Modification of breast cancer risk according to age and menopausal status: a combined analysis of five population-based case-control studies

Reproductive characteristics, menopausal status, race and ethnicity, and risk of breast cancer subtypes defined by ER, PR and HER2 status: the Breast Cancer Etiology in Minorities study

BACKGROUND

Associations between reproductive factors and risk of breast cancer differ by subtype defined by joint estrogen receptor (ER), progesterone receptor (PR), and HER2 expression status. Racial and ethnic differences in the incidence of breast cancer subtypes suggest etiologic heterogeneity, yet data are limited because most studies have included non-Hispanic White women only.

METHODS

We analyzed harmonized data for 2,794 breast cancer cases and 4,579 controls, of whom 90% self-identified as African American, Asian American or Hispanic. Questionnaire data were pooled from three population-based studies conducted in California and data on tumor characteristics were obtained from the California Cancer Registry. The study sample included 1,530 luminal A (ER-positive and/or PR-positive, HER2-negative), 442 luminal B (ER-positive and/or PR-positive, HER2-positive), 578 triple-negative (TN; ER-negative, PR-negative, HER2-negative), and 244 HER2-enriched (ER-negative, PR-negative, HER2-positive) cases. We used multivariable unconditional logistic regression models to estimate subtype-specific ORs and 95% confidence intervals associated with parity, breast-feeding, and other reproductive characteristics by menopausal status and race and ethnicity.

RESULTS

Subtype-specific associations with reproductive factors revealed some notable differences by menopausal status and race and ethnicity. Specifically, higher parity without breast-feeding was associated with higher risk of luminal A and TN subtypes among premenopausal African American women. In contrast, among Asian American and Hispanic women, regardless of menopausal status, higher parity with a breast-feeding history was associated with lower risk of luminal A subtype. Among premenopausal women only, luminal A subtype was associated with older age at first full-term pregnancy (FTP), longer interval between menarche and first FTP, and shorter interval since last FTP, with similar OR estimates across the three racial and ethnic groups.

CONCLUSIONS

Subtype-specific associations with reproductive factors overall and by menopausal status, and race and ethnicity, showed some differences, underscoring that understanding etiologic heterogeneity in racially and ethnically diverse study samples is essential. Breast-feeding is likely the only reproductive factor that is potentially modifiable. Targeted efforts to promote and facilitate breast-feeding could help mitigate the adverse effects of higher parity among premenopausal African American women.

A framework for assessing interactions for risk stratification models: the example of ovarian cancer

Generally, risk stratification models for cancer use effect estimates from risk/protective factor analyses that have not assessed potential interactions between these exposures. We have developed a 4-criterion framework for assessing interactions that includes statistical, qualitative, biological, and practical approaches. We present the application of this framework in an ovarian cancer setting because this is an important step in developing more accurate risk stratification models. Using data from 9 case-control studies in the Ovarian Cancer Association Consortium, we conducted a comprehensive analysis of interactions among 15 unequivocal risk and protective factors for ovarian cancer (including 14 non-genetic factors and a 36-variant polygenic score) with age and menopausal status. Pairwise interactions between the risk/protective factors were also assessed. We found that menopausal status modifies the association among endometriosis, first-degree family history of ovarian cancer, breastfeeding, and depot-medroxyprogesterone acetate use and disease risk, highlighting the importance of understanding multiplicative interactions when developing risk prediction models.

Impact of Mammography Screening Frequency on Breast Cancer Mortality Rates

The frequency of mammography screening remains a topic of ongoing debate. This meta-analysis aimed to investigate the impact of annual vs. biennial mammography screenings on breast cancer mortality rates. A comprehensive search of relevant literature published up to 2021 was performed, with the primary outcome being the difference in breast cancer mortality rates between annual and biennial screenings. The extracted data included relative risks and 95% confidence intervals (CIs), with studies selected based on predetermined inclusion and exclusion criteria, emphasizing the quality of methodology and minimization of bias. Of the included studies, thirteen met the criteria, covering diverse demographic cohorts and screening frequencies. The synthesized data revealed a pattern of lower relative risk in annual screenings compared to biennial screenings across all studies. Notably, subgroup analyses indicated that age and racial background might modulate the effectiveness of screening frequency. In conclusion, this meta-analysis offers strong evidence suggesting that annual mammography screenings could be more effective than biennial screenings in reducing breast cancer mortality rates, especially in certain high-risk demographics. The results emphasize the importance of personalized, evidence-based approaches to mammography, with a call for future research to validate these findings and delve deeper into optimizing breast cancer screening strategies.

