Sarcoma: An Overview
Introduction
"Sarcoma" is a term used to describe
a whole family of cancers that arise in the body's connective
tissues, which include fat, muscle, blood vessels, deep skin
tissues, nerves, bones, and cartilage.
Sarcoma is broken down into two types:
soft tissue tumors
and bone tumors.
Bone sarcomas are rare types of cancer that mainly
affect children and young adults. There are several types
of bone sarcomas that typically affect different parts of
bones and joints. The cancerous tumors can grow in any bone
in the body, however, most occur in the arms or legs.
The most common bone sarcomas include:
- Osteosarcoma (tumor usually develops
in the ends of long bones where new bone tissue forms),
- Ewing's sarcoma (tumor usually develops
in the middle of large bones such as pelvis, thigh, upper
arms and ribs), and
- Chondrosaroma (found mainly in adults,
this type of tumor forms in the cartilage that cushions
joints).
Bone sarcomas account for only 0.2% of all cancers in the
United States. There are approximately 2500 new cases a year.
Bone tumors have a higher incidence of spreading to other
parts of the body, especially the lungs so extra tests are
taken to determine if spread of the disease has occurred.
Patients diagnosed with bone sarcomas find the terms related
to the disease to be very confusing. Without a good understanding
of the treatment plan presented to you by your doctor it is
difficult to cope with your new diagnosis of cancer.
This page will first give you a better understanding of what
"cancer" is in general and
then it will take you through the steps of diagnosing and
treating bone sarcomas, here at the U-M Comprehensive Cancer
Center.
Throughout the many steps in the treatment plan you will
encounter different types of doctors to help manage your care
such as an orthopedic surgical oncologist, medical oncologist
and a radiation oncologist. This multidisciplinary team will
meet and discuss your case with a pathologist and a radiologist
to come up with an individualized treatment plan for you.
Soft tissue sarcomas come in many forms (see also
Bone Tumors):
- angiosarcoma (blood vessels
- fibrosarcoma (connective tissue)
- gastrointestinal stromal tumor (digestive system)
- Kaposi's sarcoma (skin)
- liposarcoma (fat)
- leiomyosarcoma (smooth muscle)
- malignant fibrous histiocytoma (connective tissue),
- neurofibrosarcoma (nerves)
- rhabdomyosarcoma (skeletal muscle) and
- synovial sarcoma (often near joints, but can occur anywhere).
Soft tissue sarcomas account for only 1% of all cancers in
adults. There are approximately 7000 new cases a year in the
United States.
The most common sites of origin are the extremities (legs
and arms), however sarcomas can arise in any part of the body
- including the abdomen, pelvis and head/neck region.
Patients diagnosed with soft tissue sarcomas find the terms
related to the disease to be very confusing. Without a good
understanding of the treatment plan presented to you by your
doctor it is difficult to cope with your new diagnosis of
cancer.
This web page will first give you a better understanding
of what "cancer" is in general
and then it will take you through the steps of diagnosing
and treating soft tissue sarcomas.
Throughout the many steps in the treatment plan you will
encounter different types of doctors to help manage your care
such as an orthopedic surgical oncologist, surgical oncologist,
medical oncologist and a radiation oncologist. This multidisciplinary
team will meet and discuss your case with a pathologist and
a radiologist to come up with an individualized treatment
plan for you.
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What is Cancer?
One of the most confusing aspects about being told you have
sarcoma is that doctors and other health care providers use
terms such as cancer, malignancy, tumor, growth, lump, and
nodule. It is difficult for patients to sort out what all
of these terms mean.
Cancer is a form of abnormal cell growth in tissues
of the body. Under normal circumstances, as we grow
and age the individual cells in the tissues of the body replace
themselves through a regular and organized process of cell
growth. When the cells of an organ grow out of control, the
resulting tissue may form a lump of abnormal cells called
a nodule or tumor. This is a growth of tissue made up of cells
that are no longer functioning in a normal way.
Here are some definitions to help explain the terms used
to describe soft tissue growths that might occur due to abnormal
cell growth.
Growth: A non-specific term that describes
a collection of tissue that is growing in a way that is
different from normal tissue. Growths can be benign (such
as a cyst or wart) or they can be cancerous.
Tumor: A lump of tissue that is growing
out of control. Tumors can be benign (not a threat to life)
or they can be cancerous.
Malignant tumor: A rapidly growing tumor made up
of abnormal cells.
Another term for a malignant tumor is cancer.
A malignant tumor will first grow only in the area where
it started. This is known as the primary tumor. The primary
tumor cells may spread to other tissues or organs through
the bloodstream or lymph system. Once the tumor cells have
spread to other parts of the body, they will take root and
start to grow other tumors. This process is called metastasizing.
The new tumor name in other parts of the body is called
metastatic tumor.
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Diagnosing of Your Sarcoma
Most commonly, bone sarcoma patients present with a pain
in the area of the lesion. In more advanced lesions, patients
may notice swelling in the area or present with a fracture
of the affected bone. A complete patient history is extremely
important when diagnosing bone tumors.
Physical Examination
A physician will do a complete examination of the painful
area to evaluate the surrounding skin, blood vessels, nerves
or bone and any surrounding lymph nodes.
