirrhosis and increase the risk for the development of hepatocellular carcinoma (HCC). Angiogenesis is an essential step in oncogenesis and contributes to tumor progression in adult organs; however, to what extent angiogenesis occurs in the liver during chronic viral hepatitis has not been studied. Ninety-nine matched patients affected by chronic hepatitis due to either HBV or HCV were studied together with 13 controls (5 patients were affected by familial hyperbilirubinemia with normal liver histology; 6 patients with stage II primary biliary cirrhosis; and 2 patients with pseudo inflammatory tumor). Microvessel density was assessed in liver biopsies by immunostaining using two different antibodies against endothelial cell antigens, QB-END/10 and Factor VIII. In addition, the liver homogenates and sera of HCV- or HBV-positive patients and controls were tested for their capacity to stimulate the migration and proliferation of freshly isolated human endothelial cells in vitro. Evidence of angiogenesis was significantly more frequent in HCV-positive patients compared with HBV-infected subjects or controls (74% vs. 39% vs. 8%) (χ2 = 20.78; P < .0001) (HCV+ vs. HBV+ vs. controls). The degree of microvessel density was also higher in HCV- than in HBV-positive patients or controls (χ2 = 12.28; P < .005). In addition, HCV-positive sera and liver homogenates stimulated a higher migration and proliferation of human endothelial cells in vitro compared with HBV-positive or control sera and liver homogenates. These observations indicate that angiogenesis is particularly linked to HCV infection, suggesting a possible contribution to HCV-related liver oncogenesis. (Hepatology 1997 Jan;25(1):229-34)

The identification of germline variants predisposing to hereditary nonpolyposis colorectal cancer (HNPCC) is crucial for clinical management of carriers, but several probands remain negative for such variants or bear variants of uncertain significance (VUS). Here we describe the results of integrative molecular analyses in 132 HNPCC patients providing evidences for improved genetic testing of HNPCC with traditional or next generation methods. Patients were screened for: germline allele-specific expression (ASE), nucleotide variants, rearrangements and promoter methylation of mismatch repair (MMR) genes; germline EPCAM rearrangements; tumor microsatellite instability (MSI) and immunohistochemical (IHC) MMR protein expression. Probands negative for pathogenic variants of MMR genes were screened for germline APC and MUTYH sequence variants. Most germline defects identified were sequence variants and rearrangements of MMR genes. Remarkably, altered germline ASE of MMR genes was detected in 8/22 (36.5%) probands analyzed, including 3 cases negative at other screenings. Moreover, ASE provided evidence for the pathogenic role and guided the characterization of a VUS shared by 2 additional probands. No germline MMR gene promoter methylation was observed and only one EPCAM rearrangement was detected. In several cases, tumor IHC and MSI diverged from germline screening results. Notably, APC or biallelic MUTYH germline defects were identified in 2/19 probands negative for pathogenic variants of MMR genes. Our results show that ASE complements gDNA-based analyses in the identification of MMR defects and in the characterization of VUS affecting gene expression, increasing the number of germline alterations detected. An appreciable fraction of probands negative for MMR gene variants harbors APC or MUTYH variants. These results indicate that germline ASE analysis and screening for APC and MUTYH defects should be included in HNPCC diagnostic algorithms.

Conflicting results on the shift of right-left ratio in colon cancer incidence have been reported. We examine incidence trends by subsite in a population-based study.Colorectal cancer cases diagnosed in the 1985-2005 period were identified through the Tuscany Cancer Registry. Colon subsite was defined as proximal and distal; gender, age at diagnosis, histology, and stage were analyzed. Average annual incidence and age-specific rates according to subsite were calculated.A total of 21,160 colorectal cancer cases were extracted; in 18,311 cases, the subsite was identified: 6,916 rectal, 5,239 proximal, and 6,156 distal. A larger proportion of distal colon cancers presented as early stage when compared with proximal. Incidence of rectal and distal colon cancer remained stable, while proximal colon cancer incidence increased.Proximal colon cancer incidence rate increased through the period. Temporal variations in the incidence rate by subsite could suggest different carcinogenic pathways of right- and left-sided colon cancer.

