Elevated hepatocyte paraffin 1 and neprilysin expression in hepatocellular carcinoma are correlated with longer survival.

Hepatocyte paraffin 1 (Hep Par 1) and neprilysin (CD10) are well-known markers of hepatocellular carcinoma (HCC). To assess their potential prognostic role, we conducted a retrospective analysis of 97 formalin-fixed and paraffin-embedded HCC from patients treated by surgery with curative intent, using standard immunohistochemical procedures and semiquantitative analysis. Strong Hep Par 1 expression and canalicular CD10 staining pattern were significantly correlated with smaller tumor size (p=0.007 and 0.04, respectively). On univariate analysis, longer overall survival was observed in patients with strong Hep Par 1 expression (p=0.0005) and in patients with a CD10can staining pattern (p=0.02). On multivariate analysis, the combined immunohistochemical score (CIS) obtained by addition of Hep Par 1 and CD10can scores and subtraction of cytoplasmic CD10 score was retained as the single most important prognostic factor (p=0.001). Patients with a CIS <4 had a 3.5-fold increased risk of death, as compared to those with a CIS >or=4. In conclusion, strong Hep Par 1 expression, presence of CD10can labeling, and absence of CD10cyt staining are favorable prognostic factors in HCC, which can be easily combined into a single immunohistochemical score for routine clinical use.

Monoallelic methylation of the APC promoter is altered in normal gastric mucosa associated with neoplastic lesions.

Adenomatous polyposis coli (APC) promoter hypermethylation has been reported frequently in normal gastric mucosa, but it remained to be clarified whether this occurs in every individual. In this study, methylation of the APC promoter was analyzed in histologically normal-appearing gastric mucosa samples by methylation-sensitive single-strand conformation analysis and by a methylation-sensitive dot blot assay. Epithelial cell samples were collected by microdissection from tissue sections. Equal amounts of methylated and unmethylated APC alleles were found in all gastric mucosa samples from patients without any gastric lesions (20 samples). Allele-specific methylation analysis showed that the methylation of the APC promoter was monoallelic; however, which allele was methylated depended on the cell type. Increased or decreased methylation was found in 10 of 36 (28%) normal gastric mucosa samples adjacent to a gastric or esophageal adenocarcinoma. No allelic loss was found at the APC locus. Modification of the methylation status was also found in 3 of 21 (14%) normal-appearing gastric mucosa samples adjacent to intestinal metaplasia. In contrast, all normal mucosa samples in cases with chronic gastritis but without metaplasia or dysplasia showed a monoallelic methylation pattern. Our results indicate the following: (a) In normal gastric mucosa, the APC promoter shows monoallelic methylation, which is not due to imprinting but most likely due to allelic exclusion; (b) the excluded allele differs between foveolar and glandular epithelial cells; (c) the APC methylation pattern is frequently altered in normal-appearing gastric mucosa of gastric or esophageal adenocarcinoma patients; and (d) such alterations also occur in normal gastric mucosa adjacent to intestinal metaplasia.

Mucosal ablation with photodynamic therapy in the esophagus: optimization of light dosimetry in the sheep model.

