Comparing core needle to surgical biopsies in breast cancer for cell kinetic and ploidy studies

The evaluability and reliability of proliferative activity (expressed as³H-thymidine labeling index,³H-TdR LI) and ploidy determinations on core needle biopsies were compared with those obtained on surgical material from the same breast cancers. The evaluability of³H-TdR LI on core needle biopsies was markedly lower than that on surgical material (53% vs 100%), and the association between³H-TdR LI values in the 16 cases with both evaluable determinations was poor (r_s=0.45). Conversely, determinations of ploidy on core needle biopsy and surgical material provided superimposable results, in terms of evaluability (91% vs 100%) and reliability (r_s=0.99). Further efforts are needed to improve sampling procedures for a reliable assessment of biological markers.