| 1. |
- Kaaks, Rudolf, et al.
(författare)
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Prospective study of IGF-I, IGF-binding proteins, and breast cancer risk, in Northern and Southern Sweden
- 2002
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Ingår i: Cancer Causes and Control. - 1573-7225 .- 0957-5243. ; 13:4, s. 307-316
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To examine the possible relationships of breast cancer risk to prediagnostic plasma levels of insulin; insulin-like growth factor-I (IGF-I); and IGF-binding proteins -1, -2, and -3. Methods: Within two prospective cohorts in Umea and Malmo we measured plasma concentrations of insulin, IGF-I, and IGFBPs for a total of 513 incident breast cancer cases and 987 matched controls. Results: Globally, risk was unassociated with levels of IGF-I, IGFBP-3, or IGF-I adjusted for IGFBP-3. When breaking down the analysis by subgroups of age at blood donation, an increase in risk was observed for increasing levels of IGF-I in women aged 55 or older, in the Umea cohort only (odds ratios of 1.00, 1.73, 1.76, 1.90; p(trend) = 0.05). This effect weakened, however, when the analysis was restricted to subjects who did not use exogenous hormones for the treatment of menopausal symptoms. Levels of IGF-I and IGFBP-3 were not related to risk in younger women, recruited before age 50, contrary to observations from previous studies. In a subcohort where blood samples had been collected after at least four hours of fasting, breast cancer risk showed no clear associations with levels of insulin, IGFBP-1, or IGFBP-2. Conclusions: Our results do not confirm earlier findings of an association of plasma IGF-I levels with breast cancer risk especially in young women, but suggest a possible association with postmenopausal breast cancer risk, possibly among ERT/HRT users only. Our results do not support the hypothesis that elevated plasma insulin levels, and reduced levels of IGFBP-1 and IGFBP-2, are associated with increased breast cancer risk.
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| 2. |
- Manjer, Jonas, et al.
(författare)
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Breast cancer incidence in ex-smokers in relation to body mass index, weight gain and blood lipid levels
- 2001
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Ingår i: European Journal of Cancer Prevention. - 1473-5709. ; 10:3, s. 281-287
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Tidskriftsartikel (refereegranskat)abstract
- According to several studies breast cancer is more common among former smokers. This study explores whether this association has any relationship with anthropometric measurements or blood lipid levels. The 2082 ex-smokers (mean age 49.9 years) in the Malmo Preventive Cohort were followed for an average of 13.3 years using official cancer registries. This yielded 93 incident breast cancer cases. Oestrogen receptor (ER) status was assessed by an immunological method. Incidence of breast cancer covaried with height, body mass index, weight gain and cholesterol levels. None of these associations reached statistical significance. Incidence of breast cancer increased over quartiles of serum triglycerides, Ptrend: 0.02, relative risk (RR) for triglycerides as a continuous variable: 1.46 (1.21-1.77). Nineteen tumours were ER negative; this subgroup was similarly related to high triglycerides, 1.76 (1.40-2.21). All results were similar when BMI and cholesterol levels were entered into the model. It is concluded that breast cancer incidence covaries with triglyceride levels in ex-smokers.
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| 3. |
- Manjer, Jonas, et al.
(författare)
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Breast cancer incidence in relation to smoking cessation
- 2000
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Ingår i: Breast Cancer Research and Treatment. - 1573-7217. ; 61:2, s. 121-129
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Tidskriftsartikel (refereegranskat)abstract
- High plasma levels of oestrogens are associated with increased breast cancer risk. If smoking, as has been suggested, have both a tumour initiating mutagenic effect and a protective anti-oestrogenic effect, one would assume that smokers who give up smoking have the highest incidence of breast cancer. This was evaluated in the follow-up of a cohort of 10,902 women of whom 4,359 were premenopausal. Record-linkage with official cancer registries yielded 416 incident cases during an average follow-up of 13.6 years. The adjusted relative risk in all ex-smokers was 1.31 (1.02-1.69), as compared to never smokers, and in premenopausal ex-smokers it was 1.57 (1.07-2.30). Breast cancer incidence in premenopausal ex-smokers was inversely related to time since cessation, (p for trend = 0.01), and was highest among the women who had given-up smoking less than 12 months before screening: 2.76 (1.55-4.91). There was no significant association between current smoking and breast cancer risk. We conclude that incidence of breast cancer in premenopausal women who have given up smoking is higher than it is in smokers and never smokers. To what extent this may be related to endocrine effects associated with smoking cessation remains to be evaluated.
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| 4. |
- Manjer, Jonas, et al.