La definizione di errore in anatomia patologica e estremamente difficile e non univoca; considerando che il compito principale di un servizio di anatomia patologica (mission) e quello di fornire un referto diagnostico accurato e completo, viene in genere accettato il concetto che l’errore in questo ambito sia “l’attribuzione di una diagnosi anatomo-patologica che non rappresenta la reale natura del processo patologico in un paziente” [1].

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) represent a rare and heterogeneous group of neoplasms that arise from the diffuse neuroendocrine system within the pancreas and gastrointestinal tract [1, 2]. Pancreatic neuroendocrine tumors (pNET), a sub-group of GEP-NETs, are characterized by specific tumor genetics, biology and clinicopathological features. These characteristics influence therapeutic decision-making [3–7]. Recently, the incidence of pNET increased by two-to-threefold to reach 2.2/1,000,000, whereas the incidence of pancreatic adenocarcinoma has remained stable [3, 8]. Probably, this observation reflects an improvement in diagnotic procedures because of the introduction of new methods (e.g., spiral computed tomography and ecoendoscopy) rather than a real increase in pNET incidence.

Aminotransferase elevation is a frequent cause of consultation for the Hepatologist, in both the outpatient and inpatient settings, but identifying the origin of these biochemical alterations may be challenging. Here we report a case where acute elevation of aminotransferases, associated with abdominal symptoms, was the cause of two hospitalizations in a short period of time. As the patient suffered from type 1 diabetes, celiac disease, and autoimmune thyroiditis, several potential causes of damage could be hypothesized, including celiac hepatitis, fatty liver, and autoimmune hepatitis. A liver biopsy performed in the occasion of the second hospitalization allowed to rule out autoimmune hepatitis and celiac hepatitis, showing mild signs of fatty infiltration. Staining with periodic acid-Schiff with or without diastase showed a marked accumulation of glycogen, indicating the presence of a glycogenic hepatopathy associated with poorly controlled type 1 diabetes. This condition may be a cause of liver damage in patients with type 1 and occasionally type 2 diabetes, but its occurrence is often overlooked. This case report illustrates the fact that glycogenic hepatopathy may relapse, and prompts the clinician to take into account this condition in the differential diagnosis of causes of liver injury.

This study aimed at evaluating the lymph node (LN) harvest after both open and laparoscopic colorectal cancer surgery.In the period between 1996 and 2009, 404 patients with colorectal cancer underwent open resection, whereas 147 patients underwent laparoscopic surgery.The overall number of harvested LNs was significantly higher in the laparoscopic group than in the open one (16.5 vs. 14.3, P0.001). A higher number of LNs was found in moderately differentiated tumors of the laparoscopic group when compared with the open surgery group (16.7 vs. 14.2, P0.01). The numbers of harvested LNs in the proximal tumors and in stage II and III tumors were higher in the laparoscopic group than in the open group (18.9 vs. 15.4, P0.001; 17.9 vs. 14.2, P=0.002; 17.3 vs. 15.3, P=0.02, respectively).Laparoscopic surgery for colorectal cancer can achieve LN retrieval similar to that achieved by the open approach.

Epithelial colorectal tumors are common pathologic entities. Their histology report should be comprehensive of a series of pathologic parameters essential for the correct clinical management of the patients. Diagnostic histologic criteria of adenomatous, serrated, inflammatory, and hamartomatous polyps and of polyposis syndromes are discussed. In addition, the pathologic features of early and advanced colorectal cancer are described and a checklist is given. Finally, molecular prognostic and predictive factors currently employed in the treatment of colorectal cancer are discussed.

