Overexpression selleck chemicals DAPT secretase of HER-2 was observed in three cases (11%), all male and two (67%) over 14 years of age. Pulmonary metastases were identified in only one third of the patients with HER-2 considered positive (>1+). The samples positively-stained for HER-2 did not present a description of response to chemotherapy in our medical files. We did not find significant correlation when conducting descriptive and univariate analyses. Kaplan-Meier survival curves for HER-2 are described in Figure 2. Immunohistochemistry of VEGF is demonstrated in Figure 3A, while immunohistochemistry of HER-2 is demonstrated in Figure 3B. Figure 1 Kaplan-Meier curve for (A) general survival and (B) disease-free survival for positive cases of VEGF compared with negative.

Figure 2 Kaplan-Meier curve for (A) general survival and (B) disease-free survival for positive cases of HER-2 (ErbB-2) compared with negative. Figure 3 Photomicrography of (A) osteosarcoma with cytoplasmic positivity for VEGF (400X) and photomicrography of (B) osteosarcoma with membrane positivity for HER-2 (400X). DISCUSSION The low prevalence of VEGF (15%) and HER-2 (11%) in osteosarcoma biopsies analyzed through immunohistochemistry was demonstrated in this study. Different methods to quantify the presence of biological markers theoretically involved in the proliferation and dissemination of tumors have been described in recent decades. Laboratory tests such as immunohisto-chemistry, DNA and RNA testing are among the best known.

Differences between research protocols including a wide variety of antibodies and of techniques without standardization for gene identification are responsible for the discrepancy in studies around the world. 15 , 17 Since HER-2 complementary DNA was isolated approximately 25 years ago, important discoveries have come to light in the mechanism of action of the receptor tyrosine kinases (RTK), which, when mutated or altered, become potent oncoproteins. In 1985, the Ullrich of Genentech group described the complete primary structure of supposed RTK that demonstrated a high degree of homology with the human Epidermal Growth Factor Receptor (EGFR), having been denominated human EGFR-related 2, or HER2 (17). Two years later, Slamon et al. 12 reported that HER2 was amplified in 30% of the invasive breast cancer cases and, for the first time, demonstrated significant correlation between overexpression of HER2, reduced survival and increased tumor recurrence.

In the late 1990s, two studies suggested that overexpression of HER-2 in osteosarcoma could be associated with reduced survival and the development of metastases. In one of these studies, 26 osteosarcoma samples were analyzed for HER-2 through immunohistochemistry, and overexpression of HER-2 was identified in 42% of the samples. However, the metastatic patients were included in the Dacomitinib same sample and the chemotherapy protocols were not adequately described.