The relation of lifetime alcohol intake to risk of breast cancer in pre- and postmenopausal women was examined in a case-control study in western New York. Cases with incident primary histologically confirmed breast cancer diagnosed during the period 1986-1991 (n = 740) and controls, frequency age-matched women drawn from New York state driver's license records (age < 65 yrs) and from records of the Health Care Finance Administration (age > or = 65 yrs, n = 810), were interviewed regarding intake of wine, beer, and hard liquor 2, 10, and 20 years ago and at 16 years of age. Although women in this study had generally low intakes of alcohol, there was little evidence of increased risk of breast cancer with intake of alcohol at any of the time periods or with an index of total lifetime intake. There was a weak indication of an increase in risk with beer for intakes of at least one drink per day. This risk was evident for 2, 10, and 20 years ago but not at 16 years of age. In this group with relatively low intakes of alcohol, evidence was weak for an association of increased risk of breast cancer with intake of alcohol, with the possible exception of a weak association with beer intake.
TPS1608 Background: Metformin may have growth inhibitory effects on many cancer types including breast cancer. NCIC MA.32 is a randomized placebo-controlled trial examining the effects of 5 years of metformin in women with breast cancer ( http://clinicaltrials.gov/show/NCT01101438 ). This trial offers us the opportunity to explore the effects of metformin on breast cancer biomarkers to gain an understanding of the potential chemo preventive effects of this drug. The primary aim of this companion to MA.32 (Alliance trial # A211201) is to examine the effects of 1 year of metformin vs placebo on breast density for women with Estrogen Receptor negative (ER-) breast cancer. Secondary aims of this study include: evaluation of breast density following 2 years of metformin use, and correlation of density with fasting insulin, glucose and Homeostasis Model Assessment (HOMA). Exploratory aims include examination of the effects of metformin on second cancer rates. Methods: Eligible women must have been enrolled on MA.32 (North America accrual completed January 23, 2013), have hormone receptor-negative breast cancer, and breast composition on mammography >25% glandular density, have a digital mammogram within 12 months of registration on MA.32 and have an intact, unaffected contralateral breast. Women enrolled on this study must provide menstrual cycle data (if premenopausal) and digital mammograms. All other study related information is gathered through participation in MA.32. Mammographic density will be calculated using Cumulus software (the Boyd method). Our accrual goal is 458 patients (229 per arm) and with an assumption of 20% drop out due to drug intolerance and another 20% due to ineligibility. Therefore, with a sample size of 274 (137 per arm) we will have at least 85% power to detect a 4% difference between study arms, i.e., 5% change from baseline to one year of treatment for metformin vs. 1% for placebo, using the two-sided two-sample t-test at a significance level of 5%. This study was activated in the United States on 8/22/2012 and 15 patients have been accrued to date. This study is sponsored by the NCI and the Alliance for clinical trials. Clinical trial information: NCT01666171.
Abstract The current study aimed to define the genomic functions of the vitamin D receptor (VDR) in African American (AA) prostate cancer (PCa) compared to European American (EA) counterparts. VDR-dependent ChIP-Seq and RNA-Seq gene was undertaken in EA (non-malignant HPr1AR and malignant LNCaP) and AA (non-malignant RC43N and malignant RC43T) prostate models, combined with analyses of three PCa cohorts. In AA prostate models the VDR is highly expressed, binds more frequently, and is enriched in active and poised enhancers. Motif analyses revealed selective enrichment, including ZBTB33/KAISO in AA cells and ERG family members in EA cells and, similarly, GIGGLE analyses revealed AA VDR cistromes were significantly overlapped with core circadian rhythm transcription factors (e.g. NONO). Combining VDR-dependent ChIP-Seq and RNA-Seq established that AA cells displayed a significantly stronger transcriptional response, compared to EA cells, and was most responsive in non-malignant RC43N. For example, RC43N transcriptional responses were enriched for circadian rhythm (NES 2.7) and inflammation, whereas in RC43T the same gene networks were repressed. To reveal how VDR/1,25(OH)2D3 signaling is corrupted in AA PCa, we mined TCGA data and revealed that the BAZ1A/SMARCA5 chromatin remodeling complex was uniquely altered in TMPRSS2:ERG fusion negative AA PCa. We are currently examining the impact of BAZ1A on the 1,25(OH)2D3 responsiveness. We also identified miRNA associated with progression from HGPIN to PCa in AA men, and that ~30% were bound by VDR and regulated by 1,25(OH)2D3, although ~5% of EA progression miRNA were VDR-responsive. For example, VDR binds to miR-199b, is uniquely 1,25(OH)2D3 up-regulated in RC43N but repressed in RC43T, and associates with AA progression from HGPIN to PCa. MiR-199b regulates expression of NPAS2, a core circadian transcription factor. Finally, leveraging a previously analyzed cohort of 1,25(OH)2D3-treated PCa patients revealed that AA tumors were intrinsically more 1,25(OH)2D3-responsive than EA counterparts, reflecting the cell line analyses. 1,25(OH)2D3 regulated circadian transcriptional regulators (e.g. NOCT and MYBBP1A) and inflammatory signals. Together, these data suggest VDR transcriptional control in AA men is more dynamic than in EA men, and is primed to govern inflammatory and circadian rhythm pathways. This is frequently disrupted, including by altered BAZ1A/SMARCA5 expression and/or reduced environmental-regulated serum vitamin D3 levels, and leads to altered regulation of circadian rhythm process, and inflammatory signals. Therefore, the VDR axis lies at the cross-roads of biopsychosocial processes that contributes to PCa health disparities. Citation Format: Manjunath Siddappa, Sajad D. Wani, Jaimie S. Gray, Mark D. Long, Hedieh Jafari, Hsuchang Wu, Honhe Wang, Rebecca Morgan, Gary Hardiman, James Marshall, Chanita Hughes-Halbert, Lara E. Sucheston-Campbell, Clayton L. Yates, Moray J. Campbell. Epigenetic disruption of vitamin D receptor signaling in African American prostate cancer alters circadian signaling networks [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PR05.
