| 1. |
- Kaaks, Rudolf, et al.
(författare)
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Insulin-like growth factor I and risk of breast cancer by age and hormone receptor status : A prospective study within the EPIC cohort
- 2014
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 134:11, s. 2683-2690
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Tidskriftsartikel (refereegranskat)abstract
- Experimental evidence shows cross-talk in mammary cells between estrogen, insulin-like growth factor I (IGF-I) and their respective receptors and possible synergistic effects of estrogen receptor (ER) activation and increased IGF-I signaling with regard to breast tumor development, and epidemiological evidence suggests that circulating IGF-I levels may be related more to the risk of ER-positive than ER-negative breast cancer. Using a case–control study nested within the prospective European EPIC cohort (938 breast cancer cases and 1,394 matched control subjects), we analyzed the relationships of prediagnostic serum IGF-I levels with the risk of estrogen and progesterone receptor-positive and -negative breast tumors. IGF-I levels were positively associated with the risk of ER+ breast tumors overall (pre- and postmenopausal women combined, odds ratio (OR)Q4-Q1 = 1.41 [95% confidence interval (CI) 1.01–1.98] for the highest vs. lowest quartile; OR = 1.17 [95% CI 1.04–1.33] per 1-standard deviation (SD) increase in IGF-I, ptrend = 0.01) and among women who were diagnosed with breast cancer at 50 years or older (ORQ3-Q1 = 1.38 [95% CI 1.01–1.89]; OR = 1.19 [95% CI 1.04–1.36] per 1-SD increase in IGF-I, ptrend = 0.01) but not with receptor-positive disease diagnosed at an earlier age. No statistically significant associations were observed for ER− breast tumors overall and by age at diagnosis. Tests for heterogeneity by receptor status of the tumor were not statistically significant, except for women diagnosed with breast cancer at 50 years or older (phet = 0.03 for ER+/PR+ vs. ER−/PR− disease). Our data add to a global body of evidence indicating that higher circulating IGF-I levels may increase risk specifically of receptor-positive, but not receptor-negative, breast cancer diagnosed at 50 years or older.
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| 2. |
- Kaaks, Rudolf, et al.
(författare)
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Lag Times between Lymphoproliferative Disorder and Clinical Diagnosis of Chronic Lymphocytic Leukemia : A Prospective Analysis Using Plasma Soluble CD23
- 2015
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - 1055-9965 .- 1538-7755. ; 24:3, s. 538-545
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chronic lymphocytic leukemia (CLL) is a chronic disease that often progresses slowly from a precursor stage, monoclonal B-cell lymphocytosis (MBL), and that can remain undiagnosed for a long time. Methods: Within the European Prospective Investigation into Cancer cohort, we measured prediagnostic plasma sCD23 for 179 individuals who eventually were diagnosed with CLL and an equal number of matched control subjects who remained free of cancer. Results: In a very large proportion of CLL patients' plasma sCD23 was clearly elevated 7 or more years before diagnosis. Considering sCD23 as a disease predictor, the area under the ROC curve (AUROC) was 0.95 [95% confidence interval (CI), 0.90-1.00] for CLL diagnosed within 0.1 to 2.7 years after blood measurement, 0.90 (95% CI, 0.86-0.95) for diagnosis within 2.8 to 7.3 years, and 0.76 (95% CI, 0.65-0.86) for CLL diagnosed between 7.4 and 12.5 years. Even at a 7.4-year and longer time interval, elevated plasma sCD23 could predict a later clinical diagnosis of CLL with 100% specificity at > 45% sensitivity. Conclusions: Our findings provide unique documentation for the very long latency times during which measurable B-cell lymphoproliferative disorder exists before the clinical manifestation of CLL. Impact: Our findings have relevance for the interpretation of prospective epidemiologic studies on the causes of CLL in terms of reverse causation bias. The lag times indicate a time frame within which an early detection of CLL would be theoretically possible. (c) 2014 AACR.
