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An international study designed to answer reliably whether, for women who have hormone sensitive early breast cancer (the most common type of breast cancer), 10 years of adjuvant tamoxifen (a hormone treatment) confers more benefit than just 5 years in terms of reducing the risk of relapse and improving overall, long-term survival: Adjuvant Tamoxifen - Longer Against Shorter (ATLAS)

Not Applicable
Completed
Conditions
Operable, oestrogen receptor positive breast cancer already trated with ~5 years of adjuvant tamoxifen
Cancer
Malignant neoplasm of breast
Registration Number
ISRCTN19652633
Lead Sponsor
niversity of Oxford (UK)
Brief Summary

Not available

Detailed Description

Not available

Recruitment & Eligibility

Status
Completed
Sex
Female
Target Recruitment
15262
Inclusion Criteria

Women were eligible for randomisation if:
1. They had had early breast cancer (in which, by definition, all detected disease could be removed surgically)
2. They had subsequently been on adjuvant tamoxifen for several years and were still on it (or had stopped only recently, and could therefore resume treatment without much interruption)
3. They still appeared clinically free of disease (with any local recurrence removed and no distant recurrence ever detected)
4. Long-term follow-up appeared practicable; and, fundamentally,
5. Substantial uncertainty was shared by the woman and her doctor about whether to stop tamoxifen or to continue for several more years, so compliance with random allocation to stop or to continue both seemed likely. There were no restrictions on age, type of initial surgery or histology, hormone receptor status, nodal status or what other treatments had also been given.

Exclusion Criteria

Any perceived contraindications to continuing tamoxifen precluded entry. These were specified not by the ATLAS protocol but by the judgment of the responsible clinician. However, the protocol suggested as possible contraindications to tamoxifen continuation (and hence to trial entry):
1. Intended or actual pregnancy or breast feeding
2. Retinopathy
3. Need for coagulation therapy
4. Significant endometrial hyperplasia
5. Any other serious toxicity thought to be due to tamoxifen
6. Negligibly low risk of breast cancer death
7. Presence of another major life-threatening disease

Study & Design

Study Type
Interventional
Study Design
Not specified
Primary Outcome Measures
NameTimeMethod
1. Recurrence (loco-regional, contralateral or distant)<br>2. Breast cancer mortality
Secondary Outcome Measures
NameTimeMethod
1. Overall mortality<br>2. Various first events before recurrence:<br>2.1. Cancer incidence (particularly uterine, including endometrial)<br>2.2. Hospital admissions for particular reasons (particularly uterine or vascular)<br>2.3. Cause-specific mortality
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