Abstract
Background
The present study was undertaken for quantitation of androgen (AR) and vitamin D (VDR) receptor expression in human male and female breast tumors by flow cytometry.
Methods
Nuclei isolated from sections of paraffin‐embedded tumors by pepsin digestion were treated for antigen unmasking and incubated with antibodies to AR and VDR. Flow cytometric analysis was used to determine the percentage of receptor‐positive nuclei with fluorescence greater than 95% of the isotype nuclei. Mean log fluorescence channel values were used for comparing antigen density of the isotype and the antibody‐treated nuclei.
Results
Six of 23 female breast tumors had aneuploid DNA content. Nineteen of 20 estrogen receptor–positive female tumors by immunohistochemical analysis (IHC) were also AR positive by flow analysis. Aneuploid subpopulations had higher percentages of AR‐positive nuclei than did diploid populations. Eight of 33 male breast tumors had aneuploid DNA content. Twenty‐three of 33 male breast tumors were AR positive by flow analysis compared with six that were AR positive by IHC. Six AR‐positive (IHC) male tumors were also AR positive by flow analysis. VDR expression was higher in diploid female tumors than in aneuploid tumors.
Conclusions
Lack of a strong correlation between IHC and flow analysis may be due to differences in criteria used for identification of receptor‐positive and ‐negative tumors by the two methods. © 2003 Wiley‐Liss, Inc.
