Conditions: Breast Cancer
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 95
Healthy volunteers: no

Brief summary:
The purpose of this research study is to determine whether melatonin taken every night can affect blood levels of estrogen or IGF (insulin-growth factor levels). Both IGF and estrogen are normally produced in the body and may influence breast cancer risk. Melatonin is also naturally produced in the body. Laboratory studies have shown that melatonin may decrease cancer growth and influence estrogen and IGF levels. Melatonin's effects on sleep, hot flashes, and mood will also be measured.

Detailed description:
If you agree to participate in this study you will be asked to undergo a blood test to find out if you are eligible. Approximately 2 tablespoons of blood will be drawn. The blood test will check your health and menopausal status. This test will aslo be used to help measure any additional effects of the study drug on your body. If you have had a blood test recently, it may or may not have to be repeated. If these tests show that you are eligible to participate in the research study, you will begin the study. If you do not meet the eligibility criteria, you will not be able to participate.

Because no one knows which of the study options is best, and all of the options are considered likely to work, you will be "randomized" into one of the study groups: melatonin or placebo.

Randomization means that you are put into a group by chance. It is like flipping a coin. Neither you nor the research doctor will choose what group you will be in. You will have an equal chance of being placed in either group. Neither you nor the research doctor will know what group you are in. You will not know the identity of your study treatment until after the final research analysis has taken place. Once this has happened, you will be mailed a letter from the principal research doctor telling you which study drug you received while on study.

You will be given a study drug and it will either contain melatonin or placebo (pills with no medical effect). You will take one tablet by mouth every night as close to 9:00 pm as possible. You should not make up missed doses. You will be given enough study drug to last 4 months. You will also be given a study medication-dosing calendar to write down times you took the study drug for each month you are taking the study drug.

Before taking the study drug, you will have blood tests to look at the level of estrogen and IGF in your blood. Approximately 2 tablespoons of blood will be drawn. At this visit, you will also be asked to complete a questionnaire that will take approximately 15 minutes.

A member of the research study staff will check in by telephone once a month to monitor your experiences on the research study. You may also contact a member of the research study staff at any time if you have any questions or concerns.

You should tell your research doctor if you are currently taking black cohosh, flaxseed or soy in pill or supplement form, as it may affect your participation in this research study.

After you have completed approximately 4 months of study drug, you will return to clinic to see a member of the research study staff. At this visit you will have the following tests and procedures: You will have blood tests to look at the level of estrogen and IGF in your blood. Approximately 2 tablespoons of blood will be drawn. You must return your study medication-dosing calendar and all of your pill bottles at the end of the research study to a member of the research study staff. You wil also be asked to complete a questionnaire that will take about 15 minutes.

Arms:
arm 1: Taken orally, once per day, at/around 9:00pm arm 2: Taken orally, once per day, at/around 9:00pm

Interventions: intervention 1: Melatonin 3 mg
Intervention descriptions: intervention 1: Melatonin vs. Placebo

Protocol document: