Potential rapid assessment of breast cancer prognosis using induced chromosome condensation performed on cytological specimens.

We have previously shown that assessment of chromosome alteration rate by cytogenetics is well correlated with breast cancer prognosis factors. As karyotypes are usually difficult to obtain from solid tumors using conventional methods, a new approach is proposed. Metaphase-like chromosomes were directly obtained following chromosome condensation using calyculin A (okadaic acid) from cytologic specimens of breast cancers sampled by fine needle. Chromosome counts and rearrangement rates were established in a series of 45 tumors, as early as 24-48 h after sampling. A high rate of rearranged chromosomes was found to correlate with high histological grade, TNM stage and S-phase fraction, loss of estrogen receptor expression and DNA aneuploidy. The indication of genome alteration provided by this method constitutes a simple, potent and early potential prognostic factor in breast cancer directly applied on cytological specimens.