Assessment of histopathological methods of evaluating response to neoadjuvant therapy in oesophageal and gastric adenocarcinoma

Upper gastrointestinal tract (GIT) cancers usually receive neoadjuvant therapy prior to surgery. The histological assessment of this response and if this can be predicted on the pre-treatment biopsy are the subject of this thesis. The first study assessed the inter- and intra-observer variation amongst pathologists in evaluating the degree of regression using the Mandard scoring system. The results showed that the reproducibility of this system was only fair to moderate in both cases of inter- and intra-observer testing. The second study examined the levels of expression of selected tumour markers before and after neoadjuvant chemotherapy. These included markers monitoring apoptosis (p53 and bcl-2), proliferation (Ki-67), angio- and lymphangio-genesis (VEGF, CD-31 and LYVE-1). The levels of expression in these markers were measured in the pre-treatment biopsies, to monitor if they could predict the response to neoadjuvant therapy. It was found that when the panel of chosen markers being used together, delivered a much higher power of prediction rather than adopting only one marker, where the collective power of prediction was 80.6%, whereas individually, the power of prediction ranged between 24.6% (VEGF) and 60.7% (Ki-67). The third study explored the use of digital image analysis in assessing the response to neoadjuvant therapy. It was found that while this technique paralleled the Mandard scoring system, it delivered a more objective and reproducible assessment. On the basis of these results I suggest that image analysis should be used to assess tumour regression especially in the context of clinical trials. In this retrospective study it has been shown that the pre-treatment biopsy can predict the degree of regression

Multiparameter analysis of vasculature, perfusion and proliferation in human tumour xenografts.

A method is presented in this report for concurrent analysis of vascular architecture, blood perfusion and proliferation characteristics in whole-tumour cross-sections of human larynx carcinoma and glioblastoma xenografts. Tumours were implanted subcutaneously in nude mice. After i.v. injection with Hoechst 33342 and bromodeoxyuridine (BrdUrd) as perfusion and proliferation markers, animals were killed. An antiendothelial antibody (9F1) was used to delineate vascular structures. Cross-sections were analysed by a multistep immune staining and a computer-controlled microscope scanning method. Each tumour section was stained and scanned four times (Hoechst, 9F1, BrdUrd and Fast Blue for all nuclei). When these images were combined, vasculature, perfusion and proliferation parameters were analysed. The labelling index (LI) was defined as the ratio of the BrdUrd-labelled area to the total nuclear area. The LI based on manual counting and the LI calculated by flow cytometry (FCM) were in good agreement with the LI based on surface analysis. LI decreased at increasing distance from its nearest vessel. In the vicinity of perfused vessels, the LI was 30-70% higher than near non-perfused vessels. This method shows that both vasculature/perfusion and proliferation characteristics can be measured in the same whole-tumour section in a semiautomatic way. This could be applied in clinical practice to identify combined human tumour characteristics that predict for a favourable response to treatment modifications

Minichromosome maintenance (MCM) and AgNOR proteins expression in desmoid tumours: a tissue microarray analysis.

In the present study, nuclear proliferative proteins: MCM2, MCM5, MCM7, Ki-67 and AgNORs expression was assessed in paraffin sections from sporadic desmoid tumours using a tissue microarray (TMA)-based immuno- and histochemistry, respectively. Nuclear expression of MCM7, where the percentage of positive cells was 0.87% (Âą 1.64) (range 0-5%), was found in 4/20 (20.0%) cases. In 32/32 (100%) of the examined desmoid cases no expression of nuclear proteins MCM2 and MCM5 was detected. Nuclear expression of Ki-67 was observed in 4/21 (19%) cases. Paraffin sections from 30 cases of desmoid tumours were silver-stained to visualize AgNORs. The following AgNOR parameters were calculated: mean AgNOR number per nucleus (N), mean AgNOR area per nucleus, mean AgNOR dot area per nucleus (A), and mean AgNOR content (C = N/A). In the investigated group the mean values of AgNOR parameters were the following number: 4.34 (Âą 0.11); area: 0.74 Îźm2 (Âą 0.19); dot area: 0.18 m2 (Âą 0.01), and AgNOR content: 23.73 (Âą 1.85). The mean AgNOR number per nucleus and mean AgNOR content in desmoid tumours were statistically significantly higher as compared to the controls (tonsil tissue) (

Quantification of cell cycle markers in oral precancer

The overall aims of the studies were to obtain objective measures of oral precancerous lesions based upon studies of the cell cycle and to investigate these parameters as possible prognostic indicators with regard to malignant transformation of these lesions. The majority of the precancerous lesions in the present study were dysplastic. These are the lesions which cause the greatest concern clinically with regard to malignant transformation. The first part of the study investigated the S-phase, growth fraction and the relationship of these to each other and with the degree of dysplasia with the aim of achieving objective measurements of the dysplasia and prognostic information. This was achieved by the use of BrdU for labelling of cells in the S-phase and anti-Ki67 antibody as a marker of cells in the growth fraction. The BrdU labelling index was demonstrated to provide an objective assessment of the dysplastic lesions when compared to the semi-objective method of Smith and Pindborg (1969). The ratio of the S-phase to the growth fraction was higher in those lesions which progressed to malignancy and was cited as a possible prognostic indicator. A number of methodological problems were identified from this first part of the study and these were investigated further by the development of techniques in Chapter 3. Firstly, a method was developed to enable the BrdU labelled tissue to be formalin fixed and then allow other cell cycle associated markers to be studied on sequential sections of the same tissue block. Secondly, numerous antigen retrieval techniques were carried out in order to optimise the immunohistochemical staining of Ki67 and subsequently other antibodies utilised in later parts of the study. Normal oral epithelium, derived post-mortem, was studied in Chapter 4 to investigate the apparent underestimation of proliferating cells identified by anti-Ki67 antibody in Chapter 2. It was apparent that, as in dysplastic epithelia, Ki67 significantly underestimated progenitor cells of the morphologically identified progenitor compartment. Ki67 did not identify all of those cells which would have been expected to be in the cell cycle it was originally claimed to do

