NCCN Guidelines for Patients
: Prostate Cancer
Part 1: About prostate cancer
1.1 What is the prostate?
The prostate is a gland that makes a white-colored fluid.
Sperm mixes with this fluid and other fluids to form semen.
Semen is ejected from the body through the penis during
ejaculation. The fluid from the prostate protects sperm
from the acid inside a woman’s vagina.
As shown in Figure 1, the prostate is located below the
bladder near the base of the penis. Urine from the bladder
travels through the urethra, which passes through the
prostate and into the penis. Above the prostate and behind
the bladder are two seminal vesicles. Seminal vesicles are
also glands that make a fluid that is part of semen.
Inside the prostate, 30 to 50 small sacs make and hold
the white-colored fluid. The fluid travels in ducts to the
urethra during ejaculation. Around the sacs and ducts is
The prostate begins to form while a baby is inside his
mother’s womb. After birth, the prostate keeps growing
and reaches nearly full size during puberty. At this point,
it is about the size of a walnut. Testosterone causes
the prostate to grow slowly in most men. However, the
prostate may grow to a large size in some men and cause
problems passing urine.
1.2 How prostate cancer starts
Cancer is a disease of cells—the building blocks of tissue
in the body. Inside of cells are coded instructions, called
genes, for building new cells and controlling how cells
behave. Prostate cancer occurs when normal cells begin
to grow faster or die slower, either of which causes a
tumor to form. Some prostate cancers occur due to
changes in genes, called mutations.
Aging, being of African-American descent, and having
family members with prostate cancer have been linked to
a higher chance of getting prostate cancer. Not all men
with these conditions get prostate cancer and some men
without these conditions do. Prostate cancer is common
among older men. However, prostate cancer in older men
often doesn’t become a problem.
Figure 1. The prostate
Illustration Copyright © 2014 Nucleus Medical Media, All rights reserved.