Bone
Marrow Transplants
This is the
most controversial
form of conventional treatment for breast cancer. Powerful and painful
with severe side effects, bone marrow transplants (BMT) with high dose
chemotherapy is a last resort that most physicians and insurance companies
regard as a risk not worth taking. Patients, desperate for a way to stop
the march of cancer, are often eager to take the risk. About 30,000 women
with breast cancer have undergone the procedure.
Some cancers
do respond to the combination of high doses of toxic chemicals followed
by repair to the bone marrow. What the breast
cancer community and insurance companies want to know is whether these
painful and expensive procedures, produce better results than other less
invasive and more affordable breast cancer treatment options.
Most studies
of the high dose chemotherapy regimen involved with BMT found that the
"no evidence of disease" (NED) and survival rates for this procedure were
worse than with traditional drug and radiation treatments. Why go through
dangerous bone marrow transplants and extremely toxic chemotherapy, when
changing to a different drug produced better results?
Treatments
for breast cancer sometimes make tumors resistant. Higher doses can kill
the cancer cells, but destroy the bone marrow - necessary for normal functioning
of the immune system. Before high dose chemotherapy, bone marrow from
the patient is removed and frozen. After the chemo is finished the bone
marrow is replaced. This is called autologous
bone marrow transplant. If the bone marrow is from a donor, not the
patient, it is an allogenic transplant. Another method is a peripheral
blood stem cell transplant. "Stem cells" are immature blood cells removed
by filtering the patient's blood, treated to remove any cancer cells and
frozen. When the stem cells are replaced after the high dose chemo, they
restart the production of blood cells and restore immune function.
The results
from BMT studies were negative until Dr.W.R. Bezwoda from the University
of Witwatersrand, South Africa, one of five studies reviewed at the 1999
American Society of Clinical Oncologists Conference, reported a 5 year
17% mortality rate for the bone marrow transplant group compared with
a 35% mortality rate for more traditional treatment.
Physicians,
patients and the media, eager to find a means to tackle difficult to treat,
late stage, or drug resistant breast cancers and metastases, greeted the
news with relief. Based on Bezwoda's results, many doctors began recommending
BMT and insurance carriers started covering the cost.
Then, the
news broke that the study had misreported the results. The media covered
charges of fraud and insurance
companies announced that they would no longer pay for BMT.
What caused
a well respected researcher to falsify data? Pressure to show "better"
results to receive funds may have been a factor. The doctor may have been
swayed by personal beliefs that allowed him to overlook problems with
the trial in order to promote a therapy that he believed was beneficial.
We will never know. Doctor Bezwoda denied the misconduct, and the scientific
community and breast cancer patients are left wondering what direction
to take.
BMT is still
being studied to determine whether it is worth the discomfort and risks.
Even if doctors recommend this course of treatment, the costs without
insurance coverage are prohibitive. BMT has proven worthwhile against
other forms of cancer and the jury is still out on whether this could
be an option for breast cancer. Unless current studies show that this
procedure works better than traditional drug and radiation therapy, bone
marrow transplant with high dose chemotherapy is an expensive and
dangerous experiment.
March
13, 2000
Last
updated March 31, 2006
Elsewhere
on the Web:
BMT
InfoNet
Bone
Marrow Foundation
