Increasing use of HRT over the last 2 decades could have contributed to the increasing incidence of cancer in women. Our aim was to investigate the relation between use of HRT and risk of hormone-dependent cancers in a Norwegian cohort of women. The Norwegian Women and Cancer (NOWAC) study is a representative, national, populationbased cohort study. This report includes 35,456 postmenopausal women aged 45-64 years who answered a postal questionnaire in 1996 -1998 providing information on reproduction, lifestyle and use of HRT. The women were followed up for cancer incidence. The main analyses were restricted to 31,451 postmenopausal women with complete information. Ever use of HRT was reported by 43.5% and current use, by 35% of the women. Current users had an increased risk of breast cancer (adjusted RR ‫؍‬ 2.1, 95% CI 1.5-2.5). The risk increased with increasing duration of use (p trend < 0.0001). Using a regimen of continuous estrogenprogestagen implied an increased risk. Adjusted RRs associated with <5 and >5 years' duration of use were 2.6 (95% CI 1.9 -3.7) and 3.2 (95% CI 2.2-4.6), respectively. The population-attributable risk of breast cancer due to current use of HRT was 27%. We found no significant increase in risk of ovarian cancer. Neither did we find users of estrogen-progestagen preparations to have any increase in risk of endometrial cancer. Our results suggest that HRT could be considered a major determinant for the increasing incidence of breast cancer in Norway. © HRT had a breakthrough in 1966 with the publication of Feminine Forever. 1 According to the author, the main objective of estrogen use was "to slow down the aging rate and to assure the general systemic health of postmenopausal women, the distinctly sexual benefits of estrogen treatment should not be underrated". Although most women start using HRT to ameliorate climacteric complaints, 2 promising results from observational studies during the last 2 decades 3-9 probably have encouraged more women to start and the duration of use to be extended. With the number of postmenopausal women worldwide expected to mount to 1.2 billion by 2030, 10 the potential user group for HRT is enormous.Breast cancer is the most common cancer among women worldwide. Research has shown risk to increase by diagnosed breast cancer in first-degree relatives as well as early menarche, parity, old age at first delivery, late menopause and high postmenopausal BMI. Use of HRT is associated with an increase in breast cancer risk. 11 In 1997 the Collaborative Group on Hormonal Factors in Breast Cancer reanalyzed data from 51 epidemiologic studies and found use of HRT to increase the RR of having breast cancer diagnosed by 2.6% each year. With duration of use Ն5 years, the RR of having a breast cancer diagnosis was 1.34. 12 Later published results from randomized clinical studies are consistent with these estimates. 13 Recent published results from the MWS showed a significant increase in the RR of breast cancer with increasing total duration of use in current users...

Objective: To determine the vitamin D status of middle-aged women living in the Norwegian arctic and its relationship with vitamin D intake and exposure to ultraviolet (UV) radiation. Design: Cross-sectional study. Conclusions: Increased ingestion of marine food items that provide vitamin D should be promoted and further studies should be carried out to investigate vitamin D status in arctic populations in relation to both UV exposure and traditional food sources.

Guarantor: E Riboli. Contributors: ER is overall coordinator of the EPIC study, which he designed and implemented in collaboration with his team at IARC and the principal investigators in the collaborating centres. NS developed the 24-h recall system and the food consumption database in collaboration with the EPIC centres. WA, NS, PF and ER constituted the writing group in charge of conducting statistical data analyses and preparing the manuscript. ALvK and JPS were in charge of laboratory analyses of carotenoids in plasma samples. The other authors supervised the collection and analysis of dietary data and the collection of blood samples in the participating study centres, and provided comments and suggestions on the final manuscript. Objective: The aim in this study was to assess the association between individual plasma carotenoid levels (a-carotene, b-carotene, lycopene, b-cryptoxanthin, lutein, zeaxanthin) and fruit and vegetable intakes recorded by a calibrated food questionnaire (FQ) and 24-h dietary recall records (24HDR) in nine different European countries with diverse populations and widely varying intakes of plant foods. Design: A stratified random subsample of 3089 men and women from nine countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC), who had provided blood samples and dietary and other lifestyle information between 1992 and 2000, were included. Results: b-Cryptoxanthin was most strongly correlated with total fruits (FQ r ¼ 0.52, 24HDR r ¼ 0.39), lycopene with tomato and tomato products (FQ r ¼ 0.38, 24HDR r ¼ 0.25), and a-carotene with intake of root vegetables (r ¼ 0.39) and of total carrots (r ¼ 0.38) for FQ only. Based on diet measured by FQ and adjusting for possible confounding by body mass index (BMI), age, gender, smoking status, alcohol intake, and energy intake, the strongest predictors of individual plasma carotenoid levels were fruits (R partial 2 ¼ 17.2%) for b-cryptoxanthin, total carrots (R partial 2 ¼ 13.4%) and root vegetables (R partial 2 ¼ 13.3%) for a-carotene, and tomato products (R partial 2 ¼ 13.8%) for lycopene. For 24HDR, the highest R partial 2 was for fruits in relation to b-cryptoxanthin (7.9%). Conclusions: Intakes of specific fruits and vegetables as measured by food questionnaires are good predictors of certain individual plasma carotenoid levels in our multicentre European study. At individual subject levels, FQ measurements of fruits, root vegetables and carrots, and tomato products are, respectively, good predictors of b-cryptoxanthin, a-carotene, and lycopene in plasma.

