AbstractCopy number variation (CNV) is a common form of structural variation detected in human genomes, occurring as both constitutional and somatic events. Cytogenetic techniques like chromosomal microarray (CMA) are widely used in analyzing CNVs. However, CMA techniques cannot resolve the full nature of these structural variations (i.e. the orientation and location of associated breakpoint junctions) and must be combined with other cytogenetic techniques, such as karyotyping or FISH, to do so. This makes the development of a next‐generation sequencing (NGS) approach capable of resolving both CNVs and breakpoint junctions desirable. Mate‐pair sequencing (MPseq) is a NGS technology designed to find large structural rearrangements across the entire genome. Here we present an algorithm capable of performing copy number analysis from mate‐pair sequencing data. The algorithm uses a step‐wise procedure involving normalization, segmentation, and classification of the sequencing data. The segmentation technique combines both read depth and discordant mate‐pair reads to increase the sensitivity and resolution of CNV calls. The method is particularly suited to MPseq, which is designed to detect breakpoint junctions at high resolution. This allows for the classification step to accurately calculate copy number levels at the relatively low read depth of MPseq. Here we compare results for a series of hematological cancer samples that were tested with CMA and MPseq. We demonstrate comparable sensitivity to the state‐of‐the‐art CMA technology, with the benefit of improved breakpoint resolution. The algorithm provides a powerful analytical tool for the analysis of MPseq results in cancer.
Novel Common Genetic Susceptibility Loci for Colorectal Cancer
Abstract Background Previous genome-wide association studies (GWAS) have identified 42 loci (P < 5 × 10−8) associated with risk of colorectal cancer (CRC). Expanded consortium efforts facilitating the discovery of additional susceptibility loci may capture unexplained familial risk. Methods We conducted a GWAS in European descent CRC cases and control subjects using a discovery–replication design, followed by examination of novel findings in a multiethnic sample (cumulative n = 163 315). In the discovery stage (36 948 case subjects/30 864 control subjects), we identified genetic variants with a minor allele frequency of 1% or greater associated with risk of CRC using logistic regression followed by a fixed-effects inverse variance weighted meta-analysis. All novel independent variants reaching genome-wide statistical significance (two-sided P < 5 × 10−8) were tested for replication in separate European ancestry samples (12 952 case subjects/48 383 control subjects). Next, we examined the generalizability of discovered variants in East Asians, African Americans, and Hispanics (12 085 case subjects/22 083 control subjects). Finally, we examined the contributions of novel risk variants to familial relative risk and examined the prediction capabilities of a polygenic risk score. All statistical tests were two-sided. Results The discovery GWAS identified 11 variants associated with CRC at P < 5 × 10−8, of which nine (at 4q22.2/5p15.33/5p13.1/6p21.31/6p12.1/10q11.23/12q24.21/16q24.1/20q13.13) independently replicated at a P value of less than .05. Multiethnic follow-up supported the generalizability of discovery findings. These results demonstrated a 14.7% increase in familial relative risk explained by common risk alleles from 10.3% (95% confidence interval [CI] = 7.9% to 13.7%; known variants) to 11.9% (95% CI = 9.2% to 15.5%; known and novel variants). A polygenic risk score identified 4.3% of the population at an odds ratio for developing CRC of at least 2.0. Conclusions This study provides insight into the architecture of common genetic variation contributing to CRC etiology and improves risk prediction for individualized screening.
Empowering genomic medicine by establishing critical sequencing result data flows: the eMERGE example
AbstractThe eMERGE Network is establishing methods for electronic transmittal of patient genetic test results from laboratories to healthcare providers across organizational boundaries. We surveyed the capabilities and needs of different network participants, established a common transfer format, and implemented transfer mechanisms based on this format. The interfaces we created are examples of the connectivity that must be instantiated before electronic genetic and genomic clinical decision support can be effectively built at the point of care. This work serves as a case example for both standards bodies and other organizations working to build the infrastructure required to provide better electronic clinical decision support for clinicians.
