WHAT IS PROSTATE CANCER?
Prostate cancer is a malignancy that develops in the prostate
gland. The gland is important for the proper function of the male
reproductive tract. Prostate cancer can be either slow growing
or extremely aggressive. Prostate tumors that are slow growing
cause few symptoms. Aggressive tumors can spread rapidly to other
areas of the body such as the lymph nodes, other organs, or to
the bone.
Prostate cancer occurs when the growth of cells within the prostate
become uncontrolled. There are two types of cancer:
Benign - this type of tumor is not cancerous. The cells from benign
tumors normally do not spread to other parts of the body. Benign
tumors located in the prostate are usually not life threatening.
Malignant - the cells become cancerous when they begin to divide
unpredictably and form tumors. As the tumor grows, it uses the
oxygen that would normally be used by healthy cells and secretes
protein signals that cause the formation of new blood vessels.
The cancer can spread if cancer cells leave a malignant tumor
and enter into the bloodstream. If the cancer cells spread from
the prostate gland to another part of the body and form a new
tumor, the disease is then referred to as metastatic prostate
cancer.
THE PROSTATE GLAND
The prostate is a gland located in the reproductive area of a
man's body. The prostate gland is about the size of a walnut and
is located below the bladder and in front of the rectum. It surrounds
the upper part of the urethra that is the tube that urine travels
from the bladder.
Because the prostate is situated in front of the rectum, doctors
can feel the contour of the gland during a rectal exam.
DIAGNOSIS
The most common tests performed for the detection of prostate
cancer are:
PSA BLOOD TEST - this test measures the levels of PSA (prostate-specific
antigen) in the blood. The prostate gland produces the prostate-specific
antigen, which is a small protein molecule. In men who do not
have prostate cancer, this antigen cannot be detected or is at
very low levels. The level of PSA may rise when a man has prostate
cancer. This test has the ability to detect prostate cancer at
very early stages. A healthy PSA reading is typically "4"
or less.
DIGITAL
RECTAL EXAM - this test requires that the doctor examine
the rectum by inserting a gloved finger into the rectum and
feels the prostate through the rectum wall for the texture and
size of the gland. If there is indication of prostate cancer,
the following test can be done:
TRUS - (transrectal ultrasound) - a probe is inserted into the
rectum that uses sound waves to "map" or "see"
the prostate gland for possible suspicious areas.
Biopsies - small thin needles
are inserted through the rectum for obtaining the biopsies of
the prostate gland.
PROSTASCINT® SCAN
- this scan uses low-level radioactive material
to find prostate cancer cells. This test can be used to detect
prostate cancer. The advantage of this test is that it can detect
the spread of prostate cancer to other areas within the body
such as the lymph nodes, other organs and bone. A ProstaScint
scan can be used for the detection of cancer for patients who:
- Are newly diagnosed
- Have a rising PSA level after a radical prostatectomy
- Have a rising PSA level after radiation therapy
- Those who have undergone hormonal therapy
CT scan (Computed tomographic scan) - is an x-ray procedure that
gives cross-sectional images of the body used to detect lymph
nodes in the pelvis that are enlarged by cancer.
Bone scan - is used to detect the spread of cancer to the bones.
GLEASON SCORE
If cancer is detected and diagnosed, it is then evaluated on how
aggressive it appears on a scale called the Gleason score. This
is a method of classifying cancer cells on a scale of 2 to 10.
The higher the Gleason score, the more aggressive the cancer is
likely to spread. The score may influence the recommendation for
treatment.
Grade 1: Cancer is well differentiated
Grade 2: Cancer is still well differentiated but is arranged more
loosely and more irregular in shape
Grade 3: Most common grade of prostate cancer, cancer is moderately
differentiated, varying in size from small to large
Grade 4: Cancer is poorly differentiated, unable to form separate
units, highly irregular distorted shapes: progressive invasion
of neighboring tissues
Grade 5: Cancer is undifferentiated and bears no resemblance to
normal cells
STAGING
Staging of Prostate cancer indicates the extent that the cancer
has spread and the severity of the cancer. The stage of cancer
is an important factor for the selection of treatment of the disease
and for predicting the prognosis. Staging of prostate cancer is
most commonly based on the TNM (Tumor, Nodes, Metastases) system.
Stage T1 - the tumor is confined to the prostate and was usually
discovered by the PSA test or biopsies.
Stage T2 - the tumor can be detected by the DRE exam or ultrasound
but confined to the prostate gland
Stage T3 - the cancer has spread to tissue next to the prostate
gland or the seminal vesicles.
Stage T4 - the cancer has spread to tissue or organs near the
prostate such as the bladder area, rectum, or wall of the pelvis.
Stage N+ - the prostate cancer has spread to the pelvic lymph
nodes.
Stage M+ - the prostate cancer has spread to other lymph nodes,
organs, or bone.
TREATMENT OPTIONS
After a patient has been diagnosed with prostate cancer, the next
process is determining the most appropriate course of treatment.
There are different treatment options for patients with prostate
cancer depending if the cancer is localized or has spread. The
most common types of treatment are:
Surgery - surgical removal of the prostate gland and surrounding
tissue.
Radiation therapy - high doses of the x-ray and high energy rays
that kill cancer cells. The treatment requires external beam radiation
directed at the cancer from a source outside the body
Brachytherapy - treatment in of small radioactive pellets are
implanted into the site of the prostate gland. By placing the
"seeds" into the tumor, the dose of radiation is maximize
to the tumor while minimizing the dose to the surrounding normal
tissues, nerves and blood vessels.
Hormone therapy - hormones are used to retard the growth of cancer
cells. Cancer cells depend on male hormones for growth. Hormone
therapy can slow the growth of prostate cancer. Therefore, this
treatment is not considered a curative form of treatment, but
a way to temporarily slow the growth of prostate cancer cells.
Chemotherapy - uses anticancer drugs to kill cancer cells. These
drugs kill cancer cells, but they also damage some normal cells.
Immunotherapy - uses the body's
immune system to fight cancer. This treatment stimulates or
restores the ability of the immune system to fight infection
and disease. It is also used to lessen side effects that may
be caused by some cancer treatments. It is also known as biological
therapy, biotherapy, or biological response modifier (BRM) therapy.
Watchful Waiting - this approach may be recommended if prostate
cancer is not causing any symptoms and is contained to one area.
Because prostate cancer can be slow growing, older men who have
the disease may never need any treatment.
