Timothy J. Stephenson

Photodynamic therapy for dysplastic Barrett's oesophagus: a prospective, double blind, randomised, placebo controlled trial

BACKGROUND AND AIMS Photodynamic therapy (PDT) is a treatment in which cell damage is achieved by the action of light on a photosensitising agent. We have assessed the potential use of PDT in the ablation of Barretts oesophagus. METHODS Thirty six patients with dysplastic Barretts oesophagus receiving acid suppression medication with omeprazole were randomised to receive oral 5-aminolaevulinic acid (ALA) 30 mg/kg or placebo, followed four hours later by laser endoscopy. Follow up endoscopy was performed at one, six, 12, and 24 months. RESULTS Of 18 patients in the ALA group, a response was seen in 16 (median decrease in area in the treated region 30%; range 0–60%). In the placebo group, a decrease in area of 10% was observed in two patients with no change in 16 (median 0%; range 0–10%; treatment vplacebo, p<0.001). No dysplasia was seen in the columnar epithelium within the treatment area of any patient in the PDT group. However, in the placebo group, persistent low grade dysplasia was found in 12 patients (p<0.001). There were no short or long term major side effects. The effects of treatment were maintained for up to 24 months. CONCLUSIONS This is the first randomised controlled trial of PDT for Barretts oesophagus. It demonstrates that ALA induced PDT can provide safe and effective ablation of low grade dysplastic epithelium.

Barrett's oesophagus: Intestinal metaplasia is not essential for cancer risk

Objective. Barretts oesophagus is the main identifiable risk factor for oesophageal adenocarcinoma. It has been suggested that only patients with intestinal metaplasia are at risk of cancer, but the British Society of Gastroenterology (BSG) guidelines suggest that glandular mucosa is all that is needed. The aim of this study was to quantify the risk of adenocarcinoma in columnar-lined lower oesophagus, with or without specialized intestinal metaplasia. Material and methods. All patients who had endoscopic biopsies of the lower oesophagus between 1980 and 1994 in a single-centre teaching hospital were included in the study. All histological specimens were re-examined and reported according to whether they contained columnar epithelial-lined lower oesophagus, glandular mucosa, with or without intestinal metaplasia. The primary outcome measure was the development of adenocarcinoma. Results. In total, 712 patients were identified. Of these, 379 (55.1%) were found to have specialized intestinal metaplasia (SIM), and the remaining 309 (44.9%, p=NS) were reported as having glandular mucosa (GM). The median follow-up for patients was 12 years (range 8–20 years). Twenty-eight patients went on to develop adenocarcinoma (4.1%) during the follow-up period – 17 in the SIM group (4.5%) and 11 in the GM group (3.6%, p=NS). The oesophageal malignancy rate was 0.34% per year (SIM 0.37%, GM 0.30%; p=NS). Conclusions. Patients who have glandular mucosa on biopsy without intestinal metaplasia have a similar cancer risk to those with specialized intestinal metaplasia.

Endoscopic ablation of Barrett's oesophagus: a randomized‐controlled trial of photodynamic therapy vs. argon plasma coagulation

Background : Barretts oesophagus is the major risk factor for oesophageal adenocarcinoma. 5‐Aminlevulinic acid‐induced photodynamic therapy and argon plasma coagulation have been shown to be effective for ablating Barretts oesophagus, but a comparative trial of these two modalities has not been reported.

Ablation treatment for Barrett oesophagus: what depth of tissue destruction is needed?

AIM: To establish the depth of Barretts columnar epithelium and normal squamous oesophageal epithelium, in order to determine the depth of destruction required in ablation treatment for Barrett oesophagus. METHODS: Histological specimens from 100 cases of Barrett oesophagus and 100 samples of normal squamous oesophageal epithelium were studied. Using a system of multiple measurements until the change in cumulative mean values varied by less than 5%, the overall mean and normal range of depth was calculated for each type of epithelium. RESULTS: Barrett columnar epithelium is minimally thicker (mean (SEM) 0.50 (0.004) mm; range 0.39 to 0.59 mm) than normal squamous epithelium (0.49 (0.003) mm; 0.42 to 0.58 mm), although this difference is probably too small to be of clinical relevance. CONCLUSIONS: Although there are numerous clinical reports of various methods of ablation treatment for Barrett oesophagus, little attention has been paid to the depth of tissue destruction required. This is the first study to look specifically at this issue, and it provides information on the necessary depth of epithelial ablation.