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| 3. |
- Kaaks, Rudolf, et al.
(författare)
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Premenopausal serum sex hormone levels in relation to breast cancer risk, overall and by hormone receptor status-Results from the EPIC cohort
- 2014
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 134:8, s. 1947-1957
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Tidskriftsartikel (refereegranskat)abstract
- Results from prospective studies on premenopausal serum hormone levels in relation to breast cancer risk have been inconclusive, especially with regard to tumor subtypes. Using a case-control study nested within the prospective European Prospective Investigation into Cancer and Nutrition (EPIC) cohort (801 breast cancer cases and 1,132 matched control subjects), we analyzed the relationships of prediagnostic serum estradiol, free estradiol, progesterone, testosterone, free testosterone and sex hormone-binding globulin (SHBG) levels with the risk of breast cancer by estrogen and progesterone receptor-positive and -negative breast tumors and by age at diagnoses. Higher prediagnostic serum levels of testosterone and free testosterone were associated with an increased overall risk of breast cancer [ORQ4-Q1=1.56 (95% CI 1.15-2.13), p(trend)=0.02 for testosterone and ORQ4-Q1=1.33 (95% CI 0.99-1.79), p(trend)=0.04 for free testosterone], but no significant risk association was observed for estradiol, free estradiol, progesterone and SHBG. Tests for heterogeneity between receptor-positive and -negative tumors were not significant. When analysis were stratified by age at tumor diagnosis, the odds ratios observed for estradiol were stronger and borderline significant for breast cancer diagnosed at age less than 50 [ORQ4-Q1=1.32 (95% CI 0.87-2.01), p(trend)=0.05] compared to breast cancer diagnosed at age 50 or above [ORQ4-Q1=0.94 (95% CI 0.60-1.47), p(trend)=0.34, p(het)=0.04]. In conclusion, our data indicate that higher premenopausal circulating testosterone levels are associated with an increased risk of developing breast cancer, but do not show a significant association of estradiol or progesterone with breast cancer risk, overall, by menstrual cycle phase or by tumor receptor status, although a possible risk increase with higher estradiol levels for tumors diagnosed before age 50 was seen.
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| 4. |
- Kaaks, Rudolf, et al.
(författare)
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Risk factors for cancers of unknown primary site: Results from the prospective EPIC cohort
- 2014
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 135:10, s. 2475-2481
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Tidskriftsartikel (refereegranskat)abstract
- Cancer of unknown primary site (CUP) may be called an orphan disease, as it is diagnosed when metastases are detected while the primary tumor typically remains undetected, and because little research has been done on its primary causes. So far, few epidemiological studies, if any, have addressed possible risk factors for CUP. We analyzed data from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort (N=476,940). During prospective follow-up, a total of 651 cases of incident cases of CUP were detected (ICD-O-2 code C809). Proportional hazards models were conducted to examine the associations of lifetime history of smoking habits, alcohol consumption, levels of education and anthropometric indices of adiposity with risk of being diagnosed with CUP. Risk of being diagnosed with CUP was strongly related to smoking, with a relative risk of 3.66 [95% C.I., 2.24-5.97] for current, heavy smokers (26+ cigarettes/day) compared to never smokers (adjusted for alcohol consumption, body mass index, waist circumference and level of education) and a relative risk of 5.12 [3.09-8.47] for cases with CUP who died within 12 months. For alcohol consumption and level of education, weaker associations were observed but attenuated and no longer statistically significant after adjusting for smoking and indices of obesity. Finally, risk of CUP was increased by approximately 30 per cent for subjects in the highest versus lowest quartiles of waist circumference. Our analyses provide further documentation, in addition to autopsy studies, that a substantial proportion of cancers of unknown primary site may have their origin in smoking-related tumors, in particular. What's new? When cancer appears as metastatic disease but no primary tumor can be observed, it's called cancer of unknown primary site. Little is known about the risk factors for this type of cancer. This study analyzed data from a European cohort and discovered a strong association between smoking and these cancers. Other risk factors they identified were drinking alcohol and being fat. This is the first epidemiological study of these type of cancers, and it strengthens the observations from autopsy studies that many of these cancers of unknown primary site stem from smoking-related tumors.
