In vivo aneuploidization during the expansion of renal adenocarcinoma.

BACKGROUND/AIMS: A correlation has been observed between DNA ploidy and other prognostic parameters such as tumor stage and grade. The present study evaluates tumor aneuploidization during renal adenocarcinoma expansion and growth. METHODS: A total of 252 renal tumors were analyzed between 1969 and 2001. Evaluated variables were age, TNM, Fuhrman classification, histology, size and DNA. A tumor was homogeneous when all the samples were diploid or aneuploid, and a heterogeneous tumor was the coexistence of aneuploid and diploid samples, or all-aneuploid with different aneuploid clones. RESULTS: A total of 224 tumors were included (coefficient of variation <8). The DNA study classified 129 (57.6%) as diploid and 95 (42.4%) as aneuploid. The percentage of aneuploid tumors increased significantly with the pathological stage. Both aneuploid patterns were also significantly more frequent in advanced pathological stages. Tumors with multiple aneuploid clones (n = 17) were significantly more frequent in tumors measuring `4 cm. Both aneuploid patterns showed no differences in survival (p = 0.83), indicating that the heterogeneous pattern probably represents an intermediate step between diploid and homogeneous aneuploid tumor status. CONCLUSIONS: The aneuploid pattern is more common in more advanced stages of the disease, with no clear correlation to primary tumor size. This suggests gradual aneuploidization with tumor expansion and growth.