What is prostate cancer ? what causes prostate cancer?

Prostate cancer is a disease which only affects men.
Cancer begins to grow in the prostate - a gland in the male
reproductive system.
The word "prostate" comes from Medieval Latin prostate
and Medieval French prostate . The ancient Greek word
prostates means "one standing in front", from proistanai
meaning "set before". The prostate is so called because of
its position - it is at the base of the bladder.
What is the prostate ?
The prostate is an exocrine gland of the male reproductive
system, and exists directly under the bladder, in front of the
rectum. An exocrine gland is one whose secretions end up
outside the body e.g. prostate gland and sweat glands. It is
approximately the size of a walnut.
The urethra - a tube that goes from the bladder to the end of
the penis and carries urine and semen out of the body -
goes through the prostate.
There are thousands of tiny glands in the prostate - they all
produce a fluid that forms part of the semen. This fluid also
protects and nourishes the sperm. When a male has an
orgasm the seminal-vesicles secrete a milky liquid in which
the semen travels. The liquid is produced in the prostate
gland, while the sperm is kept and produced in the testicles.
When a male climaxes (has an orgasm) contractions force
the prostate to secrete this fluid into the urethra and leave
the body through the penis.
Urine control
As the urethra goes through the prostate: the prostate gland
is also involved in urine control (continence) with the use of
prostate muscle fibers. These muscle fibers in the prostate
contract and release, controlling the flow of urine flowing
through the urethra.
The Prostate Produces Prostate-specific antigen (PSA)
The epithelial cells in the prostate gland produce a protein
called PSA (prostate-specific antigen). The PSA helps keep
the semen in its liquid state. Some of the PSA escapes into
the bloodstream. We can measure a man's PSA levels by
checking his blood. If a man's levels of PSA are high, it
might be an indication of either prostate cancer or some
kind of prostate condition.
Diagram of the location of the prostate gland and
nearby organs
It is a myth to think that a high blood-PSA level is harmful
to you - it is not. High blood PSA levels are however an
indication that something may be wrong in the prostate.
Male hormones affect the growth of the prostate, and also
how much PSA the prostate produces. Medications aimed
at altering male hormone levels may affect PSA blood
levels. If male hormones are low during a male's growth
and during his adulthood, his prostate gland will not grow to
full size.
In some older men the prostate may continue to grow,
especially the part that is around the urethra. This can
make it more difficult for the man to pass urine as the
growing prostate gland may be causing the urethra to
collapse. When the prostate gland becomes too big in this
way, the condition is called Benign Prostatic Hyperplasia
(BPH). BPH is not cancer, but must be treated.
Prostate Cancer
In the vast majority of cases, the prostate cancer starts in
the gland cells - this is called adenocarcinoma. In this
article, prostate cancer refers just to adenocarcinoma.
Prostate cancer is mostly a very slow progressing disease.
In fact, many men die of old age, without ever knowing they
had prostate cancer - it is only when an autopsy is done
that doctors know it was there. Several studies have
indicated that perhaps about 80% of all men in their eighties
had prostate cancer when they died, but nobody knew, not
even the doctor.
Experts say that prostate cancer starts with tiny alterations
in the shape and size of the prostate gland cells - Prostatic
intraepithelial neoplasia (PIN).
Doctors say that nearly 50% of all 50-year-old men have
PIN. The cells are still in place - they do not seem to have
moved elsewhere - but the changes can be seen under a
microscope. Cancer cells would have moved into other
parts of the prostate. Doctors describe these prostate gland
cell changes as low-grade or high-grade; high grade is
abnormal while low-grade is more-or-less normal.
Any patient who was found to have high-grade PIN after a
prostate biopsy is at a significantly greater risk of having
cancer cells in his prostate. Because of this, doctors will
monitor him carefully and possibly carry out another biopsy
later on.
