Allelic loss of 3p25 associated with alterations of 5q22.3∼q23.2 may affect the prognosis of conventional renal cell carcinoma

Little is known about the clinical significance at the frequent association of 3p loss with 5q gain/loss in conventional renal cell carcinoma (RCC). We analyzed the clinical significance of copy number gain and loss at 5q21∼q23 combined with allelic loss of 3p25 (including the VHL gene). Fifty RCCs were examined by dual-color fluorescence in situ hybridization with DNA probes for D3Z1 (3cen), cCI3-865 (3p25.1∼p25.3), D5S23 (5p15.2), cCI5-243 (5q21.2∼q21.3), and cCI5-215 (5q22.3∼q23.2). In patients who had 3p loss, there was a significant association of loss at 5q22.3∼q23.2 with large tumors (>7 cm) and high-grade tumors (both P < 0.05), whereas gain at 5q22.3∼q23.2 was associated with low-grade tumors (P < 0.05). There was also a significant association loss at 5q21.2∼q21.3 high-grade tumors in patients with 3p loss (P < 0.05). Patients with 3p loss and gain at 5q22.3∼q23.2 had a significantly better disease-specific survival than those who had 3p loss without such gain (P < 0.05). Allelic loss of 3p25 including the VHL gene is thought to be an immediate event in the development of conventional RCC. Copy number gains or losses of 5q21∼q23 are thought to be events that lead to tumor progression although the clinical significance of either gains or losses is not well known.