Oestrogen and progesterone receptor expression influences DNA ploidy and the proliferation potential of breast cancer cells.

The influence of oestrogen (ER) and progesterone (PgR) receptor has not been investigated in relation to DNA ploidy and cell proliferation. Here we have investigated a series of 46 breast cancer fine-needle aspirates in order to define the prognostic value of ER/PgR and possible correlations between DNA ploidy, size of the S-phase fraction (SPF) and cell cycle distribution features measured by image cytometry (ICM) and ER/PgR status of the primary tumours. The breast cancers were grouped into ER+/PgR+, ER+/PgR- and ER-/PgR-. Inter-group comparisons were made of DNA ploidy, SPF and the pattern of cell cycle distribution defined by the G0G1/G2M ratio in order to determine the influence of ER and PgR expression on the respective cell features. Our studies suggest that ER and PgR exert differential effects on the cell features examined. This study also analysed the possibility of predicting nodal involvement and 5-year disease-free survival by combining ER/PgR status with DNA ploidy, SPF and G0G1/G2M ratios. A high degree of accuracy was achieved for predicting both nodal involvement and 5-year disease-free survival. These findings suggest that a combination of ER/PgR status with DNA ploidy, SPF and cell cycle distribution provide a powerful marker for disease prognosis.