| 1. |
- Almquist, Martin
(författare)
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Calcium metabolism and breast cancer risk
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Emerging evidence suggests that calcium and its regulating hormones, i.e. vitamin D and parathyroid hormone (PTH), affect breast cancer risk. The associations between serum calcium levels and breast cancer risk, between serum calcium levels and known risk factors of breast cancer, and between serum calcium levels and breast cancer aggressiveness were examined within the Malmö Preventive Project, a population-based cohort comprising 10,902 women. Serum calcium, 25-hydroxyvitamin D (25OHD) and PTH-levels were furthermore examined in relation to breast cancer risk in a nested case-control study comprising 764 breast cancer cases within the Malmö Diet and Cancer Study. Serum calcium levels were positively associated with breast cancer risk in overweight/obese women. In premenopausal women, serum calcium was in one study negatively, and in one study positively, associated with breast cancer. Calcium was positively associated with breast cancer aggressiveness in overweight and/or premenopausal women. Premenopausal status and use of oral contraceptives and hormone-replacement therapy were negatively associated with serum calcium levels. BMI was significantly associated with serum calcium levels, with lean and overweight women having higher calcium levels than women with BMI between 20 and 25. There was a weak, statistically non-significant, inverse association between 25OHD-levels and breast cancer risk. There was no evidence for any relation between PTH-levels and breast cancer. It is concluded that serum calcium is positively associated with breast cancer risk and aggressiveness in overweight women. There may be a weak negative association between vitamin D and breast cancer risk, but this will have to be further examined.
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| 2. |
- Almquist, Martin, et al.
(författare)
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Reproductive history, lifestyle factors and season as determinants for serum calcium concentrations in women.
- 2008
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Ingår i: Scandinavian Journal of Clinical & Laboratory Investigation. - : Informa UK Limited. - 1502-7686 .- 0036-5513. ; 68, s. 777-785
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Serum calcium concentrations have been associated with the risk of malignant disease, especially breast cancer. Thus, determinants of serum calcium concentrations, with special regard to risk factors of breast cancer, are of great interest. Material and methods. Previous studies have either been small or they have not focused on reproductive factors. The present study examined serum calcium concentrations in relation to reproductive history, selected lifestyle factors and screening season in a large population-based cohort study comprising 8,114 women. ANOVA followed by the Bonferroni t-test were used for comparison of means, and logistic regression and multiple regression analysis were used to test associations. Results. Serum calcium concentrations were lower in hormone replacement therapy users versus non-users (2.321 mmol/L versus 2.364; p<0.001) and in users of oral contraceptives versus non-users (2.304 versus 2.348; p<0.001). They were higher in peri-/postmenopausal versus premenopausal women (2.357 versus 2.319; p<0.001). Overweight and obese women had higher mean calcium concentrations (2.350 and 2.355) than women with body mass index between 20 and 25 (2.342; p<0.001). Serum calcium concentrations were higher in spring and autumn than in winter (2.352 and 2.353 versus 2.343; p = 0.002). Both younger (40-45 years) (2.334; p = 0.001) and older age groups (>55 years) (2.363; p<0.001) had higher mean calcium concentrations compared to those of women aged 45-50 years (2.320), even when adjusting for menopausal status, suggesting that age has an independent influence on calcium concentrations. Conclusions. It is concluded that reproductive factors such as menopausal status, use of oral contraceptives or hormone-replacement therapy, and age, BMI and season are associated with serum calcium concentrations.
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| 3. |
- Almquist, Martin, et al.
(författare)
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Serum calcium and breast cancer risk: results from a prospective cohort study of 7,847 women.