Gastrointestinal stromal tumor (GIST) natural history per se has not been extensively investigated yet, with most data being drawn from large studies with a relevant referral bias. Hence, the estimation of prognosis still remains a critical issue. We retrospectively evaluated 929 GISTs resected between 1980 and 2000 in 35 Italian institutions. A total of 526 patients were found to be suitable for refining risk assessment through the development of a survival nomogram. Median follow-up was 126 months. On testing for potential prognostic parameters, age, tumor site, size, and mitotic index proved to be predictors of OS on both univariable and multivariable Cox model analyses, whereas necrosis and cytonuclear atypia were significant on univariable analysis only. The discriminative ability of the model, including the parameters selected after a backward procedure (C=0.72), improved compared with the National Institutes of Health 2002 (C=0.64) and the National Comprehensive Cancer Network 2007 (C=0.63). On the basis of these data we developed a prognostic nomogram for survival that considers site, size, and mitotic index as continuous variables, providing estimates stratified for patients aged ≤65 and >65 years. This nomogram is a tool based on survival. It overcomes problems that result from artificial categorization of continuous variables. We believe that in the future this should also be attempted by nomograms based on the risk of relapse.

Organ failure secondary to fibrosis is the main cause of morbidity and death in patients with systemic sclerosis. Gastrointestinal tract dysmotility is a major visceral manifestation, clinically ranging from an asymptomatic form to severe paresis. Although the oesophagus is the most frequently affected part of the gastrointestinal tract, all other segments can be involved. The present study was undertaken to evaluate the histopathological changes of the gastric wall in a series of full-thickness biopsies from systemic sclerosis patients who underwent gastric surgery due to severe gastroesophageal involvement. Gastric biopsies were processed for light microscopy and transmission electron microscopy. The histological and ultrastructural observations revealed a generalized fibrosis affecting all the gastric wall layers. The most severe changes were observed in the muscularis mucosae and muscle layers. Wide areas of marked focal fibrosis with dense collagen bundles and elastic fibre deposition surrounding smooth muscle cells were found. Myofilaments and thickened dense bodies were severely disarranged or absent in most smooth muscle cells. Nerve fibres showed ultrastructural alterations, such as oedematous axoplasm and scarce cytoskeletal elements. Abundant elastic and collagen fibres enveloped nerve fibres, nerve endings and interstitial cells of Cajal, thereby separating them from smooth muscle cells and blood microvessels. This study provides evidence for a prominent fibrosis and severe ultrastructural alterations of smooth muscle cells and nerve fibres as the main histopathological hallmarks in the gastric wall of systemic sclerosis patients.

Although Gastrointestinal stromal tumors (GISTs) affect about 0.0014% of the population, GISTs smaller than 1 cm (microGISTs) are detectable in about 20% to 30% of elderly individuals. This suggests that microGISTs likely represent premalignant precursors that evolve only in a minute fraction of cases toward overt GISTs. We sought histopathologic and molecular explanations for the infrequent clinical progression in small GISTs. To investigate the mechanisms of GIST progression and identify subsets with differential malignant potential, we carried out a thorough characterization of 170 GISTs2 cm and compared their KIT/PDGFRA status with overt GISTs. The proliferation was lower in microGISTs compared with GISTs from 1 to 2 cm (milliGISTs). In addition, microGISTs were more frequently incidental, gastric, spindle, showed an infiltrative growth pattern, a lower degree of cellularity, and abundant sclerosis. The progression was limited to 1 ileal and 1 rectal milliGISTs. KIT/PDGFRA mutations were detected in 74% of the cases. The overall frequency of KIT/PDGFRA mutation and, particularly, the frequency of KIT exon 11 mutations was significantly lower in small GISTs compared with overt GISTs. Five novel mutations, 3 in KIT (p.Phe506Leu, p.Ser692Leu, p.Glu695Lys) 2 in PDGFRA (p.Ser847X, p.Ser667Pro), plus 4 double mutations were identified. Small GISTs share with overt GIST KIT/PDGFRA mutation. Nevertheless, microGISTs display an overall lower frequency of mutations, particularly canonical KIT mutations, and also carry rare and novel mutations. These molecular features, together with the peculiar pathologic characteristics, suggest that the proliferation of these lesions is likely sustained by weakly pathogenic molecular events, supporting the epidemiologic evidence that microGISTs are self-limiting lesions.

