Esophageal carcinoma in Olmsted County, Minnesota, 1935-1971.

In order to estimate the incidence rate of esophageal carcinoma in a defined populat;on, all cases in bona fide residents of Olmstead County, Minnesota, newly diagnosed from 1935 through 1971 were identified and reviewed. There were 33 confirmed cases. The mean annual incidence was 2.6/100,000 men and 0.8/100,000 women. The age-adjusted incidence rates in this population are lower than those reported recently from other populations. Of the 27 patients whose disease was diagnosed before death, only 1 survived more than 6 years after initial diagnosis of the esophageal carcinoma, and all had died before the end of the study.

Breast cancer incidence, prevalence, mortality, and survivorship in Rochester, Minnesota, 1935 to 1974.

The epidemiologic features of breast cancer in Rochester, Minnesota, were studied over the 40-year period 1935 to 1974. During this time, the age-adjusted incidence rate increased 25% to 82.7 per 100,000 person-years. Most of the increase occurred among women 45 to 64 years of age. Overall, the incidence of breast cancer increased with advancing age, as did breast cancer prevalence, which was 901.4 per 100,000 women on Jan. 1, 1975. Age-adjusted mortality rates declined slightly from 24.9 to 23.3 per 100,000 person-years during the study period. Survival after the diagnosis of breast cancer seemed to improve somewhat among women who were less than 45 or more than 65 years old at the time of diagnosis. This was associated with a decline in the proportion of these women with regional lymph node involvement or distant metastases present at the time of initial diagnosis.

Breast cancer in DES-exposed mothers: absence of association.

Reports in the popular press have suggested that exposure to diethylstilbestrol (DES) is followed by an abnormally high incidence of breast cancer. The reports were based on a reanalysis of data not considered ominous originally; and both data and analyses are summarized here. In addition, new data are presented on mothers of young women enrolled in the National DESAD Project at its Mayo Clinic Center. Among 408 women given DES, there were 8 confirmed instances of breast cancer, in comparison with an expected number of 8.1, based on breast cancer incidence rates among parous women in the local population. A previous case-control study of the possible association of antihypertensive therapy and breast cancer in the local population revealed DES exposure in 10% of the breast cancer group and 12% of the controls. These apparently negative results clearly indicate a need of further studies of the alleged effect of DES.

PIP: Preliminary data from the Mayo Clinic Center of the National DESAD Project (DESAD = DES plus Adenosis) bearing on the occurrence of breast cancer in women given DES (diethylstilbestrol) during pregnancy are reported. Data from 408 DES-exposed women were collected in a follow-up study. 8 cases of breast cancer were confirmed in the group. This compares with an expected rate of 8.1 for parous women in that county. These preliminary data do not show an excess of observed over expected cases of breast cancer among a DES-exposed population. A previous case-control study at the Mayo Clinic designed to determine any association between breast cancer and antihypertensive therapy had found a breast cancer rate of 10% in the DES-exposed portion of the group and 12% in the controls, also denying any DES association with breast cancer causation. It is pointed out that an earlier study at the University of Chicago which did find an association between DES usage and breast cancer had utilized higher doses of DES than the current study at Mayo. There is a clear need for further research into the association between DES usage and breast cancer, taking into account dosage and duration of therapy. Excess risk, if it does exist, seems to concentrate in the under-50 age group.

Urban-rural differential in breast cancer incidence and mortality in Olmsted County, Minnesota, 1935-1974.

Between 1935 and 1974, 580 new cases of breast cancer were diagnosed among the residents of Rochester, and 187 cases were found among the women living in the remainder of Olmsted County, Minnesota. The age-adjusted incidence of breast cancer was 79.1 per 100 000 person-years among Rochester women and 56.3 per 100 000 person-years among the rural women, for an urban-rural ratio of 1.40:1. The rural incidence increased more rapidly than did the urban incidence during the period of the study, especially among women 50 years old or older; and the urban-rural ratio seemed to decline with time. No convincing explanation for these changes was found, but migration and increasing urbanisation of rural areas may be important factors. The greater urban incidence and the net migration of rural patients with breast cancer into the urban area explain the higher urban mortality rates for breast cancer.

Epidemiology of Ankylosing spondylitis in Rochester, Minnesota, 1935-1973.

The Mayo Clinic records linkage facility for residents of Rochester, Minnesota, Yielded 102 cases of ankylosing spondylitis (AS) diagnosed from 1935 through 1973. The incidence did not change significantly over the 39 years. Three times as many males as females were affected. In contrast to another recent report, survivorship of males with AS was not different from that of the general population, whereas survivorship of females with AS was reduced. The overall prevalence was 129/100,000.

Carcinoma of the gallbladder and extrahepatic biliary ducts in Rochester, Minnesota, 1935--1971.

Because the causes of carcinoma of the gallbladder and extrahepatic biliary ducts are largely unknown, a descriptive epidemiologic study has been developed. The extensive record system at the Mayo Clinic for the population of Rochester, Minnesota, provided the basis for this study of the incidence, secular trend, pathologic features, relationship with gallstones, and survivorship of patients with carcinoma of the gallbladder and extrahepatic biliary ducts in the period 1935 through 1971. The mean annual incidence rate of carcinoma of the gallbladder and extrahepatic biliary ducts was 4.4 (3.1 for men and 5.4 for women) per 100,000 population. The rates increased rapidly with age in both males and females. For the 51 known deaths, the death certificates listed carcinoma of the gallbladder or extrahepatic biliary ducts, or both, as the underlying cause of death in 39 cases and as a contributory cause in three. The frequencies of gallstones in females (75%) and males (62%) were significantly higher than the expected numbers.