Multiple tissue core arrays in histopathology research: a validation study.

The use of multiple tissue arrays allows the examination of large cohorts of tumour tissue with economies of material and technical resources. It also permits the direct comparison of tissues on the same slide. In the present study, a series of 157 breast cancers was labelled with antibodies which recognize oestrogen (ER) and progesterone (PR) receptors and the staining obtained on whole tissue sections was compared with that from a series of multicore arrays. A highly significant association was found between the staining scores (0-7) obtained from the individual tissue sections and from the multicore arrays, although there was some discordance between the receptor status (positive/negative) of the whole section and the tissue core in 5% of cases for ER and in 6.5% of cases for PR. Multiple tissue cores represent an attractive way of dealing with large cohorts of tumours for research studies, because of the significant reduction in reagents and technical time required and the overall speed with which a study can be completed. A proportion of individual tissue cores were not representative of the diagnostic section, which limits the value of multicore arrays as a tool for patient management. However, the technique provides an efficient way of assessing the potential predictive value of novel proteins in different tumour types and in large cohorts.