Premalignancy in the human breast: how is it defined, is morphology good enough?
- BA Gusterson1
© BioMed Central 2003
Published: 1 October 2003
With increasing sensitivity of methods of detection, microscopic lesions are being identified which produce a diagnostic dilemma for the pathologist. This is because their natural history is largely unknown. Some postmortem studies would suggest that what a pathologist would call a potential precursor lesion for invasive breast cancer may be present with an incidence as high as 40% in some age groups. Although we are now beginning to understand the spectrum of protein, RNA expression, gene mutations and epigenetic changes in breast cancer, this is a long way from being able to predict from a single lesion what its potential is to invade or metastasise. It is, however, reassuring that the recent advances in stem cell biology in the breast may assist in the identification of the potential target cells for carcinogenesis. These studies have relied on the use of classical markers for fully differentiated luminal and myoepithelial/basal cells. The current vogue to classify tumours on the basis of microarray data as 'basal-like' or lumenal may be leading us into assumptions about histogenesis that are not proven. Whether these studies will assist in identifing preneoplasia will be discussed in relation to our current knowledge on the evidence for myoepithelial and lumenal cell differentiation in human breast cancer.