In this study, only patients aged 50 years or older with node negative breast cancer were included. In the START-B trial, reducing the overall treatment time from 5 weeks to 3 weeks led to improved disease free survival and overall survival rates, probably due to less distant relapses. The researchers chose the same prescription dose as the FAST trial to not compromise on tumour control but treatment on consecutive days was not allowed to allow repair of normal tissues in-between fractions. The health-related quality of life (HRQoL) was observed in the group treated in 5 fractions, both immediately after RT and after 1 year. This schedule showed equivalent results for late toxicity, relapse and survival at 5 years after irradiation as a 15-fractions schedule of 2.67 Gy over 3 weeks. This schedule showed equivalent results for late toxicity, relapse and survival at 5 years after irradiation as a 15-fractions schedule of 2.67 Gy over 3 weeks. The primary endpoint of the trial is breast retraction 2 years after RT. SAS Power and Sample Size software was used for the sample size calculation with α = 0.05 and β = 0.8.
As a conclusion it is evident that, Five patients randomized to 15 fractions were actually treated in 5 fractions (protocol violation), which led to 106 patients effectively treated in 5 fractions and 94 patients in 15 fractions.
Ref link- https://www.thebreastonline.com/article/S0960-9776(20)30249-6/fulltext