Breast Cancer Incidence in Relation to Long-Term Low-Level Exposure to Air Pollution in the ELAPSE Pooled Cohort

BACKGROUND

Established risk factors for breast cancer include genetic disposition, reproductive factors, hormone therapy, and lifestyle-related factors such as alcohol consumption, physical inactivity, smoking, and obesity. More recently a role of environmental exposures, including air pollution, has also been suggested. The aim of this study, was to investigate the relationship between long-term air pollution exposure and breast cancer incidence.

METHODS

We conducted a pooled analysis among six European cohorts (n = 199,719) on the association between long-term residential levels of ambient nitrogen dioxide (NO2), fine particles (PM2.5), black carbon (BC), and ozone in the warm season (O3) and breast cancer incidence in women. The selected cohorts represented the lower range of air pollutant concentrations in Europe. We applied Cox proportional hazards models adjusting for potential confounders at the individual and area-level.

RESULTS

During 3,592,885 person-years of follow-up, we observed a total of 9,659 incident breast cancer cases. The results of the fully adjusted linear analyses showed a HR (95% confidence interval) of 1.03 (1.00-1.06) per 10 μg/m³ NO2, 1.06 (1.01-1.11) per 5 μg/m³ PM2.5, 1.03 (0.99-1.06) per 0.5 10-5 m-1 BC, and 0.98 (0.94-1.01) per 10 μg/m³ O3. The effect estimates were most pronounced in the group of middle-aged women (50-54 years) and among never smokers.

CONCLUSIONS

The results were in support of an association between especially PM2.5 and breast cancer.

IMPACT

The findings of this study suggest a role of exposure to NO2, PM2.5, and BC in development of breast cancer.

Breast Cancer Screening Strategies for Women With ATM, CHEK2, and PALB2 Pathogenic Variants: A Comparative Modeling Analysis

IMPORTANCE

Screening mammography and magnetic resonance imaging (MRI) are recommended for women with ATM, CHEK2, and PALB2 pathogenic variants. However, there are few data to guide screening regimens for these women.

OBJECTIVE

To estimate the benefits and harms of breast cancer screening strategies using mammography and MRI at various start ages for women with ATM, CHEK2, and PALB2 pathogenic variants.

DESIGN, SETTING, AND PARTICIPANTS

This comparative modeling analysis used 2 established breast cancer microsimulation models from the Cancer Intervention and Surveillance Modeling Network (CISNET) to evaluate different screening strategies. Age-specific breast cancer risks were estimated using aggregated data from the Cancer Risk Estimates Related to Susceptibility (CARRIERS) Consortium for 32 247 cases and 32 544 controls in 12 population-based studies. Data on screening performance for mammography and MRI were estimated from published literature. The models simulated US women with ATM, CHEK2, or PALB2 pathogenic variants born in 1985.

INTERVENTIONS

Screening strategies with combinations of annual mammography alone and with MRI starting at age 25, 30, 35, or 40 years until age 74 years.

MAIN OUTCOMES AND MEASURES

Estimated lifetime breast cancer mortality reduction, life-years gained, breast cancer deaths averted, total screening examinations, false-positive screenings, and benign biopsies per 1000 women screened. Results are reported as model mean values and ranges.

