A study soon to be published in Lancet found that radiotherapy reduces the recurrence of breast cancer by 50%.
An analysis including data from almost 11,000 women with breast cancer who 
were followed for ten years found that there was a clear reduction in cancer recurrence post-radiotherapy. Those women who received radiotherapy within a year of undergoing surgery were the least likely to experience a recurrence of breast cancer.
In the ten years post-surgery the risk of breast cancer recurrence was cut by 50% and the risk of mortality cut by one sixth over the fifteen years post-surgery. Over this time period only 21% of women who were given radiotherapy treatment died, in comparison to 25% of women who were not.
The authors write that the “… overall findings from these trials show that radiotherapy after breast-conserving surgery not only substantially reduces the risk of recurrence but also moderately reduces the risk of death from breast cancer.”