Eight Years of Clinical Legionella PCR Testing Illustrates a Seasonal Pattern
Background Heart rate ( HR ) recovery has been investigated in specific patient cohorts, but there is less information about the role of HR recovery in general populations. We investigated whether HR recovery has long‐term prognostic significance in primary prevention. Methods and Results Exercise tests performed between 1993 and 2010 on patients aged 30 to 79 years without cardiovascular disease were included. Mortality was determined from Mayo Clinic records and Minnesota Death Index. Total, cardiovascular , and non‐cardiovascular mortality was reported according to HR recovery <13 bpm using Cox regression. 19 551 patients were included, 6756 women (35%), age 51±10 years. There were 1271 deaths over follow‐up of 12±5 years. HR recovery declined after age 60, and was also lower according to diabetes mellitus, hypertension, obesity, current smoking, and poor cardiorespiratory fitness but not sex or β‐blockers. Adjusting for these factors, abnormal HR recovery was a significant predictor of total (hazard ratio [95% confidence interval]=1.56 [1.384–1.77]), cardiovascular (1.95 [1.57–2.42]), and non‐cardiovascular death (1.41 [1.22–1.64]). Hazard ratios for cardiovascular death according to abnormal HR recovery were significant in all age groups (30–59, 60–69, 70–79), in both sexes, in patients with and without hypertension, obesity, and diabetes mellitus, but not in patients taking β‐blockers, current smokers, and patients with normal cardiorespiratory fitness. Conclusions HR recovery is a powerful prognostic factor predicting total, cardiovascular, and non‐cardiovascular death in a primary prevention cohort. It performs consistently well according to sex, age, obesity, hypertension, and diabetes mellitus but shows diminished utility in patients taking β‐blockers, current smokers, and patients with normal cardiorespiratory fitness.
Abstract P6-10-07: Differences in genome-wide DNA methylation levels in breast milk by race and lactation duration
Abstract Introduction: Identifying biomarkers of breast cancer risk among young women would have value in developing effective screening and prevention strategies at early ages. We have proposed that DNA methylation analysis of breast milk may provide breast cancer risk information among young women, and could possibly provide etiologic clues related to the higher rates of early onset cancers among African American as compared with White women in the US. Objective: The purpose of this project was to identify associations between genome-wide DNA methylation levels in breast milk and race adjusted for other breast cancer risk factors. Study Population: Cancer-free, lactating U.S. Black (n=57) and White (n=82) women, ages 19 to 44, provided frozen breast milk samples, as well as demographic, behavioral, and reproductive data, to the Breastmilk Laboratory at University of Massachusetts Amherst. Women were uniparous and did not have a personal history of breast cancer at the time of milk donation. Methods: DNA was extracted from breast milk samples using the phenol-chloroform method. Genome-wide methylation analysis was performed on breast milk samples using the Infinium HumanMethylation450 BeadChip. Probes with 50% or more missing data, cross-reactive probes, as well as probes with minor allelic frequency greater than 0.05 in European- or African-Americans were removed, leaving 379,042 CpG sites for analysis. Multivariate generalized linear regression models were used to examine associations between race and other breast cancer risk factors and methylation beta values, adjusting for potential confounding factors. P-values less than 1E-7 were considered statistically significant. Results: Black women in this study were more likely to be never smokers, to not have used over-the-counter pain medication in the past week, and to breastfeed longer. After adjustment by age, BMI, smoking status, and batch number, race was significantly associated with differential methylation at 1143 CpG sites, including 1024 at which Black women demonstrated increased methylation levels. Additionally, breastfeeding duration was associated with 269 CpG sites, with 268 showing a significant inverse relationship with methylation. Methylation sites significantly associated with Black race and lactation duration were located within tumor suppressor and promoter genes as well as in genes implicated in obesity and diabetes. Conclusion: This preliminarily analysis of DNA methylation in breast milk suggests that Black women have increased methylation and longer breastfeeding is associated with reduced methylation. Further research to understand how etiologic factors related to breast cancer may alter DNA methylation patterns in normal breast may lead to improved understanding of breast cancer risk at a young age and potentially causes of racial disparities in breast cancer incidence between White and Black women. Citation Format: Davis Lynn BC, Bodelon C, Pfeiffer RM, Yang HP, Yang H, Lee M, Laird PW, Campan M, Weisenberger DJ, Murphy J, Sherman ME, Browne EP, Anderton DL, Arcaro KF, Gierach GL. Differences in genome-wide DNA methylation levels in breast milk by race and lactation duration [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-10-07.