Reduced-intensity conditioning regimens have reshaped the clinical presentation of graft-versus-host disease after hematopoietic stem cell transplants. However, histopathologic features of graft-versus-host disease following reduced-intensity conditioning regimens have not been fully characterized. In a series of 112 biopsies (skin, n = 60; gastrointestinal [GI] tract, n = 44; liver, n = 8), we described the morphologic profile of graft-versus-host disease following reduced-intensity conditioning and investigated whether histopathologic changes of graft-versus-host disease following reduced-intensity conditioning have a diagnostic and/or prognostic value. Forty-four patients (49.5%) experienced acute graft-versus-host disease, 2(2.2%) late-onset acute graft-versus-host disease (grade I, n = 13; grade II-IV, n = 33), 24(27.0%) chronic graft-versus-host disease (de novo n = 12, progressive n = 12) and 19 (21.3%) overlap syndrome. In the skin, we observed: (i) phase-nonspecific changes, such as acute graft-versus-host disease features in chronic graft-versus-host disease patients (n = 4/24; 16.6%), (ii) subtle alterations such as superficial fibrosis in widened dermal papillae (n = 8), in acute graft-versus-host disease/late-onset graft-versus-host disease (n = 6/46; 13.0%) or chronic graft-versus-host disease (n = 2/24, 8.3%) patients, and (iii) features of chronic and acute graft-versus-host disease coexisting in the same specimen in overlap syndrome (n = 3/19; 15.7%). In the GI tract, we did not demonstrate peculiar features differing from those commonly observed in the myeloablative setting. By univariate analysis, a reduced overall survival was associated with graft-versus-host disease type (chronic graft-versus-host disease P = .006, acute graft-versus-host disease P = .03), older age (P = .04), and histopathologic diagnosis of "consistent with" + definite graft-versus-host disease (P = .02). Histopathologic diagnosis retained an independent prognostic value by multivariate analysis (P = .01). The present study indicates that pathologists should be aware of the peculiar morphologic changes of cutaneous graft-versus-host disease following reduced-intensity conditioning and further recommends histopathology in the diagnostic workup of graft-versus-host disease in patients undergoing reduced-intensity conditioning regimen. (C) 2011 Elsevier Inc. All rights reserved.

Background Recent studies have shown that the cyclooxygenase (COX) and the inducible nitric oxide synthase (iNOS) pathways are involved in the development of tumor angiogenesis in human cancers. Aims To investigate whether a different pattern of COX-2 and iNOS expression/activity exists within different areas of colorectal tumors and to analyze the relationship between these two enzymes and tumor angiogenesis. Methods Microvessel density (MVD) and COX-2, iNOS, vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR-2) protein expression were evaluated at both the invasive front (IF) and the tumor center (TC) in 46 human colorectal cancer specimens. We also investigated the concentration of PGE 2 and NO at the same sites. Results COX-2 and iNOS protein expression and activity were significantly higher within the IF than the TC of the tumor specimens. Similarly, MVD and VEGF/VEGFR-2 expression significantly increased from the TC to the IF. Only COX-2 expression was significantly correlated with MVD and VEGF/VEGFR-2 expression at both the TC and the IF. Conclusion Our study shows a heterogeneous expression of COX-2 and iNOS in colorectal cancer. The up-regulation of COX-2 at the IF parallels an increase in vessel density and VEGF/VEGFR-2 expression, thus supporting the hypothesis that the tumor periphery is the most aggressive portion of a colorectal tumor.

