DNA hypermethylation as a predictor of extramural vascular invasion (EMVI) in rectal cancer.

PURPOSE: DNA hypermethylation in gene promoter regions (CpG islands) is emerging as an important pathway in colorectal cancer tumourigenesis. Whilst genetic mutations have been associated with extramural vascular invasion (EMVI) in rectal cancer, no such association has yet been made with epigenetic factors. METHODS: 100 consecutive neoadjuvant-naïve patients undergoing curative surgery for rectal were classified according to the presence or absence of EMVI on histopathological examination. DNA was extracted from tumours and subjected to bisulfite conversion and methylation-specific PCR to determine CIMP status (high, intermediate, or low; according to a validated panel of 8 genes). CIMP status was correlated with EMVI status, histopathological, clinical, and demographic variables, in addition to overall (OS) and disease free (DFS) survival. RESULTS: 51 patients were characterised as CIMP-low, 48 CIMP-intermediate, and one patient CIMP-high. EMVI-positivity was associated with CIMP-intermediate epigenotype (p < 0.001). Patients with EMVI-positive tumours were found to have significantly more advanced disease by pT, pN, and pAJCC categorisation (p = 0.002, p < 0.001, and = p < 0.001, respectively). EMVI-positivity was significantly associated with the requirement for adjuvant chemotherapy (p < 0.001), and worse DFS but not OS (p = 0.012 and p = 0.052). CONCLUSIONS: Given the association between CIMP-intermediate epigenotype and EMVI-positivity, and the subsequent disadvantage in pathological stage, requirement for adjuvant therapy and worse survival, tumour epigenotyping could potentially play an important role in personalising patients' cancer care. Further work is required to understand the mechanisms that underlie the observed effect, with the hope that they may provide novel opportunities for intervention and inform treatment decisions in rectal cancer.

The evaluation of renal ischaemic damage: the value of CD10 monoclonal antibody staining and of biochemical assessments of tissue viability.

BACKGROUND: It is well recognised that there is often a disparity between the structural changes observed in the kidney following renal injury and the function of the organ. For this reason, we carried out studies to explore possible means of studying and quantifying the severity of renal ischaemic damage using a laboratory model. METHODS: To do this, freshly isolated rabbit kidney tissue was subjected to warm (37 degrees C) or cold (1 degrees C) ischaemia for 20 hours. Following this, the tissue was stained using Haematoxylin and Eosin (H+E), Periodic Schiff reagent (PAS) and the novel monoclonal antibody CD10 stain. Additionally, ischaemic damage to the kidneys was assessed by biochemical tests of tissue viability using formazan-based colorimetry. RESULTS: CD 10 antibody intensely stained the brush border of control kidney tissue with mild or no cytoplasmic staining. Cell injury was accompanied by a redistribution of CD10 into the lumen and cell cytoplasm. There was good correlation between a score of histological damage using the CD 10 monoclonal antibody stain and the biochemical assessment of viability. Similarly, a score of histological damage using traditional PAS staining correlated well with that using the CD10 antibody stain. In particular, the biochemical assay and the monoclonal antibody staining techniques were able to demonstrate the efficacy of Soltran (this solution is used cold to preserve freshly isolated human kidneys prior to transplantation) in preserving renal tissue at cold temperatures compared to other randomly selected solutions. CONCLUSION: We conclude that the techniques described using the CD10 monoclonal antibody stain may be helpful in the diagnosis and assessment of ischaemic renal damage. In addition, biochemical tests of viability may have an important role in routine histopathological work by giving additional information about cellular viability which may have implications on the function of the organ.

Analysis of the premalignant stages of Barrett's oesophagus through to adenocarcinoma by comparative genomic hybridization.

