Immunohystochemical status of p53 and Ki-67 obtained with tissue micro-array in patients operated for breast carcinoma in Botucatu Medical School Hospital from 1980 to 2000: correlation with clinical and survival data

Abstract

In Brazil, breast cancer is a malignancy that affects more women with a high incidence, morbidity and mortality associated with a high cost of treatment, representing a serious public health problem. The estimate for the year 2010 was 49,240 new cases of disease in our country. According to data from Globocan (International Agency for Research on Cancer) in 2008 were recorded around the world 691 000 new cases of breast cancer in countries with low income / moderate and 692 000 in developed countries. There is need for sensitive and specific markers that allow both the early detection of breast cancer as the estimated probability of progression. The identification of tumors that have greater potential for progression may support decisions of more aggressive treatments, which can pose a greater chance of cure. In this context, immunohistochemistry has been used in different situations of breast pathology, the most important: evaluation of predictive factors and prognosis of breast cancer, metastatic epithelial cell research in the sentinel node, the differential diagnosis of breast lesions and determination the possible origin of metastatic tumors. The change in the p53 tumor suppressor gene is the most commonly described in breast cancer, suggesting the performance of a central role in the development of malignant disease, and many studies have linked its overexpression with poor prognosis. Another important marker in breast carcinoma is the Ki-67 antibody, which recognizes an antigen associated with cell nuclei expressed in all phases of the cell cycle except in G0. Some studies have shown the superiority of Ki-67 as a marker of cell proliferation, not to be influenced by internal and external factors. Moreover, its nuclear expression in a defined period of the cell cycle may represent an advantage over its use as a biological marker. The identification of markers, we have highlighted the use of the technique of Arrangement Tissue Matrix, or Tissue Microarray, described in 1998 by Kononen et al. This is the construction of a paraffin block containing cylindrical fragments or tumor tissue samples obtained from dozens or hundreds of original paraffin blocks. Cylinders tissue / tumor receiver are arranged in the block following a predetermined order. The paraffin block with hundreds of tumor samples ordered is powerful tool for investigative pathology applied. The archives of tumor Pathology services are a potential source of valuable research material, because they contain non-tumor and tumor tissue stored in paraffin used in the diagnosis and staging of disease in these patients. Recent advances in molecular biology, genomics and proteomics are used as the substrate / source of study materials, preferably fresh or frozen tissue, is considered the formaldehyde fixation and paraffin embedding as a serious limitation to the use of this material, until recently restricted to the technique of immunohistochemistry. But this process is routinely used worldwide, and provides a file storage tissue easily and inexpensively at room temperature for decades, histopathologically well-defined, classified and diagnosed. Today this material is subject to development of techniques and technologies for exploitation in the areas of cutting-edge biomedical research. In addition, this material has associated clinical information from medical records and of the disease that makes them a potential source for the study of biological markers of survival and pathogenesis research. The major impediment to the use of this material in biomedical research is the lack of clinical information and patient survival. The recovery of data in old files is not reported routinely, what we do in our project also.