Transgenic rats with high expression of HLA-B27 and human β2-microglobulin (B27TR) develop a multisystem inflammatory disease resembling human inflammatory bowel disease (IBD) and spondyloarthropaties (SpA). Tumour necrosis factor α (TNF-α) has a crucial role in sustaining chronic inflammation in the gut and joints. The aim of this work was to evaluate whether TNF-α blockade could prevent or reduce the inflammation of peripheral joints in B27TR. A first group of 9-week-old B27TR received an anti-TNF-α monoclonal antibody (mAb) or an isotypic IgG2a,k up to the age of 18 weeks. An untreated group was monitored up to the age of 18 weeks and then randomly assigned to a 9-week treatment with anti-TNF-α mAb or IgG2a,k. Each rat was monitored for clinical IBD and peripheral joint manifestations. After sacrifice the colon and hind paws were examined for macroscopical and microscopical pathological changes. Early TNF-α blockade prevented, and late treatment improved IBD signs in B27TR. Erythema, oedema, inflammatory infiltrate close to the tendons and enthesis, proliferating chondrocyte-like cells, signs of new endochondral bone ossification and bone erosion were observed in peripheral joints of four out of six IgG2a,k-treated B27TR, both at 18 and 27 weeks. Immunopositivity for phosphorylated Smad1/5/8 indicated that the process of joint remodelling was activated in B27TR. Some entheses showed chondroid nodules. Anti-TNF-α treatment reduced inflammation and preserved the enthesis organization in most animals. Occasional and transient erythema and oedema were still present in three of six of the late anti-TNF-α-treated animals. Smad1/5/8 signalling was not inhibited by late anti-TNF-α treatment. In B27TR, articular involvement follows IBD onset and develops at entheses. Early TNF-α blockade prevents the onset of IBD and consequently the development of enthesitis in peripheral joints in the B27TR model of human SpA.

The HLA-B27 gene is strongly associated with the spondyloarthropathies (SpA), a group of chronic inflammatory diseases affecting the bowel, the joints, and the axial skeleton. Yet the basis for this association remains unknown, despite extensive study in the past years. The HLA-B27 transgenic rat spontaneously develops a disease that strikingly resembles human SpA. The purpose of this article is to review the contribution of studies on the HLA-B27 transgenic rat model aimed to elucidate the intimate relationship between gut and joint involvement in SpA.

OBJECTIVE. The purpose of our study was to retrospectively evaluate the sonographic, CT, and MRI findings (number, diameter, lobar location, depth from the hepatic capsule, and appearance of lesions) in a series of nine patients with pathologically proven solitary necrotic nodules of the liver and the natural evolution at follow-up in four of the nine patients.CONCLUSION. Solitary necrotic nodules are usually small, solitary lesions, mainly located under the liver capsule of the right lobe. They are hypoechoic on sonography, hypoattenuating on CT, have low signal intensity on both T1- and T2-weighted MRI with lack of enhancement after IV contrast administration, and at follow-up have a tendency to show calcification and involution toward reduction in size.

Gastrointestinal stromal tumors are the most common mesenchymal tumors of the gastrointestinal tract. Until today, there have been few markers specific for the tumor. This has complicated the differential diagnosis of the neoplasm from tumors of smooth muscle origin. Recently, the proto-oncogene c-kit has been shown to be a very relevant marker as it almost invariably is expressed in gastrointestinal stromal tumors. Radiation exposure, hormonal and genetic factors, particularly neurofibromatosis 2, have been implicated in their development and growth. GIST initiation, either in NF2-associated or in sporadic cases, is linked to inactivation of members of the proteins 4.1 superfamily. The majority of the mutations identified in the NF2 gene result in a truncated protein and are clinically associated with a severe phenotype. Occasionally, missense mutations associated with a mild phenotype may occur. We compared NF2 gene expression in 5 cases with gastrointestinal stromal tumors by quantitative real-time polymerase chain reaction analysis. NF2 gene mRNA expression was assessed in fresh tissue of stomach from 5 consecutive patients. We detected no alterations in NF2 gene expression in the quantitative analyses of the 5 tumors.

