Association between Breast Density and Subsequent Breast Cancer Following Treatment for Ductal Carcinoma In situ

ArticleinCancer Epidemiology Biomarkers & Prevention 16(12):2587-93 · January 2008with5 Reads
DOI: 10.1158/1055-9965.EPI-07-0458 · Source: PubMed
Risk of invasive cancer following treatment for ductal carcinoma in situ (DCIS) is associated with both treatment- and tumor-related factors. However, it is unknown whether stromal factors such as breast density may also influence subsequent invasive breast events. We investigated whether breast density is an independent predictor of subsequent breast events among women treated for DCIS. Population: A prospective cohort study of 3,274 women ages 30 to 93 in the Breast Cancer Surveillance Consortium treated with lumpectomy for DCIS between 1993 and 2005. All subjects had an American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) breast density measure recorded prior to diagnosis. Ipsilateral and contralateral breast cancer following lumpectomy for DCIS were ascertained through state tumor registries, regional Surveillance Epidemiology and End Results program or pathology databases. A Cox proportional hazard model was used to compare adjusted risk of breast cancer among women with high (BI-RADS 3 or 4) versus low (BI-RADS 1 or 2) breast density. During a median follow-up period of 39 months (0-132 months), 133 women developed invasive breast cancer. After adjusting for age and radiation treatment, high breast density was associated with increased hazard for contralateral (hazard ratio, 3.1; 95% confidence interval, 1.6-6.1) but not ipsilateral (hazard ratio, 1.0; 95% confidence interval, 0.6-1.6) invasive breast events. High breast density is associated with contralateral, but not ipsilateral, invasive breast cancer following lumpectomy for DCIS. Thus, women with DCIS and high breast density may especially benefit from antiestrogenic therapy to reduce the risk of contralateral invasive disease.
    • "Studies that have examined risk of a second invasive or in situ breast cancer are summarized inTable 4. Four [79,909192 of the fi ve [79,90919293 studies show an increased risk of a second cancer in the ipsilateral breast, and three [90,91,93] of the fi ve show an increased risk in the contralateral breast. Only one [79] of the three [79,91,93] studies to examine the potential modifying role of radiation therapy found evidence that risk of a second breast cancer was higher in those who did not receive radiation. Women with higher density have been shown to have a higher risk of dying from breast cancer compared with those with lower density, but this is due largely to the increased breast cancer incidence associated with density [73,94]. "
    [Show abstract] [Hide abstract] ABSTRACT: Variations in percent mammographic density (PMD) reflect variations in the amounts of collagen and number of epithelial and non-epithelial cells in the breast. Extensive PMD is associated with a markedly increased risk of invasive breast cancer. The PMD phenotype is important in the context of breast cancer prevention because extensive PMD is common in the population, is strongly associated with risk of the disease, and, unlike most breast cancer risk factors, can be changed. Work now in progress makes it likely that measurement of PMD will be improved in the near future and that understanding of the genetics and biological basis of the association of PMD with breast cancer risk will also improve. Future prospects for the application of PMD include mammographic screening, risk prediction in individuals, breast cancer prevention research, and clinical decision making.
    Full-text · Article · Nov 2011
  • [Show abstract] [Hide abstract] ABSTRACT: Women with ductal carcinoma in situ (DCIS) are at substantially increased risk for a second breast cancer, but few strong predictors for these subsequent tumors have been identified. We used Cox regression modeling to examine the association between mammographic density at diagnosis of DCIS of 504 women from the National Surgical Adjuvant Breast and Bowel Project B-17 trial and risk of subsequent breast cancer events. In this group of patients, mostly 50 years old or older, approximately 6.6% had breasts categorized as highly dense (i.e., ≥75% of the breast occupied by dense tissue). After adjusting for treatment with radiotherapy, age, and body mass index, women with highly dense breasts had 2.8 (95% confidence interval [CI] = 1.3 to 6.1) times the risk of subsequent breast cancer (DCIS or invasive), 3.2 (95% CI = 1.2 to 8.5) times the risk of invasive breast cancer, and 3.0 (95% CI = 1.2 to 7.5) times the risk of any ipsilateral breast cancer, compared with women with less than 25% of the breast occupied by dense tissue. Our results provide initial evidence that the risk of second breast cancers may be increased among DCIS patients with highly dense breasts.
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  • [Show abstract] [Hide abstract] ABSTRACT: It is uncertain whether evidence supports routinely estimating a postmenopausal woman's risk of breast cancer and intervening to reduce risk. We systematically reviewed prospective studies about models and sex hormone levels to assess breast cancer risk and used meta-analysis with random effects models to summarize the predictive accuracy of breast density. We also reviewed prospective studies of the effects of exercise, weight management, healthy diet, moderate alcohol consumption, and fruit and vegetable intake on breast cancer risk, and used random effects models for a meta-analyses of tamoxifen and raloxifene for primary prevention of breast cancer. All studies reviewed were published before June 2008, and all statistical tests were two-sided. Risk models that are based on demographic characteristics and medical history had modest discriminatory accuracy for estimating breast cancer risk (c-statistics range = 0.58-0.63). Breast density was strongly associated with breast cancer (relative risk [RR] = 4.03, 95% confidence interval [CI] = 3.10 to 5.26, for Breast Imaging Reporting and Data System category IV vs category I; RR = 4.20, 95% CI = 3.61 to 4.89, for >75% vs <5% of dense area), and adding breast density to models improved discriminatory accuracy (c-statistics range = 0.63-0.66). Estradiol was also associated with breast cancer (RR range = 2.0-2.9, comparing the highest vs lowest quintile of estradiol, P < .01). Most studies found that exercise, weight reduction, low-fat diet, and reduced alcohol intake were associated with a decreased risk of breast cancer. Tamoxifen and raloxifene reduced the risk of estrogen receptor-positive invasive breast cancer and invasive breast cancer overall. Evidence from this study supports screening for breast cancer risk in all postmenopausal women by use of risk factors and breast density and considering chemoprevention for those found to be at high risk. Several lifestyle changes with the potential to prevent breast cancer should be recommended regardless of risk.
    Full-text · Article · Mar 2009
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