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The type and the severity of the side
effects from chemotherapy or radiation may vary depending
on the specific chemotherapy or radiation treatment regimen
used and are further influenced by the condition and age
of the patient. Treatment may also be complicated if a person
has undergone autologous stem cell transplant, the related
degree of HLA matching between donor and recipient, and
the degree of suppression of the immune system. While high
doses of chemotherapy and radiation therapy can potentially
effect any of the bodies normal cells or organs the more
common side effects may include the following:
1. Reduced production of blood cells and platelets
High-dose chemotherapy directly destroys
the bone marrow's ability to produce white blood cells,
red blood cells, and platelets. Patients experience side
effects from low numbers of white blood cells (neutropenia),
red blood cells (anemia), and platelets (thrombocytopenia).
2. Infections
The immune system may take even longer
to recover than white blood cell production thus resulting
in a susceptibility to some bacterial, fungal and viral
infections for weeks or months, including Pneumocystis carinii
pneumonia, herpes zoster infection, which commonly occurs
after high-dose chemotherapy.
3. Liver Damage: Veno-Occlusive Disease of the Liver (VOD):
High-dose chemotherapy can result in damage
to the liver which can be serious and even fatal. This complication
is increased in patients who have had a lot of previous
chemotherapy and/or radiation therapy, a history of liver
damage or hepatitis. Veno-occlusive disease of the liver
typically occurs in the first 2 weeks after high-dose chemotherapy
treatment. Patients typically experience symptoms of abdominal
fullness or swelling, liver tenderness and weight gain from
fluid retention. Development of strategies to prevent or
treat veno-occlusive disease is an active area of clinical
investigation.
4. Lung Damage: Interstitial Pneumonia Syndrome (IPS):
High-dose chemotherapy can cause damage
directly to the cells of the lungs. This may be more frequent
in patients treated with certain types of chemotherapy and/or
radiation therapy. This complication may occur anytime from
a few days after high-dose chemotherapy to several months
after treatment. Patients typically experience a dry non-productive
cough or shortness of breath. Both patients and their doctors
often misinterpret these early symptoms. Patients experiencing
shortness of breath or a new cough after allogeneic transplant
should bring this to the immediate attention of their doctor
since this can be a serious and even fatal complication.
5. Potential Long-Term Side Effects:
There are several long-term or late side
effects that result from the chemotherapy and radiation
therapy. The frequency and severity of these problems depends
on the what radiation or chemotherapy was used to treat
the patient. It is important to have the doctors providing
care to explain the specific long-term side effects that
may occur for the actual treatment they propose. Some examples
of complications may include the following;
6. Cataracts:
Cataracts occur in the overwhelming majority
of patients who receive total body irradiation in their
treatment regimen. In patients who receive chemotherapy
without total body irradiation, cataracts are much less
frequent. The onset of cataracts begins at 18-24 months
following treatment. Patients who have received large doses
of steroids will have an increased frequency and earlier
onset of cataracts. Patients are advised to have slit lamp
eye evaluations annually with early correction with artificial
lenses.
7. Infertility:
The overwhelming majority of women who
receive total body irradiation will be sterile. However,
some prepubertal and adolescent females do recover ovulation
and menstruation. In patients who receive chemotherapy only
preparative regimens, the incidence of sterility is more
variable and more age related, i.e., the older the woman
is at the time of treatment the more likely chemotherapy
will produce anovulation. These are important considerations
because of the need for hormone replacement. All females
should have frequent gynecologic followup. The overwhelming
majority of men who receive total body irradiation will
become sterile. Sterility is much more variable after chemotherapy
only regimens. Men should have sperm counts done to determine
whether or not sperm are present and should be examined
over time as recovery can occur.
8. New Cancers:
Treatment with chemotherapy and radiation
therapy is known to increase the risk of developing a new
cancer. These are called "secondary cancers" and may occur
as a late complication of high-dose chemotherapy. Patients
treated with high-dose chemotherapy and allogeneic stem
cell transplant appear to have an increased risk of developing
a secondary cancer. In a report evaluating almost 20,000
patients treated with allogeneic stem cell transplant, 80
patients developed a new cancer. This represents an approximate
2.5% greater risk compared to normal individuals. The longer
patients survived after high-dose chemotherapy, the greater
the risk of developing a secondary cancer. Patients treated
with total body irradiation appear to be more likely to
develop new cancer than those treated with lower radiation
doses or high-dose chemotherapy. High-dose chemotherapy
and allogeneic stem cell transplant is increasingly used
to treat certain cancers because it improves cure rates.
Patients should be aware of the risk of secondary cancer
following high-dose chemotherapy treatment and discuss the
benefits and risks of high-dose chemotherapy with their
primary cancer physician.
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