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| 5. |
- Riso, Lukas, et al.
(författare)
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General and abdominal adiposity and the risk of Parkinson's disease : A prospective cohort study
- 2019
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Ingår i: Parkinsonism and Related Disorders. - : Elsevier BV. - 1353-8020 .- 1873-5126. ; 62, s. 98-104
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Due to demographic change, an increase in the frequency of Parkinson's disease (PD) patients is expected in the future and, thus, the identification of modifiable risk factors is urgently needed. We aimed to examine the associations of body mass index (BMI) and waist circumference (WC) with incident PD. Methods: In 13 of the 23 centers of the European Prospective Investigation into Cancer and Nutrition (EPIC) study, a total of 734 incident cases of PD were identified between 1992 and 2012 with a mean follow-up of 12 years. Cox proportional hazards regression was used to calculate hazard ratios (HR) with 95% confidence intervals (CI). We modelled anthropometric variables as continuous and categorical exposures and performed subgroup analyses by potential effect modifiers including sex and smoking. Results: We found no association between BMI, WC and incident PD, neither among men nor among women. Among never and former smokers, BMI and waist circumference were also not associated with PD risk. For male smokers, however, we observed a statistically significant inverse association between BMI and PD risk (HR 0.51, 95%CI: 0.30, 0.84) and the opposite for women, i.e. a significant direct association of BMI (HR 1.79, 95%CI: 1.04, 3.08) and waist circumference (HR 1.64, 95%CI: 1.03, 2.61) with risk of PD. Conclusion: Our data revealed no association between excess weight and PD risk but a possible interaction between anthropometry, sex and smoking.
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| 6. |
- Tikk, Kaja, et al.
(författare)
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Circulating prolactin and breast cancer risk among pre- and postmenopausal women in the EPIC cohort
- 2014
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Ingår i: Annals of Oncology. - : Oxford University Press. - 0923-7534 .- 1569-8041. ; 25:7, s. 1422-1428
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Experimental and epidemiological evidence suggests that prolactin might play a role in the etiology of breast cancer. We analyzed the relationship of pre-diagnostic circulating prolactin levels with the risk of breast cancer by menopausal status, use of postmenopausal hormone replacement therapy (HRT) at blood donation, and by estrogen and progesterone receptor-status of the breast tumors. METHODS: Conditional logistic regression was used to analyze the data from a case-control study nested within the prospective European EPIC cohort, including 2250 invasive breast cancer and their matched control subjects. RESULTS: Statistically significant heterogeneity in the association of prolactin levels with breast cancer risk between women who were either pre- or postmenopausal at the time of blood donation was observed (Phet=0.04). Higher serum levels of prolactin were associated with significant increase in risk of breast cancer among postmenopausal women (ORQ4-Q1=1.29 [95%CI 1.05-1.58], Ptrend=0.09); however this increase in risk seemed to be confined to women who used postmenopausal HRT at blood donation (ORQ4-Q1=1.45 [95%CI 1.08-1.95], Ptrend=0.01), whereas no statistically significant association was found for the non-users of HRT (ORQ4-Q1 =1.11 [95%CI 0.83-1.49], Ptrend=0.80) (Phet=0.08). Among premenopausal women, a statistically non-significant inverse association was observed (ORQ4-Q1 =0.70 [95%CI 0.48-1.03], Ptrend=0.16). There was no heterogeneity in the prolactin-breast cancer association by hormone receptor status of the tumor. CONCLUSION: Our study indicates that higher circulating levels of prolactin among the postmenopausal HRT users at baseline may be associated with increased breast cancer risk.
