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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Magnesium for endocrine related cognitive problems in breast cancer
Scientific title
A Feasibility Study of Increasing Magnesium Levels by Supplementation for Endocrine Related Cognitive Problems in Breast Cancer
Secondary ID [1] 288141 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Endocrine related cognitive problems in breast cancer 297051 0
Condition category
Condition code
Cancer 297279 297279 0 0
Metabolic and Endocrine 297318 297318 0 0
Other endocrine disorders
Mental Health 297329 297329 0 0
Studies of normal psychology, cognitive function and behaviour

Study type
Description of intervention(s) / exposure
400mg elemental magnesium or matched placebo capsule taken daily for three months.
Adherence determined by capsule count when bottle returned.
Intervention code [1] 293453 0
Treatment: Other
Comparator / control treatment
Placebo microcrystalline cellulose and amorphous silica 1% (as lubricant) filled in opaque size ‘0’ gelatin capsules.
Control group

Primary outcome [1] 296857 0
Feasibility study of increasing magnesium levels by supplementation for endocrine related cognitive problems in breast cancer. Assessed via the evaluation of recruitment, acceptability of the questionnaires, measurement of serum magnesium (free and total) and evaluation of cognitive performance measured by the NIH toolbox and questionnaires.
Timepoint [1] 296857 0
The feasibility of the study will be assessed after three months supplementation.
Secondary outcome [1] 319548 0
To pilot the use of the NIH toolbox for measuring cognitive function in this NZ patient population. Acceptability of the NIH toolbox will be assessed using an acceptability questionnaire designed specifically for this study.
Timepoint [1] 319548 0
After three months supplementation
Secondary outcome [2] 319590 0
To assess the acceptability of the portfolio of patient related outcome questionnaires, including time commitments. Assessed using an acceptability questionnaire designed specifically for this study.
Timepoint [2] 319590 0
After three months supplementation.
Secondary outcome [3] 319591 0
To pilot the use of an electronic-diary for collecting patient reported data on hot flushes. Acceptability of using an electronic version of a validated hot flush diary will be assessed using an acceptability questionnaire designed specifically for this study.
Timepoint [3] 319591 0
After three months supplementation.
Secondary outcome [4] 319592 0
To determine the best approach for measuring magnesium and compare changes over time and between treatment and control groups. Comparative efficacy of two different laboratory tests for magnesium plasma levels will be assessed ( total levels analysed by routine biochemistry will be compared with free levels of magnesium in plasma analysed separately by the researchers).
Timepoint [4] 319592 0
After three months supplementation.
Secondary outcome [5] 319593 0
To compare baseline cognitive performance in patient groups receiving aromatase inhibitor or tamoxifen therapy to determine whether both groups should be included in the definitive randomised trial. Assessed using the NIH toolbox and validated questionnaires: Insomnia Severity Index , the Cognitive Failure Questionnaire and the Brief Fatigue Inventory.
Timepoint [5] 319593 0
After three months supplementation.
Secondary outcome [6] 319594 0
To provide a preliminary composite measure of changes in cognitive function and whether this correlates with changes in hot flushes, sleep patterns and fatigue during the study period. Assessed using regression models to explore changes in cognitive function as measured by the NIH toolbox and can be explained by changes in hot flush and/or sleep and fatigue scores (assessed through validated questionnaires -hot flush diary, Insomnia Severity Index and the Brief Fatigue Inventory). Power will be limited but this will help in the specification of the analyses for the main study.
Timepoint [6] 319594 0
After three months supplementation.
Secondary outcome [7] 319595 0
To determine the recruitment potential. Assessed by the number of patients screened, the proportion of those meeting eligibility criteria, the number agreeing to take part in the study.
Timepoint [7] 319595 0
Number of patients randomised to the trial at the beginning of the supplementation.
Secondary outcome [8] 319596 0
To pilot the blood sample collection and storage in relation to magnesium measurement and future genetic studies relating to magnesium carrier status. Assessed by collection of blood samples from multiple sites and the number of samples provided..
Timepoint [8] 319596 0
Bloods collected at baseline and after one, two and three months of supplementation.
Secondary outcome [9] 319597 0
To confirm the safety of magnesium in this clinical setting. Assessed by measuring adverse events diarrhoea, nausea, vomiting, urticaria according to CTCAE version 4.0 over the three month period. Hypermagnesia assessed in blood samples collected at one, two and three months of supplementation.
Timepoint [9] 319597 0
After three months supplementation.
Secondary outcome [10] 319628 0
To determine the acceptability of randomization and adherence to allocated regimen. Assessed by the proportion of patients randomized who return to complete the three month assessment and their compliance measured by a pill count of returned bottles.
Timepoint [10] 319628 0
At the end of the three month supplementation period.

