| 1. |
- Adami, Hans-Olov, et al.
(författare)
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The aetiology and pathogenesis of human breast cancer
- 1995
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Ingår i: Mutation research. - 0027-5107 .- 1873-135X. ; 333:1-2, s. 29-35
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Tidskriftsartikel (refereegranskat)abstract
- Whilst investigators have clearly shown that non-hereditary factors dominate the aetiology of human breast cancer, they have failed to identify quantitatively important causes, and prospects for prevention remain indeed limited. However, progress in epidemiological and basic research has taken place during the last few years. Current evidence suggests that breast cancer may be affected by the intra-uterine environment, that exposures during adolescence are particularly important, and that pregnancy has a dual effect on breast cancer risk: an early increase followed by long-term protection. Great variation exists in the structural development of the breast ductal system already in the newborn--and by inference in utero--and a pregnancy induces permanent structural changes in the mammary gland. We suggest that these observations fit into an aetiological model with the following key components: (1) breast cancer risk depends on the number of cells at risk, the susceptibility of individual cells to malignant transformation, and on the degree of cellular proliferation, notably cells which can act as founders of breast cancer; (2) the number of target cells is determined by the hormonal environment mainly early in life, perhaps already in utero; (3) in adult life, hormones which are non-genotoxic, increase breast cancer risk by increasing selective cell proliferation and thus number of target cells and the risk of retention of spontaneous somatic mutations; (4) while a pregnancy stimulates the growth of already malignant cells or cells close to malignant transformation (and thereby entails a short-term risk increase) the dominating long-term protection occurs due to permanent structural changes, terminal differentiation and perhaps decreased cell proliferation and carcinogen-binding in combination.
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| 2. |
- Ekbom, Anders, et al.
(författare)
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Perinatal characteristics in relation to incidence of and mortality from prostate cancer
- 1996
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Ingår i: BMJ (Clinical research ed.). - 0959-8138. ; 313:7053, s. 337-341
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE--To test the hypothesis that factors causing morbidity and mortality from prostate cancer may operate in utero. DESIGN--Matched case-control study of singleton men born between 1874 and 1946 at one hospital. SETTING--Uppsala University Hospital. SUBJECTS--250 patients with prostate cancer and 691 controls, including 80 patients who died from prostate cancer and their 196 matched controls. MAIN OUTCOME MEASURES--Mother's age at menarche, parity, pre-eclampsia or eclampsia before delivery, age at delivery and socioeconomic status; case or control's birth length and weight, placental weight, prematurity derived from gestational age, and presence of jaundice. RESULTS--Both pre-eclampsia (odds ratio 0, 95% confidence interval 0 to 0.71) and prematurity (0.31, 0.09 to 1.04) were inversely associated with incidence of prostate cancer. Among subjects born full term, placental weight, birth weight, and ponderal index (weight/height 3) showed non-significant positive associations with prostate cancer incidence, and stronger associations with mortality. CONCLUSION--Prenatal exposures that are likely correlates of pregnancy hormones and other growth factors are important in prostate carcinogenesis and influence the natural course as well as the occurrence of this cancer.
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| 3. |
- Galanti, M. Rosaria, et al.
(författare)
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Diet and the risk of papillary and follicular thyroid carcinoma : A population-based case-control study in Sweden and Norway
- 1997
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Ingår i: Cancer Causes and Control. - 0957-5243 .- 1573-7225. ; 8:2, s. 205-214
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Tidskriftsartikel (refereegranskat)abstract
- A population-based case-control study was conducted in two regions of Sweden and Norway to investigate the association between dietary habits and the risk of thyroid cancer. The consumption of selected foods was reported in a self-completed food-frequency questionnaire by 246 cases with histologically confirmed papillary (n = 209) and follicular (n = 37) thyroid carcinoma, and 440 age- and gender-matched controls. Odds ratios (OR) and their 95 percent confidence interval (CI) were calculated as estimates of the relative risk using conditional logistic regression. High consumption of butter (OR = 1.6, CI = 1.1-2.5) and cheese (OR = 1.5, CI = 1.0-2.4) was associated with increased risks. Residence in areas of endemic goiter in Sweden was associated with an elevated risk, especially among women (OR = 2.5, CI = 1.3-4.9). High consumption of cruciferous vegetables was associated with increased risk only in persons who ever lived in such areas. A decreased risk was associated with consumption of iodized salt in northern Norway, and with use of iodized salt during adolescence among women (OR = 0.6, CI = 0.6-1.0). The results of this study suggest a role of diet and environment in the risk of thyroid cancer.
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| 4. |
- Holmberg, Lars, et al.
