Presenter: Timothy J. Whelan Affiliation: Hamilton Regional Cancer Ctr, Hamilton, ON, Canada; Toronto Sunnybrook Regional Cancer Ctr,
Toronto, ON, Canada; McMaster Univ, Hamilton, ON, Canada; Kingston Regional Cancer Ctr, Kingston, ON, Canada; Ottawa
Regional Cancer Ctr, Ottawa,
Background: Many women with early stage breast cancer choose
definitive breast irradiation for treatment.
Typically in the US,
radiation is delivered to a dose of 46 - 50 Gy to
the whole breast
followed by a boost to about 60 Gy, all over a
course of 6 weeks. This
study evaluates the possibility of increasing the
daily fraction size
and reducing the number of treatment days by using
a dose that is
biologically equivalent to standard therapy.
Materials and Methods:
1234 women with node negative breast cancer and
clear surgical margins
following lumpectomy were randomized to either:
Arm 1. 42.5 Gy of whole breast irradiation in 16
fractions over 22
Arm 2. 50 Gy of whole breast irradiation in 25
fractions over 35 days
All treatment was delivered 5 days per week with
2 tangential fields
No breast boost was used in this study
Median followup was 4.6 years
The 5-year actuarial breast recurrence rate was
2.9% in each arm.
The 5-year diease-free survival rates were 88%
vs. 90% (p=NS) in Arm
1 vs. Arm 2.
The 5-year overall survival was 93.5% vs. 94.3%
(p = NS) in Arm 1
vs. Arm 2.
The cosmetic outcome at both 3 and 5 years was
These data suggest that a shorter course of
radiation is an
acceptable alternative to the current standard of
Such a schedule is more attractive because it is
more convenient for
patients and less resource-intensive for the
In general, increasing the daily radiation dose
can be associated
with worse cosmetic outcome and a higher
probability of normal normal
tissue complications involving the heart, brachial
plexus and lung.
The control arm of this trial did not use a
breast boost typically
administered at most US centers.
This study shows an equal efficacy in tumor
control and cosmetic
outcome between the two arms.
The relatively short followup of this study must
be taken into
account when evaluating for local control, late
toxicity and cosmesis.
Feb 11, 2010 - Whole-breast irradiation spread over fewer days (accelerated, hypofractionated radiation) following breast-conserving surgery for cancer appears non-inferior to standard radiation treatment, according to research published in the Feb. 11 issue of the New England Journal of Medicine. This adds to a study recently released Online First in The Lancet Oncology, which showed that hypofractionated radiotherapy for breast cancer patients may provide a better quality of life with no evidence of an increase in adverse effects.