| 1. |
- Aleksandrova, Krasimira, et al.
(författare)
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Adiposity, mediating biomarkers and risk of colon cancer in the European prospective investigation into cancer and nutrition study
- 2014
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Ingår i: International Journal of Cancer. - : Wiley-Blackwell. - 0020-7136 .- 1097-0215. ; 134:3, s. 612-621
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Tidskriftsartikel (refereegranskat)abstract
- Adiposity is a risk factor for colon cancer, but underlying mechanisms are not well understood. We evaluated the extent to which 11 biomarkers with inflammatory and metabolic actions mediate the association of adiposity measures, waist circumference (WC) and body mass index (BMI), with colon cancer in men and women. We analyzed data from a prospective nested case-control study among 662 incident colon cancer cases matched within risk sets to 662 controls. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression. The percent effect change and corresponding CIs were estimated after adjusting for biomarkers shown to be associated with colon cancer risk. After multivariable adjustment, WC was associated with colon cancer risk in men (top vs. bottom tertile RR 1.68, 95% CI 1.06-2.65; ptrend = 0.02) and in women (RR 1.67, 95% CI 1.09-2.56; ptrend = 0.03). BMI was associated with risk only in men. The association of WC with colon cancer was accounted mostly for by three biomarkers, high-density lipoprotein cholesterol, non-high-molecular-weight adiponectin and soluble leptin receptor, which in combination explained 46% (95% CI 37-57%) of the association in men and 50% (95% CI 40-65%) of the association in women. Similar results were observed for the associations with BMI in men. These data suggest that alterations in levels of these metabolic biomarkers may represent a primary mechanism of action in the relation of adiposity with colon cancer. Further studies are warranted to determine whether altering their concentrations may reduce colon cancer risk.
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| 2. |
- Aleksandrova, Krasimira, et al.
(författare)
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Biomarker patterns of inflammatory and metabolic pathways are associated with risk of colorectal cancer : results from the European Prospective Investigation into Cancer and Nutrition (EPIC)
- 2014
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Ingår i: European Journal of Epidemiology. - : Springer Science and Business Media LLC. - 0393-2990 .- 1573-7284. ; 29:4, s. 261-275
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Tidskriftsartikel (refereegranskat)abstract
- A number of biomarkers of inflammatory and metabolic pathways are individually related to higher risk of colorectal cancer (CRC); however, the association between biomarker patterns and CRC incidence has not been previously evaluated. Our study investigates the association of biomarker patterns with CRC in a prospective nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC). During median follow-up time of 7.0 (3.7-9.4) years, 1,260 incident CRC cases occurred and were matched to 1,260 controls using risk-set sampling. Pre-diagnostic measurements of C-peptide, glycated hemoglobin, triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), C-reactive protein (CRP), reactive oxygen metabolites (ROM), insulin-like growth factor 1, adiponectin, leptin and soluble leptin receptor (sOB-R) were used to derive biomarker patterns from principal component analysis (PCA). The relation with CRC incidence was assessed using conditional logistic regression models. We identified four biomarker patterns 'HDL-C/Adiponectin fractions', 'ROM/CRP', 'TG/C-peptide' and 'leptin/sOB-R' to explain 60 % of the overall biomarker variance. In multivariable-adjusted logistic regression, the 'HDL-C/Adiponectin fractions', 'ROM/CRP' and 'leptin/sOB-R' patterns were associated with CRC risk [for the highest quartile vs the lowest, incidence rate ratio (IRR) = 0.69, 95 % CI 0.51-0.93, P-trend = 0.01; IRR = 1.70, 95 % CI 1.30-2.23, P-trend = 0.002; and IRR = 0.79, 95 % CI 0.58-1.07; P-trend = 0.05, respectively]. In contrast, the 'TG/C-peptide' pattern was not associated with CRC risk (IRR = 0.75, 95 % CI 0.56-1.00, P-trend = 0.24). After cases within the first 2 follow-up years were excluded, the 'ROM/CRP' pattern was no longer associated with CRC risk, suggesting potential influence of preclinical disease on these associations. By application of PCA, the study identified 'HDL-C/Adiponectin fractions', 'ROM/CRP' and 'leptin/sOB-R' as biomarker patterns representing potentially important pathways for CRC development.
