Which zone is the most common site for prostate cancer?

Which zone is the most common site for prostate cancer?

• A. Peripheral zone
• B. Central zone
• C. Transitional zone
• D. Anterior fibromuscular stroma

Answer: (A)

The most common site for prostate cancer is the peripheral zone, which is located more posteriorly and laterally around most of the gland and contains the majority of prostatic glandular tissue. Because there is more glandular tissue in this zone, malignant changes occur there more frequently, making cancers arise and grow in this region more often. This location also explains why cancers in the peripheral zone are often detectable by a digital rectal exam, since they lie closest to the rectum. In contrast, the central zone surrounds the ejaculatory ducts and accounts for a smaller portion of prostate cancer, and the transitional zone—near the urethra—is more associated with benign prostatic hyperplasia than with cancer. The anterior fibromuscular stroma largely lacks glandular tissue, so cancers are rare there.

The most common site for prostate cancer is the peripheral zone, which is located more posteriorly and laterally around most of the gland and contains the majority of prostatic glandular tissue. Because there is more glandular tissue in this zone, malignant changes occur there more frequently, making cancers arise and grow in this region more often. This location also explains why cancers in the peripheral zone are often detectable by a digital rectal exam, since they lie closest to the rectum.

In contrast, the central zone surrounds the ejaculatory ducts and accounts for a smaller portion of prostate cancer, and the transitional zone—near the urethra—is more associated with benign prostatic hyperplasia than with cancer. The anterior fibromuscular stroma largely lacks glandular tissue, so cancers are rare there.