Amplification of protooncogenes and expression of the HER2/NEU oncogene in invasive breast cancer

The protooncogene HER2/neu was analyzed in 27 women with invasive breast cancer and in 26 with benign breast conditions. Gene amplification was found in 3 patients, 1 in stage 3 and 2 in stage 4. In 3 patients in stage 2 overexpression of protein was found. Although amplification of the gene was found to be a significant predictor of clinical outcome (p < 0.05), high expression of the gene did not correlate with prognosis. In women with benign breast conditions there were no alterations of HER2/neu. HER2/neu amplification may become a molecular marker in some malignancies. It should be noted that since few tumors show amplification, examination of a small series may not reveal clinical association with these alterations. Therefore, our conclusions require confirmation on a larger scale with long-term clinical follow-up.