whom prostate cancer is likely to be slow growing
and remain localized, the doctor may recommend
less invasive approaches such as diligent monitor-
ing (watchful waiting) or radiation therapy (exter-
nal beam or internal seeding).
No matter his age at the time of diagnosis, a
man must consider the many factors that con-
tribute to the relative benefits and risks of treat-
ment options for his stage and grade of cancer,
prognosis, other health conditions, and personal
desires. Treatments such as surgery and hormone
therapy may affect sexual function and have other
undesirable side effects. It is important to fully
understand the potential implications of treatment
options and their effects on QUALITY OF LIFE.
Though prostate cancer is the second-leading
cause of cancer deaths among men in the United
States (LUNG CANCERbeing first), treatment pro-
vides long-term management and prostate
cancer is not fatal in the majority of men who
develop it.
Risk Factors and Preventive Measures
The most significant risk for prostate cancer is age.
Prostate cancer is uncommon in men under age
50 though is present in about half of men over age
- Other factors that increase the risk for prostate
cancer are African American heritage and long-
term EATING HABITSthat feature foods high in satu-
rated fat. There is some evidence that dietary
consumption of SOYproteins, such as in soybean-
based foods and in nutritional supplement prod-
ucts, and LYCOPENE, found in tomatoes and pink
grapefruit, improve the ability of prostate glandu-
lar cells to resist cancerous changes. The medicinal
botanical product SAW PALMETTO, available in the
United States as a nutritional supplement, may
help maintain overall PROSTATE HEALTH.
Health experts differ in their opinions about the
value of routine screening procedures, such as
DRE and PSA blood levels, for detecting prostate
cancer and especially for improving the outcome
of treatment. PSA in particular tends to generate a
high percentage of false-positive findings, thrust-
ing men into more invasive diagnostic procedures
that have increased risks as well as heightened
emotional stress. However, both DRE and PSA are
components of a routine medical examination in
the United States for men over age 50. It is impor-
tant for a man and his doctor to carefully and
comprehensively evaluate all aspects of the man’s
personal prostate health and to weigh the risks
and benefits of further diagnostic assessment.
See also CANCER TREATMENT OPTIONS AND DECI-
SIONS; CARCINOMA; DIET AND HEALTH; LIFESTYLE AND
HEALTH; MEDICINAL HERBS AND BOTANICALS; SURGERY
BENEFIT AND RISK ASSESSMENT.prostate gland The gland in the male reproduc-
tive tract that produces most of the volume of
SEMEN. About the shape and size of a walnut, the
prostate gland wraps around the URETHRAat the
neck of the BLADDER. The back of the prostate
gland rests against the front wall of the RECTUM. A
tough, fibrous membrane forms a single capsule
enclosing the 30 to 50 clusters of glandular tissue
that make up the prostate gland. There are three
distinct structures of glandular tissue, which urol-
ogists refer to as zones—peripheral, transition, and
central—though how the zones differ in function
remains unknown. The prostate gland also con-
tains nonglandular cells, primarily MUSCLE and
connective tissue cells that help move prostatic
secretions into the urethra.
Prostate gland cells produce their secretions
under stimulation by TESTOSTERONE, which reaches
them through the BLOODcirculation. The seminal
vesicles, which lie just behind the prostate gland,
store mature SPERMencased in a thick, jellylike
solution that prevents them from motility. During
ORGASMand EJACULATION, the seminal vesicles and
the prostate gland each contract, mixing sperm
and prostatic fluid in the urethra to form semen.
The prostatic fluid contains an enzyme, PROSTATE-
SPECIFIC ANTIGEN(PSA), that thins the semen to
allow the sperm to become motile. Ejaculation
then carries the semen through the urethra and
out the tip of the PENIS.
As a man ages the prostate gland slowly
enlarges, a condition called BENIGN PROSTATIC HYPER-
PLASIA(BPH). In most men BPH remains innocu-
ous, causing no symptoms or even awareness of
its presence. Other health conditions that can
affect the prostate gland are PROSTATITIS(INFLAMMA-
TIONor INFECTION) and PROSTATE CANCER. The surgi-
cal OPERATION to remove the prostate gland is330 The Reproductive System