AIM: To evaluate the predictive value of hepatocyte proliferation and hepatic angiogenesis for the occurrence of Hepatocellular carcinoma (HCC) in hepatitis C virus (HCV) cirrhotic patients. METHODS: One hundred-five patients (69 males, 36 females; age range, 51-90 year; median 66 year) with biopsy proven HCV cirrhosis were prospectively monitored for HCC occurrence for a median time of 64 mo. Angiogenesis was assessed by using microvessel density (MVD), hepatocyte turnover by MIB1 and PCNA indexes at inclusion in liver biopsies. RESULTS: Forty six patients (43.8%) developed HCC after a median time of 55 (6-120) mo while 59 (56.2%) did not. Patients were divided into two groups according to the median value of each index. The difference between patients with low (median MVD = 3; range 0-20) and high (median MVD = 7; range 1-24) MVD was statistically significant (χ2 = 22.06; P < 0.0001) which was not the case for MIB1 or PCNA (MIB-1: χ2 = 1.41; P = 0.2351; PCNA: χ2 = 1.27; P = 0.2589). The median MVD was higher in patients who developed HCC than in those who did not. HCC-free interval was significantly longer in patients with the MVD ≤ 4 (P = 0.0006). No relationship was found between MIB1 or PCNA and MVD (MIB-1 r2 = 0.00007116, P = 0.9281; PCNA: r2 = 0.001950; P = 0.6692). MVD only was able to predict the occurrence of HCC in these patients. Among other known risk factors for HCC, only male sex was statistically associated with an increased risk. CONCLUSION: Liver angiogenesis has a role for in HCV-related liver carcinogenesis and for defining patients at higher risk.

There is an increasing need for accurate prognostic stratification of patients with Stage II colorectal cancer to identify a subgroup of high-risk patients who may benefit from adjuvant therapies. This study was designed to evaluate the prognostic impact of a wide spectrum of pathologic parameters in a consecutive series of homogenously treated and well-characterized patients with Stage IIA (T3N0M0) colorectal cancer. The study included 238 patients operated on by a single surgeon for Stage IIA colorectal tumors. The median postoperative follow-up was 110 (range, 96–120) months. At least 12 lymph nodes were harvested and examined in all the resection specimens. The prognostic value of 13 pathologic parameters, including lymph node occult disease (micrometastases) detected by immunohistochemistry, was investigated. Multivariate analysis identified tumor growth pattern (expanding or infiltrating; P = 0.01) and extent of tumor spread beyond muscularis propria (≤5 mm or >5 mm; P = 0.04) as the only factors having independent prognostic value. The combination of these two easily determined parameters allowed us to identify two groups of patients at low risk or high risk of tumor recurrence. The eight-year survival rates were 83.3 and 53.4 percent for the two groups, respectively. The high-risk group comprised those patients with infiltrating tumors and extramural tumor spread > 5 mm. We propose a new and simple prognostic model to identify patients with high-risk Stage IIA colorectal cancer for whom adjuvant therapies may be justified and effective.

e15174 Background: Capecitabine (CAP) and temozolomide (TEM) have been reported to be active as first-line treatment in pancreatic neuroendocrine neoplasms (pNENs). We retrospectively evaluated act...

Cyclooxygenase (COX)-2 and 5-lipoxygenase (5-LOX) are key enzymes involved in arachidonic acid metabolism. Their products, prostaglandins and leukotrienes, are involved in colorectal tumor development. We aimed at evaluating whether combined blocking of the COX-2 and 5-LOX pathways might have additive antitumor effects in colorectal cancer. The expression/activity of COX-2 and 5-LOX were assessed in 24 human colorectal cancer specimens. The effects of the COX-2 inhibitor celecoxib and the 5-LOX inhibitor MK886 on prostaglandin E2 and cysteinyl leukotriene production, tumor cell proliferation, cell apoptosis, and Bcl-2/Bax expression were evaluated in the Caco-2 and HT29 colon cancer cells. We also investigated the effect of the enzymatic inhibition on mitochondrial membrane depolarization, one of the most important mechanisms involved in ceramide-induced apoptosis. Up-regulation of the COX-2 and 5-LOX pathways was found in the tumor tissue in comparison with normal colon mucosa. Inhibition of either COX-2 or 5-LOX alone resulted in activation of the other pathway in colon cancer cells. Combined treatment with 10 μmol/L celecoxib and MK886 could prevent this activation and had additive effects on inhibiting tumor cell proliferation, inducing cell apoptosis, decreasing Bcl-2 expression, increasing Bax expression, and determining mitochondrial depolarization in comparison with treatment with either inhibitor alone. The administration of the ceramide synthase inhibitor fumonisin B1 could prevent some of these antineoplastic effects. In conclusion, our study showed that inhibition of 5-LOX by MK886 could augment the antitumor activity of celecoxib in human colorectal cancer. [Mol Cancer Ther 2006;5(11):2716–26]