- 2007
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Ingår i: Cancer Causes and Control. - : Springer Science and Business Media LLC. - 1573-7225 .- 0957-5243. ; 18, s. 595-602
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Tidskriftsartikel (refereegranskat)abstract
- Experimental and epidemiological studies suggest that calcium-regulating hormones-parathyroid hormone (PTH) and vitamin D-may be associated with breast cancer risk. No prospective cohort study has investigated the association between pre-diagnostic calcium levels and subsequent risk of breast cancer. We have examined this in a cohort of 7,847 women where serum calcium levels and established risk factors for breast cancer had been assessed at baseline. During a mean follow-up of 17.8 years, 437 incident breast cancer cases were diagnosed. Incidence of breast cancer was calculated in different quartiles of serum calcium levels and a Cox's proportional hazards analysis was used to obtain corresponding relative risks (RR), with a 95% confidence interval (CI), adjusted for potential confounders. In premenopausal women, serum calcium levels were inversely associated with breast cancer risk in a dose-response manner. The adjusted RR (95% CI) of breast cancer was in the 2nd calcium quartile 0.91 (0.65-1.30), in the 3rd quartile 0.89 (0.60-1.31), and in the 4th quartile 0.56 (0.32-0.98), as compared to the 1st calcium quartile. In postmenopausal overweight women (BMI > 25), breast cancer risk was higher in calcium quartiles 2-4 as compared to the 1st quartile. Our findings may have implications for primary prevention of breast cancer and for the management of asymptomatic primary hyperparathyroidism.
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| 4. |
- Almquist, Martin, et al.
(författare)
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Serum calcium and tumour aggressiveness in breast cancer: a prospective study of 7847 women.
- 2009
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Ingår i: European Journal of Cancer Prevention. - 1473-5709. ; 18, s. 354-360
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Tidskriftsartikel (refereegranskat)abstract
- Experimental, epidemiological and clinical studies suggest that calcium and/or its regulating hormones affect breast cancer risk. There has been no prospective cohort study investigating serum calcium levels and breast cancer aggressiveness, as determined by tumour histology and stage. Dichotomized prediagnostic serum calcium levels were investigated in relation to breast cancer aggressiveness as determined by grade (mitotic frequency, tubule formation, nuclear atypia) and stage (tumour size and axillary lymph node status). Cox's proportional hazards analysis and heterogeneity analysis were used to investigate the associations between low/high calcium and grade/stage in a prospective cohort study of 7847 women, out of whom 462 women were diagnosed with incident breast cancer during a mean follow-up of 17.2 years. All analyses were stratified for body mass index and menopausal status. Prediagnostic serum calcium levels in premenopausal women were positively associated with increased tumour aggressiveness as determined by a higher risk of nodal metastasis; relative risk (RR) for calcium above median as compared with calcium below median was 1.88 with a 95% confidence interval (CI) of 1.04-3.38. In overweight women, prediagnostic serum calcium levels were also associated with tumour aggressiveness, as determined by both a higher risk of nodal metastasis [RR (95% CI) 1.69 (0.95-3.02)] and severe nuclear atypia [RR (95% CI) 2.06 (1.10-3.86)]. Results also indicate that, in overweight women, calcium is positively associated with worse grade as determined by tubule formation and mitotic frequency. In conclusion, prediagnostic serum calcium levels are positively associated with increased tumour aggressiveness in premenopausal and/or overweight women.
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| 5. |
- Halthur, C., et al.
(författare)
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Serum calcium and the risk of prostate cancer
- 2009
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Ingår i: Cancer Causes and Control. - : Springer Science and Business Media LLC. - 1573-7225 .- 0957-5243. ; 20:7, s. 1205-1214
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies have suggested an association between high dietary intake of calcium and the risk of prostate cancer. Calcium-rich diet has been suggested to affect the serum levels of Vitamin D, and thereby promote cancer. We conducted the largest study of the association between prediagnostic serum levels of calcium and the risk of prostate cancer. We examined the incidence of prostate cancer in relation to prediagnostic serum calcium levels in a prospective cohort study of 22,391 healthy Swedish men, of which 1,539 incident cases of prostate cancer were diagnosed during the 30 years of follow-up until December 2006. Serum levels of calcium were measured at baseline, and categorized into quartiles. Cox regression was used to estimate the adjusted hazard ratios (HR) with 95% confidence intervals (CI). We found no evidence of an association between prediagnostic serum levels of calcium and risk of prostate cancer (HR for trend = 0.99 [95% CI;0.94-1.03]). However, a moderate significant negative association was seen in men with a BMI above 25 and aged below 45 years at baseline (Highest vs. lowest quartile, HR = 0.63 [95% CI;0.40-0.99]). These data do not support the hypothesis that high serum calcium levels is a risk factor for prostate cancer. On the contrary, the data suggest that high serum levels of calcium in young overweight men may be a marker for a decreased risk of developing prostate cancer.
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