Cancer Risk in X-Ray Technologists: Second Survey

Researchers at the National Cancer Institute and the University of Minnesota have followed a nationwide cohort of 146,022 radiologic technologists since 1982 (Boice 1992; Doody 1998; Mohan 2003; Sigurdson 2003). This is one of the largest cohorts of medical radiation workers studied to date (Yoshinaga 2003)and the only one with substantial numbers of women (73% female), extensive covariate data, both incident and death outcomes, and estimated occupational radiation doses. The overall study objectives are to: quantify radiation dose-response for cancers of the breast, thyroid, and other radiogenic sites; assess cancer risks associated with genotypic, phenotypic, or other biologically measurable factors; and determine if genetic variation modifies radiation-related cancer risks. More than 110,000 technologists completed at least one of three comprehensive questionnaire surveys administered over the last 20 years and 18,500 are deceased. The First Survey was mailed during 1984-1989 to 132,454 known living radiologic technologists, of whom 90,305 (68%) completed the survey (Boice 1992). The Second Survey was mailed during 1993-1998 to 126,628 known living technologists, of whom 90,972 (72%) completed the questionnaire (Sigurdson2003). Both surveys included detailed questions about employment as a radiologic technologist, family history of cancer, reproductive history, height, weight, other cancer risk factors (such as alcohol and tobacco use), history of personal diagnostic and therapeutic medical radiation procedures, and information on cancer and other health outcomes. A third follow-up of this cohort was recently completed. During 2003-2005, the Third Survey was mailed or administered by telephone to 101,694 living cohort members who had completed at least one of the two previous surveys; 73,838 technologists (73%) completed the survey. This questionnaire elicited information on medical outcomes to assess radiation-related risks, detailed calendar-specific employment data to refine the occupational ionizing radiation dose estimates, and behavioral and residential histories for estimating lifetime ultraviolet (UV) radiation exposures. The large number of women with estimates of cumulative radiation dose to specific organs (e.g. breast) (Simon 2006; see Figure 7 and Table 9) offers at are opportunity to study effects of low-dose radiation exposure on breast and thyroid cancers, the two most sensitive organ sites for radiation carcinogenesis in women.. We are not aware of any other study population in which both quantified radiation doses and biospecimens are available for individuals with protracted low-dose ionizing radiation exposures. Incorporation of assessment of the role of genetic polymorphisms and molecular variants in DNA repair and other genetic pathways that may be functionally important in radiation carcinogenesis would provide initial results on the possible role of genetic factors in the cancer-radiation relationship. Because large numbers of women are exposed to ubiquitous low-dose radiation from occupational, medical, and environmental sources, the presence of radiation-sensitive genetic variants that influence the risk of breast and other cancers would have important public health implications.

Sex

All

Minimum age

18 Years

Maximum age

110 Years

* INCLUSION CRITERIA:

Medical x-ray technologists certified (at least two years during 1926-1982) by the American Registry of Radiologic Technicians (ARRT).

• BACKGROUNDSimon SL, Preston DL, Linet MS, Miller JS, Sigurdson AJ, Alexander BH, Kwon D, Yoder RC, Bhatti P, Little MP, Rajaraman P, Melo D, Drozdovitch V, Weinstock RM, Doody MM. Radiation organ doses received in a nationwide cohort of U.S. radiologic technologists: methods and findings. Radiat Res. 2014 Nov;182(5):507-28. doi: 10.1667/RR13542.1. Epub 2014 Oct 31. PMID 25361400
• BACKGROUNDPreston DL, Kitahara CM, Freedman DM, Sigurdson AJ, Simon SL, Little MP, Cahoon EK, Rajaraman P, Miller JS, Alexander BH, Doody MM, Linet MS. Breast cancer risk and protracted low-to-moderate dose occupational radiation exposure in the US Radiologic Technologists Cohort, 1983-2008. Br J Cancer. 2016 Oct 25;115(9):1105-1112. doi: 10.1038/bjc.2016.292. Epub 2016 Sep 13. PMID 27623235
• BACKGROUNDKitahara CM, Preston DL, Neta G, Little MP, Doody MM, Simon SL, Sigurdson AJ, Alexander BH, Linet MS. Occupational radiation exposure and thyroid cancer incidence in a cohort of U.S. radiologic technologists, 1983-2013. Int J Cancer. 2018 Nov 1;143(9):2145-2149. doi: 10.1002/ijc.31270. Epub 2018 Feb 2. PMID 29355960