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| 3. |
- Aleksandrova, Krasimira, et al.
(författare)
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Circulating C-reactive protein concentrations and risks of colon and rectal cancer : a nested case-control study within the European Prospective Investigation into Cancer and Nutrition
- 2010
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Ingår i: American Journal of Epidemiology. - : Oxford University Press (OUP). - 0002-9262 .- 1476-6256. ; 172:4, s. 407-418
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Tidskriftsartikel (refereegranskat)abstract
- The authors investigated associations between serum C-reactive protein (CRP) concentrations and colon and rectal cancer risk in a nested case-control study within the European Prospective Investigation into Cancer and Nutrition (1992-2003) among 1,096 incident cases and 1,096 controls selected using risk-set sampling and matched on study center, age, sex, time of blood collection, fasting status, menopausal status, menstrual cycle phase, and hormone replacement therapy. In conditional logistic regression with adjustment for education, smoking, nutritional factors, body mass index, and waist circumference, CRP showed a significant nonlinear association with colon cancer risk but not rectal cancer risk. Multivariable-adjusted relative risks for CRP concentrations of > or = 3.0 mg/L versus <1.0 mg/L were 1.36 (95% confidence interval (CI): 1.00, 1.85; P-trend = 0.01) for colon cancer and 1.02 (95% CI: 0.67, 1.57; P-trend = 0.65) for rectal cancer. Colon cancer risk was significantly increased in men (relative risk = 1.74, 95% CI: 1.11, 2.73; P-trend = 0.01) but not in women (relative risk = 1.06, 95% CI: 0.67, 1.68; P-trend = 0.13). Additional adjustment for C-peptide, glycated hemoglobin, and high density lipoprotein cholesterol did not attenuate these results. These data provide evidence that elevated CRP concentrations are related to a higher risk of colon cancer but not rectal cancer, predominantly among men and independently of obesity, insulin resistance, and dyslipidemia.
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| 4. |
- Aleksandrova, Krasimira, et al.
(författare)
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Leptin and soluble leptin receptor in risk of colorectal cancer in the European prospective investigation into Cancer and nutrition cohort
- 2012
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Ingår i: Cancer Research. - Philadelphia, USA : American Association for Cancer Research. - 0008-5472 .- 1538-7445. ; 72:20, s. 5328-5337
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Tidskriftsartikel (refereegranskat)abstract
- Leptin, a peptide hormone produced primarily by the adipocytes, is hypothesized to play a role in the pathogenesis of colorectal cancer (CRC). Soluble leptin receptor (sOB-R) may regulate leptin's physiologic functions; however its relation to CRC risk is unknown. This study explored the association of leptin and sOB-R with risk of CRC in a prospective nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. A total of 1,129 incident CRC cases (713 colon, 416 rectal) were matched within risk sets to 1,129 controls. Conditional logistic regression was used to calculate relative risks (RR) and 95% confidence intervals (CI). After multivariable adjustment including body mass index (BMI), waist circumference, and baseline leptin concentrations, sOB-R was strongly inversely associated with CRC (RR comparing the highest quintile vs. the lowest, 0.55; 95% CI, 0.40-0.76; P-trend = 0.0004) and colon cancer (RR, 0.42; 95% CI, 0.28-0.63, P-trend = 0.0001); whereas no association was seen for rectal cancer (RR adjusted for BMI and waist circumference, 0.83; 95% CI, 0.48-1.44, P-trend = 0.38). In contrast, leptin was not associated with risk of CRC (RR adjusted for BMI and waist circumference, 0.85; 95% CI, 0.56-1.29, P-trend = 0.23). Additional adjustments for circulating metabolic biomarkers did not attenuate these results. These novel findings suggest a strong inverse association between circulating sOB-R and CRC risk, independent of obesity measures, leptin concentrations, and other metabolic biomarkers. Further research is needed to confirm the potentially important role of sOB-R in CRC pathogenesis. Cancer Res; 72(20); 5328-37. (C) 2012 AACR.
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| 5. |
- Aleksandrova, Krasimira, et al.
(författare)
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Metabolic syndrome and risks of colon and rectal cancer : the European prospective investigation into cancer and nutrition study.