Classification of prostate cancer
It is important to know the stage of the cancer, or how far it
has spread. Knowing the cancer stage helps the doctor
define prognosis - it also helps when selecting which
therapies to use. The most common system today for
determining this is the TNM (Tumor/Nodes/Metastases).
This involves defining the size of the tumor , how many
lymph nodes are involved, and whether there are any other
metastases.
When defining with the TNM system, it is crucial to
distinguish between cancers that are still restricted just to
the prostate, and those that have spread elsewhere. Clinical
T1 and T2 cancers are found only in the prostate, and
nowhere else, while T3 and T4 have spread outside the
prostate.
There are many ways to find out whether the cancer has
spread. Computer tomography will check for spread inside
the pelvis, bone scans will decide whether the cancer has
spread to the bones, and endorectal coil magnetic
resonance imaging will evaluate the prostatic capsule and
the seminal vesicles.
The Gleason Score
A pathologist will look at the biopsy samples under a
microscope. If cancer tissue is detected, the pathologist
then grades the tumor. The Gleason System of grading goes
from 2 to 10. The higher the number, the more abnormal the
tissues are compared to normal prostate tissue.
Two numbers are added up to get a Gleason score:
1. A number from 1 to 5 for the most common pattern
observed under the microscope. This is the
predominant grade and must be more than 51% of the
sample.
2. A number from 1 to 5 for the second most common
pattern. This is the secondary grade and must make
up more than 5% but less than 50% of the sample.
A Gleason score of 7 can have two meanings. Look at
these two examples below:
1. If the predominant grade is 3 and the secondary
grade is 4, the Gleason score is 7.
2. If the predominant grade is 4 and the secondary
grade is 3, the Gleason score is also 7.
However, the first example, with a predominant score of 3,
has a less aggressive cancer than the second example,
with a predominant score of 4.
It is crucial that the tumor is graded properly, as this
decides what treatments should be recommended.
What are the symptoms of prostate cancer ?
During the early stages of prostate cancer there are usually
no symptoms. Most men at this stage find out they have
prostate cancer after a routine check up or blood test. When
symptoms do exist, they are usually one or more of the
following :
The patient urinates more often
The patient gets up at night more often to urinate
He may find it hard to start urinating
He may find it hard to keep urinating once he has
started
There may be blood in the urine
Urination might be painful
Ejaculation may be painful (less common)
Achieving or maintaining an erection may be difficult
(less common).
If the prostate cancer is advanced the following symptoms
are also possible :
Bone pain, often in the spine (vertebrae), pelvis, or ribs
The proximal part of the femur can be painful
Leg weakness (if cancer has spread to the spine and
compressed the spinal cord)
Urinary incontinence (if cancer has spread to the
spine and compressed the spinal cord)
Fecal incontinence (if cancer has spread to the spine
and compressed the spinal cord).
What are the causes of prostate cancer ?
Nobody is really sure of what the specific causes are.
There are so many possible factors, including age, race,
lifestyle, medications, and genetics, to name a few.
Age
Age is considered as the primary risk factor. The older
a man is, the higher is his risk. Prostate cancer is rare
among men under the age of 45, but much more
common after the age of 50.
Genetics
Statistics indicate that genetics is definitely a factor in
prostate cancer risk. It is more common among
certain racial groups - in the USA prostate cancer is
significantly more common and also more deadly
among Afro-Americans than White-Americans. A man
has a much higher risk of developing cancer if his
identical twin has it. A man whose brother or father
had/had prostate cancer runs twice the risk of
developing it, compared to other men.
Studies indicate that the two faulty genes - BRCA 1
and BRCA 2 - which are important risk factors for
breast cancer and ovarian cancer, have also been
implicated in prostate cancer risk.
In a study scientists found seven new sites in the
human genome that are linked to men's risk of
developing prostate cancer.
