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- OncoLink at ASCO 2000
- OncoLink at ASCO 2000: Monday, May 22
A Randomized Trial Comparing Two Fractionation Schedules for Breast
Irradiation Postlumpectomy in Node-Negative Breast Cancer
William Levin, MD
OncoLink Assistant Editor
Last Modified: May 22, 2000
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,
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.