Approximately 30% of patients with lymph node (LN)-negative colorectal carcinoma (CRC) die of tumor recurrence, which can be related to the presence of tumor cells in LNs not detected by conventional histopathologic analysis. However, the prognostic significance of occult cancer cells still remains uncertain. We evaluated the incidence and the prognostic significance of occult cancer cells in LNs from 395 consecutive patients with curatively resected stage IIA CRC using immunohistochemistry for cytokeratin 20. Immunostained tumor cells were categorized as micrometastases (MCMs) or isolated tumor cells (ITCs) according to the American Joint Committee on Cancer criteria. The detection rates were compared with the clinicopathologic characteristics of the patients and with cancer-specific survival. The median follow-up time was 128 months. Micrometastases were detected in 39 patients (9.9%), whereas ITCs were found in 112 (28.4%), for an overall frequency of 38.2%. None of the clinicopathologic parameters examined was correlated with the presence of occult cancer cells. Patients with ITCs and those with negative LNs showed a similar survival rate (77.7% and 78.3%, respectively), whereas patients with MCMs had a lower survival rate (64.1%). At the univariate analysis, MCMs, tumor growth pattern, extent of tumor spread, and Crohn's-like lymphoid reaction influenced the survival rate significantly. Nevertheless, at the multivariate analysis, only the pattern of tumor growth and the extent of tumor spread were independent prognostic factors. The detection of immunostained tumor cells in the LNs of patients with stage IIA CRC occurs relatively frequently but has no significant effect on prognosis.

Purpose: Activity of histidine decarboxylase, the key enzyme in the synthesis of histamine, has been shown to be increased in several types of human tumors. We attempted to establish whether the possible involvement of histidine decarboxylase and histamine in colorectal carcinogenesis might be mediated by the activation of the cyclooxygenase-2 (COX-2) pathway.Experimental Design: Expression/activity of histidine decarboxylase, histamine content, and prostaglandin E2 (PGE2) production were analyzed in 33 colorectal cancer samples and in the HT29, Caco-2, and HCT116 colon cancer cell lines. The effects of histamine, celecoxib, and H1, H2, and H4 receptor antagonists on COX-2 expression/activity, cell proliferation, and vascular endothelial growth factor (VEGF) production were assessed in the three colon cancer lines that showed different constitutive COX-2 expression.Results: We showed the up-regulation of histidine decarboxylase protein expression and activity in the tumor specimens when compared with normal colonic mucosa. Histidine decarboxylase activity and histamine content were also significantly higher in metastatic tumors than in nonmetastatic ones. These variables significantly correlated with tumor PGE2 production. The administration of histamine increased COX-2 expression/activity, cell proliferation, and VEGF production in the COX-2-positive HT29 and Caco-2 cells. Treatment with either H2/H4 receptor antagonists or celecoxib prevented these effects. Histamine had no effect on both the COX-2 pathway and VEGF production in the COX-2-negative HCT116 cells.Conclusions: Our data showed that histamine exerts both a proproliferative and a proangiogenic effect via H2/H4 receptor activation. These effects are likely to be mediated by increasing COX-2-related PGE2 production in COX-2-expressing colon cancer cells.