OBJECTIVES: Barrett's oesophagus is a pre-neoplastic lesion, which develops as a complication of chronic gastro-oesophageal reflux disease and predisposes the patient to oesophageal adenocarcinoma. Our aim was to characterize karyotypic changes that may occur during the progression of Barrett's metaplasia through low-grade dysplasia and high-grade dysplasia to adenocarcinoma. METHODS: The technique of comparative genomic hybridization was used to characterize genome-wide changes in biopsies from patients with low-grade dysplasia, low-grade dysplasia plus high-grade dysplasia, high-grade dysplasia or adenocarcinoma. Both fresh and archival material was examined. RESULTS: Comparative genomic hybridization revealed a large amount of widespread chromosome instability at the high-grade dysplasia stage. No significant chromosome changes were detectable by comparative genomic hybridization in patients with low-grade dysplasia. Karyotypic changes in the adenocarcinoma patients were more specific than those found in the high-grade dysplasia patients. Chromosome 4 was amplified most often in high-grade dysplasia and chromosome 8q was amplified most frequently in the adenocarcinomas. CONCLUSIONS: These data demonstrate that high-grade dysplasia is the stage exhibiting widespread chromosome instability, which is detectable by comparative genomic hybridization. This instability is undetectable in low-grade dysplasia. The chromosome variation seen at high-grade dysplasia may be the source of more specific karyotypes that progress to adenocarcinoma. Importantly, we have identified chromosome 4 amplification as being heavily involved in the initiation of Barrett's progression. Specific chromosome changes (4 and 8q) may represent important regions on which to focus attention in future studies, with a view to identifying diagnostic markers.

Differential expression of the MAD2, BUB1 and HSP27 genes in Barrett's oesophagus-their association with aneuploidy and neoplastic progression.

Chromosomal instability (CIN) leading to aneuploidy is a ubiquitous and early event in the progression of Barrett's oesophagus, but its origins are unknown. Hence, the transcriptional levels of components of the mitotic spindle checkpoint (important in ensuring precise chromosome segregation) were examined in Barrett's lesions and correlated with the degree of aneuploidy present in the tissues. Gene expression levels of the MAD2 and BUB1 mitotic spindle checkpoint genes were assessed in 37 Barrett's patients (with histology ranging from metaplasia to adenocarcinoma) by real-time RT-PCR. In addition, the transcriptional levels of HSP27 were also examined as firstly, its expression is known to be down regulated in Barrett's metaplasia (BM) and thus was included as a positive control for the real-time RT-PCR assay. While, secondly, the expression pattern of this gene during Barrett's neoplastic progression was investigated, as this has not been previously assessed. Both over and under expression of the MAD2 and BUB1 mitotic spindle checkpoint genes were detected at all Barrett's histological stages with no apparent selective trend with neoplastic progression. In addition, no correlation with aneuploidy was established, indicating an alternative mechanism must underlie Barrett's associated chromosomal instability. HSP27 expression was reduced in metaplasia and then significantly increased with progression. Gender-related differences were observed and HSP27 expression was higher in poorly-differentiated adenocarcinomas than in well-differentiated forms. HSP27 transcriptional patterns therefore present potential as a prognostic tool to predict the aggressiveness of oesophageal adenocarcinomas (OA).

Recurrent carpal tunnel syndrome owing to an implantation epidermoid cyst after carpal tunnel decompression: case report.

OBJECTIVE: Implantation epidermoid cysts have been reported after a variety of surgical procedures. Although carpal tunnel surgery is the most common peripheral nerve operation, there have been no previous reports of these cysts after carpal tunnel decompression. We present a case of an implantation epidermoid cyst after carpal tunnel surgery. CLINICAL PRESENTATION: A 41-year-old man presented with recurrence of carpal tunnel syndrome and an enlarging mass at the site of his previous carpal tunnel decompression. INTERVENTION: The operation site was re-explored, and a subcutaneous mass was removed. This was histologically shown to be an implantation epidermoid cyst. CONCLUSION: The possibility of an implanted epidermoid cyst should be considered in any patient who presents with a recurrence of carpal tunnel symptoms and a mass at the site of the previous operation. It is possible that the occurrence of these cysts may be related to the use of polyglactin sutures for wound closure. In this case, the result of surgery was excellent.