Clinical and genomic features of prostate cancer (PCa) vary considerably between Asian and Western populations. PTEN loss is the most frequent abnormality in intraductal carcinoma of the prostate (IDC-P) in Western populations. However, its prevalence and significance in Asian populations have not yet been well studied. In the present study, we evaluated PTEN expression in IDC-P in a Japanese population and its association with ERG expression. This study included 45 and 59 patients with PCa with and without IDC-P, respectively, who underwent radical prostatectomy. PTEN loss was observed in 10 patients with PCa with IDC-P (22%) and nine patients with PCa without IDC-P (17%). ERG expression was relatively frequent in patients with PCa with PTEN loss, although a significant difference was not observed. The co-occurrence of PTEN loss and ERG expression was observed in four patients with PCa with IDC-P and one without IDC-P. PTEN loss and ERG expression did not affect progression-free survival, regardless of the presence of IDC-P. The frequency of PTEN loss in IDC-P is lower in Asian patients than in Western patients. Our results indicate that mechanisms underlying IDC-P in Asian populations are different from those of Western populations.

中文翻译：

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日本患者前列腺导管内癌中 PTEN 缺失的发生率较低

亚洲和西方人群的前列腺癌 (PCa) 的临床和基因组特征差异很大。PTEN 缺失是西方人群中前列腺导管内癌 (IDC-P) 最常见的异常。然而，其在亚洲人群中的患病率和重要性尚未得到充分研究。在本研究中，我们评估了日本人群 IDC-P 中 PTEN 的表达及其与 ERG 表达的关联。这项研究分别包括 45 名和 59 名接受根治性前列腺切除术的 PCa 患者（伴 IDC-P 和不伴 IDC-P）。在 10 名患有 IDC-P 的 PCa 患者 (22%) 和 9 名不患有 IDC-P 的 PCa 患者 (17%) 中观察到 PTEN 丢失。ERG 表达在 PTEN 缺失的 PCa 患者中相对频繁，但未观察到显着差异。在四名患有 IDC-P 的 PCa 患者和一名不患有 IDC-P 的 PCa 患者中观察到 PTEN 缺失和 ERG 表达同时发生。无论是否存在 IDC-P，PTEN 缺失和 ERG 表达都不影响无进展生存期。亚洲患者 IDC-P 中 PTEN 丢失的频率低于西方患者。我们的结果表明亚洲人群 IDC-P 的潜在机制与西方人群不同。