Ploidy
Analysis
June, 2000
An analysis
of the tumor cells DNA content, or ploidy, is a valuable prognostic
tool. Normal DNA is comprosed of a pair of chromosome, and is thus
termed "diploid." Diploid status is more commonly associated
with tumors of a low to moderate Gleason score, whereas abnormal ploidy
(aneuploid) status is more commonly associated with tumors of a higher
Gleason score. However, this is not a hard and fast rule.
The landmark
paper from the Mayo Clinic in Rochester, Minnesota substantiates the
value of the ploidy analysis, although other prostate cancer centers
dispute its significance. The importance of ploidy as an independent
prognostic factor is clearly demonstrated by Lerner, et al.13 In
this paper, Lerner, et al examined the 5-year relapse rates in patients
undergoing RP and having "apparent" OCD. When the data were
analyzed below with respect to PSA, GS and ploidy status, a significantly
higher rate of disease relapse was seen in patients with non-diploid
tumors.