Interest in the chemopreventive effects of the trace element selenium has spanned the past three decades. Of >100 studies that have investigated the effects of selenium in carcinogen-exposed animals, two-thirds have observed a reduction in tumor incidence and/or preneoplastic endpoints (G. F. Combs and S. B. Combs, The Role of Selenium in Nutrition Chapter 10, pp. 413–462. San Diego, CA: Academic Press, 1986, and B. H. Patterson and O. A. Levander, Cancer Epidemiol. Biomark. Prev., 6: 63–69, 1997). The Nutritional Prevention of Cancer Trial, a randomized clinical trial reported by Clark et al. (L. C. Clark et al. , JAMA, 276: 1957–1963, 1996), showed as a secondary end point, a statistically significant decrease in lung cancer incidence with selenium supplementation. The adjusted hazard ratio (HR) was 0.56 [95% confidence interval (CI), 0.31–1.01; P = 0.05]. These results were based on active follow-up of 1312 participants.
This reanalysis used an extended Nutritional Prevention of Cancer Trial participant follow-up through the end of the blinded clinical trial on February 1, 1996. The additional 3 years added 8 cases to the selenium-treated group and 4 cases to the placebo group, and increased follow-up to 7.9 years. The relative risk of 0.70 (95% CI, 0.40–1.21; P = 0.18) is not statistically significant. Whereas the overall adjusted HR is not significant (HR = 0.74; 95% CI, 0.44–1.24; P = 0.26), and the HR for current and former smokers was not significant, the trend is toward a reduction in risk of incident lung cancer with selenium supplementation. In a subgroup analysis there was a nominally significant HR among subjects with baseline plasma selenium in the lowest tertile (HR = 0.42; 95% CI, 0.18–0.96; P = 0.04). The analysis for the middle and highest tertiles of baseline showed HRs of 0.91 and 1.25. The current reanalysis indicates that selenium supplementation did not significantly decrease lung cancer incidence in the full population, but a significant decrease among individuals with low baseline selenium concentrations was observed.
Genome-wide association studies and subsequent replication studies have shown that single nucleotide polymorphisms (SNPs) in the chromosomal region 8q24 are associated with colorectal cancer susceptibility. We examined 11 SNP markers in the 8q24 region between 128.47 and 128.54 Mb, using a total of 1,987 colon cases and 2,339 controls who self-reported as white from two independent, well-characterized study populations. Analysis was performed separately within each study, and combined using random effects meta-analysis. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) and to test for effect modification by known colon cancer risk factors. We also performed a meta-analysis combining our results with previous studies. We observed evidence of association for four SNPs in low to high linkage disequilibrium (r2 ranging from 0.18 to 0.93) localized in a 16.2 kb region defined by rs10505477 and rs1056368. The combined results for our two studies of colon cancer showed an OR of 1.10 (95% CI: 1.01-1.20, Ptrend = 0.023), and a meta-analysis of our results with previously reported studies of colon and colorectal cancer strongly support the association for this SNP (combined OR for rs6983267 = 1.21, 95% CI: 1.18-1.24, p = 5.5 × 10-44). We did not observe any notable evidence of effect modification by known colon cancer risk factors, and risk did not differ significantly by tumor site or stage. Our study confirms the association between polymorphisms on chromosome 8q24 and colon cancer risk and suggests that the susceptibility locus in region 8q24 is not strongly modified by various lifestyle, environmental, and demographic risk factors for colon cancer.