Baseline recreational physical activity, history of sports participation, and postmenopausal breast carcinoma risk in the Netherlands Cohort Study.

BACKGROUND: The aim of the current study was to evaluate the relation between physical activity and breast carcinoma risk with specific emphasis on interaction with other aspects of energy balance. METHODS: The Netherlands Cohort Study on diet and cancer was conducted among 62,537 women ages 55-69 years at baseline. Information regarding baseline recreational physical activity, history of sports participation, and occupational physical activity was collected with a questionnaire in 1986. After 7.3 years of follow-up, 1208 incident breast carcinoma cases were available for case-cohort analyses. RESULTS: A summed total of baseline recreational physical activity (including walking, cycling, gardening) showed an inverse association with breast carcinoma risk. Women who were active in the above-mentioned activities for > 90 minutes a day had a rate ratio (RR) of 0.76 (95% confidence interval [95% CI], 0.58-0.99) compared with women who were active < 30 minutes a day. Women who ever participated into sports before baseline had a RR of 1.13 (95% CI, 0.94-1.37) compared with women who never participated in sports. The relation between sports participation and breast carcinoma risk did not appear to be dependent on the time window of participation (before/after menarche, before/after birth of the first child, before/after age 20 years). No interaction was found between baseline recreational physical activity, body mass index (BMI) (kg/m(2)), energy intake, and weight gain/loss during adult life in relation to breast carcinoma, although in the subgroup of women with a high BMI we found a stronger inverse relation between recreational physical activity and breast carcinoma risk independent of energy intake. Occupational physical activity was not found to be related to breast carcinoma risk. CONCLUSIONS: The current study findings support the hypothesis that recreational physical activity is associated inversely with breast carcinoma risk.

Energy restriction in childhood and adolescence and risk of prostate cancer: results from the Netherlands Cohort Study.

This study investigated the association between prostate cancer risk and energy restriction during childhood. The authors examined the hypothesis among 58,279 men aged 55-69 years enrolled in the Netherlands Cohort Study on Diet and Cancer. Information on diet and risk factors was collected by questionnaire in 1986. Additional information was collected on residence during the Dutch Hunger Winter (1944-1945) and the World War II years (1940-1944) and father's employment status during the economic depression of 1932-1940, used as indicators of exposure. A case-cohort approach was used. After 7.3 years of follow-up (through December 1993), 903 prostate cancer cases were available for analysis. Analyses were carried out for all prostate cancer cases. The prostate cancer rate ratio for men who had lived in a western Netherlands city in 1944-1945 was 1.15 (95% confidence interval (CI): 0.80, 1.31), and the rate ratio for men who had lived in a western rural area in 1944-1945 was 1.30 (95% CI: 0.97, 1.73). Residence during the war years (1940-1944) and father's employment in 1932-1940 showed no relation to prostate cancer risk. In subgroup analyses in which exposure before, during, and after the adolescent growth spurt was evaluated, the same pattern as that of the overall data was shown. The authors found no evidence for the hypothesis that energy restriction early in life decreases prostate cancer risk later in life.

Diet in adolescence and the risk of breast cancer: results of the Netherlands Cohort Study.

OBJECTIVES: In The Netherlands, part of the population experienced food restriction and severe famine during World War II. The purpose of this study was to study the effects of severe undernutrition during adolescence on the risk of breast cancer later in life. METHODS: We examined the hypothesis in the Netherlands Cohort Study on diet and cancer (NLCS), among 62,573 women aged 55-69 years. Baseline information on diet and other risk factors was collected with a questionnaire in 1986. Information was collected on residence in the Hunger winter (1944-1945) and War years (1940-1944) and fathers' employment status in 1932-1940 as indicators of exposure. After 6.3 years of follow-up, 1009 incident breast cases were available for analysis. RESULTS: In multivariate case-cohort analysis, residents of the western part of the country in 1944-1945 had an increased breast cancer risk (western city RR = 1.1, 95% CI: 0.9-1.4, western rural area RR = 1.5, 95% CI: 1.1-1.9). For the War years (1940-1944) we found no association between breast cancer risk and urban vs. rural residence. Women whose fathers were unemployed during the Depression years (1932-1940) had a non-significant decrease in breast cancer risk (RR = 0.9, 95% CI: 0.7-1.2). Exposure to energy restriction during the adolescent growth spurt or during the period between menarche and birth of the first child did not change the RRs substantially. CONCLUSIONS: We found no clear evidence in this study for the hypothesis that energy restriction in adolescence leads to a decreased breast cancer risk.

Height, weight weight change, and postmenopausal breast cancer risk: The Netherlands Cohort Study.

The association between several anthropometric indices and breast cancer risk was evaluated within the Netherlands Cohort Study on diet and cancer, which began in 1986 and is conducted among 62,573 women aged 55 to 69 years at baseline. After 4.3 years of follow-up, data on 626 women with incident breast cancer were available with complete information on height and weight at baseline. In multivariate case-cohort analyses, a significantly positive association between adult height and breast cancer was found (P trend < 0.001). Compared with women with height < or = 155 cm, the rate ratios of breast cancer for women with heights up to 160, 165, 170, 175, and > or = 175 cm were 1.22, 1.19, 1.44, 1.77, and 2.06, respectively. For weight at baseline, the significant positive association with breast cancer observed in age-adjusted analysis disappeared in multivariate analysis with adjustment for height and other confounders. For body mass index (BMI) (wt[kg]/ht[m]2) at baseline, no association was observed with breast cancer in multivariate analysis; compared with women with a BMI less than 23, the RR for women with a BMI of 30 or more was 0.98 with P trend = 0.46. Weight and BMI at age 20 showed weak inverse associations with breast cancer risk. For gain in weight or BMI between age 20 and cohort baseline age, inconsistent increases in risk were found, with no significant trends. These data support a positive association between height and breast cancer risk among postmenopausal women. Further study is needed to evaluate the role of early diet and breast cancer in this population, and its relationship to height.