(författare)
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Increased incidence of small and well-differentiated breast tumours in post-menopausal women following hormone-replacement therapy
- 2001
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 92:6, s. 919-922
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Tidskriftsartikel (refereegranskat)abstract
- Exposure to hormone-replacement therapy (HRT) has consistently been associated with an increased incidence of breast cancer, particularly of small tumours. Other tumour characteristics in relation to HRT have received less scientific attention. Our aim in this population-based prospective cohort study was to assess whether HRT is associated with an increased incidence of breast-cancer subgroups defined in terms of stage, type (according to the WHO system), Nottingham grade and the Nottingham Prognostic Index (NPI). Evaluation was based on a cohort of 5,865 post-menopausal women followed for an average of 9.8 years. Twenty percent of women reported current use of HRT at the time of the baseline interview. Record linkage with the Swedish Cancer Registry and local clinical registries identified 141 incident invasive breast-cancer cases. All tumours were reclassified by 1 pathologist. The incidence of breast cancer in HRT users was 377/10(5) and in non-users 221/10(5) person-years [relative risk (RR) = 1.72, 95% confidence interval (CI) 1.17-2.52]. This risk remained statistically significant after adjustment for established risk factors in a Cox proportional hazards analysis (RR = 1.66, 95% CI 1.12-2.45). Among HRT users, there was over-representation of cases with stage I tumours (adjusted RR = 2.33, 95% CI 1.44-3.76), of lobular carcinomas (RR = 4.38, 95% CI 1.60-12.0) and of tubular tumours (RR = 4.81, 95% CI 1.37-16.8). Nottingham grade I/II carcinomas (RR = 2.02, 95% CI 1.29-3.16) and cases with NPI < or = 3.4 (RR = 2.29, 95% CI 1.41-3.72) were similarly over-represented among HRT users. Incidence of breast cancer was increased in post-menopausal women who used HRT at baseline. Among HRT users, there was over-representation of tumours that, with regard to stage, type and grade, are associated with a favourable prognosis.
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| 5. |
- Manjer, Jonas, et al.
(författare)
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Intra-urban differences in breast cancer mortality: a study from the city of Malmo in Sweden
- 2000
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Ingår i: Journal of Epidemiology and Community Health. - : BMJ. - 1470-2738 .- 0143-005X. ; 54:4, s. 279-285
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Tidskriftsartikel (refereegranskat)abstract
- STUDY OBJECTIVE: To assess whether in an urban population stage at breast cancer diagnosis is related to area of living and to what extent intra-urban differences in breast cancer mortality are related to incidence respectively stage at diagnosis. DESIGN: National registries were used to identify cases. Mortality in 17 residential areas was studied in relation to incidence and stage distribution using linear regression analysis. Areas with high and low breast cancer mortality, incidence and proportion of stage II+ tumours at diagnosis were also compared in terms of their sociodemographic profile. SETTING: City of Malmo in southern Sweden. PATIENTS: The 1675 incident breast cancer cases and 448 deaths that occurred in women above 45 years of age in Malmo 1986-96. MAIN RESULTS: Average annual age standardised breast cancer mortality ranged between residential areas, from 35/10(5) to 107/10(5), p = 0.04. Mortality of breast cancer was not correlated to incidence, r = 0.22, p = 0.39. The ratio of stage II+/0-I cancer incidence varied between areas from 0.45 to 1.99 and was significantly correlated to breast cancer mortality, r = 0.53, p = 0.03. Areas with high proportion of stage II+ cancers and high mortality/incidence ratio were characterised by a high proportion of residentials receiving income support, being foreigners and current smokers. CONCLUSIONS: Within this urban population there were marked differences in breast cancer mortality between residential areas. Stage at diagnosis, but not incidence, contributed to the pattern of mortality. Areas with high proportion of stage II+ tumours differed unfavourably in several sociodemographic aspects from the city average.
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| 6. |
- Manjer, Jonas, et al.
(författare)
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Postmenopausal breast cancer risk in relation to sex steroid hormones, prolactin and SHBG (Sweden)
- 2003
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Ingår i: Cancer Causes and Control. - 1573-7225. ; 14:7, s. 599-607
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Tidskriftsartikel (refereegranskat)abstract
- Objective: High levels of sex steroid hormones and prolactin have been suggested to enhance breast cancer development. Low levels of SHBG may indicate high levels of (bio-available) steroid hormones. The present study investigates whether high levels of sex steroid hormones and prolactin, and/or low levels of SHBG, are associated with high breast cancer risk. Methods: Blood samples were collected in about 65,000 women participating in two population-based prospective cohort studies in Sweden. Follow-up yielded 173 postmenopausal breast cancer cases who had not been exposed to HRT. Levels of estrone, estradiol, SHBG, FSH, prolactin, testosterone, androstenedione and DHEAs were analysed in cases and 438 controls. Logistic regression analysis yielded odds ratios (ORs), with 95% confidence intervals, adjusted for potential confounders. Results: The risk of breast cancer was associated with the highest versus lowest quartiles of estrone, OR: 2.58 (1.50 - 4.44), estradiol (dichotomised: high versus low) (1.73: 1.04 - 2.88), and testosterone (1.87: 1.08 - 3.25). High risks, although not statistically significant, were seen for androstenedione (1.58: 0.92 - 2.72) and DHEAs ( 1.62: 0.89 - 2.72). No strong associations were seen between SHBG or prolactin and risk of breast cancer. Conclusions: High levels of estrone, estradiol, testosterone, and possibly androstenedione and DHEAs, in postmenopausal women are associated with a high risk of subsequent breast cancer.
