| 1. |
- Archambault, Alexi N., et al.
(författare)
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Cumulative Burden of Colorectal Cancer Associated Genetic Variants Is More Strongly Associated With Early-Onset vs Late-Onset Cancer
- 2020
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Ingår i: Gastroenterology. - : Elsevier BV. - 0016-5085 .- 1528-0012. ; 158:5, s. 1274-1286.e12
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: Early-onset colorectal cancer (CRC, in persons younger than 50 years old) is increasing in incidence; yet, in the absence of a family history of CRC, this population lacks harmonized recommendations for prevention. We aimed to determine whether a polygenic risk score (PRS) developed from 95 CRC-associated common genetic risk variants was associated with risk for early-onset CRC.METHODS: We studied risk for CRC associated with a weighted PRS in 12,197 participants younger than 50 years old vs 95,865 participants 50 years or older. PRS was calculated based on single nucleotide polymorphisms associated with CRC in a large-scale genome-wide association study as of January 2019. Participants were pooled from 3 large consortia that provided clinical and genotyping data: the Colon Cancer Family Registry, the Colorectal Transdisciplinary Study, and the Genetics and Epidemiology of Colorectal Cancer Consortium and were all of genetically defined European descent. Findings were replicated in an independent cohort of 72,573 participants.RESULTS: Overall associations with CRC per standard deviation of PRS were significant for early-onset cancer, and were stronger compared with late-onset cancer (P for interaction = .01); when we compared the highest PRS quartile with the lowest, risk increased 3.7-fold for early-onset CRC (95% CI 3.28-4.24) vs 2.9-fold for late-onset CRC (95% CI 2.80-3.04). This association was strongest for participants without a first-degree family history of CRC (P for interaction = 5.61 x 10(-5)). When we compared the highest with the lowest quartiles in this group, risk increased 4.3-fold for early-onset CRC (95% CI 3.61-5.01) vs 2.9-fold for late-onset CRC (95% CI 2.70-3.00). Sensitivity analyses were consistent with these findings.CONCLUSIONS: In an analysis of associations with CRC per standard deviation of PRS, we found the cumulative burden of CRC-associated common genetic variants to associate with early-onset cancer, and to be more strongly associated with early-onset than late-onset cancer, particularly in the absence of CRC family history. Analyses of PRS, along with environmental and lifestyle risk factors, might identify younger individuals who would benefit from preventive measures.
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| 2. |
- Su, Yu-Ru, et al.
(författare)
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Validation of a genetic-enhanced risk prediction model for colorectal cancer in a large community-based cohort
- 2023
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - : American association for cancer research. - 1055-9965 .- 1538-7755. ; 32:3, s. 353-362
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Polygenic risk scores (PRS) which summarize individuals' genetic risk profile may enhance targeted colorectal cancer screening. A critical step towards clinical implementation is rigorous external validations in large community-based cohorts. This study externally validated a PRS-enhanced colorectal cancer risk model comprising 140 known colorectal cancer loci to provide a comprehensive assessment on prediction performance.METHODS: The model was developed using 20,338 individuals and externally validated in a community-based cohort (n = 85,221). We validated predicted 5-year absolute colorectal cancer risk, including calibration using expected-to-observed case ratios (E/O) and calibration plots, and discriminatory accuracy using time-dependent AUC. The PRS-related improvement in AUC, sensitivity and specificity were assessed in individuals of age 45 to 74 years (screening-eligible age group) and 40 to 49 years with no endoscopy history (younger-age group).RESULTS: In European-ancestral individuals, the predicted 5-year risk calibrated well [E/O = 1.01; 95% confidence interval (CI), 0.91-1.13] and had high discriminatory accuracy (AUC = 0.73; 95% CI, 0.71-0.76). Adding the PRS to a model with age, sex, family and endoscopy history improved the 5-year AUC by 0.06 (P < 0.001) and 0.14 (P = 0.05) in the screening-eligible age and younger-age groups, respectively. Using a risk-threshold of 5-year SEER colorectal cancer incidence rate at age 50 years, adding the PRS had a similar sensitivity but improved the specificity by 11% (P < 0.001) in the screening-eligible age group. In the younger-age group it improved the sensitivity by 27% (P = 0.04) with similar specificity.CONCLUSIONS: The proposed PRS-enhanced model provides a well-calibrated 5-year colorectal cancer risk prediction and improves discriminatory accuracy in the external cohort.IMPACT: The proposed model has potential utility in risk-stratified colorectal cancer prevention.
