ArticlesRadiotherapy and tamoxifen in women with completely excised ductal carcinoma in situ of the breast in the UK, Australia, and New Zealand: randomized controlled trial
Introduction
Before the National Health Service (NHS) breast screening programme was introduced in the UK in 1988, only a very small proportion of newly diagnosed breast cancers were ductal carcinoma in situ. However, the frequency of diagnosis of this type of disease was expected to increase as a result of the screening programme,1 and randomised trials were needed to define the best management of small impalpable screen-detected ductal carcinoma in-situ lesions. Before screening programmes, this form of breast cancer was often treated by mastectomy; although effective, this approach is probably an over-treatment for many lesions detected by screening. At that time, results of several randomised trials had shown that breast conservation for invasive cancer was a safe alternative to mastectomy,2, 3, 4, 5 but there was little evidence to recommend this treatment in women with ductal carcinoma in situ.
Since ipsilateral breast irradiation is useful in the management of invasive disease treated by complete local excision, we chose to assess this approach in the ductal carcinoma in situ trial. When our trial begain, two other trials of radiotherapy after breast-conserving surgery for women with ductal carcinoma in situ (NSABP B-17 and EORTC 10853) were recruiting patients, but results were not available.
We chose also to assess adjuvant tamoxifen in the study because of evidence that this treatment can reduce rates of ipsilateral and contralateral breast cancer in women who had breast-conserving surgery for invasive disease.6, 7 After our trial began, one other study (NSABP B-17 and EORTC 10853) were recruiting patients, but results were not available.
We chose also to assess adjuvant tamoxifen in the study because of evidence that this treatment can reduce rates of ipsilateral and contralateral breast cancer in women who had breast-conserving surgery for invasive disease.6, 7 After our trial began, one other study (NSABP B-24) started to investigate the role of tamoxifen in ductal carcinoma in situ after complete local incision and radiotherapy.8
In our 2·2 factorial trial, we aimed to compare the efficacy of complete local excision alone with excision followed by radiotherapy to the residual ipsilateral breast, or excision followed by tamoxifen for 5 years, or both, in reducing the incidence of subsequent ipsila-teral invasive breast carcinoma in patients with ductal carcinoma in situ.
Our second objective was to determine the incidence of subsequent ductal carcinoma in situ in the ipsilateral and contralateral breasts of patients treated by complete local excision alone with complete local excision followed by radiotherapy or tamoxifen.
Section snippets
Patients
We included patients who had unilateral or bilateral ductal carcinoma in situ detected in a breast screening programme, and who were deemed suitable for breast conservation. All UK centres in the national screening programme were invited to participate. The Australian- New Zealand Breast Cancer Trials Group (ANZBCTG) joined the trial in September, 1991. Patients with symptoms who had the ductal carcinoma in situ confirmed in the same way as in screening clinics were also eligible for inclusion.
Discussion
We report the first analysis of the 1694 eligible patients in the UK/ANZ Trial. Ipsilateral invasive disease was not reduced by tamoxifen. However, radiotherapy was associated with a reduced incidence of ipsilateral ductal carcinoma in situ, but there was no effect on contralateral incidence. 1030 patients were randomly allocated to the radiotherapy comparison, which is about the same number of patients investigated in each of the previously reported trials of radiation after breast conserving
References (12)
- et al.
Breast conservation is a safe method in patients with small cancer of the breast. Long-term results of three randomised trials on 1,973 patients
Eur J Cancer
(1995) - et al.
Factors influencing local relapse and survival and results of salvage treatment after breastconserving therapy in operable breast cancer: EORTC Trial 10801, breast conservation compared with mastectomy in TNM stage I and II breast cancer
Eur J Cancer
(1992) - et al.
Tamoxifen and contra-lateral breast cancer
Lancet
(1985) - et al.
Tamoxifen in the treatment of intraductal breast cancer: National Surgical Adjuvant Breast and Bowel Project B-24 randomised control trial
Lancet
(1999) - et al.
Radiotherapy in breast conserving treatment for ductal carcinoma in situ: first results of the EORTC randomised phase 3 trial 10853
Lancet
(2000) - et al.
Comparative pathology of breast cancer in a randomised trial of screening
Br J Cancer
(1991)
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