Faulty BRCA2 gene linked to aggressive form of
prostate cancer - researchers at the The Institute of
Cancer Research, UK, reported in the Journal of Clinical
Oncology (April 2013 issue) that men who have
inherited the faulty BRCA2 gene are more likely to
have the faster-spreading type of prostate cancer. The
scientists say these men should receive treatment
immediately after diagnosis with surgery or radiation
therapy, rather than receive the "watchful waiting"
approach.
Senior author Ros Eeles wrote that experts have
already known that those with the faulty BRCA2 gene
have a higher risk of developing prostate cancer. This
is the first large study to demonstrate that the faulty
gene is also linked to a faster spread of the disease
and poorer survival.
This new discovery will make some health authorities
around the world rethink their policies and procedures.
In the United Kingdom, the National Health Service
offers the same prostate cancer treatment for both
carriers and non-carriers of the faulty BRCA2 gene.
Prof. Eeles said "It must make sense to start offering
affected men immediate surgery or radiotherapy, even
for early-stage cases that would otherwise be
classified as low-risk. We won't be able to tell for
certain that earlier treatment can benefit men with
inherited cancer genes until we've tested it in a clinical
trial, but the hope is that our study will ultimately save
lives by directing treatment at those who most need
it."
Diet
A
review of diets indicated that the Mediterranean diet
may reduce a person's chances of developing prostate
cancer . Another study indicates that soy, selenium
and green tea , offer additional possibilities for disease
prevention - however, a more recent study indicated
that combination therapy of vitamin E, selenium and
soy does not prevent the progression from high-grade
prostatic intraepithelial neoplasia (HGPIN) to prostate
cancer. A diet high in vegetable consumption was
found in a study to be beneficial.
A US pilot study on men with low risk prostate cancer
found that following an intensive healthy diet and
lifestyle regime focusing on low meat and high
vegetable and fruit intake, regular exercise, yoga
stretching, meditation and support group participation,
can alter the way that genes behave and change the
progress of cancer, for instance by switching on tumor
killers and turning down tumor promoters.
Other studies have indicated that lack of vitamin D, a
diet high in red meat may raise a person's chances of
developing prostate cancer.
A study published in the journal Clinical Cancer
Research suggests vitamin D deficiency may predict
aggressive prostate cancer .
Medication
Some studies say there might be a link between the
daily use of anti-inflammatory medicines and prostate
cancer risk. A study found that statins, which are used
to lower cholesterol levels, may lower a person's risk
of developing prostate cancer.
Obesity
A study found a clear link between obesity and raised
prostate cancer risk, as well as a higher risk of
metastasis and death among obese people who
develop prostate cancer.
Sexually transmitted diseases (STDs)
Men who have had gonorrhea have a higher chance of
developing prostate cancer, according to research
from the University of Michigan Health System.
Agent Orange
Veterans exposed to Agent Orange have a 48% higher
risk of prostate cancer recurrence following surgery
than their unexposed peers, and when the disease
comes back, it seems more aggressive, researchers
say . Another study found that Vietnam War veterans
who had been exposed to Agent Orange have
significantly increased risks of prostate cancer and
even greater risks of getting the most aggressive form
of the disease as compared to those who were not
exposed.
Enzyme PRSS3 linked to aggressive prostate cancer
Scientists from the Mayo Clinic, Florida, reported in
Molecular Cancer Research that PRSS3, an enzyme,
changes the environment of prostate cancer cells,
making the cancer much more likely to metastasize .
Senior researcher, Evette Radisky, Ph.D., said "This
molecule is a protease, which means it digests other
molecules. Our data suggests PRSS3 activity changes
the environment around prostate cancer cells -
perhaps by freeing them from surrounding tissue - to
promote malignancy and invasiveness. I don't think
PRSS3 is the only factor involved in driving aggressive
prostate cancer, but it may be significant for a certain
subset of this cancer - the kind that is potentially
lethal."
Recent developments on prostate cancer causes
from MNT news
Chronic prostate inflammation tied to nearly double
risk of prostate cancer - a study reported in the
journal Cancer Epidemiology, Biomarkers & Prevention,
finds that compared to men with no such signs,
men with chronic inflammation in non-cancerous
prostate tissue may have nearly double the risk of
developing prostate cancer.