Expression of proteinases and inhibitors in human breast cancer progression and survival

Aims: The expression of proteinases and their inhibitors determines the extracellular matrix (ECM) turnover in normal and pathological processes. In cancer, proteolysis is abnormally regulated, favouring ECM degradation, which aids tumour invasion and metastasis. Previous studies have determined the expression of proteinases and inhibitors in breast cancer using a variety of techniques, including immunohistochemistry; however, most have looked at the expression of individual proteinases and/or inhibitors. Therefore, the aim of the current study was to determine the simultaneous cellular expression of matrix metalloproteinases (MMPs), plasminogen activators (PAs), and tissue inhibitors of metalloproteinases (TIMPs) in patients with breast cancer and correlate this with clinical pathological staging and survival. Methods: Immunohistochemistry was used to determine the expression of proteinases (MMP-1, MMP-2, MMP-3, MMP-9, urokinase-type PA, and tissue-type PA) and inhibitors (TIMP-1 and TIMP-2) in 44 patients with breast cancer. Results: The expression of all the factors studied was stronger or equivalent in tumour cells than in fibroblasts or inflammatory cells within the tumour section. Both positive and negative trends have emerged in the correlation between the cellular expression of proteinases and inhibitors and breast tumour pathology (tumour grade, lymphovascular invasion, and Nottingham prognostic index). Conclusions: The interactions between proteinases and their inhibitors in breast cancer progression are complex. Although there are differences in the expression of these factors that relate to differences in breast cancer pathology, there are no outstanding individual factors that consistently correlate with prognosis. Therefore, different factors are probably important at different stages of the process, and the balance in the relative concentrations of proteinases and inhibitors probably determines ECM degradation in breast tumour invasion and metastasis in vivo.

The Interobserver Reproducibility of Thyroid Fine-Needle Aspiration Using the UK Royal College of Pathologists’ Classification System

The overall interobserver reproducibility of thyroid fine-needle aspiration (FNA) has not been comprehensively assessed. A blinded 6-rater interobserver reproducibility study was conducted of 200 thyroid FNA cases using the UK System, which is similar to The Bethesda System for Reporting Thyroid Cytology: Thy1, nondiagnostic; Thy2, nonneoplastic; Thy3a, atypia, probably benign; Thy3f, follicular lesion; Thy4, suspicious of malignancy; and Thy5, malignant. There was good interobserver agreement for the Thy1 (κ = 0.69) and Thy5 (κ = 0.61), moderate agreement for Thy2 (κ = 0.55) and Thy3f (κ = 0.51), and poor agreement for Thy3a (κ = 0.11) and Thy4 (κ = 0.17) categories. Combining categories implying surgical management (Thy3f, Thy4, and Thy5) achieved good agreement (κ = 0.72), as did combining categories implying medical management (Thy1, Thy2, and Thy3a; κ = 0.72). The UK thyroid FNA terminology is a reproducible and clinically relevant system for thyroid FNA reporting. This study demonstrates that international efforts to harmonize and refine thyroid cytology classification systems can improve consistency in the clinical management of thyroid nodules.

Proteolysis in human breast cancer

Background—The process of proteolysis is important at several stages of the metastatic cascade. A balance between the expression of the genes encoding endogenous proteinases and inhibitors exists and when the production of proteinases exceeds that of inhibitors proteolysis occurs. Aims—To determine whether differences in the profile and activity of proteinases and inhibitors exist within breast tumour tissue (n = 51), surrounding background breast tissue (n = 43), normal breast tissue from breast reduction mammoplasty operations (n = 10), and cells of the breast cancer cell line, MCF-7. Methods—Proteinase (matrix metalloproteinase 1 (MMP-1), MMP-2, MMP-3, MMP-9, urokinase-type plasminogen activator (uPA), and tissue-type PA (tPA)) and inhibitor (tissue inhibitor of metalloproteinases; TIMP-1 and TIMP-2) expression and proteinase activity were compared using substrate zymography, western blotting, immunohistochemistry, and quenched fluorescent substrate hydrolysis. Results—The presence of all proteinases and inhibitors was greater in breast tumour tissue when compared with all other types of breast tissue (p < 0.05). The activity of total MMPs as determined by quenched fluorescent substrate hydrolysis was also greater in breast tumours (p < 0.05). Conclusion—There is increased proteolysis in human breast tumours when compared with other breast tissues.