- 2011
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Ingår i: Cancer prevention research (Philadelphia, Pa.). - 1940-6215. ; 4:11, s. 1873-83
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Tidskriftsartikel (refereegranskat)abstract
- Metabolic syndrome (MetS) is purportedly related to risk of developing colorectal cancer; however, the association of MetS, as defined according to recent international criteria, and colorectal cancer has not been yet evaluated. In particular, it remains unclear to what extent the MetS components individually account for such an association. We addressed these issues in a nested case-control study that included 1,093 incident cases matched (1:1) to controls by using incidence density sampling. Conditional logistic regression was used to estimate relative risks (RR) and 95% CIs. MetS was defined according to the criteria of the National Cholesterol Education Program/Adult Treatment Panel III (NCEP/ATPIII), the International Diabetes Federation (IDF), and the 2009 harmonized definition. Among individual components, abdominal obesity (RR = 1.51; 95% CI: 1.16-1.96) was associated with colon cancer, whereas abnormal glucose metabolism was associated with both colon (RR = 2.05; 95% CI: 1.57-2.68) and rectal cancer (RR = 2.07; 95% CI: 1.45-2.96). MetS, as defined by each of the definitions, was similarly associated with colon cancer (e.g., RR = 1.91; 95% CI: 1.47-2.42 for MetS by NCEP/ATPIII), whereas MetS by NCEP/ATPIII, but not IDF or harmonized definition, was associated with rectal cancer (RR = 1.45; 95% CI: 1.02-2.06). Overall, these associations were stronger in women than in men. However, the association between MetS and colorectal cancer was accounted for by abdominal obesity and abnormal glucose metabolism such that MetS did not provide risk information beyond these components (likelihood ratio test P = 0.10 for MetS by NCEP/ATPIII). These data suggest that simple assessment of abnormal glucose metabolism and/or abdominal obesity to identify individuals at colorectal cancer risk may have higher clinical utility than applying more complex MetS definitions. Cancer Prev Res; 4(11); 1873-83. ©2011 AACR.
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| 6. |
- Aleksandrova, Krasimira, et al.
(författare)
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Total and high-molecular-weight adiponectin and risk of colorectal cancer : the European prospective investigation into cancer and nutrition study
- 2012
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Ingår i: Carcinogenesis. - : Oxford University Press (OUP). - 0143-3334 .- 1460-2180. ; 33:6, s. 1211-1218
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Tidskriftsartikel (refereegranskat)abstract
- Adiponectin - an adipose-tissue-derived protein may provide a molecular link between obesity and colorectal cancer (CRC), but evidence from large prospective studies is limited. In particular, no epidemiological study explored high-molecular-weight (HMW) and non-HMW adiponectin fractions in relation to CRC risk, despite they were hypothesised to have differential biological activities, i.e. regulating insulin sensitivity (HMW-adiponectin) versus inflammatory response (non-HMW-adiponectin). In a prospective nested case-control study we investigated whether pre-diagnostic serum concentrations of total, HMW and non-HMW-adiponectin are associated with risk of CRC, independent of obesity and other known CRC risk factors. A total of 1206 incident cases (755 colon, 451 rectal) were matched to 1206 controls using incidence density sampling. In conditional logistic regression, adjusted for dietary and lifestyle factors, total adiponectin and non-HMW-adiponectin concentrations were inversely associated with risk of CRC [relative risk (RR) comparing highest versus lowest quintile = 0.71, 95% confidence interval (CI) = 0.53-0.95, P (trend)=0.03 for total adiponectin and 0.45, 95%CI=0.34-0.61, P (trend)<0.0001 for non-HMW-adiponectin]. HMW-adiponectin concentrations were not associated with CRC risk (RR=0.91, 95%CI=0.68-1.22, P (trend)=0.55). Non-HMW-adiponectin was associated with CRC risk even after adjustment for body mass index and waist circumference (RR=0.39, 95%CI=0.26-0.60, P (trend)<0.0001); whereas the association with total adiponectin was no longer significant (RR=0.81, 95%CI=0.60-1.09, P (trend)=0.23). When stratified by cancer site, non-HMW-adiponectin was inversely associated with both colon and rectal cancer. These findings suggest an important role of the relative proportion of non-HMW-adiponectin in CRC pathogenesis. Future studies are warranted to confirm these results and to elucidate the underlying mechanisms.
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| 7. |
- Bamia, Christina, et al.
