EXTRAORDINARY
HEALING THERAPY CANCER PATIENTS CURED 94%
The American scientist Stanley
Riddell and described the results of a therapy that could revolutionize cancer
treatment in the future.
Using one's own immune system
cells of patients with terminal cancer, Riddell and his colleagues managed, in
one study, symptoms of the disease disappeared in 94% of cases.
But Riddell himself warned
that this is a small study and there is a risk of side effects.
BBC World will explain what
the new therapy, why it has generated so many expectations and what their
limitations are.
Why you talk about a
revolutionary therapy?
Riddell presented his research
at the annual meeting of the American Association for the Advancement of
Science, AAAS for its acronym in English, which takes place in Washington.
The results of the work of the
scientist, Center Fred Hutchinson Cancer Research in Seattle, recently will be
published in detail in the coming months.
All studies involved patients
with different types of blood cancer in an advanced stage.
In the most promising study,
35 patients with acute lymphoblastic leukemia (ALL acronym in English), 94%
went into remission.
In other words, the symptoms
disappeared, which does not mean that patients are cured.
In a second study with more
than 40 lymphoma patients, 50% achieved remission.
And in a group of patients
with Non-Hodgkin lymphoma, 80% responded to treatment, showing a reduction in
symptoms.
"We are talking about
patients in whom no treatment was no longer working. Most of our patients had a
life expectancy of two to five months," Riddell said.
What is therapy?
Image copyright THINKSTOCK
Image caption therapy was used
in different types of blood cancer, but not yet tested in solid tumors.
Treatment genetically
engineered to immune system cells called lymphocytes T or T cells that
coordinate cellular immune responses.
The scientists extracted cells
from these patients and attached them receptor molecules that recognize target
a specific type of cancer. The modified cells were then reintroduced into the
patient.
The molecules are called
antigens chimeric receptors, chimeric antigen receptors or CARs for its acronym
in English, and reduce the cancer's ability to defend the immune system.
Cancer cells have clever to
hide from lymphocytes or can completely overwhelm the immune system mechanisms.
"Essentially what this
technique is genetically reprogrammed T cells to seek, recognize and destroy
cancer cells," Riddell told the BBC.
Can you be serious side
effects?
The main problem of this study
was the risk of a serious side effect associated with excessive immune
response.
Twenty patients developed
symptoms of fever, hypotension, nausea and neurotoxicity associated with the
storm called cytokines, cytokine release syndrome, SCRs for its acronym in
English, a potentially fatal immune reaction defensive.
Seven patients required
hospitalization in the intensive care unit and two died.
What other limitations does
the therapy?
The Riddell himself warned
that "there are reasons to be optimistic and reasons to be
pessimistic".
One of the next steps will be
to conduct further studies with lower doses of modified T cells to avoid the
risk of side effects.
Image copyright THINKSTOCK
Image caption cancer cells in
a case of acute lymphoblastic leukemia. The study of 35 patients with this
disease achieved remission of 94%.
He also warned that it is
still unclear how long patients remain in remission.
"We still have a long way
to go. The cancer has recurred in some patients, but the data we have so far
are unprecedented," Riddell said.
Studies have also limited to
blood cancers and scientist now hopes to test the therapy in patients with
solid tumors, such as breast cancer.
Alan Worsley, researcher at
the British center Cancer Research UK, described the therapy as "a first
step".
"This treatment looks
promising in some types of blood cancer. But the real challenge will be to work
in other cancers," Worsley told the BBC.
However, studies point to a
paradigm shift in the fight against cancer, according to Riddell.
For the researcher of Seattle,
"immunotherapy is finally a pillar of cancer therapy. As chemotherapy and
radiotherapy, will not be a cure for all cases, but end up being applied in
certain types of tumors of certain types patients. "