Ewing's sarcoma, Part 1 — Introduction, symptoms and treatment
What is Ewing’s sarcoma?
Ewing's sarcoma is the most common type of sarcoma (cancer of bone or
soft tissues) in children under the age of ten. Most children diagnosed
with this are between the ages of 5 and 25. This cancer usually arises
within bone but occasionally is found in soft tissues. The cancer is named
after one of the first pathologists to describe the tumor. There is no
definitive evidence of what type of tissue this cancer makes (compare
to osteosarcoma). There appears to be some relationship to immature (primitive)
nerve cells. There is a typical abnormality in the DNA in this tumor,
but there is no evidence that the susceptibility to this tumor is inherited.
Incidence and Prevalence
The peak incidence is between ages 10 and 20, it is less common in children
under 5 or in adults over 30. Prior to adolescence, the number of males
and females affected are equal. After adolescence, however, the number
of males affected is slightly higher than the number of females. Ewing’s
tumors account for 4% of childhood and adolescent malignancies. Ewing's can occur in any bone in the body. However,
the most common sites are the pelvis,
thigh, lower leg, upper arm, and rib. The incidence of Ewing’s sarcoma
from birth to age 20 years is 2.9 per million population annually. Approximately
10% of patients with Ewing’s sarcoma are aged 20-30 years. Cases
occurring later in life are infrequent. The tumor is composed of small
round blue cells. Ewing's sarcoma can also arise in soft tissue (extra-skeletal).
Symptoms
Patients with Ewing's sarcoma typically present with pain. They also
occasionally have a mass that you can feel and a fever. The pain is usually
out of proportion, in
both severity and duration, to any specific trauma or injury. These children
frequently have pain at night. The cancer is found at the end of
bones (near joints)
or in the middle, or shaft, of bones.
The diagnosis of Ewing's sarcoma is made by a biopsy. This cancer can
spread through the blood stream to the lungs, other bones, or bone marrow.
About 25% of
patients have cancer found elsewhere (metastases) when initially seen.
Metastases are found by doing a computed tomography (CAT or CT) scan of
the lungs, bone
scan to see the rest of the bones, and aspirate (with the needle) of the
bone marrow of the pelvis.
Treatment
Although metastases may not be present initially, they can occur at any
time. Treatment of only the tumor in the bone does not keep metastases
from showing up and
usually leads to only short-term survival. Therefore, treatment of Ewing's
sarcoma starts with chemotherapy. The better the response to chemotherapy,
the better
the chance that the child will survive. The side effects of chemotherapy,
as seen with other cancers, include fever, increased risk of infection,
and increased risk of
bleeding with trauma. The specific side effects depend on the drugs used
and the timing of treatment.
Treatment of the bone with the cancer depends on the size of the tumor.
This cancer frequently breaks out through the bone, involving a substantial
amount of
adjacent soft tissue (muscle, nerves, blood vessels). Large tumors are
particularly seen in the pelvis. If so much tissue needs to be removed
surgically that the
extremity no longer is able to function, radiation therapy is used to
kill the cancer. For smaller tumors, the bone can be removed surgically
and replaced with either a
piece of metal that is shaped to look like the bone (similar to the replacements
in older people with arthritis) or a bone that is the same size as the
removed bone.
Although this cancer responds to radiation, there is some evidence that
the cancer is less likely to come back if removed surgically, rather than
irradiated.
Side effects of medication
In addition to surgery, people with Ewing’s sarcoma usually must
have chemotherapy treatments. Like other cancers, a combination of chemotherapy
drugs (a group of different very strong medications used to treat cancer)
are usually used to treat Ewing’s sarcoma. The side effects depend
on which drugs are used to treat the patient. Common side effects include
- nausea
- vomiting
- tiredness
- low blood cell counts
- susceptibility to infection
- hair loss
Ewing's, Part 1 — Introduction, symptoms and treatment
For more information, please contact:
Kathy Davis, MSEd, PhD
kdavis2@kumc.edu
(913) 588-6305