(författare)
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Mediterranean diet and colorectal cancer risk: results from a European cohort
- 2013
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Ingår i: European Journal of Epidemiology. - Dordrecht : Springer Science and Business Media LLC. - 1573-7284 .- 0393-2990. ; 28:4, s. 317-328
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Tidskriftsartikel (refereegranskat)abstract
- The authors investigated the association of adherence to Mediterranean diet with colorectal cancer (CRC) risk in the European Prospective Investigation into Cancer and nutrition study. Adherence to Mediterranean diet was expressed through two 10-unit scales, the Modified Mediterranean diet score (MMDS) and the Centre-Specific MMDS (CSMMDS). Both scales share the same dietary components but differ in the cut-off values that were used for these components in the construction of the scales. Adjusted hazard ratios (HR) for the associations of these scales with CRC incidence were estimated. After 5,296,617 person-years of follow-up, 4,355 incident CRC cases were identified. A decreased risk of CRC, of 8 and 11 % was estimated when comparing the highest (scores 6-9) with the lowest (scores 0-3) adherence to CSMMDS and MMDS respectively. For MMDS the HR was 0.89 (95 % confidence interval (CI): 0.80, 0.99). A 2-unit increment in either Mediterranean scale was associated with a borderline statistically significant 3 to 4 % reduction in CRC risk (HR for MMDS: 0.96; 95 % CI: 0.92, 1.00). These associations were somewhat more evident, among women, were mainly manifested for colon cancer risk and their magnitude was not altered when alcohol was excluded from MMDS. These findings suggest that following a Mediterranean diet may have a modest beneficial effect on CRC risk.
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| 8. |
- Dahlin, Anna M, 1979-, et al.
(författare)
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Colorectal cancer prognosis depends on T-cell infiltration and molecular characteristics of the tumor
- 2011
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Ingår i: Modern Pathology. - : Elsevier BV. - 0893-3952 .- 1530-0285. ; 24, s. 671-682
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to relate the density of tumor infiltrating T cells to cancer-specific survival in colorectal cancer, taking into consideration the CpG island methylator phenotype (CIMP) and microsatellite instability (MSI) screening status. The T-cell marker CD3 was stained by immunohistochemistry in 484 archival tumor tissue samples. T-cell density was semiquantitatively estimated and scored 1-4 in the tumor front and center (T cells in stroma), and intraepithelially (T cells infiltrating tumor cell nests). Total CD3 score was calculated as the sum of the three CD3 scores (range 3-12). MSI screening status was assessed by immunohistochemistry. CIMP status was determined by quantitative real-time PCR (MethyLight) using an eight-gene panel. We found that patients whose tumors were highly infiltrated by T cells (total CD3 score ≥7) had longer survival compared with patients with poorly infiltrated tumors (total CD3 score ≤4). This finding was statistically significant in multivariate analyses (multivariate hazard ratio, 0.57; 95% confidence interval, 0.31-1.00). Importantly, the finding was consistent in rectal cancer patients treated with preoperative radiotherapy. Although microsatellite unstable tumor patients are generally considered to have better prognosis, we found no difference in survival between microsatellite unstable and microsatellite stable (MSS) colorectal cancer patients with similar total CD3 scores. Patients with MSS tumors highly infiltrated by T cells had better prognosis compared with intermediately or poorly infiltrated microsatellite unstable tumors (log rank P=0.013). Regarding CIMP status, CIMP-low was associated with particularly poor prognosis in patients with poorly infiltrated tumors (multivariate hazard ratio for CIMP-low versus CIMP-negative, 3.07; 95% confidence interval, 1.53-6.15). However, some subset analyses suffered from low power and are in need of confirmation by independent studies. In conclusion, patients whose tumors are highly infiltrated by T cells have a beneficial prognosis, regardless of MSI, whereas the role of CIMP status in this context is less clear.
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| 9. |
- Dahlin, Anna M, 1979-, et al.
