Cytogenetic observations were made to investigate the roles played by chromosomes in malignant tumours of the human urogenital tracts. The presence of any characteristic chromosomal patterns for specific carcinomas were searched for, and a possibility of clinical application of chromosomal findings in diagnosis and treatment was also investigated.
Satisfactory preparations of chromosomes from human solid tumours were considerably difficult to obtain by the technique of the direct methods as used in the present study, although this method is preferable for exclusion of in vitro alterations which may be adherent to the tissue culture methods. In the author's study, successful chromosome preparations in which more than 7 metaphase plates could be examined were obtained in 24 tumours-3 renal carcinomas, 2 carcinomas of the renal pelvis, 13 urinary bladder carcinomas, 1 prostatic carcinoma and 5 testicular tumours-out of 58 tumours examined cytogenetically.
The results were as follows:
1) Three renal carcinomas and 2 carcinomas of the renal pelvis tended to be near diploid or hypodiploid.
2) In the analysis of 12 cases of bladder carcinomas, of which histological diagnosis showed to be transitional cell carcinoma, it was found that tumours of the low grade malignancy had the tendency towards near diploidy and those with high grade malignancy had the tendency to be near triploid and also had wider distributions in chromosome numbers. However, in two exceptional cases, where histological patterns were of lower malignancy (Grade II) in spite of triploid range, frequent recurrences were observed at the site of resection. These findings may suggest that the tendency to polyploidy and/or wide distribution of chromosome numbers in the transitional cell carcinoma of the bladder indicates needs of more careful follow-up study and of radical treatment.
3) A case of prostatic adenocarcinoma showed hypodiploid range in chromosome number.
4) In 2 cases of seminomas, one was near diploid, and the other had a wide distribution of chromosome number without any mode formation. So was in a case of embryonal carcinoma. One benign teratoma was near diploid and one malignant teratoma tended to be hyperdiploid.
5) Though no tumor-specific chromosomal aberrations were observed in the present study of human tumours of the urogenital tract, it was suggested that further cytogenetic studies of human tumours might give significant aids in clinical diagnosis, selection of treatment methods, or prognostic evaluation.