Some women with early
breast cancer might benefit from a "one-and-done" treatment, in which
they receive a single dose of targeted radiation therapy during the surgery
that removes their tumour.
A pair of new studies found
that this procedure works about as well as current protocols that require six
weeks of daily radiation therapy following surgery.
The new procedure uses
miniature devices that deliver radiation directly to the site of the tumour,
while the site remains exposed by surgery following lumpectomy.
"It's right in front
of the surgeon's and the radiation oncologist's eyes, so we can put the beam
precisely where it is needed," said study co-author Dr Michael Baum,
emeritus professor of surgery and a principal research associate at the
University College London Medical School. "We can form the cavity to the
shape of the beam. It's elegant and dead simple."
The procedure also appears
safer, in terms of radiation exposure. Fewer women who received targeted
therapy died during Baum's study, an occurrence they chalked up to the
patients' more limited exposure to radiation.
Comparable to standard treatment
In Baum's trial, women
received one dose of radiation therapy for 20 to 45 minutes following surgery.
About 15% of the patients had tumour complications that required them to return
for the standard weeks of radiation therapy. However, radiation treatment was
completed for the rest of the women, and with cancer recurrence rates
comparable to standard treatment.
"You can say 80% or
more of these women will complete their therapy at the time of surgery,"
This therapy could prove an
advantage for women who live in remote areas without easy access to a radiation
therapy centre, Baum said.
He said these women often
have to undergo a full mastectomy even if they are eligible for breast-saving
cancer surgery, simply because they can't make it to the follow-up radiation
therapy sessions that will prevent their cancer from recurring.
"I think this will be
a boon for American women, even though you are a wealthy country," Baum
said. "Even for the wealthiest country in the world, there are many women
living in rural areas who don't have the option of travelling two or three
hours a day back and forth to a radiotherapy centre. This will cut down on the
number of mastectomies."
Only certain women may benefit
However, only certain women
with early-stage breast cancer will be able to benefit, noted Dr Stephanie
Bernik, chief of surgical oncology at Lenox Hill Hospital, in New York City.
Women best suited for the
procedure are over age 45, will have small, single tumours, and the cancer will
not have spread to their lymph nodes, she said.
"In certain carefully
selected women you can do this, but it does not apply to all women across the
board," Bernik said. "We have to be careful not to apply this to
every cancer patient who comes through the door."
Baum's study was published
online in The Lancet. Over a period of 12 years, his team tracked 1 721
women who received radiation therapy during their breast cancer surgery and
compared their outcomes to those of 1 730 women who underwent standard therapy.
Overall deaths reduced
The researchers found that
radiation therapy during surgery worked just as well as conventional treatment
in reducing a woman's five-year risk of breast cancer recurrence.
Further, they found that
overall deaths were reduced in the group that received radiation therapy during
surgery, only 3.9% compared with 5.3% for those who received conventional
treatment. However, the rate of deaths caused by breast cancer itself was
similar in both groups.
"There was an excess
of deaths for other causes in women receiving whole-breast radiotherapy,"
Baum said. "We think these are the toxic side effects of radiotherapy to
the heart causing heart attacks, and radiation causing other cancers."
'Boost' of radiation therapy
The second trial, published
in The Lancet Oncology, involved 651 women who received radiation
therapy following surgery at the European Institute of Oncology in Milan,
Italy. This trial used a slightly different device to deliver radiation
directly to the tumour site.
The women who received the
targeted therapy had higher levels of breast cancer recurrence – 4.4%, versus
0.4% in the comparison group that underwent conventional therapy.
Despite this, overall
five-year survival rates did not differ significantly between the two groups.
Baum said researchers next
will look at whether providing a "boost" of radiation therapy during
surgery will provide benefits to those women who will still need to undergo
weeks of conventional therapy. "We think the results will be significantly
better," he said.
US oncologist Bernik
predicts that radiation therapy during surgery will become more common, but
that there are many kinks left to work out.
"This is the beginning
of a new trend," Bernik said. "We have a lot of work to do to get to
a point where this will be perfected."
For more information on
breast cancer, visit the US National
Library of Medicine.
Picture: Radiation from Shutterstock
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