Self-reported stress levels predict subsequent breast cancer in a cohort of Swedish women.

The association between stress and breast cancer has been studied, mostly using case-control designs, but rarely examined prospectively. The purpose of this paper is to describe the role of stress as a predictor of subsequent breast cancer. A representative cohort of 1,462 Swedish women aged 38-60 years were followed for 24 years. Stress experience at a baseline examination in 1968-69 was analysed in relation to incidence of breast cancer with proportional hazards regression. Women reporting experience of stress during the five years preceding the first examination displayed a two-fold rate of breast cancer compared with women reporting no stress (age-adjusted relative risk 2.1; 95% CI [1.2-3.7]). This association was independent of potential confounders including reproductive and lifestyle factors. In conclusion, the significant, positive relationship between stress and breast cancer in this prospective study is based on information that is unbiased with respect to knowledge of disease, and can be regarded as more valid than results drawn from case-control studies.

Malignant disease observed in a cohort of women. A validation of Swedish Cancer Registry data.

A longitudinal study of altogether 1462 women aged 38 to 60 years started in Gothenburg, Sweden in 1968-69. Based on information from the population study and from the Swedish Cancer Registry 35 women had a history of malignant disease when initially examined in 1968-69. During a 12-year follow-up period a total of 79 malignant tumours developed in 73 women. A comparison was made between the 1988 Cancer Registry listing and the observations made in the population study. All but one out of 103 cases (99%) were registered in the Cancer Registry and all but one (99%) in the population study. It may be concluded that the accuracy of the population study registration as well as that of the Cancer Registry at that time were very high. This enables us to draw relatively safe conclusions from our own material when testing for risk factors.

Energy and macronutrient intake in relation to cancer incidence among Swedish women.

Two dietary reporting methods were used to examine associations between macronutrient intake and subsequent cancer incidence in a cohort of Swedish women born between 1908 and 1930. 1361 subjects gave 23-h dietary recalls at their baseline examinations in 1968-1969, and 412 of them also provided detailed dietary histories. The cohort was followed up 19 years later by means of linkages with the National Cancer and Death Registries. Both dietary methods indicated that subjects who were ranked in the highest tertile of energy intake, relative to the lowest, were at significantly greater risk of developing cancer (all-site). Relative risks across energy intake tertiles were 1, 1.15 and 2.04, respectively, using the dietary history method and 1, 1.02 and 1.55 using the 24-h recall data. Examination of specific macronutrient energy sources indicated that dietary fat and carbohydrate are likely to have made the largest contribution to this association. However, after adjustment for total energy, none of the individual macronutrients was significantly associated with all-site cancer, by either dietary reporting method. When expressed as a percentage of total energy, low protein density of the diet was associated with increased cancer risk, by both dietary methods. However, this appeared to be a function of high energy intake rather than low protein intake. Simultaneous statistical adjustment for seven potential confounders of the association between energy intake and cancer was performed using both the 24-h recall and the dietary history data.(ABSTRACT TRUNCATED AT 250 WORDS)

Malignant neoplastic disease in women.

This study refers to a longitudinal population study of women in Gothenburg, Sweden. The prevalences of malignant neoplastic disease in two cross-sectional studies in 1968-1969 and in 1980-1981, respectively, and incidence figures for the 12-year period between these cross-sectional studies are presented. The data on malignant neoplasms were based on interview of the participants in the population study, on information from the Cancer Registry of the Swedish National Board of Health and Welfare and from the Swedish National Bureau of Statistics and were confirmed by death certificates, inpatient and outpatient records and reexaminations of tissue specimens from the tumor tissue. The prevalences of malignant neoplastic disease increased with age from 0.3% at the age of 38 to 9.9% in women aged 60. The incidence rates during the 12-year period increased with age from about 2% in women aged 38 at the beginning of the study to be about 10% in women initially aged 60. Breast cancer was found to be the most common single malignant neoplasm followed by cancer of uterus and cancer of the ovaries.

Adipose tissue distribution and female carcinomas. A 12-year follow-up of participants in the population study of women in Gothenburg, Sweden.

A longitudinal population study of 1462 women, aged 38-60 years, was carried out in Gothenburg, Sweden, in 1968-69. In univariate analysis anthropometric variables indicating centrally localized adipose tissue (waist circumference, the ratio of waist to hip circumference and the subscapular skinfold) showed significant age-standardized positive associations with the occurrence (prevalence + incidence data) of endometrial carcinoma. Incidence data suggested that measurements of centrally localized adipose tissue might be of predictive value for this malignancy as well as for ovarian carcinoma. In contrast, measurements of generalized obesity (body weight or body mass index) or peripherally localized adipose tissue (triceps skinfold) showed no associations to these malignancies. No relationship was observed between the anthropometric variables studied and breast carcinoma. The association observed between endometrial and ovarian carcinomas with central adipose tissue did, however, not remain in multivariate analysis when generalized obesity was taken into account. Centrally localized adipose tissue is known to be associated with endocrine abberations including irregular ovulation and menstruation, re-emphasizing the importance of endocrine factors for the pathogenesis of endometrial and ovarian carcinomas. No positive association was found between development of the carcinomas and initial measurements of blood glucose, serum lipids or blood pressure, found to be elevated in cross-sectional studies. An increase in these variables therefore probably are parallel phenomena rather than predictors. The women with endometrial or breast carcinomas smoked more than the remaining women. Although the number of end-points observed was limited these results suggest that measurements of adipose tissue distribution might be a valuable addition to the predictors of endometrial and ovarian carcinomas.(ABSTRACT TRUNCATED AT 250 WORDS)