Early diagnostic indices for the prevention of Alzheimer''s disease

A flow-cytometric (FCM) and fluorescence in situ hybridization (FISH) study was performed in 153 patients with clinically localised prostate cancer (PC) to evaluate retrospectively the prognostic significance of DNA ploidy, S-phase fraction (SPF) and chromosome 7 copy number. Deletions in 7q31.1 were analysed in a subset of 26 tumours. The mean follow-up time was 6 years (range 4-16 years). Twelve cases of benign prostatic hyperplasia (BPH) were studied as a control. Chromosome 7 enumeration and deletion studies were conducted using the alpha-satellite D7Z1 probe and a cosmid probe specific for the marker D7S522 on 7q31.1. Higher SPF was associated with shorter overall survival and shorter time to local progression and metastasis. Near diploid (DNA index 1.05-1.20) cases had a lower frequency of metastases and lower Gleason scores than aneuploid cases. Increased absolute chromosome 7 copy number (centromere count) was associated with higher Gleason score, higher SPF and shorter local progression-free and prostate cancer survival. Absolute chromosome 7 copy number was concordant with FCM DNA ploidy in the majority (75%) of cases. Relative gain or loss of chromosome 7 (centromere counts compared to ploidy) was infrequent, and no correlation was found with clinical parameters. Deletions in 7q31.1 were infrequent. Our results indicate that in localised PC (i) SPF is a prognostic factor, (ii) absolute chromosome 7 copy number is concordant with the ploidy status of the tumour (relative gain or loss of chromosome 7 is infrequent and has no independent prognostic value) and (iii) the frequency of deletions in 7q31.1 is low and not correlated with clinical outcome.