Cytogenetic and molecular studies of male germ-cell tumors

Abstract

Summary Although the biological significance of GCTs to the study of malignancy and differentiation has been well recognized for some time, detailed genetic analysis based on fresh tumor biopsies has not been initiated until recently. The first stage of such studies, as with other, more extensively investigated tumor systems, has been cytogenetic analysis. To date, cytogenetic data on 225 tumors are available which, although small in number, have already yielded valueble insights into the biology of these tumors and a clinically useful marker. Thus, initial correlations between chromosome change and histology have been recorded, gene amplification associated with malignant progression has been identified, cytogenetic basis of malignant differentiation in teratomatous lesions has been clarified, and sites of candidate tumor suppressor genes unique to this system have been identified. The usefulness of i(12p) as a diagnostic marker, especially in tumors of uncertain histologies has been established. Because of the clinical usefulness of this marker, molecularly based methods for its detection, without the need for formal cytogenetic analysis, have been developed. Cytogenetic analysis of larger prospectively ascertained series than have been performed so far and analysis of large numbers of tumors utilizing molecular techniques can be expected to yield significant insights into the biology and clinical behavior of these tumors.