Cancer of the Prostate

Prostate cancer is a malignant growth that originates in the prostate gland.

The prostate is a small walnut-shaped gland that sits under the bladder, in front of the rectum. It secretes an alkaline milky liquid, called prostatic fluid, which contains nutrients to nourish the sperm, support its movement, and help it survive in the acidic environment of the vagina.

Now, the urethra travels through the prostate before reaching the penis. During ejaculation, smooth muscles in the prostate contract and push prostatic fluid into the urethra where it joins the sperm, along with the semen.

The prostate can be divided into distinct zones based on their histological differences, including the peripheral, central, transitional, and fibromuscular zones. The peripheral zone is the outermost posterior section and is the largest of the zones, containing most of the prostate’s glandular tissue. It’s also the most common site for development of prostate cancers and is the part of the prostate that’s palpated during a prostate exam, called a digital rectal examination or DRE.

Moving inward, there’s the central zone, followed by the transitional zone, the site that undergoes hyperplasia in a condition called benign prostatic hyperplasia, which is considered a normal part of aging. Part of the transitional zone that surrounds the urethra is sometimes called the periurethral gland region. Lastly, a fibromuscular zone covers the anterior portion of the prostate.

Okay, so, the development and normal function of prostate cells depend on androgens, or sex hormones, like testosterone. Although most of the body’s testosterone is produced by the testes, a portion of testosterone is made in the prostate. In the prostate, testosterone is converted by the enzyme 5α-reductase into highly potent dihydrotestosterone, or DHT, which happens when dehydroepiandrosterone, or DHEA, produced by the adrenal glands enters the prostate and is converted into testosterone.

Now, although the cause of prostate cancer is unknown, it's linked to a genetic mutation in a prostate cell, such as the BRCA1 and BRCA2 genes. Epigenetic factors also play a role by altering the expression of tumor suppressor genes that regulate cell division, and supporting the formation of oncogenes, which are mutated genes that have the potential to cause cancer.