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To investigate the role of medical history in the etiology of multiple myeloma (MM) we analyzed the data from a population-based case-control study in Connecticut women. A total of 179 incident MM cases (21-84 years, diagnosed 1996-2002) and 691 population-based controls were included in this study. Information on medical conditions, medication use, and medical radiation was obtained by in-person interviews. A total of 17 selected conditions including autoimmune, allergic, infectious, and inflammatory disorders that cause prolonged stimulation of the immune system, 28 commonly used drugs and drug groups, types of diagnostic radiation exposures, as well as history of radiation treatment, were examined in relation to MM risk in this study. We calculated odds ratios (OR) as measures of relative risks using logistic regression models. Duration of medication was categorized into tertiles (short, moderate, long) based on distribution of controls' duration of use. An increased risk of MM was found among women who used gout medication (OR=9.8, 95% CI 1.9-52.3, n=5 cases vs 2 controls), prednisone treatment (OR=5.1, 95% CI 1.8-14.4, n=8 cases vs 8 controls), and insulin use (OR=3.3, 95% CI 1.2-9.2, n=8 cases vs 8 controls). When we stratified our analyses by duration of treatment, long prednisone use (OR=10.3, 95% CI 1.7-62.3), and moderate duration of insulin therapy (OR=6.0, 95% CI 1.1-33.8) were associated with further elevated MM risk. A reduced MM risk was found in women who had a medical history of scarlet fever (OR=0.2, 95% CI 0.2-0.9, n=10 cases vs 82 controls) or bursitis (OR=0.3, 95% CI 0.2-0.7, n=13 cases vs 115 controls), or who had used estrogen replacement (OR=0.6, 95% CI 0.4-0.9, n=29 cases vs 160 controls) or anti-lipid HMG-CoA reductase inhibitor therapy (OR=0.4, 95% CI 0.2-0.8, n=8 cases vs 65 controls). No statistically significant association was found between MM and history of the other medical conditions and of use of the other drugs or drug groups under study. We found no association between diagnostic X-rays and MM risk while prior exposure to radiation treatment was associated with an increased risk of MM (OR=2.2, 95% CI 1.2-4.1, n=17 cases vs 36 controls), particularly among those who had been given radiotherapy for tumors (OR=3.4, 95% CI 1.5-7.5, n=12 cases vs 15 controls). However, given the small sample size, the lack of information on radiation doses, limitations of self-reporting, as well as a negative literature from available registry linkage studies, the observed association between radiotherapy and MM risk should be interpreted with caution. If our results are confirmed, mechanistic studies examining how certain prior medication use (insulin, prednisone, and perhaps gout medication) might promote increased occurrence of MM and how other medical drugs (HMG-CoA reductase inhibitors and estrogen replacement therapy) and prior medical conditions might protect against MM, may provide insights to the as yet unknown etiology of MM.

[Proc Amer Assoc Cancer Res, Volume 47, 2006]