Mesothelioma, more precisely known as
malignant mesothelioma is a rare cancer
of the mesothelial cells, most commonly those in the lining that covers
the lungs (pleura). Mesothelial cells exist in the lining (membrane)
that covers the outer surface of our body organs. The majority of people
with mesothelioma have been exposed to asbestos at some time during
their life.
Doctors usually divide mesothelioma into three types:
- Pleural mesothelioma - affects the pleura, the lining surrounding the lungs. This is the most common form.
- Peritoneal mesothelioma - the cancer attacks the lining of the abdomen, the peritoneum. This is the second most common form.
- Pericardial mesothelioma - the cancer attacks the protective layer covering the heart. This is the rarest form.
All three forms of mesothelioma are nearly always caused by asbestos exposure.
Mesothelioma is an aggressive form of cancer. For the majority of
patients there is no cure. Doctors usually focus on improving the
quality of life as the disease progresses - making the patient as
comfortable as possible.
In the United Kingdom, approximately 2,000 patients are diagnosed with
mesothelioma annually. According to the CDC (Centers for Disease Control
and Prevention), mesothelioma kills over 2,700 people in the USA every
year. According to the Mesothelioma register, deaths from this type of
cancer rose more than tenfold from 1969 to 2009 in the UK. About
four-fifths of all deaths are among men.
According to Medilexicon's medical dictionary,
mesothelioma is:
"A rare neoplasm derived from the lining cells of the pleura or
peritoneum that grows as a thick sheet covering the viscera and is
composed of spindle cells or fibrous tissue that may enclose glandlike
spaces lined by cuboidal cells."
What are the signs and symptoms of mesothelioma?
A symptom is something the patient feels and describes; while a sign is
something other people can see, including doctors and nurses. For
example, a symptom may be pain, while a sign could be a rash.
Exposure to asbestos and asbestos dust can take up to thirty years to
show symptoms. Often, patients are diagnosed when the disease is already
advanced. Outcomes depend on how early the malignancy can be diagnosed.
Mesothelioma signs and symptoms vary, depending on where in the body the cancer is.
Pleural mesothelioma (tissue surrounding the lungs)
- Shortness of breath
- Coughing, often painful
- Unexpected and unexplained loss of weight
- Pain under the rib cage
- Sometimes lumps may be detectable under the skin in the chest area
- Lower back pain
- Discomfort in the side of the chest
- Exhaustion
- Some people may experience sweating, fever, or difficulty swallowing
Peritoneal mesothelioma (lining in the abdomen)
- Unexplained weight loss
- Pain in the abdomen
- Swelling in the abdomen
- Lumps in the abdomen
- Nausea, some patients may experience vomiting
Pericardial mesothelioma (lining in the heart area)
- Low blood pressure
- Shortness of breath
- Fluid retention (edema), often in the legs
- Heart palpitations
- Fatigue, extreme after light exertion
- Chest pain
What are the causes of mesothelioma?
Experts say that
prolonged exposure to asbestos particles is the primary cause of mesothelioma.
The risk of developing the disease is closely linked to asbestos
particle dosage - i.e. the likelihood of developing mesothelioma is
directly proportional to how long a person was exposed, and how much
they inhaled.
People in jobs where exposure to asbestos fibers are common have the
highest risk of developing the disease. Asbestos was commonly used for
insulation, soundproofing, fireproofing, roofing, and ironing board
covers.
jobrapido.com/work+australia
Industries that may have involved asbestos exposure for some of their
workpeople include constructions sites, steel mills, shipyards, oil
refineries and power plants.
When the asbestos particles or fibers are inhaled or ingested, they
build up in the lining of the abdomen, chest or lungs. This accumulation
considerably increases the chances of cancerous cells developing.
When asbestos is damaged and particles or fibers are released into the
air, the environment can become hazardous to human health. The fibers
can be breathed in or swallowed, they get embedded in tissue, and
eventually lead to mesothelioma.
Asbestos is a group of minerals that occur naturally. They exist
as fibers or bundles. These fibers may be found in soil or rocks and
exist in many parts of the world naturally. Asbestos is made of silicon,
oxygen and some other elements.
