8p22 loss concurrent with 8c gain is associated with poor outcome in prostate cancer

A critical issue in the management of prostate cancer is the ability to distinguish patients at risk of disease recurrence. The aim of this study was to determine whether specific physical alterations of chromosome 8 may be associated with disease recurrence and poor outcome using postoperative prostate-specific antigen (PSA) values as surrogate end points.

To test this hypothesis, we examined paired normal and tumor radical prostatectomy tissues from 25 patients with prostate cancer for chromosome 8 alterations using dual fluorescence in situ hybridization with a fluorescein-labeled 8p22-specific (8p) cosmid probe and a rhodamine-labeled 8-centromere-specific (8c) probe. The probes were enumerated in 200 nuclei per tissue.

Of the 25 tumors examined, 22 demonstrated distinct classes of genetic alterations, or nuclear types, including disomy for 8p and 8c (1 tumor), loss of 8p and disomy for 8c (10 tumors), or loss of 8p concurrent with gain of 8c (11 tumors). The presence of even a small population of tumor nuclei characterized by the loss of 8p concurrent with the gain of 8c was correlated with poor tumor grade (P = 0.009), preoperative PSA values 11 ng/mL or higher (P = 0.022), high tumor stage (P = 0.086), and detectable, rising postoperative PSA values (P = 0.086). These observations are consistent with the hypothesis that a gain of chromosome 8 is associated with poor outcome in prostate cancer.

8p loss concurrent with 8c gain may successfully predict disease recurrence and poor clinical outcome before the observation of detectable postoperative PSA values in patients with prostate cancer.