前立腺偶発癌に関する研究 第1報: 頻度と臨床病理学的検討

Abstract

1)偶発癌発見頻度は膀胱全摘症例では12例中3例.被膜下摘除症例では173例中34例, TUR-P症例では405例中32例の順であった.またstage A1は51.5%, A2は48.5%であった.2)偶発癌では高分化腺癌が67.6%, Gleason score 2～4群が69.1%と, 分化度の高い癌が臨床癌よりも高率であった.3)被膜下摘除症例では全例外科的被膜下の3 mm以内に少なくとも癌の一部が存在していた.4)高分化腺癌は82.6%が単発例で, 中・低分化癌は91%が多発例であった.高分化腺癌では癌占有体積0.3 cm3未満の症例が78.3%であったが, 中・低分化腺癌では45.4%と少なくなった.5)偶発癌の癌占有体積は, 加齢にともなう増加傾向はみられず, 低年齢の癌体積の大きな症例はすでに臨床癌に移行していることが示唆された.また加齢にともない増加するのは高分化腺癌であった

To clarify the clinico-pathological characteristics of incidental carcinoma of the prostate, we investigated a total of 590 prostatic tissues which had been operated under the diagnosis of benign prostatic hyperplasia (BPH), including 12 whole prostatic specimens which were obtained by total cystectomy due to bladder cancer. Histological examination and estimation of the tumor volume were carried out by either a 3-mm step-section in 185 prostates obtained by open surgery, or by mounting whole specimens in 405 TUR cases. Incidental cancers were detected in 69 of the 590 patients (12%) with nearly equal numbers of stage A1 and stage A2 diseases. The age and the size of the prostate were significantly greater in the patients with cancer, compared to those without cancer. However, these parameters were not in agreement with each other. Histological analysis revealed that 46 of the 69 (67%) incidental cancers were well differentiated and nearly corresponded to Gleason's sum score of 2-4. In the analysis of the differentiation of the tumor cells and the tumor extension, nearly 80% of the 23 well differentiated cancers were manifest in a single lesion and were smaller than 0.3 cm3, whereas 90% of the 11 moderately or poorly differentiated cancers were diffusely invasive. Six of the 11 cases (55%) were larger than 0.3 cm3. The prognosis of the 16 incidental cancer patients who had survived more than 5 years after the surgery were compared with the controls. The controls were selected among the cases without incidental cancer, and matched for age and the time of operation in a 1 to 2 fashion without knowledge of their prognoses.(ABSTRACT TRUNCATED AT 250 WORDS)