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document
Effect of age and radiation dose on local control after breast conserving treatment : EORTC trial 22881-10882 . PURPOSE To determine whether the effect of an additional " boost " radiation after breast conservative therapy ( BCT ) on local control depends on age and evaluate the impact of a treatment policy with a threshold for age . PATIENTS AND METHODS We used data from EORTC 22881-10882 trial , with median follow-up of 77.4 months . Patients receiving BCT and 50Gy whole breast irradiation were randomized to no boost and 16Gy boost ( N=5318 ) . RESULTS In univariate analysis , a boost reduced local failure by a factor of 2 ( P < 0.0001 ) . Multivariate analysis showed local control increased with age ( P=0.0003 ) . There was no evidence that the relative effect of a boost on local control depends on age ( P=0.97 ) However in younger patients the 5-year local failure was higher , therefore the absolute reduction was greater . If the threshold-age for boost treatment were set at 40 years , 8.4 % of the study population would receive a boost , resulting in a 5-year local failure of 6.1 % in the study population . Changing the threshold-age to 60 years , 67 % of the study population would receive a boost and the 5-year local failure would be reduced to 4.4 % . CONCLUSIONS In younger patients a boost dose resulted in a greater absolute reduction of local failure . The relative risk reduction was however similar for all ages . Applying a treatment policy with a threshold-age of 60 would result in 0.6 % increase in local failure in the total study population , while sparing the boost to 1/3 of the patients .
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Intervention_Physical
radiation
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Intervention_Control
breast conserving treatment
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Intervention_Physical
" boost " radiation
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Intervention_Physical
breast conservative therapy ( BCT )
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Intervention_Physical
BCT and 50Gy whole breast irradiation
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Intervention_Physical
no boost and 16Gy boost
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Intervention_Physical
boost
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Intervention_Physical
boost
28840
Intervention_Physical
boost
28841
Intervention_Physical
boost
28842
Outcome_Physical
local control
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Outcome_Physical
local failure
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Outcome_Physical
local control
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Outcome_Physical
local control
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Outcome_Physical
local failure
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Outcome_Physical
local failure
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Outcome_Physical
local failure
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Outcome_Physical
local failure
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Outcome_Other
relative risk reduction
28851
Outcome_Physical
local failure
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Participant_Condition
BCT and 50Gy whole breast irradiation
28853
Participant_Age
younger patients