Role of tumour necrosis factor gene polymorphisms (-308 and -238) in breast cancer susceptibility and severity

IntroductionGenetic polymorphisms in the promoter region of the tumour necrosis factor (TNF) gene can regulate gene expression and have been associated with inflammatory and malignant conditions. We have investigated two polymorphisms in the promoter of the TNF gene (-308 G>A and -238 G>A) for their role in breast cancer susceptibility and severity by means of an allelic association study.MethodsUsing a case–control study design, breast cancer patients (n = 709) and appropriate age-matched and sex-matched controls obtained from the Breast Screening Unit (n = 498) were genotyped for these TNF polymorphisms, using a high-throughput allelic discrimination method.ResultsAllele frequencies for both polymorphisms were similar in both breast cancer cases and controls. However, the -308 polymorphism was found to be associated with vascular invasion in breast tumours (P = 0.024). Comparison with other standard prognostic indices did not show any association for either genotype.ConclusionsWe demonstrated no association between the -308G>A polymorphism and the -238G>A polymorphism in the promoter region of TNF and susceptibility to breast cancer, in a large North European population. However, the -308 G>A polymorphism was found to be associated with the presence of vascular invasion in breast tumours.

5-Aminolevulinic acid photosensitization of dysplastic Barrett's esophagus: a pharmacokinetic study.

Photodynamic therapy (PDT) using 5‐aminolevulinic acid (ALA)‐induced protoporphyrin IX (PpIX) may have a role in the treatment of dysplastic Barretts esophagus. Before ALA‐induced PDT can be used clinically, optimum treatment parameters must be established. In this study of 35 patients, the issues of drug dosage, time interval between drug and light delivery and side effects of oral ALA administration are addressed. Spectrofluoro‐metric analysis of tissue samples demonstrates that oral ALA administration induces porphyrin accumulation in esophageal tissues, with maximum levels at 4–6 h. High‐performance liquid chromatography confirms the identity of this porphyrin as PpIX, and fluorescence microscopy analysis demonstrates that it preferentially accumulates in the esophageal mucosa, rather than in the underlying stroma. Side effects of ALA administration included malaise, headache, photosensitivity, alopecia, transient derangement of liver function, nausea and vomiting. Fewer side effects and less hepatic toxicity was seen with 30 mg/kg than 50 mg/kg ALA. In conclusion, oral ALA administration induces preferential PpIX accumulation in the esophageal mucosa, with peak PpIX fluorescence noted at 4 h and minimal systemic toxicity at a dose of 30 mg/kg.

Analysis of colorectal tumor progression by microdissection and comparative genomic hybridization.

This investigation aimed to identify patterns of copy number change in colorectal tumor progression from adenoma to liver metastasis. Fifty‐three microdissected sub‐regions from 17 cases of colorectal cancer were assigned to one of six histopathologically defined categories: coexisting adenoma, tumor above the muscularis layer, tumor within the muscularis layer, tumor extending through the bowel wall to serosal fat, lymph node metastasis, and liver metastasis. Microdissected samples were treated by a microwave processing step and then used as templates for universal PCR amplification. PCR products were fluorophore labeled and subjected to comparative genomic hybridization. Copy number changes were found in all samples, and every chromosome arm (excluding acrocentric short arms) was affected. More losses than gains were detected, but there were no significant differences between the numbers of changes seen in each category. Each individual sample revealed unique changes, additional to those shared within each case. The most frequently observed gains were of X and 12q. The most common losses were of 8p, 16p, 9p, 15q, 18q, and 10q. Nominally significant associations were observed between metastatic tumor and loss of 12q24.1 or 10p13–14, non‐metastatic tumor and loss of 8q24.1, tumor extending to serosal fat and loss of 6q24–25 or gain of 4q11–13, tumor extending to serosal fat and metastatic lesions and loss of 4q32–34 or 22q11–12, and adenoma and loss of 15q24. Loss of 4q32–34 remained highly significant after correction for multiple testing. Adenoma was the only category not to show loss of 17p. These data reveal a genetically heterogeneous picture of tumor progression, with a small number of changes associated with advanced disease.