Vasectomy linked with aggressive prostate cancer
risk - In the largest and most comprehensive study
of its kind, researchers from Harvard School of
Public Health in Boston, MA, find that vasectomy is
associated with a small increased risk of prostate
cancer, and a larger increased risk for advanced or
lethal prostate cancer.
Prostate cancer: high cholesterol, triglyceride levels
may raise risk of recurrence - Among men who
have surgery for prostate cancer, those who have
high total cholesterol and triglyceride levels - two
types of fat found in blood - may be at increased
risk of disease recurrence. This is according to a
study published in the journal Cancer Epidemiology,
Biomarkers & Prevention .
What are the treatments for prostate cancer ?
Early stage prostate cancer
If the cancer is small and contained - localized - it is usually
managed by one of the following treatments:
Watchful waiting - not immediate treatment is carried
out. PSA blood levels are regularly monitored.
Radical prostatectomy - the prostate is surgically
removed.
Brachytherapy - radioactive seeds are implanted into
the prostate.
Conformal radiotherapy - the radiation beams are
shaped so that the region where they overlap is as
close to the same shape as the organ or region that
requires treatment, thus minimizing healthy tissue
exposure to radiation.
Intensity modulated radiotherapy - beams with
variable intensity are used. An advanced form of
conformal radiotherapy usually delivered by a
computer-controlled linear accelerator.
Treatment recommendations really depend on
individual cases. In general, if there is a good
prognosis and the cancer is in its early stages, all
options can be considered. However, they all have
their advantages and disadvantages. The patient
should discuss available options thoroughly with his
doctor.
More advanced prostate cancer
If the cancer is more aggressive, or advanced, the
patient may require a combination of radiotherapy and
hormone therapy. Radiotherapy requires treatment on
an everyday basis for up to about eight weeks. Radical
surgery is also an option - the prostate is removed.
Traditional surgery requires a hospital stay of up to
ten days, with a recovery time that can last up to three
months. Robotic keyhole surgery has the advantage
just a couple of days in hospital, followed by a much
shorter recover period. However, even robotic keyhole
surgery may not be ideal for very elderly patients.
In advanced prostate cancer hormone therapy is very
effective in slowing down, and even stopping the
growth of cancer cells. Even if the hormone therapy
stops working after a while, there are still other
options the patient will be able to discuss with his
doctor, such as participating in clinical trials.
Radioactive injection helps advanced prostate cancer
patients live longer - scientists at The Royal Marsden
NHS Foundation Trust and The Institute of Cancer
Research, UK, reported in NEJM (New England Journal
of Medicine) that radium-233 , a radiation injection,
directly targets tumors in the bone delivering short
range radiation, causing minimal damage to healthy
tissue. Radium, like calcium, is absorbed by the bone.
Dr Chris Parker and colleagues found that late-stage
prostate cancer patients who were given the
radioactive injection lived for an average of 15 weeks
longer than those given an inert placebo injection.
Dr Parker said "We're excited by the prospects for this
ingenious new treatment, which takes advantage of
the properties of tumors growing within bone to home
in and deliver a highly targeted dose of radiation. We
were delighted to show that radium 223 allowed many
men in our trial to live to see a few extra, precious
months. Not only did they live longer, these men had a
much better quality of life."
Delivering estrogen through skin patches may be an
easier and safer way to treat prostate cancer than the
hormone therapies that are currently used , British
researchers explained in Lancet Oncology (March 2013
issue).
In May 2013, the US FDA approved Xofigo (radium Ra
223 dichloride) for metastatic castration-resistant
prostate cancer that has reached bones but not other
organs. Enzalutamide is taken in combination with
docetaxel, another cancer medication.