RESULTS

The mean model-estimated lifetime breast cancer risk was 20.9% (18.1%-23.7%) for women with ATM pathogenic variants, 27.6% (23.4%-31.7%) for women with CHEK2 pathogenic variants, and 39.5% (35.6%-43.3%) for women with PALB2 pathogenic variants. Across pathogenic variants, annual mammography alone from 40 to 74 years was estimated to reduce breast cancer mortality by 36.4% (34.6%-38.2%) to 38.5% (37.8%-39.2%) compared with no screening. Screening with annual MRI starting at 35 years followed by annual mammography and MRI at 40 years was estimated to reduce breast cancer mortality by 54.4% (54.2%-54.7%) to 57.6% (57.2%-58.0%), with 4661 (4635-4688) to 5001 (4979-5023) false-positive screenings and 1280 (1272-1287) to 1368 (1362-1374) benign biopsies per 1000 women. Annual MRI starting at 30 years followed by mammography and MRI at 40 years was estimated to reduce mortality by 55.4% (55.3%-55.4%) to 59.5% (58.5%-60.4%), with 5075 (5057-5093) to 5415 (5393-5437) false-positive screenings and 1439 (1429-1449) to 1528 (1517-1538) benign biopsies per 1000 women. When starting MRI at 30 years, initiating annual mammography starting at 30 vs 40 years did not meaningfully reduce mean mortality rates (0.1% [0.1%-0.2%] to 0.3% [0.2%-0.3%]) but was estimated to add 649 (602-695) to 650 (603-696) false-positive screenings and 58 (41-76) to 59 (41-76) benign biopsies per 1000 women.

CONCLUSIONS AND RELEVANCE

This analysis suggests that annual MRI screening starting at 30 to 35 years followed by annual MRI and mammography at 40 years may reduce breast cancer mortality by more than 50% for women with ATM, CHEK2, and PALB2 pathogenic variants. In the setting of MRI screening, mammography prior to 40 years may offer little additional benefit.

Metabolic Syndrome and Risk of Breast Cancer by Molecular Subtype: Analysis of the MEND Study

Metabolic syndrome is a cluster of biological irregularities that is a known risk factor for cardiovascular disease, stroke, and diabetes. In a case-control study of 555 West African women, we observed that metabolic syndrome was strongly associated with breast cancer and the aggressive triple-negative molecular subtype, highlighting a need for clinical and lifestyle interventions targeting metabolic syndrome to reduce breast cancer risk in this population.

Risk of Breast Cancer Among Carriers of Pathogenic Variants in Breast Cancer Predisposition Genes Varies by Polygenic Risk Score

PURPOSE

This study assessed the joint association of pathogenic variants (PVs) in breast cancer (BC) predisposition genes and polygenic risk scores (PRS) with BC in the general population.

METHODS

A total of 26,798 non-Hispanic white BC cases and 26,127 controls from predominately population-based studies in the Cancer Risk Estimates Related to Susceptibility consortium were evaluated for PVs in BRCA1, BRCA2, ATM, CHEK2, PALB2, BARD1, BRIP1, CDH1, and NF1. PRS based on 105 common variants were created using effect estimates from BC genome-wide association studies; the performance of an overall BC PRS and estrogen receptor-specific PRS were evaluated. The odds of BC based on the PVs and PRS were estimated using penalized logistic regression. The results were combined with age-specific incidence rates to estimate 5-year and lifetime absolute risks of BC across percentiles of PRS by PV status and first-degree family history of BC.

RESULTS

The estimated lifetime risks of BC among general-population noncarriers, based on 10th and 90th percentiles of PRS, were 9.1%-23.9% and 6.7%-18.2% for women with or without first-degree relatives with BC, respectively. Taking PRS into account, more than 95% of BRCA1, BRCA2, and PALB2 carriers had > 20% lifetime risks of BC, whereas, respectively, 52.5% and 69.7% of ATM and CHEK2 carriers without first-degree relatives with BC, and 78.8% and 89.9% of those with a first-degree relative with BC had > 20% risk.

CONCLUSION

PRS facilitates personalization of BC risk among carriers of PVs in predisposition genes. Incorporating PRS into BC risk estimation may help identify > 30% of CHEK2 and nearly half of ATM carriers below the 20% lifetime risk threshold, suggesting the addition of PRS may prevent overscreening and enable more personalized risk management approaches.

