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Purpose: We updated an earlier study in this community from 1945-1974 in order to assess trends in the incidence of, risk factors for, and survival from endometrial cancer in 1975-1991., Methods: Incidence rates were based on all new cases of endometrial cancer diagnosed among Olmsted County, Minnesota, women during the years 1975-1991, with the population denominator from decennial census data. Risk factors were assessed with conditional logistic regression comparing the incidence cases to age- and gender-matched controls with intact uteri seen the same year the case was diagnosed. Survival was assessed using the Kaplan-Meier method., Results: The incidence of endometrial cancer (age-adjusted to 1970 United States total) in 1975-1991 was 14.3 per 100,000 person-years, which is slightly increased from 1965-74. The rate was 21.7 per 100,000 person-years after adjustment for hysterectomy prevalence. As in the previous study, conjugated estrogen use for six months or more (odds ratio [OR] 2.71; 95% confidence interval [CI] 1.14-6.46) and body mass index (OR 1.06; 95% CI 1.01-1.11) increased the risk of endometrial cancer. The five-year relative survival rate (82%) was not improved over the earlier study., Conclusions: A small increase in endometrial cancer incidence was linked to the same risk factors identified in an earlier study in this community. No improvement in survival was seen.

Purpose: To determine trends in incidence and survival between 1935 and 1991 and to evaluate risk factors for ovarian cancer among Olmsted County, Minnesota women., Methods: All newly diagnosed cases of ovarian cancer among Olmsted County women in 1975-1991 were identified using the medical records linkage system of the Rochester Epidemiology Project. In order to assess trends, incidence rates in the subset of Rochester women were compared with Rochester rates for 1935-1974. Survival was evaluated by the Kaplan-Meier product-limit method. A case-control analysis of risk factors compared Olmsted County women with invasive epithelial ovarian cancer and an age-matched group of women from the community by logistic regression., Results: Altogether, 129 Olmsted County women were newly diagnosed with ovarian cancer in 1975-1991. The age-adjusted (to 1970 United States whites) incidence rate was 22.5 per 100,000 person-years. Median survival from initial diagnosis was 3.7 years. Compared to an equal number of controls, the 103 women with invasive epithelial disease were more likely to be nulliparous (odds ratio [OR] 1.9; 95% CI 0.95-3.9) but less likely to have a history of thyroid disease (OR 0.4; 95% CI 0.2-0.8), hypertension (OR 0.4; 95% CI 0.1-0.9) or nonsteroidal estrogen use (OR 0.5; 95% CI 0.2-0.9). Prior hysterectomy (OR 0.5; 95% CI 0.2-0.9) and unilateral oophorectomy (OR 0.2; 95% CI 0.04-0.7) were also associated with reduced risk., Conclusion: The incidence of ovarian cancer in this community in 1975-1991 was little changed from rates 20 years earlier. There has been some improvement in survival from ovarian cancer in this population compared to 1935-1974, but still less than 50% survive for 5 years. Prior hysterectomy and unilateral oophorectomy appear protective for ovarian cancer.

A family history of breast cancer is well established as a risk factor for the disease. Because family history is a dynamic rather than a static characteristic, longitudinal studies of entire families can be very instructive in quantifying the significance of risk classification. The Minnesota Breast Cancer Family Study is a historical cohort study of relatives of a consecutive series of 426 breast cancer cases (probands) identified between 1944 and 1952. The incidence of cancer and the measurement of risk factors in sisters, daughters, granddaughters, nieces, and marry-ins was determined through telephone interviews and mailed questionnaires. Ninety-eight percent of eligible families were recruited, and 93% of members participated. A total of 9073 at-risk women were studied: 56% were biological relatives of the case probands, whereas the others were related through marriage. Through 1996, 564 breast cancers were identified in nonprobands. Compared to the rate of breast cancer among marry-ins (188 cases), sisters and daughters of the probands were at a 1.9-fold greater age-adjusted risk (128 cases; 95% confidence interval, 1.4-2.4); granddaughters and nieces were at a 1.5-fold greater risk (248 cases, 95% confidence interval, 1.2-1.8). The breast cancer risk since 1952 was not distributed equally across families: although all biological relatives had a family history of breast cancer, 166 families (39%) experienced no additional cases. Most of the cases occurred among a subset of families: 21 families had 5 breast or ovarian cancers, 8 had 6, 2 had 7, and 4 had > or =8. There was no evidence of significantly increased risk for cancer at other sites, including the ovaries, cervix, uterus, colon, pancreas, stomach, or lymphatic tissue, although there was some evidence that stomach cancer in previous generations may help define the susceptible subset. These families contain four to five generations of validated occurrences of cancer, thus minimizing the uncertainty of genetic risk inherent in a disease with a late and variable age at onset. The patterns of breast cancer in these multigeneration families is consistent with the influence of autosomal dominant susceptibility in a subset, low penetrance genes in another, and purely environmental influences in the remainder.