(författare)
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The role of the CpG island methylator phenotype in colorectal cancer prognosis depends on microsatellite instability screening status
- 2010
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Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 16:6, s. 1845-1855
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this study was to relate the CpG island methylator phenotype (CIMP; characterized by extensive promoter hypermethylation) to cancer-specific survival in colorectal cancer, taking into consideration relevant clinicopathologic factors, such as microsatellite instability (MSI) screening status and the BRAF V600E mutation. EXPERIMENTAL DESIGN: Archival tumor samples from 190 patients from the Northern Sweden Health and Disease Study (NSHDS) and 414 patients from the Colorectal Cancer in Umeå Study (CRUMS), including 574 with cancer-specific survival data, were analyzed for an eight-gene CIMP panel using quantitative real-time PCR (MethyLight). MSI screening status was assessed by immunohistochemistry. RESULTS: CIMP-low patients had a shorter cancer-specific survival compared with CIMP-negative patients (multivariate hazard ratio in NSHDS, 2.01; 95% confidence interval, 1.20-3.37; multivariate hazard ratio in CRUMS, 1.48; 95% confidence interval, 1.00-2.22). This result was similar in subgroups based on MSI screening status and was statistically significant in microsatellite stable (MSS) tumors in NSHDS. For CIMP-high patients, a shorter cancer-specific survival compared with CIMP-negative patients was observed in the MSS subgroup. Statistical significance was lost after adjusting for the BRAF mutation, but the main findings were generally unaffected. CONCLUSIONS: In this study, we found a poor prognosis in CIMP-low patients regardless of MSI screening status, and in CIMP-high patients with MSS. Although not consistently statistically significant, these results were consistent in two separate patient groups and emphasize the potential importance of CIMP and MSI status in colorectal cancer research.
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| 10. |
- Dahlin, Anna, 1979-
(författare)
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The CpG island methylator phenotype in colorectal cancer : studies on risk and prognosis
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background Colorectal cancer (CRC) is the second most common malignancy in developed countries. The mortality is high, with nearly half of patients dying from the disease. The primary treatment of CRC is surgery, and decisions about additional treatment with chemotherapy are based mainly on tumor stage. Novel prognostic markers that identify patients at high risk of recurrence and cancer-related death are needed. The development of CRC has been described in terms of two different pathways; the microsatellite instability (MSI) and chromosomal instability (microsatellite stable, MSS) pathway. More recently, the CpG island methylator phenotype (CIMP), characterized by frequent DNA hypermethylation, has been described as an alternative pathway of tumorigenesis. The event of DNA methylation is dependent on one-carbon metabolism, in which folate and vitamin B12 have essential functions. The purpose of this thesis was to study CIMP in CRC. The specific aims were to investigate the potential role of components of one-carbon metabolism as risk factors for this subgroup of tumors, and the prognostic importance of CIMP status, taking into consideration important confounding factors, such as MSI and tumor-infiltrating T cells. Methods CRC cases and referents included in the Northern Sweden Health and Disease Study (NSHDS, 226 cases and 437 referents) and CRC cases in the Colorectal Cancer in Umeå Study (CRUMS, n=490) were studied. Prediagnostic plasma concentrations of folate and vitamin B12 were analyzed in NSHDS. In both study groups, CIMP status was determined in archival tumor tissue by real-time quantitative PCR using an eight-gene panel (CDKN2A, MLH1, CACNA1G, NEUROG1, RUNX3, SOCS1, IGF2 and CRABP1). MSI screening status and the density of tumor-infiltrating T cells were determined by immunohistochemistry. Results An inverse association was found between plasma concentrations of vitamin B12 and rectal, but not colon, cancer risk. We also found a reduced risk of CIMP-high and CIMP-low CRC in study subjects with the lowest levels of plasma folate. We found that patients with CIMP-low tumors in both NSHDS and CRUMS had a poorer prognosis compared with CIMP-negative, regardless of MSI screening status. We also found that MSS CIMP-high patients had a poorer prognosis compared with MSS CIMP-negative. The density of tumor-infiltrating T cells and CIMP status were both found to be independent predictors of CRC patient prognosis. A particularly poor prognosis was found in patients with CIMP-low tumors poorly infiltrated by T cells. In addition, the density of T cells appeared to be more important than MSI screening status for predicting CRC patient prognosis. Conclusion Rather than being one disease, CRC is a heterogeneous set of diseases with respect to clinico-pathological and molecular characteristics. We found that the association between risk and plasma concentration of vitamin B12 and folate depends on tumor site and CIMP status, respectively. Patient prognosis was found to be different depending on CIMP and MSI screening status, and the density of tumor-infiltrating T cells.
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