PTEN loss in intraductal carcinoma of the prostate has low incidence in Japanese patients

Abstract

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.

Implications of unconventional histological subtypes on magnetic resonance imaging and oncological outcomes in patients who have undergone radical prostatectomy

“…A correlation between IDC-P and DNA damage repair gene alterations has been reported, and the National Comprehensive Cancer Network (NCCN) guidelines recommend genetic testing for patients with a family history of PCa if IDC-P is detected in prostate biopsy 28 . Meanwhile, Ito et al demonstrated a lower frequency of PTEN loss in Asian patients than in Western populations 29 . Thus, although evidence is accumulating regarding genomic alterations of PCa with UH, large-scale genomic analyses across ethnic groups is warranted to unravel the underlying molecular mechanisms.…”