IMAGE CYTOMETRY OF BREAST CARCINOMAS THAT ARE DNA DIPLOID BY FLOW-CYTOMETRY - TIME TO REVISE THE CONCEPT OF DNA DIPLOIDY

OBJECTIVE: To investigate whether breast carcinomas found to be DNA di ploid by flow cytometry (FCM) are still diploid if reassessed by image cytometry (ICM). STUDY DESIGN: In a series of 286 breast cancers anal yzed by FCM there were 100 (35%) cancers that were classified as DNA d iploid. Fourteen of the 100 diploid cases were selected for further an alysis with ICM because the patient had died of breast cancer within 1 1-84 months after the diagnosis (a group with unfavorable outcomes), a nd 19 cases were selected at random from the cases who had no recurren ce of cancer cancer during follow-up of six or more years (a favorable group). RESULTS: Eleven (33%) of the 33 cases turned out to be DNA no ndiploid, with a DNA index greater than or equal to 1.2 when analyzed by ICM. Nine of the 11 DNA aneuploid samples by ICM were found among t he 14 patients with unfavorable prognoses and only 2 among the 19 pati ents with favorable outcomes (P=.002). The five-year survival rate of the women with DNA diploid cancer by both methods was 86%, whereas tha t of patients with DNA aneuploid cancer by ICM was 36% (P=.002). CONCL USION: The results show that some breast carcinomas classified as DNA diploid based on FCM are not DNA diploid by ICM and that such carcinom as are associated with poorer outcomes than the ones that are DNA dipl oid also by ICM. The prognostic significance of DNA ploidy in breast c ancer may need to be reexamined in studies where both FCM and ICM are used.