ErbB-2 protein levels in healthy, asymptomatic women

Abstract Recently, a number of studies have found a relationship between having breast cancer and elevated serological levels of the extracellular domain (ECD) of the erbB-2 protein. This study focuses on healthy, asymptomatic women, and evaluates the relationship between serological concentration of the ECD of erbB-2 protein and the following parameters: age, ethnicity, smoking status, age at menarche, age at first live birth, menopausal status, whether surgery had been performed within the prior year, history of breast cancer, history of any other cancer, family history of breast cancer, history of other cancers in first degree relatives, and number of prior benign breast biopsies. Blood samples were stored at -70°C and analysed within 3 weeks of phlebotomy. Statistical analysis indicates that in healthy women, the level of erbB-2 protein in the blood is directly related to age (p = 0.0002) and inversely related to having had a live birth (p = 0.018). The relationship to age is independent of the association between the oncoprotein level and menopausal status. The data indicate that rather than having only one threshold value for serological erbB-2 positivity, it may be necessary to have values that reflect age and nulliparity status.