Ductal carcinoma in situ (DCIS) occurs in the duct cells lining the milk ducts. This is a form of pre-cancer that is still confined to the ducts and has not spread outside. The usual way of treating such a pre-cancer is surgery and radiotherapy. Sometimes mastectomy may also be necessary.
"First, not using radiotherapy in young patients with DCIS resulted in an unacceptable number of women having their cancer return and second, these patients benefit from an additional boost dose," said lead author Guenther Gruber of the Kantonsspital in Aarau, Switzerland.
Around one-sixth of the patients had surgery and radiotherapy, while the rest had radiotherapy plus a booster. The risk of a relapse decreased with each successive dose of radiation. The researchers admit that more research is needed to confirm the findings.