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Elad Ziv

Publications and source records attributed to Elad Ziv.

26 records · Page 2Linked to original sources
PubMed2004

Mammographic density and estrogen receptor status of breast cancer.

BACKGROUND: The density of breast tissue on a mammogram is a strong predictor of breast cancer risk and may reflect cumulative estrogen effect on breast tissue. Endogenous and exogenous estrogen exposure increases the risk of estrogen receptor (ER)-positive breast cancer. We determined if mammographic density is associated more strongly with ER-positive breast cancer than with ER-negative breast cancer. METHODS: We analyzed data from 44,811 participants in the San Francisco Mammography Registry of whom 701 developed invasive breast cancer. Mammographic density was measured using the Breast Imaging Reporting and Data System (BI-RADS) classification system (1 = almost entirely fat, 2 = scattered fibroglandular, 3 = heterogeneously dense, 4 = extremely dense). We tested for associations between mammographic density and ER-positive and ER-negative breast cancer separately. Analyses were adjusted for age, body mass index, postmenopausal hormone use, family history of breast cancer, menopausal status, parity, and race/ethnicity. RESULTS: Mammographic density was strongly associated with both ER-positive and ER-negative breast cancers. Compared with women with BI-RADS 2, women with BI-RADS 1 (lowest density) had a lower risk of ER-positive cancer [adjusted hazard ratio (HR), 0.28; 95% confidence interval (95% CI), 0.16-0.50] and ER-negative cancer (adjusted HR, 0.17; 95% CI, 0.04-0.70). Women with BI-RADS 4 (highest density) had an increased risk of ER-positive breast cancer (adjusted HR, 2.21; 95% CI, 1.64-3.04) and an increased risk of ER-negative breast cancer (adjusted HR, 2.21; 95% CI, 1.16-4.18). CONCLUSION: Surprisingly, women with high mammographic density have an increased risk of both ER-positive and ER-negative breast cancers. The association between mammographic density and breast cancer may be due to factors besides estrogen exposure.

Adult↗
PubMed2003

Lower bronchodilator responsiveness in Puerto Rican than in Mexican subjects with asthma.

In the United States, Puerto Ricans and Mexicans have the highest and lowest asthma prevalence, morbidity, and mortality, respectively. To determine whether ethnicity-specific differences in therapeutic response, clinical response, and/or genetic factors contribute to differences in asthma outcomes, we compared asthma-related clinical characteristics among 684 Mexican and Puerto Rican individuals with asthma recruited from San Francisco, New York City, Puerto Rico, and Mexico City. Puerto Ricans with asthma had reduced lung function, greater morbidity, and longer asthma duration than did Mexicans with asthma. Bronchodilator responsiveness, measured as percentage change from baseline FEV1, was significantly lower among Puerto Ricans with asthma than among Mexicans with asthma. Puerto Ricans with asthma had on average 7.3% (95% confidence interval [CI], 4.6 to 9.9; p < 0.001) lower bronchodilator reversibility in FEV1, higher risk of an emergency department visit in the previous year (odds ratio, 2.63; 95% CI, 1.6 to 4.3; p < 0.001), and of previous hospitalization for asthma (odds ratio, 1.94; 95% CI, 1.2 to 3.2; p = 0.009) than Mexicans. Subgroup analysis corroborated that Puerto Ricans with asthma had more severe disease than did Mexicans on the basis of lung function measurements, responsiveness to beta2-adrenergic agonists, and health care use. We conclude that Puerto Ricans with asthma respond less to albuterol than do Mexicans with asthma. These findings underscore the need for additional research on racial/ethnic differences in asthma morbidity and response to therapy.

Asthma↗
PubMed2003

ADAM33 is not associated with asthma in Puerto Rican or Mexican populations.

A recent study identified the ADAM33 gene as a promising candidate contributing to asthma. In Puerto Rican and Mexican populations, we have genotyped six single nucleotide polymorphisms (SNPs) that were used in the Genetics of Asthma in Latino Americans Study. We chose to study these two populations because in the United States, Puerto Ricans have the highest asthma prevalence, morbidity, and mortality and Mexicans the lowest. We used the transmission disequilibrium test to analyze associations between the ADAM33 gene variants and asthma, asthma severity, bronchodilator responsiveness, and total IgE levels using single SNPs, two to six SNP combinations, and specific haplotypes in 583 trios (proband with asthma and both biological parents). We also genotyped matched control samples to allow case-control analyses. None of the transmission disequilibrium test or case-control results showed significant association in either population. We found no evidence for association of single SNPs with asthma severity, bronchodilator response, or IgE levels in Mexicans or in the combined population. Two SNPs showed a modest association in Puerto Ricans, insignificant when the number of comparisons was taken into account. We conclude that the ADAM33 gene is not an important risk factor for asthma or for asthma-associated phenotypes in Mexicans or in Puerto Ricans.

ADAM Proteins↗
PubMed2003

Mammographic breast density and family history of breast cancer.

The association between mammographic breast density and breast cancer risk may be the result of genetic and/or environmental factors that determine breast density. We reasoned that if the genetic factors that underlie breast density increase breast cancer risk, then breast density should be associated with family history of breast cancer. Therefore, we determined the association between mammographic density and family history of breast cancer among women in the San Francisco Mammography Registry. Mammographic density was classified using the four BI-RADS criteria: 1 = almost entirely fatty, 2 = scattered fibroglandular tissue, 3 = heterogeneously dense, and 4 = extremely dense. We adjusted for age, body mass index, hormone replacement therapy use, menopause status, and personal history of breast cancer. Compared with women with BI-RADS 1 readings, women with higher breast density were more likely to have first-degree relatives with breast cancer (BI-RADS 2, odds ratio [OR] = 1.37, 95% confidence interval [CI] = 0.96 to 1.89; BI-RADS 3, OR = 1.70, 95% CI = 1.19 to 2.40; BI-RADS 4, OR = 1.70, 95% CI = 1.05 to 2.71). Thus, the genetic factors that determine breast density may determine breast cancer risk.

Adipose Tissue↗
PubMed2003

Human population structure and genetic association studies.

Population substructure and recent admixture may confound the results of genetic association studies in unrelated individuals, leading to a potential excess of both false positive and false negative results. The possibility of false associations depends on the population sampled, the trait being studied and the marker being tested. Although family based tests of association avoid the possibility of confounding due to population substructure and admixture, association studies in unrelated individuals may be preferred in many situations due to their feasibility. Unlinked genetic markers may be used to detect confounding in association studies. In addition, the information from unlinked markers may be used to adjust genetic associations.

Genetic Linkage↗