Richard Pazdur, M.D., from the FDA, said "Xofigo
binds with minerals in the bone to deliver radiation
directly to bone tumors, limiting the damage to the
surrounding normal tissues. Xofigo is the second
prostate cancer drug approved by the FDA in the past
year that demonstrates an ability to extend the survival
of men with metastatic prostate cancer."
Xtandi (enzalutamide) was approved by the FDA in
August 2012 for patients with metastatic castration-
resistant prostate cancer that has spread or recurred.
The problem with the Internet for many prostate cancer
patients
Researchers from Loyola University Medical Center reported
in the Journal of Urology that one third of American lay
people find it hard to understand most information
websites regarding prostate cancer. Senior author, Gopal
Gupta, MD, said: "This is problematic for one-third of
Americans who seek to further educate themselves using
online resources."
Coffee and prostate cancer
Heavy coffee drinking may prevent cancer recurrence or
progression - men with prostate cancer who consume at
least four cups of coffee per day may have a lower risk of
disease progression or recurrence, researchers from the
Fred Hutchinson Cancer Research Center reported in the
journal Cancer Causes and Control.
Recent developments on prostate cancer from MNT
news
Accurate test for aggressive prostate cancer steps
closer with genetic study - Researchers behind a
new genetic study led by the University of
Pittsburgh School of Medicine, PA, suggest their
findings will lead to a more accurate test for
aggressive prostate cancer and new ways to treat
it.
Writing about their work in the American Journal of
Pathology, the team explains how they found
prostate cancer patients with certain genetic
mutations have a 91% chance of their cancer
coming back.
Specific baldness pattern linked with increased
prostate cancer risk - Men with a specific pattern of
baldness at age 45 have a 40% increased risk of
later developing aggressive prostate cancer,
according to a new study published in the Journal of
Clinical Oncology .
Physical activity linked to lower death risk in men
with localized prostate cancer - Around 1 in 7 men
will develop prostate cancer in their lifetime. But a
new study suggests men with localized prostate
cancer could reduce their risk of all-cause and
prostate cancer-specific mortality simply by
exercising more.
Scientists reveal genetic root of prostate cancer -
An international team of scientists have revealed
the genetic root of prostate cancers in individual
men, demonstrating that tumors share common
gene faults which could potentially offer new targets
for treatment.
What are the possible complications of
prostate cancer ?
Metastasis - the cancer can spread to other parts of
the body through the bloodstream or the lymphatic
system to other organs or bones. If the cancer
spreads to the ureters, the tubes that carry urine from
the kidneys to the bladder, there is a risk of serious
kidney problems.
If the cancer spreads to the bones, there may be pain
and fractures . Doctors say that when prostate cancer
has spread to other parts of the body, it can no longer
be cured, but may possibly be controlled.
Incontinence - the prostate cancer itself, or treatments
can cause urinary incontinence.
Erectile dysfunction - the prostate cancer or prostate
cancer treatment can lead to erectile dysfunction - the
inability to achieve a penile erection, or maintain one.
Metabolic factors - a man's risk of dying from prostate
cancer is much higher if he has high blood pressure,
raised blood sugar levels, high blood lipid levels, and a
high BMI (body mass index), which collectively are
known as metabolic factors. This was reported in the
journal Cancer (October 2012 issue) by scientists from
Umeå University in Sweden.
Fertility advice crucial for male cancer
survivors
Researchers at the University of Sheffield, UK, found that
the majority of male cancer patients are not receiving vital
fertility advice. Males with cancer who are at risk of long-
term infertility should be advised on the advantages and
benefits of sperm banking.
Cancer treatments, such as radiotherapy and
chemotherapy , can seriously affect a cancer patient's long
term fertility, head researcher Dr Allan Pacey explained.
Dr Pacey said: "Trying to engage men with this subject is
notoriously difficult. For those of us who run sperm banks,
many men store their sperm and then do not contact us
again, even though there are legal reasons to keep in
contact. Our research suggests that there is a need to
educate men about the benefits of attending follow-up
fertility clinics and the long-term consequences of non-
attendance."