DNA content, nuclear grading and early tumor progression in renal cell cancer: a prospective study on frozen specimens.

Renal cell carcinoma is a neoplasia with an unpredictable behavior. Nuclear grade and pathologic stage are widely accepted as valuable prognostic factors. More recently DNA content has been proposed as an adjunctive parameter of the clinical course of the disease. In order to substantiate these findings we prospectively analyzed 36 frozen specimens from patients submitted to radical nephrectomy for renal cell carcinoma. The study population had a 2:1 male/female ratio with a median age of 57 years. Six of 33 patients died of tumor progression with a median survival time of 11 months. The tumor DNA index (DI) ranged from 0.86 to 2.06 with a mean coefficient of variation of 4.59. Ten cases (27.8%) had a diploid DNA content, whereas 26 (72.2%) showed a distinct aneuploid population. In 10 cases different DI values were observed in different samples from the same tumor. Aneuploidy was significantly associated with advanced pathologic stages, high nuclear grade, and tumor progression.