[Radiotherapy in breast-conserving treatment for ductal carcinoma in situ: first results of the EORTC randomised phase III trial 10853].

TLDR: Radiotherapy after local excision for DCIS reduced the overal number of both invasive and non-invasive recurrence s in the ipsilaterall breast at a median follow-up of 4.25 years.

Abstract: t BackgroundBackground Ductal carcinoma in situ (DCIS) of the breast is a disorder that has become moree common since it may manifest as microcalcifications that can be detected by screeningg mammography . Since selected women with invasive cancer can be treated safel yy with breast-conservatio n therapy it is paradoxical that total mastectomy has remainedd the standar d treatment for DCIS. We did a randomised phase III clinical trial too investigat e the role of radiotherapy after complet e local excision of DCIS. MethodsMethods Between 1986 and 1996, women with clinically or mammographicall y detectedd DCIS measuring less than or equal to 5 cm were treated by complet e local excisionn of the lesion and then randoml y assigned to either no further treatment (N=503)) or to radiotherapy (N=507. 50 Gy in five weeks to the whole breast) . The mediann duration of follow-up was 4.25 years (maximum 12.0). All analyses were by intentionn to treat. ResultsResults 502 patient s were followed up in the no further treatment group and 502 in the radiotherapyy group. In the no further treatment group 83 women had local recurrence s (444 recurrence s of DCIS. and 40 invasive breast cancer) . In the radiotherapy group 53 womenn had local recurrence s (29 recurrence s of DCIS, and 24 invasive breast cancer) . Thee 4-year local relapse-fre rate was 84/r in the group treated with local excision alone comparedd with 919f in the women treated by local excision plus radiotherapy (logrank P=0.005.. Hazard Ratio=0.62) . Similar reductions in the risk of invasive (40%. P=0.04) andd non-invasive (35%. P=0.06) local recurrence were seen. ConclusionsConclusions Radiotherap y after local excision for DCIS. as compared to local excision alone,, reduced the overal number of both invasive and non-invasive recurrence s in the ipsilaterall breast at a median follow-up of 4.25 years. RadiotherapyRadiotherapy in breast-conserving treatment for DCIS 33 33