BACKGROUND: Photodynamic therapy is an attractive technique for mucosal ablation in patients with superficial squamous cell carcinoma of the esophagus, or high-grade dysplasia or early stage adenocarcinoma arising in Barrett's esophagus. Although illumination with green light is assumed to be safe, choice of the light has been empirical in clinical studies; light dose is often reduced to avoid potential complications. The present study assessed the safety of green and blue lights during photodynamic therapy in the esophagus by progressively administrating increasing doses in an attempt to standardize the dose and determine a safe upper limit. This would considerably simplify photodynamic therapy and improve therapeutic results. METHODS: The sheep model was chosen because of similarities with humans regarding the thickness and histologic structure of the esophagus. Irradiation with a 180 degrees windowed cylindrical light distributor was performed in 19 sheep 4 days after injection of 0.15 mg/kg of tetra(m-hydroxyphenyl) chlorin. Light doses ranged from 10 to 500 J/cm(2) at 514 nm (argon ion laser) and from 5 to 250 J/cm(2) at 413 nm (krypton laser). RESULTS: Follow-up endoscopies revealed a tissue response with a fibrinous area at almost all light doses, whereas application of extremely high light doses tended to induce circumferential necrosis with subsequent stenosis. Three months after irradiation with green light, histologic examination of the resected specimens revealed transmural scarring at doses higher than 100 J/cm(2). After illumination with blue light, partial or more extensive fibrosis of the muscular layer was observed only at light doses of 175 to 250 J/cm(2). CONCLUSIONS: Application of high doses of green light after sensitization with tetra(m-hydroxyphenyl) chlorin led to severe complications in the esophagus of the sheep that are highly likely to occur in humans as well. Blue light causes significantly less damage than green light and may, therefore, be considered as an alternative for photodynamic therapy of early stage superficial esophageal cancer.

p16 inactivation by methylation of the CDKN2A promoter occurs early during neoplastic progression in Barrett's esophagus.

BACKGROUND & AIMS: The potential role of p16 inactivation by CDKN2A/p16 promoter hypermethylation and/or loss of heterozygosity (LOH) of the CDKN2A gene was investigated in neoplastic progression of Barrett's esophagus. METHODS: CDKN2A promoter hypermethylation was studied by methylation sensitive single-strand conformation analysis and sequencing using bisulfite modified DNA in Barrett's esophageal adenocarcinomas, premalignant lesions, and normal squamous esophageal epithelium. All of the lesions of interest were sampled by microdissection from paraffin-embedded fixed tissue sections. RESULTS: No methylation of the CDKN2A promoter was found in normal esophageal squamous cell epithelia, whereas methylation was detected in 18 of 22 (82%) adenocarcinomas and 10 of 33 (30%) premalignant lesions, including 4 of 12 (33%) samples with intestinal metaplasia only. LOH at the CDKN2A gene locus was found in 68% of adenocarcinomas and in 55% of premalignant lesions. Of 28 samples without p16 immunoreactivity, 25 (89%) showed CDKN2A promoter hypermethylation with or without LOH of CDKN2A. Only 2 (8%) samples expressing p16 protein were found to be methylated; these showed a mixture of completely methylated and unmethylated CDKN2A promoters. In 7 of 19 (37%) informative samples without LOH of CDKN2A, the CDKN2A promoter was found to be methylated at both alleles. Loss of p16 protein expression was strongly associated with CDKN2A promoter hypermethylation (P < 0.00001), but not with LOH (P = 0.33). CONCLUSIONS: Our results indicate that methylation of the CDKN2A promoter is the predominant mechanism for p16 inactivation. This hypermethylation is a very common event in esophageal adenocarcinoma and occurs as early as metaplasia.

Beta-catenin expression and its association with prognostic factors in adenocarcinoma developed in Barrett esophagus.

The majority of the adenocarcinomas arising in Barrett esophagus manifest clinically at an advanced stage and have a poor prognosis. As a result of this poor prognosis, much attention has been directed toward the exploration of markers for neoplastic progression in Barrett esophagus. The objective of the present study was to determine the expression of beta-catenin by immunohistochemical analysis in 70 adenocarcinomas developed in Barrett esophagus and to examine its relationship to various prognostic factors currently in use. Abnormal beta-catenin expression, consisting of the loss of membranous staining and the appearance of the nuclear staining, was found in 43 cases (61%). Of patients with the 43 tumors showing abnormal beta-catenin expression, 25 (58%) survived more than 1 year. In contrast, only 7 (26%) of 27 patients with tumors showing normal beta-catenin expression survived longer than 1 year. Most of the superficial (Tis-T1) tumors (83% [10/12]) exhibited abnormal beta-catenin expression compared with only 53% (31/58) in the T2-T3 group. These results suggest a possible correlation among beta-catenin expression, tumor stage, and length of survival as prognostic factors in patients with adenocarcinoma in Barrett esophagus.