Mesothelioma Treatment by
stage
Treatment depends on where the cancer is, how far it
has spread, and the patient's age and general health.
Standard treatment may be considered because of its
effectiveness in patients in past studies, or participation in a
clinical trial may be considered. Not all patients are cured with
standard therapy and some standard treatments may have more side
effects than are desired. For these reasons, clinical trials are
designed to find better ways to treat cancer patients and are based on
the most up-to-date information. Clinical trials are ongoing in many
parts of the country for many patients with malignant mesothelioma.
Advanced Malignant
Mesothelioma (Stages II, III, and IV)
Treatment may be one of the following:
-
Draining of fluid in the chest or abdomen
(thoracentesis or paracentesis) to reduce discomfort. Drugs also may
be put into the chest or abdomen to prevent further collection of
fluid.
-
Surgery to relieve symptoms.
-
Radiation therapy to relieve symptoms.
-
Chemotherapy.
-
A clinical trial of surgery, radiation therapy, and
chemotherapy.
-
Chemotherapy given in the chest or abdomen.
Localized Malignant
Mesothelioma (Stage I)
The cancer is found in the lining of the
chest cavity near the lung and heart or in the diaphragm or the lung.
If the cancer is only in one place in the chest or abdomen, treatment
will probably be surgery to remove part of the pleura and some of the
tissue around it. If the cancer is found in a larger part of the
pleura, treatment may be one of the following:
-
Surgery to remove the pleura and the tissue near it
to relieve symptoms, with or without radiation therapy after
surgery.
-
Surgery to remove sections of the pleura, the lung,
part of the diaphragm, and part of the lining around the heart.
-
External beam radiation therapy to relieve symptoms.
-
A clinical trial of surgery followed by chemotherapy
given inside the chest.
-
A clinical trial of surgery, radiation therapy,
and/or chemotherapy.
Pleural mesothelioma
Pleural mesothelioma is of two kinds: (1) diffuse and
malignant (cancerous), and (2) localized and benign (non-cancerous.)
Benign mesotheliomas can often be removed surgically,
are generally not life-threatening, and are not usually related to
asbestos exposure. Malignant mesotheliomas, however, are very serious.
Fortunately, they are rare - about two thousand people are diagnosed
with mesothelioma in the U.S. each year.
The remainder of this section is about diffuse
malignant pleural mesothelioma.
Pleural mesothelioma is a cancer of the cells that
make up the pleura or lining around the outside of the lungs and
inside of the ribs. Its only known cause in the U.S. is previous
exposure to asbestos fibers, including chrysotile, amosite or
crocidolite. This exposure is likely to have happened twenty or more
years before the disease becomes evident, since it takes many years
for the disease to "incubate." It is the most common type of
mesothelioma, accounting for about 75% of all cases.
Mesothelioma is sometimes diagnosed by coincidence,
before there are any symptoms. For instance, tumors have been
discovered through routine chest x-rays. However, when symptoms occur,
they may include shortness of breath, weakness, weight loss, loss of
appetite, chest pains, lower back pains, persistent coughing,
difficulty in swallowing, alone or in combination. An initial medical
examination often shows a pleural effusion, which means an
accumulation of fluid in the pleural space - the area between the
lungs and the chest wall.
The first step in detecting pleural mesothelioma is,
typically, a chest x-ray or CT scan. This is often followed by a
bronchoscopy, using a viewing scope to look inside the lungs.
The actual diagnosis usually requires obtaining a
piece of tissue through a biopsy. This could be a needle biopsy, an
open biopsy, or through a tube with a camera (thoracoscopy or chest
scope.) If an abnormality is seen through the camera then a tissue
sample can be taken at the same time, using the same tube. This is a
hospital procedure that requires anesthesia, but is not usually
painful. The tissue sample is tested by a pathologist.
Fluid build-up from the pleural effusion can generally
be seen on a chest x-ray and heard during a physical examination, but
a firm diagnosis of mesothelioma can only be made through a biopsy and
pathological testing. This is important because there are also benign
pleural effusions and other tumors that have a similar appearance to
mesothelioma. Diagnosing mesothelioma can be quite difficult; it
requires special lab stains, and much experience in understanding
them.
The spread of the tumor over the pleura causes pleural
thickening. This can reduce the flexibility of the pleura and encase
the lungs in an increasingly restrictive girdle. With the lungs
restricted, they get smaller and less functional, and breathing
becomes more difficult. At first a person with mesothelioma may be
breathless only when he or she exercises, but as lung function drops,
he or she can become short of breath even while resting.
The tumor spreads by direct invasion of surrounding
tissue. As it spreads inward it can compress the lungs. As the tumor
spreads outward it can invade the chest wall and ribs, and this can be
extremely painful.
