The value of molecular genetic analysis in the diagnosis and prognosis of renal cell tumours.

Renal cell tumours have a heterogeneous morphology, which may also be changed during tumour progression. Through the use of molecular cytogenetic techniques, it has become possible to divide renal cell tumours into genetically well-defined entities. Papillary renal cell tumours are characterized by loss of the Y chromosome and trisomy of chromosomes 3q, 7, 8, 12, 16, 17 and 20. Non-papillary renal cell carcinomas show a specific loss of chromosome 3p and trisomy of chromosome 5q sequences and frequent loss of chromosome 6q, 8p, 9 and 14q sequences. Chromophobe renal cell carcinomas are marked by a highly specific combination of loss of chromosomes 1, 2, 6, 10, 13, 17 and 21 and gross rearrangement of mitochondrial DNA. Subsets of renal oncocytomas show minimal karyotype alterations or translocation 11q13;? or loss of the Y chromosome and chromosome 1. There are some data suggesting that molecular genetic markers may be used not only for diagnosing of renal cell tumours but also for predicting the prognosis of tumour subtypes. Trisomy of chromosomes 7 and 17 and loss of the Y chromosome marks papillary renal cell adenomas, whereas additional trisomies such as those of chromosomes 3q, 8, 12, 16 and 20 are associated with papillary renal cell carcinomas. Although non-papillary renal cell tumours develop as a carcinoma, their clinical behaviour is in strong correlation with secondary karyotype changes such as loss of chromosomes 6q, 8p, 9 and 14q.