Background & Aims: Inadequate data are available about retreatment of nonresponders to interferon (IFN) and ribavirin. Thus, this study evaluated the efficacy and tolerability of a 48-week therapy with pegylated IFN-α-2b plus high-dose ribavirin in patients who have failed to respond to the combination. Treatment up to 48 weeks also in patients who have failed to clear hepatitis C virus (HCV) RNA by week 24 was also evaluated. Methods: One hundred forty-one patients who previously did not respond to IFN and ribavirin, 86% with genotype 1 or 4 infection, 52% with high viral load (>800.000 IU/mL), 22% with cirrhosis, were retreated with pegylated IFN-α-2b 1.5 μg/kg per week and ribavirin 1000–1200 mg/day for 48 weeks and followed up for 24 weeks. Results: By intent-to-treat analysis, 20% of patients achieved a sustained virologic response (SVR). SVR of genotype 1 patients was 19%. Independent predictors of SVR were low γ-glutamyltransferase levels (OR, 22.9; 95% CI: 6.6–79.6) and low viral load (OR, 3.8; 95% CI: 1.1–12.6). Twelve (23%) out of 51 patients who were HCV RNA positive after 24 weeks of therapy achieved a late virologic response (after week 24) and 5 (10%) of them, all with genotype 1, achieved an SVR. Genotype was not associated with response ( P = .2) or with early response ( P = .3). Conclusions: Retreatment with pegylated IFN-α-2b and ribavirin of multiexperienced and "difficult to treat" nonresponder patients produced a very promising SVR. Accurate selection of patients, such as those with low viral load and low γ-glutamyltransferase levels, and prolongation of therapy beyond 24 weeks also in HCV RNA-positive patients may further increase the rate of SVR.

In hereditary non-polyposis colorectal cancer (HNPCC) patients, the cancer frequently arises in the proximal colon and is often multiple (synchronous or metachronous). Pathologic differences seem to exist between hereditary and sporadic large bowel cancer, but the data are not uniform. Many authors reported that the following histologic features are often present in HNPCC: 1) mucinous histotype, 2) poorly differentiated tumors, 3) presence of peritumoral lymphocytic infiltrate, with Crohn's-like lymphoid reaction. Such features have also been found in apparently sporadic colorectal cancer with, but not in sporadic colorectal cancer without DNA replication errors. Many studies have suggested that adenoma plays a main role in HNPCC carcinogenesis, and that the “adenoma-carcinoma sequence” may be the pathway to cancer in HNPCC as in sporadic colorectal cancer. Moreover, HNPCC adenomas show an early onset, villous component, high-grade dysplasia, and positivity for DNA replication errors more frequently than sporadic adenomas. Such data suggest that the adenoma-carcinoma sequence is accelerated in HNPCC and that surveillance in these patients should therefore be strict to avoid cancer development.

We analysed by immunohistochemistry the expression of p53 protein in a case of micro-invasive carcinoma of the conjunctiva. About 50% of tumor cells showed a strong nuclear positivity for p53. This suggests that p53 gene alterations play a role in the development of this type of tumor.

Lymph node involvement is the most important prognostic factor for patients who have undergone radical surgery for colorectal carcinoma. An accurate examination of the surgical specimens is mandatory for the correct assessment of the lymph node status of the tumor. The risk of understaging is particularly high for patients with tumors classified as Dukes B (TNM stage II). The aim of this study was to determine if a specified minimum number of lymph nodes examined per surgical specimen could have any effect on the prognosis of patients who had undergone radical surgery for Dukes B colorectal cancer. Between 1988 and 1995 a total of 140 patients underwent radical resection of Dukes B colorectal cancer by the same surgeon (C.C.). The relation between clinicopathologic variables and survival was estimated using the Kaplan-Meier method. The Cox proportional hazard regression model was used to identify the variables that can independently influence survival. A median of 12 lymph nodes (range 3-38) was examined per tumor specimen. The 5-year survival rate of Dukes B patients who had had eight or fewer lymph nodes examined after surgery was 54.9%, whereas the survival rate for those who had had nine or more lymph nodes examined was 79.9% (p < 0.001). Cox regression analysis identified the number of lymph nodes as the only independent prognostic factor (p = 0.01). Seventy patients with one to four metastatic lymph nodes (Dukes C patients) who had been operated on during the same period were included in the survival analysis for comparison. The 5-year survival rate of the Dukes B patients with eight or fewer lymph nodes examined was similar to that of the 70 Dukes C patients (54.9% and 51.8%, respectively). Examination of eight or fewer lymph nodes in Dukes B colorectal patients may be considered a high risk factor for missing positive lymph nodes in the surgical specimens. Our results suggest that harvesting and examining a minimum of nine lymph nodes per surgical specimen may be sufficient for reliable staging of lymph node-negative tumors.