There are two principle types of asbestos fibers:
- Serpentine asbestos - this is the most common type used in industry. It is known as white asbestos, or chrysotile. The fibers are curly.
- Amphibole asbestos - these include anthophyllite, amosite,
actinolite, crocidolite, and tremolite. The fibers are straight, like
needles. This type of asbestos, particularly crocidolite, is considered
to be more likely to cause cancer. However, even serpentine asbestos has
been linked to cancer.
Although asbestos is much less used today than it used to be, exposure
is still possible, and continues to be a serious problem. Older
materials containing asbestos can break down, releasing a dust composed
of tiny particles than can be inhaled or ingested. Exposure can occur
when older buildings are demolished or renovated.
Even family members who never set foot in a working environment that
contained asbestos can be exposed. The fibers can be carried home in the
workers clothing, and then breathed in by other members of the
household.
Asbestos can also be swallowed, as may occur when water flows through
asbestos cement pipes. Inhaled asbestos can be coughed up, and then
swallowed (when the person swallows the saliva).
WHO (World Health Organization) in 2005 said that approximately 125
million people globally were exposed to asbestos at work in that year,
despite their employers having known about the link to cancer and other
lung diseases for over six decades. Most work-related exposure today
occurs in developing nations.
In much rarer cases, mesothelioma may be linked to irradiation, the
inhalation of eronite or some other fibrous silicate, and intrapleural
thorium dioxide (Thorotrast - a suspension containing radioactive
particles, used in X-ray diagnostics during the 1930s and 1940s, and
even in the 1950s in some nations including the USA). Some experts
believe that SV40 (simian virus 40) could be involved in the development
of the disease.
How is mesothelioma diagnosed?
Digital chest x-ray of advanced malignant mesothelioma (on left)
After asking certain diagnostic questions, such as the patient's
symptoms, where he/she has worked, medical history and family history,
and carrying out a physical examination, the doctor may order some
imaging scans. This could be a CT scan or X-ray of the abdomen or chest
to rule out any abnormalities. Usually, depending on the results of the
scans, further testing may be recommended.
Biopsy - some tissue is surgically removed so that it can be
examined in the laboratory under a microscope. To determine whether a
patient has mesothelioma, this will have to be done. How the biopsy is
carried out depends on which part of the body is targeted:
Targeting either the chest or abdominal area
- Fine-needle aspiration - a small needle is inserted into the abdomen and chest and some fluid or piece of tissue is removed
Targeting the chest area
- Thoracoscopy - the surgeon inserts a thoracoscope through a small
incision between the patient's ribs. A thoracoscope is an endoscope for
examination of the chest cavity - it is a tube with a small camera at
the end. The surgeon removes a piece of tissue with special tools.
- Thoracotomy - in this surgical intervention, the chest is opened
between the ribs so that the surgeon can see the target area and check
for signs of cancer. Some tissue may also be removed and sent to the
laboratory for testing.
Targeting the abdominal area
- Laparoscopy - a small incision is made in the abdominal wall, a
laparoscope is inserted through the incision into the abdomen, where the
surgeon can have a look. The laparoscope is a long tube with a camera
at the end. With specialized tools, tissue samples can be removed.
- Laparotomy - the surgeon opens the abdomen and has a look. Sometimes tissue samples may be removed and sent to the lab.
When the tissue or fluid sample is viewed through a microscope, the
pathologist can tell whether there is malignancy (e.g. malignant
mesothelioma), what types of cells are involved, and how advanced the
cancer is. How advanced a cancer is, defining it, is called
Staging.
Staging - in medicine, specifically cancer, staging is the
process of carrying out tests and examinations to determine the extent
of the cancer, how advanced it is, and whether it has metastasized
(spread from its original site to other parts of the body).
As soon as mesothelioma has been confirmed (diagnosed), other tests will
be ordered to help determine the stage of the cancer. These may include
such scans as CT,
MRI
(magnetic resonance imaging), PET (positron emission tomography), or a
chest X-ray. What type of scan is used depends on several different
factors.
