A multivariate Cox proportional hazards model, applying a forward likelihood ratio, was used to rule out any influence on TTP or OS from the following factors: age, ethnicity (Caucasian, South Asian or East Asian), histological tumour type (ductal non-specific type, lobular or other), tumour size (<20.0 mm, 20.0–49.9 mm or 50.0+ mm), tumour grade (I, II or III), unifocal or multifocal disease, number of involved axillary lymph nodes (none, 1–3 or 4+), ER status (positive or negative), PR status (positive or negative), ERBB2 status (positive or negative). This evidence concerns the gene ERBB2 and neoplasm.