Tissue Microarray Construction and Immunohistochemical evaluation of Bcl-2 Gene Expression in Iraqi and Italian Breast Cancer Samples.

Breast cancer is a heterogeneous disease and remains one of the most leading causes of death among women world wild. Anti-apoptotic Bcl-2 family members inhibits cell death and promote proliferation of cancer cells. Overexpression of Bcl-2 has been shown to inhibit the initiation of apoptosis, in the presence of some stimuli including anticancer drugs in a number of systems. To study the expression of Bcl-2 tissue microarray (TMA) investigation was designed and constructed. Using 3 TMAs; the second for the 50 Iraqi breast cancer cases, one for the 30 Italian cases and the third for the 10 benign cases. Each sample represented in a triplicate in the recipient block, all these TMAs expressed to the same condition for construction and IHC staining. TMAs are a powerful, fast and economic technique. IHC was used to study the Bcl-2 expression. The results are represented as differences in the number of samples expressed the Bcl-2 and the intensity of the expression between the Iraqi and the Italian groups. Bcl-2 expression was found elevated in 26 (52%) of the 50 Iraqi breast cancer samples and 11 (36.66%) of the 30 Italian samples compared to the control samples. And in which only 1 (10%) out of 10 samples. The overexpression of Bcl-2 associated with poor prognosis for the patients. Level of Bcl-2 expression can be used as prognostic marker to monitor patient therapy. For the Iraqi cases the overexpression may be attributed to many factors like exposure to depleted uranium and bad food quality during the 90th when Iraq was under the siege of the United Nation (UN).

Cancer and Leukemia Group B Pathology Committee Guidelines for Tissue Microarray Construction Representing Multicenter Prospective Clinical Trial Tissues

Practice-changing evidence requires confirmation, preferably in multi-institutional clinical trials. The collection of tissue within such trials has enabled biomarker studies and evaluation of companion diagnostic tests. Tissue microarrays (TMAs) have become a standard approach in many cooperative oncology groups. A principal goal is to maximize the number of assays with this precious tissue. However, production strategies for these arrays have not been standardized, possibly decreasing the value of the study. In this article, members of the Cancer and Leukemia Group B Pathology Committee relay our experiences as array facility directors and propose guidelines regarding the production of high-quality TMAs for cooperative group studies. We also discuss statistical issues arising from having a proportion of patients available for TMAs and the possibility that patients with TMAs fail to represent the greater study population.