It typically begins in the posterior peripheral zone of the prostate and can be detected using a digital rectal examination.

它一般起源于前列腺外周区，可以通过直肠指诊检查。

That's because the majority of prostate cancers arise in the posterior peripheral zone, which is far away from the urethra.

因为大多数的前列腺癌起源于外周带，离尿道较远。

The peripheral zone, which is the outermost posterior section, is the largest of the zone and contain about 70% of the prostate's glandular tissue.

外周区，即前列腺后壁最外层的区域，是其中最大的一个区，70%的前列腺腺体位于此处。

But if the tumor arises elsewhere, like in the anterior peripheral zone, then the tumor would be out of reach during the digital rectal exam.

但如果肿瘤位于其他部位，例如前部的外周区，直肠指检可能会检查不到。