Virtual tissue microarrays: a novel and viable approach to optimizing tissue microarrays for biomarker research applied to ductal carcinoma in situ.

Aims: Tissue microarrays (TMAs) are effective tools for performing high-throughput standardization analyses of biomarkers, but evidence indicating the core number required to be representative of the whole tumour is lacking. Ductal carcinoma in situ (DCIS) is a non-obligate precursor of invasive breast cancer. The number and size of cores that can best represent a DCIS lesion are unknown.