Radiotherapy and tamoxifen in women with completely excised ductal carcinoma in situ of the breast in the UK, Australia, and New Zealand: randomised controlled trial.
BACKGROUND
As a consequence of mammographic breast screening programmes, ductal carcinoma in situ is diagnosed with increasing frequency. Mastectomy for localised ductal carcinoma in situ is thought to be an over-treatment by many physicians, but there is much controversy as to whether complete local excision alone is sufficient. We aimed to assess the effectiveness of adjuvant radiotherapy and tamoxifen.


METHODS
We used a 2x2 factorial design in a randomised controlled trial. Between May, 1990, and August, 1998, 1701 patients recruited from screening programmes were randomised to both treatments in combination or singly, or to none, or to either one (eg, radiotherapy) with an elective decision to give or to withhold the other (ie, in this case tamoxifen). Patients had complete surgical excision of the lesion confirmed by specimen radiography and histology. Patients have been followed up at least once a year. Median follow-up was 52.6 (range 2.4-118.3) months. Our primary endpoint was the incidence of ipsilateral invasive disease.


RESULTS
Ipsilateral invasive disease was not reduced by tamoxifen but recurrence of overall ductal carcinoma in situ was decreased (hazard ratio 0.68 [0.49-0.96]; p=0.03). Radiotherapy reduced the incidence of ipsilateral invasive disease (0.45 [0.24-0.85]; p=0.01) and ipsilateral ductal carcinoma in situ (0.36 [0.19-0.66]; p=0.0004), but there was no effect on the occurrence of contralateral disease. There was no evidence of interaction between radiotherapy and tamoxifen.


CONCLUSIONS
Radiotherapy can be recommended for patients with ductal carcinoma in situ treated by complete local excision; however, there is little evidence for the use of tamoxifen in these women.
Houghton
Joan
J
Clinical Trials Group, Department of Surgery, Royal Free and University College Medical School, Charles Bell House, London W1W 7EJ, UK. j.houghton@ctg.ucl.ac.uk <j.houghton@ctg.ucl.ac.uk>
George
W D
WD
Cuzick
Jack
J
Duggan
Catherine
C
Fentiman
Ian S
IS
Spittle
Margaret
M
D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001315:Australia; D001943:Breast Neoplasms / Q000628:therapy*; D002278:Carcinoma in Situ / Q000628:therapy*; D018270:Carcinoma, Ductal, Breast / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009520:New Zealand; D018714:Radiotherapy, Adjuvant; D013629:Tamoxifen / Q000627:therapeutic use*; D006113:United Kingdom
D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen