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Peggy L. Porter, MD

Program Head
Divisions of Human Biology and Public Health Sciences
Fred Hutchinson Cancer Research Center
Seattle, Washington

Current Research

  • Exploring the effect of environmental exposure to low dose radiation on future breast cancer risk.
  • Studies are planned to assess genetic changes in breast tumor cells in patients who lived in the path of radioactive fallout from the Chernobyl nuclear accident.
  • This study will provide much needed information on the risks of long-term exposure that can inform prevention and treatment strategies.

The risk of cancer due to acute exposure to high doses of radiation is well documented. Less is known about the effect of long-term exposure to low-dose radiation on risk of cancer. Dr. Porter is conducting a study in women who lived in the path of radiation fallout following the Chernobyl nuclear accident 30 years ago when they were young girls. This study can lead to a better understanding of environmental exposures to radiation and future risk of breast cancer and potential therapeutic targets for treatment of radiation-induced breast cancers.

Full Research Summary

Exposure to ionizing radiation is well documented as a risk factor for breast cancer in women. Most of the evidence for this relationship comes from studies of exposure to high doses of radiation, such as survivors of atomic bombings and individuals exposed medically for therapeutic and diagnostic reasons. In contrast, few large, well-controlled studies have assessed breast cancer risk in relation to low-dose radiation exposure over time.

The Chernobyl nuclear accident occurred over 30 years ago. The women living in the path of radioactive fallout from the accident have been exposed to a mix of radionucleotides, resulting in a relatively low radiation dose over the years. A sufficient period of time has elapsed since the accident for potential radiation-associated breast cancer to appear. 

Dr. Porter’ s research group is conducting an epidemiological study to assess the risk of breast cancer in relation to this protracted radiation exposure. In the upcoming year, they will directly address what specific types of genomic changes are seen in breast tumors as a result of the radiation. Immature breast cells are particularly sensitive to radiation, and the team will assess the risk and the molecular changes in tumors of women exposed before puberty.

A better understanding of the relationship between environmental sources of radiation and human disease, especially for exposures resulting from low doses delivered gradually over time, is a continuing need.

The outcome of this study could have broad-reaching impacts. From a public health standpoint, protracted, low-dose exposure to radiation is most relevant to the types of environmental and occupational exposures likely to be encountered today. In addition, characterizing these tumors at the molecular level can reveal novel therapeutic targets for women who have developed a known radiation-associated breast cancer.


Dr. Peggy Porter, a pathologist and researcher, is a member of the Human Biology and Public Health Sciences Divisions at Fred Hutchinson Cancer Research Center and Professor of Pathology at the University of Washington. As head of the multi-institutional Women’s Cancer Research Program centered at the Hutchinson Center, Dr. Porter leads a dynamic group of basic scientists, epidemiologists, surgeons, oncologists and pathologists dedicated to reducing the incidence and subsequent mortality of breast cancer. Her lab focuses on identifying and understanding the molecular events associated with initiation and progression of breast cancer, particularly the role of abnormal cell cycle control. Her lab continues to integrate new technologies and apply them in large-scale studies to identify tumor markers of progression in diverse populations and specific breast cancer subtypes that can be used for detection, prognosis and prediction of response to therapy. Current studies include the determination of breast cancer risk and molecular alterations associated with radiation exposure in Chernobyl and the relationship of ancestry and breast cancer risk in Hispanic women. She obtained her medical degree in 1987 from the University of New Mexico and completed her residency in Pathology at the University of Washington where she was a recipient of the American Cancer Society Clinical Oncology Fellowship.

Large Researcher Headshot - Porter Peggy

BCRF Investigator Since


Donor Recognition

The Clinique Award