Citations

Abstract Chromosomal aberrations occur frequently during malignant progression from Barrett's esophagus (BE) to esophageal adenocarcinoma (EAC). In this study, we applied Illumina's 317K high-density SNP arrays to profile chromosomal aberrations at each of the four sequential stages of progression - Barrett's metaplasia (BM), low-grade dysplasia (LGD), high-grade dysplasia (HGD), and EAC. We observed significant trends of increasing LOH/deletion associated with the degree of progression. The average numbers of chromosome arms with LOH/deletion per sample were 0.30, 3.21, 7.70, and 11.90 for BM, LGD, HGD, and EAC, respectively (p-for trend=4.82×10−7). The mean percentages of SNPs with LOH/deletion events were 0.1%, 1.8%, 6.6%, and 17.2% for BM, LGD, HGD, and EAC, respectively (p-for trend=2.64×10−6). In BM, there were scattered chromosome deletions at 3p14.2 (10%), 16q23.1 (5%), and 9p21 (5%), which became predominant aberrations in LGD. More importantly, the 3p14.2 (68.4%) and 16q23.1 (50%) LOH/deletion in LGD was exclusively limited to narrow regions within the FHIT (3p14.2) and WWOX (16q23.1) genes, the two most frequent common fragile sites in the human genome. In contrast, the 9p21 deletion (68.4%) occurred in larger regions (encompassing p16 gene), often involving the whole 9p arm. A significant increase in LOH/deletion of other chromosomes was seen in HGD and there was widespread LOH/deletion across the whole genome in EAC. 17p (47.6%) LOH was the most frequent event in EAC, which mostly spanned the entire 17p arm with only one focal site of LOH at 17p13.1. There were many recurrent small regions of LOH/deletion that disrupted a single gene, most of which are common fragile sites in the human genome. RUNX1 is a potential tumor suppressor gene in EAC. Amplifications were rarer than LOH/deletions. The average numbers of chromosome arms with amplification per sample were 0.30, 0.42, 1.90, and 8.50 for BM, LGD, HGD, and EAC, respectively (p-for trend=1.35×10−9). The mean percentages of SNPs with amplification were 0.5%, 0.4%, 1.5%, and 8.0% for BM, LGD, HGD, and EAC, respectively (p-for trend=1.26×10−8). The most frequent chromosome amplifications in EAC were 8q24.21 (36.6%, MYC), 8p23.1 (31.7%, CTSB), 7q21 (30.8%, CDK6), 20q13.2 (28.6%, ZNF217), and 7p11.2 (25.6%, EGFR). We then analyzed the associations of chromosomal aberrations with clinical features and pathological response in EAC patients treated with neoadjuvant chemoradiation. The number and size of LOH/deletion were significantly associated with pathological response. Non-responders had a greater number (16.4 vs. 8.5, p=0.060) and larger size (662.2 Mb vs. 290.7 Mb, p=0.034) of LOH/deletions, and higher percentage of aberrant SNPs (25.2% vs. 11.2%, p=0.030) than responders. This study provides a genome-wide catalogue of chromosome aberrations occurring during the malignant progression from BE to EAC with the highest resolution to date. Our data support genetic instability and p16 loss as drivers of early neoplastic progression from metaplasia to dysplasia, and p53 aberrations as late events critical for progression to adenocarcinoma. Chromosomal aberrations can predict malignant progression and treatment response in EAC, which may have important clinical implications for cancer prevention and personalized treatment of EAC. Citation Information: Cancer Prev Res 2010;3(1 Suppl):A14.

