ABSTRACT
Breast cancer is a major source of mortality and morbidity in women. A number of strategies have evolved for managing both women who present with signs of breast cancer (‘symptomatic’ patients) and those women who are screened for breast cancer as part of a programme for early detection of the disease (‘screening’ patients). A diagnosis of breast carcinoma is commonly achieved by X-ray mammography, often in conjunction with breast ultrasound, with pre-treatment diagnosis confirmed with image-guided fine needle aspiration cytology and/or core biopsy. For the majority of women the diagnosis is seldom in doubt and the extent of disease in the breast is relatively easy to quantify. However mammography has some well-documented disadvantages, in particular relating to the difficulties in detecting small lesions or differentiating them from benign tissue, resulting in a proportion of cancers presenting in the intervals between screening rounds. Tumour size, histology and the density of adjacent breast parenchyma are all implicated in the fact that at least 20% of cancers in screened populations manifest in the interval between screening rounds (Homer 1985; Bird et al 1992; Jackson et al 1993; Harvey et al 1993). These same factors contribute to understaging of primary cancer, as multifocal and multicentric disease may be missed.
