Purpose: There is a significant difference in prostate cancer incidence and stage corrected mortality between
African-American (AA) and Caucasian-American (CA) men. These differences have largely been contributed to socialeconomic
factors, yet variation in prostate cancer related gene expression has been found as well. The aim of this study
was to analyze whether these differences are reflected also in the 3-D distribution patterns of the nuclear chromatin.
Materials and Methods: Prostatectomy sections from 21 prostate cancer patients (10 AA and 11 CA) were cut and nuclear
DNA was stained with TO-PRO-3. 3-D image stacks of selected malignant areas were obtained by confocal laser scanning
microscopy. Image analysis was performed using in-house developed software for 3-D semi-automated segmentation
and computation of DNA content and our previously developed 3-D nuclear texture features. The power of these features
to discriminate between AA and CA patients was established by univariate ROC and linear discriminant analyses, stratifying
Results: Five 3-D texture features discriminated between AA and CA men irrespective of prognosis, 27 features had discriminative
value for AA and CA men in the subgroup of bad prognosis patients, and 8 features in the good prognosis
subgroup. Several features had additional discriminative value in multivariate discriminant analysis.
Conclusions: There are differences in the 3-D nuclear chromatin distribution between AA and CA men with similar prognosis.
This is further evidence that the differences of prostate cancer in AA and CA men are not only related to socioeconomic
differences, but also to genomic differences.