Randomised double blind trial to evaluate prevention of breast cancer using tamoxifen in high risk women

ISRCTN	ISRCTN07027313
DOI	https://doi.org/10.1186/ISRCTN07027313
Protocol serial number	283A
Sponsor	Royal Marsden Hospital (UK)
Funder	The Royal Marsden Hospital (UK)

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Not provided at time of registration

Prof Trevor Powles
Scientific

Parkside Oncology Clinic
49 Parkside
Wimbledon
London
SW19 5NB
United Kingdom

Primary study design	Interventional
Study design	Randomised, controlled clinical trial
Secondary study design	Randomised controlled trial
Study type	Participant information sheet
Scientific title
Study acronym	Tamoplac
Study objectives	The hypothesis that oestrogen is an important promoter of carcinogenically induced mammary neoplasia opens up some attractive possibilities for the prevention of clinical breast cancers.
Ethics approval(s)	Approved by the Royal Marsden Hospital Ethics Committee in October 1986.
Health condition(s) or problem(s) studied	Women at high risk of developing breast cancer
Intervention	20 mg/day oral tamoxifen versus placebo, treatment will continue for up to eight years.
Intervention type	Drug
Phase	Not Specified
Drug / device / biological / vaccine name(s)	Tamoxifen
Primary outcome measure(s)	Incidence of histologically confirmed invasive breast cancer
Key secondary outcome measure(s)	1. Death from breast cancer 2. Overall survival 3. Long-term changes in hormones, lipid profile and bone mineral density 4. Incidence of other disease, especially vascular
Completion date	01/10/2006

Participant type(s)	Patient
Age group	Adult
Sex	Female
Target sample size at registration	2500
Key inclusion criteria	1. Healthy women 2. Aged 30 to 70 years 3. Life expectancy of more than ten years 4. Psychologically and physically suitable for tamoxifen/placebo and long term follow-up 5. At increased risk of breast cancer by virtue of: a. at least one first degree relative aged under 50 with breast cancer b. one first degree relative with bilateral breast cancer c. one first degree relative of any age plus another affected first or second degree relative d. history of a high risk benign breast biopsy
Key exclusion criteria	1. Clinical or screening evidence of breast cancer 2. Pregnant or lactating women 3. Pregnancy risk - unless a disclaimer was signed 4. Oral contraceptives within the previous three months 5. Previous history of non-invasive or invasive breast cancer 6. Previous history of other malignancy (except Basal Cell Carcinoma [BCC] or Carcinoma [CA] in situ of the cervix) 7. History of deep vein thrombosis or pulmonary embolism
Date of first enrolment	01/10/1986
Date of final enrolment	01/10/2006

Parkside Oncology Clinic

London
SW19 5NB
United Kingdom

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
IPD sharing plan

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article	Results publication:	11/07/1998		Yes	No
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes