Numerical aberrations of chromosomes 9 and 11 detected by FISH in Greek bladder cancer patients.

BACKGROUND Bladder cancer is a genetically heterogeneous disease. The chromosomal aberrations observed are non-random and they are often correlated with disease progression. Several environmental risk factors have also been reported to be implicated in the pathogenesis of this disease. The aim of this study was to evaluate, by FISH technique, the numerical aberrations of chromosomes 9 and 11 in Greek bladder cancer patients and to correlate them with grade and histological stage of the tumors. MATERIALS AND METHODS FISH with a-satellite DNA probes specific for chromosomes 9 and 11 were applied to 35 primary bladder tumors directly processed for cytogenetic study. RESULTS Numerical aberrations of chromosome 9 were observed in 23 out of 27 tumors (85.18%). Monosomy 9 was detected in 12 cases (44.45%) and polysomy in 11 cases (40.74%). Statistical analysis showed that polysomy 9 was linked to histological stage (p = 0.024) and grade (p = 0.01) of the tumors, while monosomy 9 was correlated with tumor stage (p = 0.050). Numerical aberrations of chromosome 11 were observed in 25 out of 35 cases (71.43%). Polysomy was detected in 24 cases (68.57%), while only one case (2.86%) had monosomy 11. Polysomy 11 was found mainly in high-grade and advanced-stage tumors. CONCLUSION Numerical aberrations of chromosome 9 could be a potential biomarker for bladder cancer screening. Further studies must be carried out to investigate gene alterations reflected by numerical aberrations of chromosomes 9 and 11 also contributing to the classification of this disease.