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| 7. |
- Manjer, Jonas, et al.
(författare)
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Risk of breast cancer in relation to anthropometry, blood pressure, blood lipids and glucose metabolism: a prospective study within the Malmo Preventive Project
- 2001
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Ingår i: European Journal of Cancer Prevention. - 1473-5709. ; 10:1, s. 33-42
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Tidskriftsartikel (refereegranskat)abstract
- Insulin resistance may be a risk factor for breast cancer, possibly through increased levels of oestrogens or insulin-like growth factor I. Insulin resistance has been associated with obesity, hypertension, dyslipidaemia and impaired glucose tolerance. We studied the relation of these factors to breast cancer risk in a prospective cohort study of 9738 women. Menopausal status was defined a priori, and 112 cases of invasive breast carcinoma occurred in women who were premenopausal at baseline and 157 cases in subjects who were peri/postmenopausal. Relative risks (RR) for breast cancer were calculated by Cox's proportional hazards analysis for different quartiles of height, weight, body mass index, blood pressure, pulse rate and serum levels of total cholesterol, triglycerides, fasting blood glucose and glucose at 120 min after an oral dose of glucose. Peri/postmenopausal women had a significantly increased age-adjusted relative risk of breast cancer associated with height (RR = 1.78 for the highest versus lowest quartile), and the RR was increased over quartiles of cholesterol levels (P-value for trend: 0.05). No other significant associations were found. Adjustments for potential confounding factors or restriction of the analysis to cases and person-years before 55 years of age (premenopausal women), or after 55 years (peri/postmenopausal women), did not change
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| 8. |
- Manjer, Jonas, et al.
(författare)
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Smoking associated with hormone receptor negative breast cancer
- 2001
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Ingår i: International Journal of Cancer. - 0020-7136. ; 91:4, s. 580-584
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Tidskriftsartikel (refereegranskat)abstract
- Women who smoke have less favourable prognosis following breast-cancer diagnosis. Some studies suggest that this is due to a more advanced stage at diagnosis, on average. Our present aim was to assess whether smoking is associated with other prognostic markers as well, e.g., hormone receptor status, histopathology and tumour differentiation. The evaluation was based on 268 incident cases in a cohort of 10,902 women (35% smokers) followed for an average of 12.4 years. An immunohistochemical method on recuts of tumour tissue was used to assess hormone receptor status. One pathologist classified all tumours according to the WHO system, Nottingham grade and Nottingham Prognostic Index. The relative risk (RR) of oestrogen receptor-negative tumours was, for current smokers, 2.21 [95% confidence interval (CI) 1.23-3.96] and, for ex-smokers, 2.67 (95% CI 1.41-5.06) compared to never-smokers. Ex-smokers had an increased risk of progesterone receptor-negative tumours (RR = 1.61, 95% CI 1.07-2.41), but there were no other significant associations between smoking habits and oestrogen receptor-positive or progesterone receptor-positive or -negative tumours. The incidence of Nottingham grade III tumours was higher in ex-smokers than in never-smokers (RR = 2.03, 95% CI 1.17-3.54). In terms of histopathological type or Nottingham Prognostic Index, there were no significant differences between smoking groups. We conclude that smoking is associated with an increased occurrence of hormone receptor-negative tumours.
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| 9. |
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| 10. |
- Manjer, Jonas, et al.
(författare)
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The Malmö Diet and Cancer Study: representativity, cancer incidence and mortality in participants and non-participants
- 2001
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Ingår i: European Journal of Cancer Prevention. - 1473-5709. ; 10:6, s. 489-499
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Tidskriftsartikel (refereegranskat)abstract
- In order to investigate potential selection bias in population-based cohort studies, participants (n = 28098) and non-participants (n = 40807) in the Malmo Diet and Cancer Study (MDCS) were compared with regard to cancer incidence and mortality. MDCS participants were also compared with participants in a mailed health survey with regard to subjective health, socio-demographic characteristics and lifestyle. Cancer incidence prior to recruitment was lower in non-participants, Cox proportional hazards analysis yielded a relative risk (RR) with a 95% confidence interval of 0.95 (0.90-1.00), compared with participants. During recruitment, cancer incidence was higher in non-participants, RR: 1.08 (1.01-1.17). Mortality was higher in non-participants both during, 3.55 (3.13-4.03), and following the recruitment period, 2.21 (2.03-2.41). The proportion reporting good health was higher in the MDCS than in the mailed health survey (where 74.6% participated), but the socio-demographic structure was similar. We conclude that mortality is higher in non-participants than in participants during recruitment and follow-up. It is also suggested that non-participants may have a lower cancer incidence prior to recruitment but a higher incidence during the recruitment period.
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