Randomized Trial With Trastuzumab Versus Observation in Breast Cancer Patients

Epithelial tumor cells can be detected in the bone marrow and/or the peripheral blood \[disseminated and circulating tumor cells, (DTCs) and (CTCs) respectively\] of otherwise metastases-free patients with early breast cancer. Several studies have shown that the presence of these cells is an independent factor associated with an increased incidence of early disease relapse and disease-related death. In almost 50% of the patients, adjuvant chemotherapy cannot eliminate these occult tumor cells and this is also associated with a higher probability of early relapse and death. In 60-70% of the patients, DTCs and/or CTCs express the HER2/c-neu molecule and one or two administrations of their monoclonal antibody trastuzumab (HERCEPTIN) could eliminate these cells for a period ranging from 3-12 months.