Epidemiology: Sunlight Exposure and the Risk of Breast Cancer

Principal Investigator
Lawrence S. Engel, PhD

Co-Principal Investigator
Michael Alavanja, PhD
National Cancer Institute

Study Objectives

  • To evaluate the relationship between sunlight exposure and breast cancer risk.
  • To determine the relationship between Vitamin D receptor gene (VDR) variants and breast cancer risk and the joint effects of sunlight exposure and VDR variants on this risk.
  • To examine the association of physical activity with breast cancer risk.

Why is This Study Important?

Though sunlight exposure, physical activity, and polymorphisms in the vitamin D receptor (VDR) gene have been investigated in relation to the risk of breast cancer in a number of previous studies, their potential role in the etiology of breast cancer remains unresolved. Sunlight exposure and physical activity represent modifiable lifestyle factors that, if shown to be important in breast cancer etiology, could be adopted as appropriate by individuals to substantively affect their breast cancer risk.

Who Is Conducting This Study?

Investigators at Memorial Sloan Kettering Cancer Center and in the Agricultural Health Study (AHS). The AHS is a prospective cohort study of farmers and their spouses in Iowa and North Carolina and is a collaborative effort of the National Cancer Institute, National Institute of Environmental Health Sciences, National Institute for Occupation Safety and Health, and the Environmental Protection Agency.

Study Overview and Progress

This study includes approximately 31,000 farmers' wives who have been followed up since the mid-1990s, with almost 600 incident cases of breast cancer identified through 2004. Detailed data on lifestyle, occupation, and reproductive history are available for the study participants at the time of enrollment and of follow-up interviews. About 300 cases and 600 controls are included in the genetic component of this study. Analyses are underway.

Contact Information

Larry Engel