Diagnostic X-ray Procedures and Risk of Leukemia, Lymphoma, and Multiple Myeloma
- John D. Boice, Jr, ScD;
- Michele M. Morin, MS;
- Andrew G. Glass, MD;
- Gary D. Friedman, MD;
- Marilyn Stovall, MS;
- Robert N. Hoover, ScD, MD;
- Joseph F. Fraumeni, Jr, MD
- From the Epidemiology and Biostatistics Program, Division of Cancer Etiology, National Cancer Institute, Bethesda, Md (Drs Boice, Hoover, and Fraumeni and Ms Morin); the Kaiser Permanente Medical Care Program, Portland, Ore (Dr Glass); the Kaiser Permanente Medical Care Program, Oakland, Calif (Dr Friedman); and the M. D. Anderson Cancer Center, Houston, Tex (Ms Stovall).
Abstract
Exposure to diagnostic x-rays and the risk of leukemia, non-Hodgkin's lymphoma (NHL), and multiple myeloma were studied within two prepaid health plans. Adult patients with leukemia (n = 565), NHL (n = 318), and multiple myeloma (n = 208) were matched to controls (n = 1390), and over 25 000 x-ray procedures were abstracted from medical records. Dose response was evaluated by assigning each x-ray procedure a score based on estimated bone marrow dose. X-ray exposure was not associated with chronic lymphocytic leukemia, one of the few malignant conditions never linked to radiation (relative risk [RR], 0.66). For all other forms of leukemia combined (n = 358), there was a slight elevation in risk (RR, 1.17) but no evidence of a dose-response relationship when x-ray procedures near the time of diagnosis were excluded. Similarly, patients with NHL were exposed to diagnostic x-ray procedures more often than controls (RR, 1.32), but the RR fell to 0.99 when the exposure to diagnostic x-ray procedures within 2 years of diagnosis was ignored. For multiple myeloma, overall risk was not significantly high (RR, 1.14), but there was consistent evidence of increasing risk with increasing numbers of diagnostic x-ray procedures. These data suggest that persons with leukemia and NHL undergo x-ray procedures frequently just prior to diagnosis for conditions related to the development or natural history of their disease. There was little evidence that diagnostic x-ray procedures were causally associated with leukemia or NHL. The risk for multiple myeloma, however, was increased among those patients who were frequently exposed to x-rays.
(JAMA. 1991;265:1290-1294)
Footnotes
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Reprint requests to Radiation Epidemiology Branch, National Cancer Institute, 6130 Executive Blvd, Executive Plaza North, Room 408. Bethesda, MD 20852 (Dr Boice).
