Zachary S. Fredericksen

Clinically Confirmed Type 2 Diabetes Mellitus and Colorectal Cancer Risk: A Population-Based, Retrospective Cohort Study

OBJECTIVES:Patients with type 2 diabetes mellitus (DM) may be at increased colorectal cancer (CRC) risk. However, existing data are inconsistent. We investigated CRC risks, overall and by anatomic subsite, within a population-based inception cohort of clinically confirmed type 2 DM subjects.METHODS:All residents of Rochester, Minnesota who first met standardized criteria for type 2 DM from 1970 to 1994 (997 men and 978 women) were identified and followed forward in time until emigration, death, or December 31, 1999. Incident CRC cases were identified by review of inpatient and outpatient medical records. Standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were estimated to compare CRC incidence within the type 2 DM inception cohort with previously published rates for the Rochester general population.RESULTS:Over 19,158 person-years of follow-up, 51 incident CRC cases were identified within the type 2 DM cohort, while only 36.8 cases were expected (SIR = 1.39, 95% CI 1.03–1.82). Among men, type 2 DM was associated with increased overall (SIR = 1.67, 95% CI 1.16–2.33) and proximal (SIR = 1.96, 95% CI 1.16–3.10) CRC risks; distal CRC risk was also increased, but the point estimate was not statistically significant (SIR = 1.43, 95% CI 0.82–2.32). Among women, type 2 DM was not a risk factor for overall, proximal, or distal CRC (SIR = 1.03, 95% CI 0.60–1.66; SIR = 1.17, 95% CI 0.58–2.09; and SIR = 0.74, 95% CI 0.24–1.72, respectively). Within the type 2 DM cohort, current and former cigarette smokers were at higher CRC risk (SIR = 1.77, 95% CI 1.24–2.47) than never smokers (SIR = 0.99, 95% CI 0.57–1.61) and the interaction between type 2 DM and cigarette smoking status was statistically significant (p = 0.05).CONCLUSIONS:In this population-based, retrospective cohort study, clinically confirmed type 2 DM was associated with increased CRC risk, predominantly among men. Cigarette smoking appeared to positively modify DM-associated CRC risk, which to our knowledge has not been previously reported. These data suggest that further investigation of potential interactions between endogenous and exogenous factors involved in colorectal carcinogenesis may help to clarify the magnitude and extent of CRC risk experienced by persons with type 2 DM.

Risk of estrogen receptor-positive and -negative breast cancer and single-nucleotide polymorphism 2q35-rs13387042

BACKGROUND A recent genome-wide association study identified single-nucleotide polymorphism (SNP) 2q35-rs13387042 as a marker of susceptibility to estrogen receptor (ER)-positive breast cancer. We attempted to confirm this association using the Breast Cancer Association Consortium. METHODS 2q35-rs13387042 SNP was genotyped for 31 510 women with invasive breast cancer, 1101 women with ductal carcinoma in situ, and 35 969 female control subjects from 25 studies. Odds ratios (ORs) were estimated by logistic regression, adjusted for study. Heterogeneity in odds ratios by each of age, ethnicity, and study was assessed by fitting interaction terms. Heterogeneity by each of invasiveness, family history, bilaterality, and hormone receptor status was assessed by subclassifying case patients and applying polytomous logistic regression. All statistical tests were two-sided. RESULTS We found strong evidence of association between rs13387042 and breast cancer in white women of European origin (per-allele OR = 1.12, 95% confidence interval [CI] = 1.09 to 1.15; P(trend) = 1.0 x 10(-19)). The odds ratio was lower than that previously reported (P = .02) and did not vary by age or ethnicity (all P > or = .2). However, it was higher when the analysis was restricted to case patients who were selected for a strong family history (P = .02). An association was observed for both ER-positive (OR = 1.14, 95% CI = 1.10 to 1.17; P = 10(-15)) and ER-negative disease (OR = 1.10, 95% CI = 1.04 to 1.15; P = .0003) and both progesterone receptor (PR)-positive (OR = 1.15, 95% CI = 1.11 to 1.19; P = 5 x 10(-14)) and PR-negative disease (OR = 1.10, 95% CI = 1.06 to 1.15; P = .00002). CONCLUSION The rs13387042 is associated with both ER-positive and ER-negative breast cancer in European women.

