Clinicopathological importance of anterior prostate cancer in Japanese Men

Abstract

Prostate cancer of transition zone origin or anterior location has been recognized as infrequent, smaller in size and indolent, whereas, our previous report showed that transition zone/anterior cancer was frequently experienced in Japanese men. The current study was conducted to show clinicopathological characteristics of transition zone/anterior cancer. A total of 201 radical prostatectomy specimens were categorized as cancer of anterior or posterior prostate where more than two thirds of the tumor existed in the specific area. Clinicopathological characteristics including Gleason score, pathological stage, lymph node metastasis, extraprostatic extension, surgical incision into the prostate (shown as pT2+), and surgical margin status were compared between anterior and posterior cases. Cases were divided as 83, 73, and 45 of anterior, posterior cancer, and no dominance, respectively. Anterior cancers included significant numbers of high grade tumors (13/83 cases: 15.7%), which was less than posterior cancers (28.8%: 21/73). The cases in pT2+ were significantly more frequent in anterior cases than posterior ones (22.9% vs. 4.1%). No seminal vesicle invasion was shown in anterior cases. Thus, although anterior cancers are less aggressive than posterior cancers, a significant numbers of clinically important cancers were located in the anterior portion in Japanese men.

Transition zone prostate cancer is associated with better clinical outcomes than peripheral zone cancer

“…Several studies from Western countries have shown that the majority of PCa arose in the PZ, and cancer in the TZ was less frequent (4%‐20%) 5–8 . However, our previous study showed that the prevalence of TZ cancer was as much as 42% in a Japanese cohort, and subsequent studies from eastern Asian countries also showed a higher prevalence of TZ cancers (30%‐46%) than those from Western countries 9–13 …”

“…[5][6][7][8] However, our previous study showed that the prevalence of TZ cancer was as much as 42% in a Japanese cohort, and subsequent studies from eastern Asian countries also showed a higher prevalence of TZ cancers (30%-46%) than those from Western countries. [9][10][11][12][13] Although the genetic features of PCa remain unclear to date, the racial differences associated with the most frequent genetic alterations of the transmembrane protease, serine 2 (TMPRSS2)v-ets avian erythroblastosis virus E26 oncogene homolog (ERG) gene fusion and phosphatase and tensin homolog (PTEN) inactivation have been reported. The prevalence of the TMPRSS2-ERG gene fusion/ERG-overexpression in PCa was approximately 50% in Western countries, [14][15][16] although the prevalence is less at 10%-20% in east-Asian countries.…”

Characteristics and oncological outcome of clinical T3a prostate cancer patients undergoing radical prostatectomy in multi-parametric MRI era

“…It has been reported that transitional zone/anterior cancers diagnosed by RP specimens are commonly seen in Japanese cohorts; however, anterior cancers are less aggressive. 16 Additionally, the mpMRI has improved the chances of detecting local invasion whose prognosis are better. Previous studies reported that the maximum joint sensitivity and speci city for detecting local invasion using mpMRI reached 71%.…”

Detection of clinically significant cancer in the anterior prostate by transperineal biopsy

“…Differences in diagnostic accuracy, however, remain unclear. Emerging evidence suggests that TP biopsy identifies cancers in the anterior prostate at higher rates than was previously expected, potentially due to the different biopsy trajectory in a TP compared to transrectal approach [8][9][10].…”