[Study of incidental carcinoma of the prostate. II. Nuclear DNA analysis]

The clinical significance of cytofluorometric nuclear DNA analysis, ploidy pattern and DNA content, was investigated in 47 incidental prostatic carcinomas, 24 stage A1 and 23 stage A2 cases, 9 clinically advanced cases and 25 BPHs. The results were compared to clinical stage and histological differentiation. The mean nuclear DNA content of stage A1 cancer, which was similar to BPH, differed from that of stage A2 cases. The latter was almost identical to that of advanced cases. In moderately and poorly differentiated carcinomas it was higher than that of well differentiated ones. A non-diploid pattern was distributed in 33% of stage A1, 78% of stage A2 and 89% of clinically advanced cases. It was detected in 42% of the well-, 77% of the moderately- and 100% of the poorly differentiated adenocarcinomas. The DNA analysis of incidental prostatic cancer thus correlated well to the clinical and pathological parameters. If limited to well differentiated carcinomas, however, 17% of the stage A1 cases showed an aneuploid, and 29% of the stage A2 cases, a diploid pattern. No diploid pattern was detected in clinically advanced cases. Although we have not been able to prove any difference in prognosis in the present cases, these findings suggest that the nuclear DNA analysis is another parameter in defining the prognosis of incidental prostatic carcinoma. Further follow-up of the patients and accumulation of the data are necessary to determine the clinical validity of this method.