Objective: To identify different dietary patterns in Norway using a combination of cluster and factor analysis. Design: Cross-sectional study. Setting: Nation-wide, population-based study. Subjects: The Norwegian EPIC cohort is a subcohort of the Norwegian Women and Cancer study (NOWAC), and consist 37.226 women aged 41-56 y who answered a food frequency questionnaire (FFQ) in 1998. Interventions: The associations among 50 food variables were first investigated by using principal component analysis. Five important factors were found. The five principal components were then used as input in the cluster analysis. Different socioeconomic and lifestyle variables were examined. Results: Six clusters of dietary patterns were found, and were labelled accordingly: 'traditional fish eaters', 'healthy eaters', 'average, less fish, less healthy', 'Western', 'traditional bread eaters', and 'alcohol users'. The traditional fish eaters and the traditional bread eaters were both highly represented in the north and west of Norway and were more likely to be present among persons with lower income and lower education. The healthy and the alcohol drinkers were found mostly in the south and east and were more likely to have higher income. Persons in the alcohol group were more likely to be current smokers. The western group had the highest percentage of three or more persons in the household and the shortest time since last birth, indicating that families with children dominate this group. Conclusion: Our data indicate six different dietary patterns in Norway, each with different socio-demographic and lifestyle characteristics.

ContextThe intake of vegetables and fruits has been thought to protect against breast cancer. Most of the evidence comes from case-control studies, but a recent pooled analysis of the relatively few published cohort studies suggests no significantly reduced breast cancer risk is associated with vegetable and fruit consumption.Objective To examine the relation between total and specific vegetable and fruit intake and the incidence of breast cancer. Design, Setting, and ParticipantsProspective study of 285 526 women between the ages of 25 and 70 years, participating in the European Prospective Investigation Into Cancer and Nutrition (EPIC) study, recruited from 8 of the 10 participating European countries. Participants completed a dietary questionnaire in 1992-1998 and were followed up for incidence of cancer until 2002. Main Outcome MeasuresRelative risks for breast cancer by total and specific vegetable and fruit intake. Analyses were stratified by age at recruitment and study center. Relative risks were adjusted for established breast cancer risk factors. ResultsDuring 1486402 person-years (median duration of follow-up, 5.4 years), 3659 invasive incident breast cancer cases were reported. No significant associations between vegetable or fruit intake and breast cancer risk were observed. Relative risks for the highest vs the lowest quintile were 0.98 (95% confidence interval [CI], 0.84-1.14) for total vegetables, 1.09 (95% CI, 0.94-1.25) for total fruit, and 1.05 (95% CI, 0.92-1.20) for fruit and vegetable juices. For 6 specific vegetable subgroups no associations with breast cancer risk were observed either. ConclusionAlthough the period of follow-up is limited for now, the results suggest that total or specific vegetable and fruit intake is not associated with risk for breast cancer.

There is current interest in fish consumption and marine omega-3 (n-3) fatty acids and breast cancer risk. Some in vitro and animal studies have suggested an inhibitory effect of marine n-3 fatty acids on breast cancer growth, but the results from epidemiological studies that have examined the association between fish consumption and breast cancer risk in humans are inconsistent. We examined fish consumption and breast cancer risk in 310,671 women aged between 25 and 70 yr at recruitment into the European Prospective Investigation Into Cancer and Nutrition (EPIC). The participants completed a dietary questionnaire between 1992-98 and were followed up for incidence of breast cancer for a median of 6.4 yr. Hazard ratio for breast cancer by intake of total and lean and fatty fish were estimated, stratified by study centre and adjusted for established breast cancer risk factors. During follow-up, 4,776 invasive incident breast cancers were reported. No significant associations between intake of total fish and breast cancer risk were observed, hazard ratio (HR) 1.01 (95% confidence interval [CI] 0.99-1.02; p 5 0.28 per 10 g fish/day). When examining lean and fatty fish separately, we found a positive significant association only in the highest quintile for fatty fish (HR 1.13, 95% CI 1.01-1.26), but test for trend was not significant (p 5 0.10).

The aim of our study was to examine the risk of breast cancer according to specific types of estrogens and progestagens in oral contraceptives (OCs) based on the prospective Norwegian Women and Cancer study (NOWAC). Between 1991-97 women aged 30 -70 years were drawn at random from the central person register and mailed an invitation and a questionnaire. Women (102,443) were enrolled with follow-up information collected throughout 1999 by linkage with national registries of cancer, mortality and emigration based on the unique national identification number. Among the 96,362 women included in the present analysis 851 invasive breast cancer were diagnosed. The adjusted risk of breast cancer increased with 25% for ever use of OCs and the risk increased with increasing duration of use (test for trend: p ‫؍‬ 0.007). No association between time since last use and breast cancer risk was found after stratification on duration of use. Positive trend was still found for total duration of use among women who used OCs more than 5 years ago. Second generation of OCs had an increased risk with increasing duration of use. Classifying progestagens according to chemical groups, the relative risk increased significantly with increasing cumulative dose of levonorgestrel progestagen. It was difficult to conclude for the other groups due to lack of power. In a multivariate analysis the cumulative dose for all progestagen groups were non-significant, although we observed a significant increased risk with increasing milligrammonths of estrogen exposure (p ‫؍‬ 0.002). In conclusion, the increased risk of breast cancer related with OC formulations could be due mostly to estrogen component.

Background: Pregnancy-related pelvic pain is a common condition, and use of hormonal contraceptives before pregnancy has been proposed as a risk factor. We used data from a subsample of women participating in the "Norwegian Women and Cancer study" (NOWAC) to assess the association between hormonal contraceptive use and pelvic pain in pregnancy.