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| 3. |
- Holm, C, et al.
(författare)
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Phosphorylation of the oestrogen receptor alpha at serine 305 and prediction of tamoxifen resistance in breast cancer
- 2009
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Ingår i: JOURNAL OF PATHOLOGY. - : Wiley. - 0022-3417 .- 1096-9896. ; 217:3, s. 372-379
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Tidskriftsartikel (refereegranskat)abstract
- Phosphorylation of oestrogen receptor a at serine 305 (ER alpha S305-P) induces tamoxifen resistance in experimental studies, but does not influence response to other endocrine agents, such as fulvestrant. We evaluated ER alpha S305-P using immunohistochemistry in 377 breast carcinomas from premenopausal participants of a randomized trial (n = 248) and patients with advanced disease (n = 129). Among the premenopausal patients, adjuvant tamoxifen improved recurrence-free survival (RFS) for ER alpha S305-P-negative tumours (multivariate HR = 0.53, 95% CI 0.32-0.86, p = 0.010), but not for ER alpha S305-P-positive tumours (multivariate HR = 1.01, 95% CI 0.33-3.05, p = 0.99) (interaction p = 0.131). Notably, ER alpha S305-P was not significantly associated with RFS in patients not treated with tamoxifen (multivariate HR = 0.64, 95% CI 0.30-1.37, p = 0.248), indicating that ER alpha S305-P is a marker for treatment outcome rather than tumour progression. Given the direct experimental link between ER alpha S305-P and tamoxifen resistance and these first clinical data suggesting that premenopausal patients with ER alpha S305-P-positive breast cancer are resistant to adjuvant tamoxifen, further research is encouraged to study whether alternative endocrine treatment should be considered for this subgroup.
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| 4. |
- Schouten, Stefan, et al.
(författare)
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An interlaboratory study of TEX86 and BIT analysis of sediments, extracts, and standard mixtures
- 2013
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Ingår i: Geochemistry Geophysics Geosystems. - 1525-2027. ; 14:12, s. 5263-5285
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Tidskriftsartikel (refereegranskat)abstract
- Two commonly used proxies based on the distribution of glycerol dialkyl glycerol tetraethers (GDGTs) are the TEX86 (TetraEther indeX of 86 carbon atoms) paleothermometer for sea surface temperature reconstructions and the BIT (Branched Isoprenoid Tetraether) index for reconstructing soil organic matter input to the ocean. An initial round-robin study of two sediment extracts, in which 15 laboratories participated, showed relatively consistent TEX86 values (reproducibility +/- 3-4 degrees C when translated to temperature) but a large spread in BIT measurements (reproducibility +/- 0.41 on a scale of 0-1). Here we report results of a second round-robin study with 35 laboratories in which three sediments, one sediment extract, and two mixtures of pure, isolated GDGTs were analyzed. The results for TEX86 and BIT index showed improvement compared to the previous round-robin study. The reproducibility, indicating interlaboratory variation, of TEX86 values ranged from 1.3 to 3.0 degrees C when translated to temperature. These results are similar to those of other temperature proxies used in paleoceanography. Comparison of the results obtained from one of the three sediments showed that TEX86 and BIT indices are not significantly affected by interlaboratory differences in sediment extraction techniques. BIT values of the sediments and extracts were at the extremes of the index with values close to 0 or 1, and showed good reproducibility (ranging from 0.013 to 0.042). However, the measured BIT values for the two GDGT mixtures, with known molar ratios of crenarchaeol and branched GDGTs, had intermediate BIT values and showed poor reproducibility and a large overestimation of the true (i.e., molar-based) BIT index. The latter is likely due to, among other factors, the higher mass spectrometric response of branched GDGTs compared to crenarchaeol, which also varies among mass spectrometers. Correction for this different mass spectrometric response showed a considerable improvement in the reproducibility of BIT index measurements among laboratories, as well as a substantially improved estimation of molar-based BIT values. This suggests that standard mixtures should be used in order to obtain consistent, and molar-based, BIT values.
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