Nearly 10 percent of brain cancer patients who received
radiation in
combination with chemotherapy were still alive five years after
diagnosis,
the best long-term survival rate ever reported for a group of
patients
stricken with the aggressive tumor, researchers reported.
The treatment regimen described in the journal Lancet Oncology
parallels
the approach used by cancer specialists to treat Senator Edward M.
Kennedy,
the Massachusetts Democrat who was diagnosed in May with a
malignant brain
tumor.
The researchers, based at hospitals in Europe and Canada, gave
patients
both radiation and a chemotherapy drug called temozolomide for six
weeks;
patients then continued taking the drug alone five days a month for
the
following six months.
The combination therapy proved superior to radiation alone at
every
milestone measured. After three years, for example, 16 percent of
the
patients who had received radiation and chemo were still alive,
compared
with just 4.4 percent of those who had only radiation.
The survival difference was even more pronounced at the
five-year mark,
with patients who had received the combination regime five times
more
likely to be alive.
Cancer specialists hailed the findings as hopeful for patients
with brain
tumors, but cautioned that the disease remains exceptionally
difficult to
defeat.
"This is a true advance for the field," said Dr. Tracy
Batchelor, chief
of neuro-oncology at the Massachusetts General Hospital Cancer
Center,
which is overseeing Kennedy's care. "We are very happy to see that
these
beneficial effects are sustained for up to five years in this
patient
population, but nevertheless, it is not the cure that we are all
looking
for."
For years, doctors had little to offer brain cancer patients
other than
surgery to remove the rapidly spreading tumor, followed by
radiation to
bombard as many stray cancer cells as possible. But the results
were
dismal, with few patients surviving longer than two years.
When temozolomide was first tried as a stand-alone treatment,
results were
disappointing, said Dr. Ren?-Olivier Mirimanoff, senior author of
the
study published Sunday. But then researchers in Switzerland decided
to see
what would happen if they gave it at the same time as radiation.
"The results were fairly amazing because for the first time, we
could see
the survival of patients was beyond two, three years," said
Mirimanoff, a
radiation oncologist at University Hospital in Lausanne,
Switzerland.
The scientists then embarked on the larger study that was
reported Sunday.
They followed 573 patients, with half receiving combination therapy
and
half getting radiation exclusively.
Specialists theorize that the chemotherapy drug boosts the
potency of
radiation therapy. What's less clear, though, is how much
temozolomide
helps on its own during the period after radiation.
The study conducted in Europe and Canada limited participation
to patients
70 and younger; Kennedy was 76 when he was diagnosed with brain
cancer.
Batchelor said there is preliminary evidence from other studies
that older
patients derive similar benefits when treated with radiation and
temozolomide together, although that has not been established
definitively.
Younger, healthy patients - those under 50 - benefited the most
from the
combination treatment, with up to 28 percent still alive after five
years.
Patients whose tumors carried a certain genetic profile also tended
to fare
better, further evidence, researchers said, that gene
fingerprinting can
help design more effective treatment protocols.
Mirimanoff, who trained in radiation oncology at Mass. General,
said the
modest success of the combination treatment had fueled a notable
shift in
attitude among doctors, especially when confronted with patients
whose
cancer had returned.
Now, he said, doctors appear more willing to suggest a second
surgery to
patients, followed by radiation and chemotherapy.
Stephen Smith can be reached at stsmith@globe.com.
c.2009 The Boston Globe