Childhood growth and body size across the life course: pathways to breast cancer

Jennifer Baker's research study looks at how a woman's body size throughout her life affects the risk of breast cancer

  • Topic: Breast cancer
  • Institution: Frederiksberg Hospital
  • Country: Denmark
  • Status: Ongoing

This project seeks to understand how a number of events across a woman’s life, from birth until old age, combine to either increase or decrease the risk of breast cancer. By combining this information in one study, we will be able to create a fuller picture of how life events shape a woman’s risk of breast cancer, allowing for earlier prevention of this disease. Body size from birth to old age, as well as a woman’s age at menarche, have associations with breast cancer. However, these patterns differ by a woman’s menopausal status and by the subtype of breast cancer. Using a woman’s body size from young and older ages, we will be able to identify if body size at a particular age and growth during particular ages (such as when she enters puberty and how her body size develops across her life) relates to her risk of cancer later in life. In addition to body size, we will look at what happens to the risk of breast cancer if a woman has benign breast disease (non-cancerous lumps) or a lot of dense breast tissue (milk glands, milk ducts and supportive tissue). Our study will create a full picture of how these different pieces of information come together across a woman’s life and influence her risk of breast cancer, as well as her chances of surviving after a diagnosis.

Aims and objectives

Our study will focus on how the combination of a woman’s body size as a child; size when she entered puberty and her adult body size lead to the risk of breast cancer. In addition to this, we will also look at whether benign breast disease and breast density (from mammography) further increase or decrease a woman’s risk of breast cancer based on a woman’s body size across her life. We will examine the risk of having breast cancer or dying from it separately, based on pre- and postmenopausal forms, and by hormone receptor subtypes.

How it will be done

We will use information from health records of 158,431 girls from the ages of seven to 13 years old who were born from 1930 to 1992 and attended school in Copenhagen, Denmark. Using government-issued identification numbers, we will electronically link these records to national health registers and studies. These health registers and studies contain information on women’s body size as adults, other lifestyle and health information as well as diagnoses of benign breast disease, mammographic density and breast cancer in adulthood.

In this project, we will put all of these pieces of information together and see how body size over a woman’s life and the other events predict whether or not a woman will be diagnosed with different subtypes of breast cancer, as well as her chances of surviving after a diagnosis.

Potential impact

Our project will show if there are combinations of a woman’s childhood body size and growth, her body size as an adult and whether or not she had benign breast disease or dense breasts that either raise or lower her risk of developing breast cancer or dying from this disease later in life. These combinations of body size, health conditions and the ages at which they occur will show if there are particularly important periods of time in a woman’s life that contribute to her risk of having, or dying from, breast cancer. From this, we can add to what is known already about how women can reduce their risk of developing breast cancer. Our work will contribute to the building of a risk profile that can be used to guide preventive efforts and research into the mechanisms that increase a woman’s risk of breast cancer at very specific points across her life.