(författare)
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A search for recall bias in a case-control study of diet and breast cancer
- 1996
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Ingår i: International Journal of Epidemiology. - 0300-5771 .- 1464-3685. ; 25:2, s. 235-244
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND. In retrospective studies of dietary habits and breast cancer risk, recall bias is a concern since diet has been publicized as a cause of breast cancer. METHODS. In a case-control study of diet and breast cancer risk nested within a cohort of women screened with mammography, we contrasted answers to a retrospective dietary interview with answers to a dietary questionnaire which was filled out before any diagnostic procedures for breast cancer were undertaken. The source population was all women aged 40-74 in two counties in Sweden invited to mammographic screening and asked to fill out a questionnaire before the screening. Cases and controls were subsequently defined -- matched on age, county of residence, and time of mammography -- and approached for an interview. RESULTS. In all, 265 cases and 431 controls participated in the study. Means of frequencies differed between the agreement in the questionnaire's and the interview's classifications of study subjects into quartiles of monthly intake varied between 31 percent and 57 percent. Kappa statistics in all food groups were below 0.41. In a regression analysis, case subjects with low responses on the questionnaire about intake of meat, snacks, and coffee and tea gave higher responses on interview than did controls who had low questionnaire responses for these food groups. The reverse was also true: cases' responses that were high on the questionnaire were lower on interview for these food groups than were controls' responses. CONCLUSIONS. We found few signs of recall bias, and the few indications of a differential misclassification that we found were not in food groups that have been publicly discussed as causes of breast cancer.
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| 5. |
- Holmberg, Lars, et al.
(författare)
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Alcohol intake and breast cancer risk : effect of exposure from 15 years of age
- 1995
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - 1055-9965 .- 1538-7755. ; 4:8, s. 843-847
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Tidskriftsartikel (refereegranskat)abstract
- Research regarding the relationship between alcohol intake and breast cancer risk has suggested an association between the two, although the data are inconsistent regarding dose effects and susceptible populations. To clarify these issues, we investigated the association of breast cancer risk with alcohol intake at various ages in a population-based case-control study nested within a screening cohort in Sweden. Subjects were women 40-75 years old who participated in a screening program in central Sweden. Information about personal characteristics, diet, and alcohol intake was obtained by a questionnaire sent out at the invitation to the screening interview and at a supplementary interview conducted among a sample of women who did and did not develop breast cancer. Alcohol intake did not affect breast cancer risk among women under 50 years old. However, among those over 50 years of age, ever-drinking conferred a relative risk of 1.8 (95% confidence interval = 1.2-2.6). Current and former drinkers had similar increases in risk. No particular latent period of alcohol effect was identified, but drinking later in life to have a bigger effect than did drinking earlier in life.
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| 6. |
- Jumaan, Aisha O., et al.
(författare)
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Beta-carotene intake and risk of postmenopausal breast cancer
- 1999
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Ingår i: Epidemiology. - : Ovid Technologies (Wolters Kluwer Health). - 1044-3983 .- 1531-5487. ; 10:1, s. 49-53
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Tidskriftsartikel (refereegranskat)abstract
- We assessed the relation between beta-carotene consumption at various times in life and breast cancer risk by conducting a case-control study nested within a population-based cohort of women screened for breast cancer in Sweden. We conducted a telephone interview with 273 incident breast cancer cases and 371 controls about their diet at various ages throughout their lifetime. Controls were frequency matched to cases on age, month and year of mammography, and county of residence. We used unconditional logistic regression to measure the association between beta-carotene intake and breast cancer risk while adjusting for total energy intake, recency of intake, and the matching variables. Women were at lower risk with increasing levels of reported intake of beta-carotene. This pattern of association between breast cancer and beta-carotene intake was similar at various times before screening. These findings indicate that although diets high in beta-carotene may be associated with lower breast cancer risk, there does not seem to be evidence of a critical time period during which such diets are more relevant.
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| 7. |
- Melhus, Håkan, et al.