Key inclusion criteria
1. Women 18 years or older with early breast cancer on adjuvant endocrine therapy for at least 6 months.
2. Receiving either tamoxifen or an aromatase inhibitor.
3. Able to provide written informed consent in English (NB: The NIH Toolbox is only available in English).
Minimum age
18 Years
Maximum age
No limit
Can healthy volunteers participate?
Key exclusion criteria
1. Evidence of metastatic disease
3.Abnormal renal function defined as a serum creatinine of >1.5 x upper limit of normal.
4.Abnormal hepatic function defined as a bilirubin of >1.5 x the upper limit of normal, except in Gilbert’s Syndrome, or ALT or ALP >2.5 x the upper limit of normal.
5.Inadequate haematological function defined as haemoglobin < 100g/L or neutrophil count < 1.5 x E+9/L or platelet count < 120 x E+9/L
6.Inflammatory bowel disease or other bowel disorder that causes ongoing diarrhoea.
7.Any known cause of hypomagnesaemia, including: current treatment with loop diuretics, e.g. frusemide or thiazide; cyclosporine; amphotericin B; pentamidine; aminoglycosides; EGFR antagonists, e.g. cetuximab; past treatment with cisplatin; hypercalcaemia; uncontrolled diabetes; excess alcohol consumption; known familial magnesium wasting syndrome.
8.A major psychiatric disorder and/or heavy alcohol, or illicit drug consumption, a history of traumatic brain injury or any condition unrelated to breast cancer treatment known to affect cognitive function.
9.Receiving antidepressants, sedatives such as some antihistamines or gabapentin.
10.Women who have been taking magnesium supplement within the last one month.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
In Maglev the treatment allocation will use the following method; All treatment bottles (study treatment) will be assigned a 3 digit code prior to the study opening for recruitment. The 3 digit codes will represent the treatment allocation. Only unblinded staff will know which 3 digit codes represent which treatment. When a patient is randomised they will be assigned the appropriate 3-digit code via the central study database.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The treatment allocation for endocrine treatment tamoxifen or aromatase inhibitor will be done using permuted block randomisation with concealed block size (using SAS 9.3).
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Recruitment to supportive care trials can be more challenging than therapeutic trials, so determining likely recruitment and adherence rates is crucial. The feasibility study will determine the ability of the contributing sites to recruit to a study of this design, permitting estimates of the number of sites and the duration of recruitment that will be necessary for the main study.
A total of 50 patients, who meet the eligibility criteria, will be randomised into this study over a period of six months, with three months study treatment.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 7417 0
New Zealand
State/province [1] 7417 0

Funding & Sponsors
Funding source category [1] 292550 0
Government body
Name [1] 292550 0
Health Research Council New Zealand
Address [1] 292550 0
Level 3
110 Stanley St
Auckland 1010
Country [1] 292550 0
New Zealand
Funding source category [2] 292551 0
Name [2] 292551 0
The New Zealand Breast Cancer Foundation
Address [2] 292551 0
11 York Street
Auckland 1149
Country [2] 292551 0
New Zealand
Funding source category [3] 294143 0
Name [3] 294143 0
Lottery Health Research Grant
Address [3] 294143 0
The Department of Internal Affairs
46 Waring Taylor Street
Country [3] 294143 0
New Zealand
Primary sponsor type
University of Auckland
Cancer Trials New Zealand
Discipline of Oncology
Faculty of Medical and Hekath Sciences
University of Auckland
Private Bag 92019
Auckland 1142
New Zealand
Secondary sponsor category [1] 291270 0
Name [1] 291270 0
Address [1] 291270 0
Country [1] 291270 0

Ethics approval
Ethics application status
Ethics committee name [1] 294027 0
NZ Health and Disability Ethics Committees
Ethics committee address [1] 294027 0
Ministry of Health
Freyberg Building
20 Aitken Street
PO Box 5013
Ethics committee country [1] 294027 0
New Zealand
Date submitted for ethics approval [1] 294027 0
Approval date [1] 294027 0
Ethics approval number [1] 294027 0

Brief summary
Tamoxifen and the aromatase inhibitors letrazole, anastrozole and exemestane are commonly prescribed following surgery with the intent of reducing the likelihood that the breast cancer returns in the future. They work by blocking the effects of oestrogen & progesterone, hormones found naturally in the body, including in the brain. Some side effects from taking these drugs are poor memory, difficulties with concentration and memory, hot flushes, sweating & tiredness. Some researchers think that these memory and concentration problems are due to low oestrogen levels in the brain. Research shows that magnesium (Mg) levels in the body are controlled by oestrogen. We would like to find out if poor memory & concentration in this group of women, may be caused by low Mg caused by low oestrogen. Mg is a mineral and is important for many functions in the body. We tend to get the Mg we need from our food. If our levels of Mg are low however, we can take it as a supplement. Some studies of people taking Mg
supplement have shown an improvement in their memory and concentration. Hot flushes & tiredness in menopausal women have also been shown to reduce in some studies. We want to look at the effect of Mg on improving memory and concentration in women on endocrine therapy for the treatment of breast cancer. This study is a pilot study, to see if a larger one will work. We will look at the results of concentration and memory tests in women who have taken Mg and those who have taken a placebo. The participant, or the Dr, will not know if they are taking the Mg or placebo.
The results will give us a useful indication about whether supplementing the diet with Mg can help reduce some of the memory and concentration problems that women on endocrine therapy experience. We will also see if Mg helps with hot flushes and fatigue. We are looking to enrol 50 women for this pilot study in NZ.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 62182 0
Dr David Porter
Address 62182 0
Auckland Regional Cancer and Blood Services
Building 7
Medical Oncology, Auckland City Hospital
2 Park Rd
Auckland 1023

Country 62182 0
New Zealand
Phone 62182 0
+64 9 307 4949 ext 23863
Fax 62182 0
Email 62182 0
Contact person for public queries
Name 62183 0
Ms Christine Crooks
Address 62183 0
Cancer Trials NZ
Building 505, Level 1
University of Auckland
85 Park Road
Auckland 1023
Country 62183 0
New Zealand
Phone 62183 0
+64 9 473 4222
Fax 62183 0
Email 62183 0
Contact person for scientific queries
Name 62184 0
Dr David Porter
Address 62184 0
Auckland Regional Cancer and Blood Services
Building 7
Medical Oncology, Auckland City Hospital
2 Park Rd
Auckland 1023
Country 62184 0
New Zealand
Phone 62184 0
+64 9 307 4949 ext 23863
Fax 62184 0
Email 62184 0

No information has been provided regarding IPD availability
Summary results
No Results