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| 7. |
- Tikk, Kaja, et al.
(författare)
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Circulating prolactin and in situ breast cancer risk in the European EPIC cohort : a case-control study
- 2015
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Ingår i: Breast Cancer Research. - : Springer Science and Business Media LLC. - 1465-5411 .- 1465-542X. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Introduction The relationship between circulating prolactin and invasive breast cancer has been investigated previously, but the association between prolactin levels and in situ breast cancer risk has received less attention.Methods We analysed the relationship between pre-diagnostic prolactin levels and the risk of in situ breast cancer overall, and by menopausal status and use of postmenopausal hormone therapy (HT) at blood donation. Conditional logistic regression was used to assess this association in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, including 307 in situ breast cancer cases and their matched control subjects.Results We found a significant positive association between higher circulating prolactin levels and risk of in situ breast cancer among all women [pre-and postmenopausal combined, ORlog2 = 1.35 (95% CI 1.04-1.76), P-trend = 0.03]. No statistically significant heterogeneity was found between prolactin levels and in situ cancer risk by menopausal status (P-het = 0.98) or baseline HT use (P-het = 0.20), although the observed association was more pronounced among postmenopausal women using HT compared to non-users (P-trend = 0.06 vs P-trend = 0.35). In subgroup analyses, the observed positive association was strongest in women diagnosed with in situ breast tumors <4 years compared to >= 4 years after blood donation (P-trend = 0.01 vs P-trend = 0.63; P-het = 0.04) and among nulliparous women compared to parous women (P-trend = 0.03 vs P-trend = 0.15; P-het = 0.07).Conclusions Our data extends prior research linking prolactin and invasive breast cancer to the outcome of in situ breast tumours and shows that higher circulating prolactin is associated with increased risk of in situ breast cancer.The relationship between circulating prolactin and invasive breast cancer has been investigated previously, but the association between prolactin levels and in situ breast cancer risk has received less attention.
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| 8. |
- Tikk, Kaja, et al.
(författare)
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Prolactin Determinants in Healthy Women : A Large Cross-Sectional Study within the EPIC Cohort
- 2014
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - 1055-9965 .- 1538-7755. ; 23:11, s. 2532-2542
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Tidskriftsartikel (refereegranskat)abstract
- Background: Experimental and epidemiologic data suggest that higher circulating prolactin is associated with breast cancer risk; however, how various risk factors for breast cancer influence prolactin levels in healthy women is not clear. Methods: We analyzed cross-sectional associations between several suggested reproductive and lifestyle risk factors for breast cancer and circulating prolactin among pre- and postmenopausal women, taking into account the use of current postmenopausal hormone therapy, among 2,560 controls from a breast cancer nested case-control study within the EPIC cohort. Results: Adjusted geometric mean prolactin levels were significantly higher among premenopausal women, and among postmenopausal women using hormone therapy compared with nonusers (8.2, 7.0, and 6.3 ng/mL, respectively; P-cat = <0.0001). Furthermore, prolactin levels were significantly higher among users of combined estrogen-progestin hormone therapy compared with users of estrogen-alone hormone therapy (6.66 vs. 5.90 ng/mL; P-cat = 0.001). Prolactin levels were lower among parous women compared with nulliparous women (8.61 vs. 10.95 ng/mL; P-cat = 0.0002, premenopausal women); the magnitude of this difference depended on the number of full-term pregnancies (22.1% lower, >= 3 vs. 1 pregnancy, P-trend = 0.01). Results for parity were similar but lower in magnitude among postmenopausal women. Prolactin did not vary by other studied factors, with the exception of lower levels among postmenopausal smokers compared with never smokers. Conclusions: Our study shows that current hormone therapy use, especially the use of combined hormone therapy, is associated with higher circulating prolactin levels in postmenopausal women, and confirms prior findings of lower circulating prolactin in parous women. Impact: Our study extends the knowledge linking various breast cancer risk factors with circulating prolactin.
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