(författare)
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Excessive dietary intake of vitamin A is associated with reduced bone mineral density and increased risk for hip fracture
- 1998
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Ingår i: Annals of Internal Medicine. - : American College of Physicians. - 0003-4819 .- 1539-3704. ; 129:10, s. 770-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The highest incidence of osteoporotic fractures is found in northern Europe, where dietary intake of vitamin A (retinol) is unusually high. In animals, the most common adverse effect of toxic doses of retinol is spontaneous fracture. OBJECTIVE: To investigate whether excessive dietary intake of vitamin A is associated with decreased bone mineral density and increased risk for hip fracture. DESIGN: A cross-sectional study and a nested case-control study. SETTING: Two counties in central Sweden. PARTICIPANTS: For the cross-sectional study, 175 women 28 to 74 years of age were randomly selected. For the nested case-control study, 247 women who had a first hip fracture within 2 to 64 months after enrollment and 873 age-matched controls were selected from a mammography study cohort of 66,651 women 40 to 76 years of age. MEASUREMENTS: Retinol intake was estimated from dietary records and a food-frequency questionnaire. Bone mineral density was measured with dual-energy x-ray absorptiometry. Hip fracture was identified by using hospital discharge records and was confirmed by record review. RESULTS: In multivariate analysis, retinol intake was negatively associated with bone mineral density. For every 1-mg increase in daily intake of retinol, risk for hip fracture increased by 68% (95% CI, 18% to 140%; P for trend, 0.006). For intake greater than 1.5 mg/d compared with intake less than 0.5 mg/d, bone mineral density was reduced by 10% at the femoral neck (P = 0.05), 14% at the lumbar spine (P = 0.001), and 6% for the total body (P = 0.009) and risk for hip fracture was doubled (odds ratio, 2.1 [CI, 1.1 to 4.0]). CONCLUSION: High dietary intake of retinol seems to be associated with osteoporosis.
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| 8. |
- Melhus, Håkan, et al.
(författare)
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Smoking, Antioxidant Vitamins, and the Risk of Hip Fracture
- 1999
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431 .- 1523-4681. ; 14:1, s. 129-135
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Tidskriftsartikel (refereegranskat)abstract
- Smoking increases the concentrations of free radicals, which have been suggested to be involved in bone resorption. We examined whether the dietary intake of antioxidant vitamins may modify the increased hip fracture risk associated with smoking. We prospectively studied 66,651 women who were 40-76 years of age. Forty-four of the cohort members who sustained a first hip fracture within 2-64 months of follow-up (n = 247) and 93 out of 873 age-matched controls were current smokers. Information on diet was obtained by a validated food-frequency questionnaire. The relative risk of hip fracture for current versus never smokers was analyzed in relation to the dietary intake of antioxidant vitamins stratified into two categories (low/high), where median intakes among the controls were used as cut-off points. After adjustment for major osteoporosis risk factors, the odds ratio (OR) for hip fracture among current smokers with a low intake of vitamin E was 3.0 (95% confidence interval 1.6-5.4) and of vitamin C 3.0 (1.6-5.6). In contrast, the OR decreased to 1.1 (0.5-2.4) and 1.4 (0.7-3.0) with high intakes of vitamin E and C, respectively. This effect was not seen for beta-carotene, selenium, calcium, or vitamin B6. In current smokers with a low intake of both vitamins E and C, the OR increased to 4.9 (2.2-11.0). The influence of the intake of these two antioxidant vitamins on hip fracture risk was less pronounced in former smokers. Our results suggest a role for oxidant stress in the adverse effects on the skeleton of smoking, and that an insufficient dietary intake of vitamin E and C may substantially increase the risk of hip fracture in current smokers, whereas a more adequate intake seems to be protective.
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| 9. |
- Michaëlsson, Karl, et al.
(författare)
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A high dietary calcium intake is needed for a positive effect on bone density in Swedish postmenopausal women
- 1997
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Ingår i: Osteoporosis International. - 0937-941X .- 1433-2965. ; 7:2, s. 155-161
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Tidskriftsartikel (refereegranskat)abstract
- The importance of dietary calcium for bone health is unclear, partly since most investigations have dealt only with a fairly narrow range of calcium intake. In the present population-based observational study with longitudinal dietary assessment, we investigated women with a mean age of 60 years and with a consistently high (range 1417-2417, mean 1645 mg, n = 40), intermediate (800-1200, mean 1006 mg, n = 35) or low (400-550, mean 465 mg, n = 40) estimated daily consumption of calcium. Measurements of bone mineral density (BMD) of the lumbar spine, femoral neck and total body were performed by dual-energy X-ray absorptiometry, as well as ultrasound of the heel. In a multivariate analysis, with adjustment for energy intake the risk factors for osteoporosis (age, body mass index, physical activity, menopausal age, use of estrogens, smoking and former athletic activity), the group with the highest calcium intake had higher values for BMD than the others at all measured sites. The average mean difference compared with the low and the intermediate calcium group was 11% for the femoral neck, 8-11% for the lumbar spine and 5-6% for total body BMDs. In univariate analyses and multivariate models which did not include energy intake, the differences between the groups were less pronounced. The women in the intermediate calcium group had approximately the same mean BMD values as those in the low calcium group. These findings support the view that only a high calcium intake (3% highest percentiles in the studied population) protects against osteoporosis in Swedish postmenopausal women.
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| 10. |
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