When all the data is gathered together, the health care professional
will assign the cancer a stage. The staging below is for pleural
mesothelioma (lungs):
- Stage 1 - the cancer is localized. It is still inside the lining around the lung. It has not spread out.
- Stage 2 - the cancer may have spread to a lung or the diaphragm.
- Stage 3 - the cancer may have reached the lymph nodes, and possibly other parts of the chest
- Stage 4 - the cancer has either spread more extensively in the
chest, or may even have reached other parts of the body far from the
original site. It may have reached other lymph nodes, or even the brain.
What are the treatment options for mesothelioma?
The treatment the doctor will recommend depends on several factors, including:
- Where the cancer is
- The stage of the cancer (how advanced it is)
- The patient's general health and age
Sadly, this type of cancer is usually spotted when it has been
progressing for a while. Add to this the fact that mesothelioma is
usually an aggressive type of cancer, and you have two reasons why so
few patients are cured.
If the cancer is very advanced, the tumor(s) can no longer be surgically
removed. The only option left, in many cases, is to control the cancer,
try to slow down its progress, and focus on making the patient as
comfortable as possible.
It is vital that the medical team explains all the options to the
patient - including their pros and cons - and if necessary, to his/her
loved ones and/or caregivers. Fighting the cancer aggressively may mean
enduring very unpleasant side effects, while just focusing on pain and
quality of life for the remaining time, might be a better option. This
is something the patient needs to discuss thoroughly with the medical
team, and perhaps family members or close friends.
Surgery - this means removing tumors by surgery. Surgery is
usually only an option during the early stages of the cancer. It may
remove the whole cancer, or at least reduce some symptoms and slow it
down.
- Fluid accumulation in the lung area - surgery may be recommended if
there is fluid accumulation in the chest, resulting in breathing
difficulties. The fluid is drained with a tube or catheter. A drug may
be injected into the chest to stop a recurrence of fluid build-up.
Drugs, such as tetracycline, talc powder, or bleomycin are instilled
inside the space between the two layers of tissue lining the lungs
(pleura); this causes inflammation,
making the two pleura tack together, leaving no space for fluid
build-up. Treatment for preventing this type of fluid build-up is called
pleurodesis.
- Pleurectomy or peritonectomy - the lining around the lungs or
abdominal cavity may be surgically removed. The aim is to relieve
mesothelioma symptoms.
- Debulking - removing as much of the tumor as possible, if it is not possible to remove all of it.
- Removing a lung - signs and symptoms may be relieved if the surgeon
removes the affected lung and its surrounding tissue. This will be
followed by radiotherapy.
Chemotherapy - if tumors cannot be surgically removed, chemotherapy
may help shrink them, as well as to slow down their progress.
Neoadjuvant chemotherapy may also be recommended - administering
chemotherapy before surgery which can make it easier to remove a tumor.
Chemotherapy used after surgery to try to prevent recurrence is called
adjuvant chemotherapy.
Radiotherapy - also known as radiation therapy. For those with
pleural mesothelioma, it may help relieve symptoms. Radiotherapy is
sometimes administered to prevent metastasis after biopsy or surgery.
Radiation therapy can help relieve symptoms
Clinical trials - human studies using novel treatment methods.
The patient should discuss what the trial is about, as well as what to
expect realistically, thoroughly with the doctor.
What is the prognosis for mesothelioma?
Cancer is a very unpredictable disease, and providing an accurate prognosis is not easy.
In general, prognoses for patients with mesothelioma are not encouraging.
Malignant mesothelioma is a very aggressive type of cancer;
it also has a long latency period. In the majority of cases, the
disease is only detected when it is already in an advanced stage.
In most cases, survival for pleural malignant mesothelioma after
diagnosis is no more than one or two years. The patient needs to bear in
mind that there are exceptions, and new treatments are being researched
and appear all the time.
Written by Christian Nordqvist
from : http://www.medicalnewstoday.com/articles/140859.php
Get This Image For Your Site