Radiological Imaging (X-rays and scans)
- Plain X-ray Films:
Standard x-rays are taken to evaluate the bone. They can
show tumor location. Usually more detailed imaging such,
as a MRI or CT scan is needed to further evaluate. Chest
x-rays are also useful to evaluate for metastatic tumors
in the lung.
- Magnetic Resonance Imaging (MRI):
This is one of the most useful methods to image tumors
in the extremities. It provides the physician with a detailed
view of the tumor and its surroundings.
- Computed Tomography (CT scan):
This is another way to image a tumor. Especially useful
in tumors which are in the abdomen and pelvis.
CT scan of the chest is also frequently recommended
to assess for metastases of sarcoma, or disease which
might have traveled to the lungs.
- Positron Emission Tomograhy (PET scan):
This is a newer study done in Nuclear Medicine, which
looks at the metabolic activity of cells in the body.
Tumor cells often have very active metabolism and therefore
can be seen on a PET scan. However, other conditions involved
increased metabolism (including healing scars) sometimes
show up on PET scans as well. PET scans are occasionally
used for sarcoma patients, but usually are not as useful
as CT and MRI scans.
- Bone Scan:
This is study done in nuclear medicine, which uses radioactive
dye to highlight the bones. This scan is sometimes used
to look for cancer in other parts of the bone that has
metastasized.
NOTE: Each physician chooses which method
of imaging they prefer to give them the best view of the primary
tumor and any other tumors, which may be present.
Biopsy
A biopsy is the only way to tell for sure if you
have a malignant tumor and, if so, what kind of cancer it
is. Because sarcomas are rare, a specialist in sarcoma pathology
generally reviews the results of the biopsy before any treatment
starts. Tumor location determines what type of biopsy will
be used.
Generally two types of biopsies can be used:
- Core needle biopsy:
This procedure is less invasive than the other method
described next. It can be done in the office by your surgeon
using local anesthesia. The surgeon will numb the area
around the tumor and extract a small amount of tissue
from the tumor with a special biopsy needle for the pathologist
to examine.
- Incisional biopsy:
A small incision (about an inch) is made, and
tissue is removed for examination. This is a more invasive
procedure and is most often done in the operating room
under either local or general anesthesia. The advantage
of this procedure is that is provides more tissue for
the pathologist to review.
NOTE: Once the pathologist has tissue from
a biopsy, the type of soft tissue sarcoma and how aggressive
it is can be determined.
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Treatment of Your Sarcoma
Once your physicians know the type of bone sarcoma, the
location of the primary tumor and if there are any metastatic
tumors in the body, all the physicians who are involved in
the multidisciplinary discussion of your case can come up
with a plan for treatment.
Remember: the order of
treatment is determined by the size of the tumor and its location,
as well as whether there is metastatic tumor anywhere else
in the body.
Surgery
Surgery is considered to be the primary treatment for bone
sarcomas, and for some, is the only treatment.
The first goal of the orthopedic surgeon is to remove the
tumor, along with some healthy tissue around it. This ensures
that no cancer cells remain.
The second goal is to retain as much function as possible
to the operative site. Sometimes manmade material is used
to replace bone, artificial joints and devices are inserted
and sometimes amputation is needed. The involvement of the
surrounding tissue, muscle, nerves and blood vessels determine
the extent to which that is possible.
Your orthopedic oncologist prior to your surgery will discuss
all your options. A thoracic surgeon performs surgery for
sarcomas inside the chest or lungs (usually metastatic tumors).
RadiationTherapy
Radiation usually is administered after surgery, and is
given to patients who are at risk for local tumor reoccurrence
if only surgery was used for control of the tumor locally.
The goal of radiation therapy is to direct additional therapy
at the tumor site to kill any remaining cancer cells that
could remain after surgery.
The radiation oncologist uses your preoperative x-rays,
information from your surgeon and their own treatment plan
to determine the region that needs to be treated.
Radiation treatment is given daily Monday through Friday
for 5-7 weeks depending on the plan discussed by your radiation
oncologist.
Chemotherapy
Many factors influence the use of chemotherapy or drug treatment
of sarcoma.
These factors include:
- the aggressiveness of the tumor or grade
- the size of the tumor and
- if the tumor has already spread to other areas in the
body.
There are many cases in which chemotherapy is given prior
to surgery to help shrink down the primary tumor so the
surgeon can fully remove the tumor and maintain function
of the affected area. It is also used after surgery to destroy
any stray cancer cells and to prevent cancer from recurring.
Chemotherapy is often given in high doses and it can cause
you to feel sick at times. The details of the chemotherapy
regimen and toxicities (side effects) related to the chemotherapy
will be discussed by your medical oncologist and staff.
(you can also visit our web page: What
to Expect: A Guide to Chemotherapy).
The chemotherapy is given to you in the outpatient clinic
or in the hospital and the length of treatment is determined
by which regimen your medical oncologist presents to you.
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Conclusion
Hopefully this page has helped you better understand your
sarcoma and has helped you understand how a treatment plan
is formed.
You need to remember that every case is individualized.
Your team of physicians has worked closely together to come
up with a plan that will give you the best chance of survival
and a good quality of life. They are very willing to answer
questions and want to be sure you understand exactly what
is being recommended and why.
Please make sure to ask questions of the doctors and staff
to be sure you understand all of your options.
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