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BackgroundBenign breast disease is an important risk factor for breast cancer. We studied a large group of women with benign breast disease to obtain reliable estimates of this risk.MethodsWe identified all women who received a diagnosis of benign breast disease at the Mayo Clinic between 1967 and 1991. Breast-cancer events were obtained from medical records and questionnaires. To estimate relative risks, we compared the number of observed breast cancers with the number expected on the basis of the rates of breast cancer in the Iowa Surveillance, Epidemiology, and End Results registry.ResultsWe followed 9087 women for a median of 15 years. The histologic findings were nonproliferative lesions in 67 percent of women, proliferative lesions without atypia in 30 percent, and atypical hyperplasia in 4 percent. To date, 707 breast cancers have developed. The relative risk of breast cancer for the cohort was 1.56 (95 percent confidence interval, 1.45 to 1.68), and this increased risk persisted for at least 25 years after biopsy. The relative risk associated with atypia was 4.24 (95 percent confidence interval, 3.26 to 5.41), as compared with a relative risk of 1.88 (95 percent confidence interval, 1.66 to 2.12) for proliferative changes without atypia and of 1.27 (95 percent confidence interval, 1.15 to 1.41) for nonproliferative lesions. The strength of the family history of breast cancer, available for 4808 women, was a risk factor that was independent of histologic findings. No increased risk was found among women with no family history and nonproliferative findings. In the first 10 years after the initial biopsy, an excess of cancers occurred in the same breast, especially in women with atypia.ConclusionsRisk factors for breast cancer after the diagnosis of benign breast disease include the histologic classification of a benign breast lesion and a family history of breast cancer.

A letter to the editor is presented in response to an article in the November 13, 1997 issue concerning privacy and medical-records research.

A response by B. Lawrence Riggs and L. Joseph Melton to a letter to the editor on their article about osteoporosis is presented.

Although fluoride increases bone mass, the newly formed bone may have reduced strength. To assess the effect of fluoride treatment on the fracture rate in osteoporosis, we conducted a four-year prospective clinical trial in 202 postmenopausal women with osteoporosis and vertebral fractures who were randomly assigned to receive sodium fluoride (75 mg per day) or placebo. All received a calcium supplement (1500 mg per day). Sixty-six women in the fluoride group and 69 women in the placebo group completed the trial. As compared with the placebo group, the treatment group had increases in median bone mineral density of 35 percent (P less than 0.0001) in the lumbar spine (predominantly cancellous bone), 12 percent (P less than 0.0001) in the femoral neck, and 10 percent (P less than 0.0001) in the femoral trochanter (sites of mixed cortical and cancellous bone), but the bone mineral density decreased by 4 percent (P less than 0.02) in the shaft of the radius (predominantly cortical bone). The number of new vertebral fractures was similar in the treatment and placebo groups (163 and 136, respectively; P not significant), but the number of nonvertebral fractures was higher in the treatment group (72 vs. 24; P less than 0.01). Fifty-four women in the fluoride group and 24 in the placebo group had side effects sufficiently severe to warrant dose reduction; the major side effects were gastrointestinal symptoms and lower-extremity pain. We conclude that fluoride therapy increases cancellous but decreases cortical bone mineral density and increases skeletal fragility. Thus, under the conditions of this study, the fluoride-calcium regimen was not effective treatment for postmenopausal osteoporosis.

Three hundred eighty-one total hip arthroplasties were performed on residents of Olmsted County, Minnesota, during the period from 1969 to 1980, for a rate (adjusted for sex and age) of 44.6 per 100,000 person-years. Rates rose with age, were higher for women than men, and were higher among urban than rural residents of the county. If we assume that the Olmsted County experience is medically optimal and apply it to the 1980 United States population, we calculate a national requirement of over 100,000 total hip arthroplasties per year, well above the current actual figure. If this calculated number of total hip arthroplasties were actually performed each year, over 1.4 million hospital days would be required, and direct medical costs would probably exceed $1 billion annually.

To assess the risk of hip fracture associated with the use of four classes of psychotropic drugs, we performed a case-control study of 1021 patients with hip fractures and 5606 controls among elderly Medicaid enrollees. Persons treated with hypnotics-anxiolytics having short (less than or equal to 24 hours) elimination half-lives had no increased risk of hip fracture. By contrast, a significantly increased risk was associated with current use of hypnotics-anxiolytics having long (greater than 24 hours) elimination half-lives (odds ratio, 1.8; 95 percent confidence interval, 1.3 to 2.4), tricyclic antidepressants (odds ratio, 1.9; 95 percent confidence interval, 1.3 to 2.8), and antipsychotics (odds ratio, 2.0; 95 percent confidence interval, 1.6 to 2.6). The risk increased in relation to the doses of drugs in these three classes. An analysis for possible confounding by dementia did not alter the results. Previous but noncurrent use of drugs in these classes conferred no increase in risk. Although a cause-and-effect relation was not proved, these data support the hypothesis that the sedative and autonomic effects of psychotropic drugs increase the risk of falling and fractures in elderly persons. The results suggest the need for studies of this association in other populations and for evaluation of newer psychotropic drugs with fewer undesirable sedative and autonomic effects.