Abstract P3-01-01: Management of the axilla in metaplastic breast carcinoma
Abstract Background Metaplastic breast cancer (MBC), characterized by a mixture of epithelial, squamous or mesenchymal elements and a usually triple-negative (TN) phenotype, accounts for <1% of breast cancer diagnoses. MBC has a poor prognosis with frequent distant spread, but, paradoxically, a lower than expected rate of nodal positivity (6 to 40%). Due to its rarity there is little data on how best to evaluate and manage the axilla in women with these tumors. Thus we undertook this study to evaluate axillary management and oncologic outcomes. Methods With IRB approval, we identified adult patients diagnosed with MBC at our institution from 2001 to 2011 from our prospective surgical pathology database. Patient, pathology, imaging, treatment and outcome data were obtained from electronic medical record, tumor registry, pathology slide and imaging review. Median follow-up for surviving patients was 66 months. Statistical analyses were performed using JMP 10.0 software. Results We identified 41 MBC patients, median age 60 years (range 33-89 years), with a median tumor size of 2.7 cm; 33 (80%) were TN. 23 patients (56%) had a preoperative axillary ultrasound (AUS): 9 (39%) showed at least one suspicious axillary lymph node (LN) of whom 6 had a preoperative fine needle LN biopsy (FNA) of which 3 were positive for metastasis. 6 patients, including the 3 LN+ on FNA, had neoadjuvant chemotherapy (NAC). Operation included axillary dissection (ALND) in 14, sentinel LN biopsy (SLNB) in 23, and SLNB followed by ALND in 1, while 3 patients had no axillary surgery. 10 patients were LN+ at operation. Among 22 patients who had both an AUS and axillary surgery, AUS had a sensitivity of 100% and specificity of 78%. Patient and tumor variables in association with pathologic LN status are summarized in the table. LN positivity correlated with increasing tumor size, T stage, grade and angiolymphatic invasion. 16 patients recurred, most with distant disease (10/16, 63%), although there was a solitary axillary recurrence 8 months after a negative SLNB in one patient who did not have a preoperative AUS. Thus the accuracy of SLNB was 96% (23/24) overall, but among those without preoperative AUS, 1/7 (14%) SLNBs were falsely negative. 5-year disease-free and breast cancer-specific survival estimates were 49% and 63%. LN- N=28 (74%)LN+ N=10 (26%)p-valueSize, median (IQR), cm2.7 (1.6-4.6)6.6 (2.5-16.5)0.001T stage 0.03T19 (100%)0 (0%) T214 (78%)4 (22%) T33 (60%)2 (40%) T42 (33%)4 (67%) Grade 0.04Low6 (16%)0 (0%) Intermediate/High22 (58%)10 (26%) Estrogen Receptor 0.61Positive (>1%)5 (71%)2 (29%) Negative (<1%)23 (74%)8 (26%) Angiolymphatic Invasion 0.002No26 (87%)4 (13%) Yes2 (25%)6 (75%) Dominant Histology 0.65Adenosquamous2 (100%)0 (0%) Matrix producing4 (80%)1 (20%) Spindle cell14 (74%)5 (26%) Squamous*8 (67%)4 (33%) *any squamous component Conclusion Our study is the first to specifically address AUS and SLNB for patients with metaplastic breast cancer. AUS had 100% sensitivity and 78% specificity, while one patient without a preoperative AUS had a falsely negative SLNB. Further, AUS with FNA of suspicious LNs was useful for staging at the time of diagnosis and informing treatment. We recommend this approach for patients with MBC. Citation Format: Murphy BL, Fazzio RT, Hoskin TL, Glazebrook KN, Keeney MG, Habermann EB, Hieken TJ. Management of the axilla in metaplastic breast carcinoma [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-01-01.
Contemporary Risk Factors and Outcomes of Transfusion-Associated Circulatory Overload*
Objectives: Transfusion-associated circulatory overload is characterized by hydrostatic pulmonary edema following blood transfusion. Restrictive transfusion practice may affect the occurrence and severity of transfusion-associated circulatory overload in critically ill patients. We sought to examine contemporary risk factors and outcomes for transfusion-associated circulatory overload. Design: Case-control study. Setting: Four tertiary care hospitals. Patients: We prospectively enrolled 200 patients with transfusion-associated circulatory overload identified by active surveillance and 405 controls matched by transfusion intensity. Interventions: None. Measurements and Main Results: Among 20,845 transfused patients who received 128,263 blood components from May 2015 until July 2016, transfusion-associated circulatory overload incidence was one case per 100 transfused patients. In addition to cardiovascular comorbidities, multivariable analysis identified the following independent predictors of transfusion-associated circulatory overload: acute kidney injury, emergency surgery, pretransfusion diuretic use, and plasma transfusion—the latter especially in females. Compared with matched controls, transfusion-associated circulatory overload cases were more likely to require mechanical ventilation (71% vs 49%; p < 0.001), experienced longer intensive care and hospital lengths of stay following transfusion, and had higher mortality (21% vs 11%; p = 0.02) even after adjustment for other potentially confounding variables. Conclusions: Despite restrictive transfusion practice, transfusion-associated circulatory overload remains a frequent complication of transfusion and is an independent risk factor for in-hospital morbidity and mortality. In addition to cardiovascular and renal risk factors, plasma transfusion was associated with transfusion-associated circulatory overload after controlling for other covariates. Additional research is needed to examine the benefit of reduced erythrocyte or plasma exposure in patients at high risk for transfusion-associated circulatory overload.
Prostacyclin Use Among Patients with Pulmonary Arterial Hypertension in the United States: A Retrospective Analysis of a Large Health Care Claims Database