Current medical science does not know exactly how and
why, at a cellular level, asbestos fibers cause mesothelial cells to
become abnormal (malignant or cancerous.) Thus it is not known whether
only one fiber causes the tumor or whether it takes many fibers. It
seems that asbestos fibers in the pleura can start a tumor as well as
promote its growth; the tumor does not depend on any other processes
for its development.
There is as yet no known cure for malignant
mesothelioma. The prognosis depends on various factors, including the
size and stage of the tumor, the extent of the tumor, the cell type,
and whether or not the tumor responds to treatment. KMESA has
represented many clients who lived for five to ten years after
diagnosis, most of them in good health for a majority of those years.
Some mesothelioma victims succumb within a few months; the average
survival time is about a year.
The treatment options for people with mesothelioma
have improved significantly, especially for those whose cancer is
diagnosed early and treated vigorously. Many people are treated with a
combination of therapies, sometimes known as multimodal therapy.
Specific types of treatment include:
There are also experimental treatments like gene
therapy and immunotherapy, angiogenesis inhibitors, and clinical
trials for various new treatments and combinations of treatments.
Treatments that reduce pain and improve lung function,
are becoming more successful (although they cannot cure mesothelioma.)
Pain control medications have become easier to administer. Debulking
is a surgical process of removing a substantial part of the tumor and
reducing the pleural thickening; this can provide significant relief.
X-ray therapy has also been successfully used to control the tumor and
the pain associated with it for a while.
Peritoneal mesothelioma
Many of the organs in the abdomen are enveloped by a
thin membrane of mesothelial cells, known as the peritoneum.
Peritoneal mesothelioma is a tumor of this membrane.
Its only known cause in the U.S. is previous exposure to asbestos, but
it can be many years after exposure before the disease appears.
Peritoneal mesotheliomas account for about one-fifth of all
mesotheliomas.
Like pleural mesothelioma, peritoneal mesothelioma can
be either benign or malignant. This discussion is only about malignant
peritoneal mesothelioma.
Mesothelioma is sometimes diagnosed by coincidence,
before any symptoms have appeared. For example, the tumor is sometimes
seen on a routine abdominal x-ray for a check-up or before surgery.
When the symptoms of peritoneal mesothelioma appear,
they typically include abdominal pains, weakness, weight loss, loss of
appetite, nausea, and abdominal swelling. Fluid often accumulates in
the peritoneal space, a condition known as ascites. Over time the
wasting symptoms can become more and more severe.
The growing tumor can exert increasing pressure on the
organs in the abdomen, leading to bowel obstruction and distention. If
the tumor presses upward, it can impair breathing capacity. If the
tumor pushes against areas with many nerve fibers, and the bowel
distends, the amount of pain can increase.
X-rays and CT scans are, typically, the first step
towards detecting peritoneal mesothelioma. The actual diagnosis is
typically achieved by obtaining a piece of tissue. The medical
procedure of looking at the peritoneum is known as a peritoneoscopy.
It is a hospital procedure and requires anesthesia. If an abnormality
is seen, the doctor will attempt to obtain a tissue sample - this is
known as a biopsy. The tissue sample will be examined by a pathologist
who makes a diagnosis using microscopic analysis of specialized
stains.
There are at least two explanations for how asbestos
fibers can get into the peritoneum. The first is that fibers caught by
the mucus of the trachea and bronchi end up being swallowed. Some of
them lodge in the intestinal tract and from there they can move
through the intestinal wall into the peritoneum. The second
explanation is that fibers that lodge in the lungs can move into the
lymphatic system and be transported to the peritoneum.
Medical science does not know exactly how or why, at a
cellular level, a carcinogen like asbestos causes a cell to become
malignant (cancerous.) Thus it is not known whether only one fiber can
cause a tumor to develop or whether it takes many fibers, or what the
exact conditions and predispositions are for this change to happen.
At this time there are treatments, but no known cure,
for peritoneal mesothelioma. The prognosis depends on various factors,
including the size and stage of the tumor, its extent, the cell type,
and whether or not the tumor responds to treatment.
Benign Mesothelioma:
A rare form of mesothelioma is the cycstic
mesothelioma of the peritoneum. Its prognosis is benign. Its
occurrence has been described primarily in young women. However the
diagnosis presents difficulties, requiring extensive electron
miscroscopy and immunohistochemical studies.
Rare Sites:
Mesothelioma of the pericardium, is a very seldom seen
cardiac cancer. The mass is usually detected at a late stage by
echocardiography, the prognosis is very poor , with or without
therapy. Mesothelioma of the ovaries and the scrotum have also been
reported in the literature. The management differs based on the stage
of the disease, the prognosis is also very poor. The etiology of the
few cases of mesothelioma described in children remains unclear and is
not believed to be asbestos-related, the therapy and prognosis differ
on an individual basis.