Evidence on the importance of these factors is, however, weak. Mastectomy is a disfiguring procedure. Invasive breast cancer detected early may often be adequately treated with less radical procedures. Consequently, the appropriate use of mastectomy in the management of DCIS remains unclear, although it is often considered for patients with extensive disease. There are no ongoing randomised trials addressing this issue.
Radiation therapy is, however, associated with some toxicity.
There is also a lack of reliable evidence of any reduction in risk resulting from treatment with radiotherapy on distant relapse or death from breast cancer, the risk of both being very small. Radiotherapy therefore appears to be an appropriate treatment in reducing the risk of local recurrence of invasive cancer in patients at sufficient risk. However its overall role in the management of DCIS remains unclear. This issue is being addressed in several ongoing randomised trials. The evidence to be provided by the ongoing randomised trials will be vital in this regard.