PLOIDY LEVEL DETERMINATION AND QUANTITATIVE CHROMATIN PATTERN DESCRIPTION IN PREGNANCY-ASSOCIATED BREAST CANCERS

The present study deals with the characterization of hormone-sensitivi ty in pregnancy-associated breast cancers (PBCs). This characterizatio n was carried out in 22 PBCs as opposed to 88 non-pregnancy-associated breast cancers (NPBCs).For this study, we used the digital cell image analysis of Feulgen-stained nuclei to assess the type of hormone-sens itivity. In a previous study it was demonstrated that the chromatin pa ttern in breast cancers is related to the amounts of estrogen receptor s they contain. Our results demonstrated that the quantitative descrip tion of the chromatin pattern by means of 15 parameters (relating to m orphometric, densitometric, and textural features) made it possible to identify typical cell nuclei populations in the PBC and NPBC groups. The use of specific statistical analyses (principal-components and dis criminant) made it possible to quantify the proportion of each cell nu cleus type in the PBCs. Furthermore, of the 22 PBCs under study, 13 co ntained a large majority of cell nuclei whose chromatin pattern was ch aracteristic of hormone-sensitive cells, while 5 cases contained a lar ge majority of typically hormone-insensitive ones. The remaining 4 cas es contained a relatively similar proportion of typically hormone-sens itive and insensitive cell nuclei. The quantitative chromatin pattern description thus made it possible to characterize the hormone-sensitiv ity level in PBCs, whereas DNA ploidy level determination did not enab le any such characterization to be carried out. The chromatin pattern assay described here, which enables hormone-sensitive pregnancy-associ ated breast cancers to be identified from hormone-insensitive ones ind ependently from biochemical assays, should help the physician regardin g therapy adaptation.