Y chromosome losses are exceedingly rare in prostate cancer and unrelated to patient age.

BACKGROUND: Loss of the Y chromosome is a frequently reported chromosomal abnormality in many tumor types. This study was undertaken to investigate the frequency of Y chromosome losses and this chromosomal abnormality might play a potential role in prostate cancer. METHODS: A preexisting prostate cancer tissue microarray (TMA) containing samples of 3,261 patients treated by radical prostatectomy with clinical follow-up data was used in this study. TMA sections were analyzed by fluorescence in situ hybridization (FISH) using a dual labeling probe for the centromeres of the X and Y chromosome. RESULTS: Unequivocal losses of the Y chromosome were seen in only 12 of 2,053 analyzable cases. No significant associations were found between Y loss and patient age, pT stage, and the risk of PSA recurrence. Interestingly, in our study the presence of Y losses was significantly associated with high Gleason grade (P = 0.0034). CONCLUSIONS: Loss of the Y chromosome is a rare event in prostate cancer. Y losses occur in much higher rates in most other cancer types. For this reason, we suggest that the expression of at least one Y chromosome gene is essential for prostate epithelial cells and it is possible that such a gene could represent a suitable target for future therapy of prostate cancer.

Y chromosome loss is a frequent early event in urothelial bladder cancer.

AIMS: Y chromosome losses have been described in 10-40% of bladder cancers and were suggested to be age-related. The clinical significance of chromosome Y losses is largely unknown, since only small sets of male bladder cancer patients have been evaluated in previous studies. The aim of this study was to further clarify the potential relevance of Y chromosome losses in bladder cancer with respect to clinical outcome and patient age. METHODS: A pre-existing bladder cancer tissue microarray (TMA) with clinical follow-up data including 516 urothelial bladder cancers from male patients was utilised in this study. Y chromosome losses were analysed by multicolour fluorescence in situ hybridisation (FISH) using a centromere Y probe and a centromere X probe. p53 immunostaining data were available for all patients from a previous study. RESULTS: Y chromosome losses were seen in 23% of 477 interpretable cancers from male patients. There was no significant difference in patient age in tumours with (67.4 +/- 4.3 years) or without (67.3 +/- 2.3 years) Y chromosome losses (p = 0.9068). Y chromosome losses were equally frequent in tumours of all grades (p = 0.7831) and stages (p = 0.6140). There was also no association with p53 immunostaining (p = 0.4092). Y chromosome losses were not associated with survival in 224 invasive urothelial cancers (pT2-4; p = 0.2324), an increased risk for recurrences in 197 pTa tumours (p = 0.7649) or increased progression risk in 76 pT1 tumours (p = 0.4582). CONCLUSION: The data of this study show that Y chromosome losses are frequent in urothelial bladder cancer of all grades and stages, which could imply that loss of the Y chromosome is an early event in bladder cancer development. p53 mediated genomic instability is evidently not required for the development of Y chromosome losses. Since there was no correlation between Y chromosome losses and clinical outcome, detection of Y losses has no clinical relevance in urothelial bladder cancer.