According to a study published in the journal Cancer, female radiologic technologists who began working before 1940 have an increased risk of breast cancer compared to those who started working in later years. Risk was also elevated among women with the highest estimated cumulative radiation exposure. These results were published in the journal Cancer.
Exposure to high or intermediate levels of radiation is known to increase the risk of breast cancer, but there is less information about the risk posed by long-term exposure to low doses of radiation. Female radiologic technologists may experience this type of exposure.
To explore breast cancer risk in this population, researchers conducted a study among more than 50,000 female radiologic technologists. The women had been certified as radiologic technologists between 1925 and 1980. Information about employment history, demographics, lifestyle factors, and reproductive and medical history was collected from the participants by questionnaire. Cumulative radiation exposure was estimated for each subject based on the year she began working, total years worked, and work facility (hospital or physician office).
Between 1983 and 1998, 1,050 of the study participants were diagnosed with breast cancer.
- Radiologic technologists who started working before 1940 had a roughly two-fold increased risk of breast cancer compared to radiologic technologists who started working in 1970 or later. Risk was even more elevated among the women who started working before 1935.
- Risk of breast cancer increased with the number of years worked before 1940, but not with the number of years worked after 1940.
- Women with the highest estimated cumulative radiation exposure had a 50% greater risk of breast cancer than women with the lowest estimated exposure.
In this study of breast cancer in radiologic technologists, the researchers conclude, “The increased risk for total years worked before 1940, but not later, was consistent with decreasing occupational radiation exposures, improvements in radiation technology, and more stringent radiation protection standards over time.” Although the researchers found no evidence that recent radiation dose levels increase the risk of breast cancer, they offer the reminder that no radiation dose is completely safe, and that all radiation workers need to be protected.
Reference: Doody MM, Freedman DM, Alexander BH et al. Breast Cancer Incidence in U.S. Radiologic Technologists. Cancer . 2006; Early Online Publication April 25, 2006.