Nuclear medicine imaging of lung cancer and esophagus cancer

Background: Somatostatin receptors (SSTRs) occur in cancer tissue, and 99mTc-depreotide is a labelled somatostatin receptor analogue, binding to SSTRs subtype 2, 3, and 5. Purpose: The general aim of the present thesis was to study somatostatin receptor scintigraphy (SSTRS) with 99mTc-depreotide in the diagnosis and characterization of cancers in the lung and oesophagus. Study I evaluated the diagnostic value of the SSTRS with 99mTc-depreotide in 99 patients with suspected lung cancer. The sensitivity to detect malignancy was 94%, and to detect lung cancer 98%. The specificity was calculated on two sets of data. When all cases are used, the specificity was 52%. If the 12 pneumonias are excluded, the specificity was 77%. Study II was performed on 19 patients with histologically proven non-small-cell lung cancer (NSCLC), where the expression of SSTR subtype 2 was looked for and found by immunochemical methods. The quantitative evaluation of 99mTc-depreotide was performed using region-of-interest analysis and includes tumour counts/cm3, background counts/cm3, and the ratio between tumour and background counts. SSTR subtype 2 expression was positively correlated to the degree of the tumour’s differentiation (p < 0.05). 99mTc-depreotide uptake in tumour cells did not correlate with tumour grade or SSTR subtype 2, MIB-1, or p53 expression. Study III showed the feasibility of imaging oesophageal carcinoma with SSTRS with 99mTc- depreotide and optimal time intervals for imaging. None of the 13 cancer-free Barrett’s oesophagus patients in this study showed an increased 99mTc-depreotide uptake. Study IV investigated the expression of SSTRs of subtype 2A, 2B, 3, and 5 in 28 patients with suspected oesophageal cancer, where expression was detected in small amount in adenocarcinoma and was absent in squamous cell carcinoma. There was no correlation between the 99mTc-depreotide uptake and the amount of SSTRs, and no correlation between the amount of SSTRs and the differentiation grade of the tumour. Conclusion: SSTRS with the labeled somatostatin receptor analogue 99mTc-depreotide has a very high sensitivity for detecting lung cancer. A negative scintigraphy strongly suggests a benign lesion, and the method is useful in decision making with respect to surgery. There is an expression of SSTRS subtype 2 in NSCLC with a positive correlation between tumour differentiation and presence of SSTR subtype 2. There is no correlation between 99mTc-depreotide uptake compared to tumour differentiation, presence of SSTR subtype 2, p53, or MIB-1, and SSTRS cannot be used as a prognostic factor in patients with lung cancer. SSTRS with 99mTc-depreotide of oesophageal cancer is feasible, but not suitable, for either screening or primary diagnosis, because of the method’s modest sensitivity. However, this method has a high specificity. The majority of patients with adenocancer of the oesophagus have a low amount of SSTRs, while most of the patients with squamous cell cancer do not have any of SSTRs

From Barrett's esophagus to adenocarcinoma and metastasis

The first description of islets of ectopic gastric mucosa in the esophagus was by Schmidt in 1805. One century later, in 1906, Tileston described peptic ulcerations in columnar epithe

Oral Submucous Fibrosis a study of Prevalence Potential Biomarkers of Malignancy and Chemopreventive Agents In vitro

Oral submucous fibrosis (OSF) is a chronic progressive, precancerous condition of the oral mucosa, which is associated with areca nut chewing habit widely prevalent in India and South-East Asia. It is clinically characterized by burning sensation of the oral mucosa accompanied by pallor and progressive, irreversible fibrosis leading to difficulty in opening the mouth, speech and swallowing. It is a potentially malignant condition. The main histopathological feature of OSF is the increased deposition of newlinecollagen in the oral mucosa, due to a collagen-metabolic disorder, resulting from newlineexposure to the areca nut alkaloids. Other histopathological changes in established newlineOSF include reduced vascularity, reduced number of inflammatory cells, and subepithelial hyalinization. newlineIn the background of the wide prevalence of areca nut use in its various forms, newlineregional variations in its use, easy availability of areca nut products, the irreversible fibrosis and associated morbidity, its potential for malignant transformation and the relative paucity of data on this habit in Tamilnadu, this study was done in a Dental institution in Chennai. AIMS AND OBJECTIVES:To study the prevalence of OSF, different type of chewing habits, and their relation in a hospital based population. To study potential surrogate biomarkers of malignant transformation in OSF by evaluating immunohistochemically the following antigens in the epithelium:RESULTS: The results of the study highlight the increasing use of pan masala by the younger individuals. The use of these products is associated with earlier onset of OSF, which could lead to increased incidence of cancer in the younger age group: a trend that has been observed in certain parts of India. These findings highlight the need for intervention programs targeted at the younger individuals and creation of increased public awareness of the harmful effect of these products. This is all the more important because of the recalcitrant nature of OSF and absence of effective treatment for OSF as of date