Abstract Background: Genome-wide association studies (GWAS) identified variants at 19p13.1 and ZNF365 (10q21.2) as risk factors for breast cancer among BRCA1 and BRCA2 mutation carriers, respectively. We explored associations with ovarian cancer and with breast cancer by tumor histopathology for these variants in mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Methods: Genotyping data for 12,599 BRCA1 and 7,132 BRCA2 mutation carriers from 40 studies were combined. Results: We confirmed associations between rs8170 at 19p13.1 and breast cancer risk for BRCA1 mutation carriers [HR, 1.17; 95% confidence interval (CI), 1.07–1.27; P = 7.42 × 10−4] and between rs16917302 at ZNF365 (HR, 0.84; 95% CI, 0.73–0.97; P = 0.017) but not rs311499 at 20q13.3 (HR, 1.11; 95% CI, 0.94–1.31; P = 0.22) and breast cancer risk for BRCA2 mutation carriers. Analyses based on tumor histopathology showed that 19p13 variants were predominantly associated with estrogen receptor (ER)-negative breast cancer for both BRCA1 and BRCA2 mutation carriers, whereas rs16917302 at ZNF365 was mainly associated with ER-positive breast cancer for both BRCA1 and BRCA2 mutation carriers. We also found for the first time that rs67397200 at 19p13.1 was associated with an increased risk of ovarian cancer for BRCA1 (HR, 1.16; 95% CI, 1.05–1.29; P = 3.8 × 10−4) and BRCA2 mutation carriers (HR, 1.30; 95% CI, 1.10–1.52; P = 1.8 × 10−3). Conclusions: 19p13.1 and ZNF365 are susceptibility loci for ovarian cancer and ER subtypes of breast cancer among BRCA1 and BRCA2 mutation carriers. Impact: These findings can lead to an improved understanding of tumor development and may prove useful for breast and ovarian cancer risk prediction for BRCA1 and BRCA2 mutation carriers. Cancer Epidemiol Biomarkers Prev; 21(4); 645–57. ©2012 AACR.

Abstract Aims For patients with refractory atrial fibrillation (AF) undergoing atrioventricular nodal ablation (AVNA), initial single-chamber right ventricular (RV)-only pacing is standard. Given the deleterious effects of chronic RV-only pacing, the impact of an initial biventricular (BiV) pacing strategy post-ablation is of interest. Methods and results We conducted a meta-analysis to determine the effect of BiV vs. RV-only pacing in patients undergoing AVNA for refractory atrial fibrillation. A search of multiple electronic databases identified 921 reports, which included four randomized controlled trials (n = 534). Mean New York Heart Association (NYHA) class was 2.3 and mean left ventricular ejection fraction (LVEF) was 44%. When compared with RV-only pacing, BiV pacing was not associated with reduced mortality [risk ratio 0.85, 95% confidence interval (CI) 0.40–1.82, P = 0.68]. In three studies comprised of patients with left ventricular systolic dysfunction (mean EF 41 ± 3%), BiV pacing demonstrated a non-significant reduction in cardiac mortality (risk ratio 0.59, 95% CI 0.25–1.39; P = 0.23). Compared with RV-only pacing, BiV pacing was associated with significant improvement in symptoms [Minnesota Living with Heart Failure Questionnaire (MLWHFQ) 2.72 points fewer, 95% CI 1.45–3.99] and increased LVEF (+2.6%, 95% CI 1.69–3.44), but no significant change in 6 min walk distance (6MWD) (5.02 ms more, 95% CI −1.56 to 11.59; P = 0.13). Conclusions In patients with refractory AF undergoing AVNA, BiV pacing was not associated with significantly improved survival when compared with RV-only pacing. A modest, but significant improvement in structural and functional response to BiV pacing was observed.

Abstract The 19p13.1 breast cancer susceptibility locus is a modifier of breast cancer risk in BRCA1 mutation carriers and is also associated with the risk of ovarian cancer. Here, we investigated 19p13.1 variation and risk of breast cancer subtypes, defined by estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2) status, using 48,869 breast cancer cases and 49,787 controls from the Breast Cancer Association Consortium (BCAC). Variants from 19p13.1 were not associated with breast cancer overall or with ER-positive breast cancer but were significantly associated with ER-negative breast cancer risk [rs8170 OR, 1.10; 95% confidence interval (CI), 1.05–1.15; P = 3.49 × 10−5] and triple-negative (ER-, PR-, and HER2-negative) breast cancer (rs8170: OR, 1.22; 95% CI, 1.13–1.31; P = 2.22 × 10−7). However, rs8170 was no longer associated with ER-negative breast cancer risk when triple-negative cases were excluded (OR, 0.98; 95% CI, 0.89–1.07; P = 0.62). In addition, a combined analysis of triple-negative cases from BCAC and the Triple Negative Breast Cancer Consortium (TNBCC; N = 3,566) identified a genome-wide significant association between rs8170 and triple-negative breast cancer risk (OR, 1.25; 95% CI, 1.18–1.33; P = 3.31 × 10−13]. Thus, 19p13.1 is the first triple-negative–specific breast cancer risk locus and the first locus specific to a histologic subtype defined by ER, PR, and HER2 to be identified. These findings provide convincing evidence that genetic susceptibility to breast cancer varies by tumor subtype and that triple-negative tumors and other subtypes likely arise through distinct etiologic pathways. Cancer Res; 72(7); 1795–803. ©2012 AACR.