前立腺偶発癌に関する研究 第2報: 核DNA量解析

Abstract

1) non-diploid症例はstage A1の8/24例, A2の18/23例, 進行癌の8/9例にみられ, 平均核DNA量とともに病期が進むほど増加した.2) non-diploid症例は高分化腺癌の13/31例, 中分化腺癌の10/13例, 低分化腺癌の3/3例にみられ, 平均核DNA量とともに分化度が低いほど増加した.3)癌占有体積との比較で, diploidに比べnon-diploidの癌占有体積は大きかった.4)高分化腺癌の病期別の検討では, A2, 進行癌ではA1に比べ核DNA量の異常な症例を多く認めた.予後良好とされるstage A1でも4/24例にaneuploidを認め, A2の高分化腺癌でも2/7例がdiploidであった.以上から核DNA量解析は, 病期分類, 組織学的分類, 癌占有体積とまったく同質ではなく, 前立腺偶発癌の潜在的悪性度も含めた予後規制因子としての有用性が示唆された

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.