Ancestry-shift refinement mapping of the C6orf97-ESR1 breast cancer susceptibility locus.

We used an approach that we term ancestry-shift refinement mapping to investigate an association, originally discovered in a GWAS of a Chinese population, between rs2046210[T] and breast cancer susceptibility. The locus is on 6q25.1 in proximity to the C6orf97 and estrogen receptor α (ESR1) genes. We identified a panel of SNPs that are correlated with rs2046210 in Chinese, but not necessarily so in other ancestral populations, and genotyped them in breast cancer case∶control samples of Asian, European, and African origin, a total of 10,176 cases and 13,286 controls. We found that rs2046210[T] does not confer substantial risk of breast cancer in Europeans and Africans (OR = 1.04, P = 0.099, and OR = 0.98, P = 0.77, respectively). Rather, in those ancestries, an association signal arises from a group of less common SNPs typified by rs9397435. The rs9397435[G] allele was found to confer risk of breast cancer in European (OR = 1.15, P = 1.2×10−3), African (OR = 1.35, P = 0.014), and Asian (OR = 1.23, P = 2.9×10−4) population samples. Combined over all ancestries, the OR was 1.19 (P = 3.9×10−7), was without significant heterogeneity between ancestries (Phet = 0.36) and the SNP fully accounted for the association signal in each ancestry. Haplotypes bearing rs9397435[G] are well tagged by rs2046210[T] only in Asians. The rs9397435[G] allele showed associations with both estrogen receptor positive and estrogen receptor negative breast cancer. Using early-draft data from the 1,000 Genomes project, we found that the risk allele of a novel SNP (rs77275268), which is closely correlated with rs9397435, disrupts a partially methylated CpG sequence within a known CTCF binding site. These studies demonstrate that shifting the analysis among ancestral populations can provide valuable resolution in association mapping.

Assessing interactions between the associations of common genetic susceptibility variants, reproductive history and body mass index with breast cancer risk in the breast cancer association consortium: a combined case-control study.

IntroductionSeveral common breast cancer genetic susceptibility variants have recently been identified. We aimed to determine how these variants combine with a subset of other known risk factors to influence breast cancer risk in white women of European ancestry using case-control studies participating in the Breast Cancer Association Consortium.MethodsWe evaluated two-way interactions between each of age at menarche, ever having had a live birth, number of live births, age at first birth and body mass index (BMI) and each of 12 single nucleotide polymorphisms (SNPs) (10q26-rs2981582 (FGFR2), 8q24-rs13281615, 11p15-rs3817198 (LSP1), 5q11-rs889312 (MAP3K1), 16q12-rs3803662 (TOX3), 2q35-rs13387042, 5p12-rs10941679 (MRPS30), 17q23-rs6504950 (COX11), 3p24-rs4973768 (SLC4A7), CASP8-rs17468277, TGFB1-rs1982073 and ESR1-rs3020314). Interactions were tested for by fitting logistic regression models including per-allele and linear trend main effects for SNPs and risk factors, respectively, and single-parameter interaction terms for linear departure from independent multiplicative effects.ResultsThese analyses were applied to data for up to 26,349 invasive breast cancer cases and up to 32,208 controls from 21 case-control studies. No statistical evidence of interaction was observed beyond that expected by chance. Analyses were repeated using data from 11 population-based studies, and results were very similar.ConclusionsThe relative risks for breast cancer associated with the common susceptibility variants identified to date do not appear to vary across women with different reproductive histories or body mass index (BMI). The assumption of multiplicative combined effects for these established genetic and other risk factors in risk prediction models appears justified.

The Mayo Clinic Biobank: A Building Block for Individualized Medicine

OBJECTIVE To report the design and implementation of the first 3 years of enrollment of the Mayo Clinic Biobank. PATIENTS AND METHODS Preparations for this biobank began with a 4-day Deliberative Community Engagement with local residents to obtain community input into the design and governance of the biobank. Recruitment, which began in April 2009, is ongoing, with a target goal of 50,000. Any Mayo Clinic patient who is 18 years or older, able to consent, and a US resident is eligible to participate. Each participant completes a health history questionnaire, provides a blood sample, and allows access to existing tissue specimens and all data from their Mayo Clinic electronic medical record. A community advisory board provides ongoing advice and guidance on complex decisions. RESULTS After 3 years of recruitment, 21,736 individuals have enrolled. Fifty-eight percent (12,498) of participants are female and 95% (20,541) of European ancestry. Median participant age is 62 years. Seventy-four percent (16,171) live in Minnesota, with 42% (9157) from Olmsted County, where the Mayo Clinic in Rochester, Minnesota, is located. The 5 most commonly self-reported conditions are hyperlipidemia (8979, 41%), hypertension (8174, 38%), osteoarthritis (6448, 30%), any cancer (6224, 29%), and gastroesophageal reflux disease (5669, 26%). Among patients with self-reported cancer, the 5 most common types are nonmelanoma skin cancer (2950, 14%), prostate cancer (1107, 12% in men), breast cancer (941, 4%), melanoma (692, 3%), and cervical cancer (240, 2% in women). Fifty-six percent (12,115) of participants have at least 15 years of electronic medical record history. To date, more than 60 projects and more than 69,000 samples have been approved for use. CONCLUSION The Mayo Clinic Biobank has quickly been established as a valuable resource for researchers.

GWAS of follicular lymphoma reveals allelic heterogeneity at 6p21.32 and suggests shared genetic susceptibility with diffuse large B-cell lymphoma.

Non-Hodgkin lymphoma (NHL) represents a diverse group of hematological malignancies, of which follicular lymphoma (FL) is a prevalent subtype. A previous genome-wide association study has established a marker, rs10484561 in the human leukocyte antigen (HLA) class II region on 6p21.32 associated with increased FL risk. Here, in a three-stage genome-wide association study, starting with a genome-wide scan of 379 FL cases and 791 controls followed by validation in 1,049 cases and 5,790 controls, we identified a second independent FL–associated locus on 6p21.32, rs2647012 (ORcombined = 0.64, Pcombined = 2×10−21) located 962 bp away from rs10484561 (r2<0.1 in controls). After mutual adjustment, the associations at the two SNPs remained genome-wide significant (rs2647012:ORadjusted = 0.70, Padjusted = 4×10−12; rs10484561:ORadjusted = 1.64, Padjusted = 5×10−15). Haplotype and coalescence analyses indicated that rs2647012 arose on an evolutionarily distinct haplotype from that of rs10484561 and tags a novel allele with an opposite (protective) effect on FL risk. Moreover, in a follow-up analysis of the top 6 FL–associated SNPs in 4,449 cases of other NHL subtypes, rs10484561 was associated with risk of diffuse large B-cell lymphoma (ORcombined = 1.36, Pcombined = 1.4×10−7). Our results reveal the presence of allelic heterogeneity within the HLA class II region influencing FL susceptibility and indicate a possible shared genetic etiology with diffuse large B-cell lymphoma. These findings suggest that the HLA class II region plays a complex yet important role in NHL.

Common Breast Cancer Susceptibility Loci Are Associated with Triple-Negative Breast Cancer

Triple-negative breast cancers are an aggressive subtype of breast cancer with poor survival, but there remains little known about the etiologic factors that promote its initiation and development. Commonly inherited breast cancer risk factors identified through genome-wide association studies display heterogeneity of effect among breast cancer subtypes as defined by the status of estrogen and progesterone receptors. In the Triple Negative Breast Cancer Consortium (TNBCC), 22 common breast cancer susceptibility variants were investigated in 2,980 Caucasian women with triple-negative breast cancer and 4,978 healthy controls. We identified six single-nucleotide polymorphisms, including rs2046210 (ESR1), rs12662670 (ESR1), rs3803662 (TOX3), rs999737 (RAD51L1), rs8170 (19p13.1), and rs8100241 (19p13.1), significantly associated with the risk of triple-negative breast cancer. Together, our results provide convincing evidence of genetic susceptibility for triple-negative breast cancer.

Age-specific Trends in Mammographic Density The Minnesota Breast Cancer Family Study

Mammographic density is a strong risk factor for breast cancer, yet few studies have evaluated density trends, and associated factors, over time. The authors retrieved and digitized mammograms (> or =1 per woman) imaged in 1990-2003 to evaluate percent density (PD) in the Minnesota Breast Cancer Family cohort. Multivariable-adjusted, mixed-effects, repeated-measures models incorporating a natural cubic spline provided estimates of nonlinear trends in PD with age and were used to examine association with covariates. Overall, 5,698 mammograms from 1,689 women with covariate information were digitized. In descriptive analyses, the highest median PD was 33.1% (interquartile range, 21.8%; n = 230) among premenopausal women, 31.0% (interquartile range, 23.2%; n = 175) among women who transitioned from pre- to postmenopause, and 18.7% (interquartile range, 22.2%; n = 1,284) among postmenopausal women. On average, premenopausal compared with postmenopausal women had 1.9% (p = 0.001) higher PD. In repeated-measures analyses, greater declines in PD occurred with menopause and among women with higher baseline PD; current postmenopausal hormone use and higher body mass index modified these declines (p interaction < 0.001). No significant modification of the density change with age was seen with parity/age at first birth, age at menarche, oral contraceptive use, family history of breast or ovarian cancer in a first- or second-degree relative, educational level, smoking status, or alcohol intake were observed. These data suggest that menopause, baseline PD, postmenopausal hormone use, and body mass index predict changes in mammographic density trends during adult life.

Risk factors for intrahepatic cholangiocarcinoma: Association between metformin use and reduced cancer risk

The associations between diabetes, smoking, obesity, and intrahepatic cholangiocarcinoma (ICC) risk remain inconclusive. Metformin is purportedly associated with a reduced risk for various cancers. This case‐control study evaluated risk factors for ICC and explored the effects of metformin on ICC risk in a clinic/hospital‐based cohort. ICC patients observed at the Mayo Clinic (Rochester, MN) between January 2000 and May 2010 were identified. Age, sex, ethnicity, and residential area‐matched controls were selected from among Mayo Clinic Biobank participants. The associations between potential factors and ICC risk were determined. Six hundred and twelve cases and 594 controls were identified. Factors associated with increased ICC risk included biliary tract diseases (adjusted odds ratio [AOR]: 81.8; 95% confidence interval [CI]: 11.2‐598.8; P < 0.001), cirrhosis (AOR, 8.0; 95% CI: 1.8‐36.5; P = 0.007), diabetes (AOR, 3.6; 95% CI: 2.3‐5.5; P < 0.001), and smoking (AOR, 1.6; 95% CI: 1.3‐2.1; P < 0.001). Compared to diabetic patients not treated with metformin, the odds ratio (OR) for ICC for diabetic patients treated with metformin was significantly decreased (OR, 0.4; 95% CI: 0.2‐0.9; P = 0.04). Obesity and metabolic syndrome were not associated with ICC. Conclusion: This study confirmed diabetes and smoking as independent risk factors for ICC. A novel finding was that treatment with metformin was significantly associated with a 60% reduction in ICC risk in diabetic patients. (HEPATOLOGY 2013)

Association of Genetic Variation in Genes Implicated in the β-Catenin Destruction Complex with Risk of Breast Cancer

Aberrant Wnt/β-catenin signaling leading to nuclear accumulation of the oncogene product β-catenin is observed in a wide spectrum of human malignancies. The destruction complex in the Wnt/β-catenin pathway is critical for regulating the level of β-catenin in the cytoplasm and in the nucleus. Here, we report a comprehensive study of the contribution of genetic variation in six genes encoding the β-catenin destruction complex (APC, AXIN1, AXIN2, CSNK1D, CSNK1E, and GSK3B) to breast cancer using a Mayo Clinic Breast Cancer Case-Control Study. A total of 79 candidate functional and tagging single nucleotide polymorphisms (SNP) were genotyped in 798 invasive cases and 843 unaffected controls. Of these, rs454886 in the APC tumor suppressor gene was associated with increased breast cancer risk (per allele odds ratio, 1.23; 95% confidence intervals, 1.05-1.43; Ptrend = 0.01). In addition, five SNPs in AXIN2 were associated with increased risk of breast cancer (Ptrend < 0.05). Haplotype-based tests identified significant associations between specific haplotypes in APC and AXIN2 (P ≤ 0.03) and breast cancer risk. Further characterization of the APC and AXIN2 variants suggested that AXIN2 rs4791171 was significantly associated with risk in premenopausal (Ptrend = 0.0002) but not in postmenopausal women. The combination of our findings and numerous genetic and functional studies showing that APC and AXIN2 perform crucial tumor suppressor functions suggest that further investigation of the contribution of AXIN2 and APC SNPs to breast cancer risk are needed. (Cancer Epidemiol Biomarkers Prev 2008;17(8):2101–8)