Cost-effectiveness of risk-based breast cancer screening: A systematic review

To analyse published evidence on the economic evaluation of risk-based screening (RBS), a full systematic literature review was conducted. After a quality appraisal, we compared the cost-effectiveness of risk-based strategies (low-risk, medium-risk and high-risk) with no screening and age-based screening. Studies were also analysed for modelling, risk stratification methods, input parameters, data sources and harms and benefits. The 10 modelling papers analysed were based on screening performance of film-based mammography (FBM) (three); digital mammography (DM) and FBM (two); DM alone (three); DM, ultrasound (US) and magnetic resonance imaging (one) and DM and US (one). Seven studies did not include the cost of risk-stratification, and one did not consider the cost of diagnosis. Disutility was incorporated in only six studies (one for screening and five for diagnosis). None of the studies reported disutility of risk-stratification (being considered as high-risk). Risk-stratification methods varied from only breast density (BD) to the combination of familial risk, genetic susceptibility, lifestyle, previous biopsies, Jewish ancestry and reproductive history. Less or no screening in low-risk women and more frequent mammography screening in high-risk women was more cost-effective compared to no screening and age-based screening. High-risk women screened annually yielded a higher mortality rate reduction and more quality-adjusted life years at the expense of higher cost and false positives. RBS can be cost effective compared to the alternatives. However, heterogeneity among risk-stratification methods, input parameters, and weaknesses in the methodologies hinder the derivation of robust conclusions. Therefore, further studies are warranted to assess newer technologies and innovative risk-stratification methods.

Contribution of Germline Predisposition Gene Mutations to Breast Cancer Risk in African American Women

BACKGROUND

The risks of breast cancer in African American (AA) women associated with inherited mutations in breast cancer predisposition genes are not well defined. Thus, whether multigene germline hereditary cancer testing panels are applicable to this population is unknown. We assessed associations between mutations in panel-based genes and breast cancer risk in 5054 AA women with breast cancer and 4993 unaffected AA women drawn from 10 epidemiologic studies.

METHODS

Germline DNA samples were sequenced for mutations in 23 cancer predisposition genes using a QIAseq multiplex amplicon panel. Prevalence of mutations and odds ratios (ORs) for associations with breast cancer risk were estimated with adjustment for study design, age, and family history of breast cancer.

RESULTS

Pathogenic mutations were identified in 10.3% of women with estrogen receptor (ER)-negative breast cancer, 5.2% of women with ER-positive breast cancer, and 2.3% of unaffected women. Mutations in BRCA1, BRCA2, and PALB2 were associated with high risks of breast cancer (OR = 47.55, 95% confidence interval [CI] = 10.43 to >100; OR = 7.25, 95% CI = 4.07 to 14.12; OR = 8.54, 95% CI = 3.67 to 24.95, respectively). RAD51D mutations were associated with high risk of ER-negative disease (OR = 7.82, 95% CI = 1.61 to 57.42). Moderate risks were observed for CHEK2, ATM, ERCC3, and FANCC mutations with ER-positive cancer, and RECQL mutations with all breast cancer.

CONCLUSIONS

The study identifies genes that predispose to breast cancer in the AA population, demonstrates the validity of current breast cancer testing panels for use in AA women, and provides a basis for increased referral of AA patients for cancer genetic testing.

Perinatal and postnatal exposures and risk of young-onset breast cancer

Background

Perinatal factors have been associated with some adult health outcomes, but have not been well studied in young-onset breast cancer. We aimed to evaluate the association between young-onset breast cancer and perinatal exposures and to explore etiologic heterogeneity in the relationship between associated perinatal factors and estrogen receptor status of the tumor.

Methods

We addressed this in a sister-matched case-control study. Cases were women who had been diagnosed with ductal carcinoma in situ or invasive breast cancer before the age of 50. Each case had a sister control who was free of breast cancer up to the same age at which her case sister developed the disease. The factors considered were self-reported and included the mother’s preeclampsia in that pregnancy, mother’s smoking in that pregnancy, gestational hypertension, prenatal diethylstilbestrol use, and gestational diabetes, as well as low birth weight (less than 5.5 pounds), high birth weight (greater than 8.8 pounds), short gestational length (less than 38 completed weeks), and being breastfed or being fed soy formula.

Results

In conditional logistic regression analyses, high birth weight (odds ratio [OR] = 1.59, 95% confidence interval [CI] 1.07–2.36) and preeclampsia (adjusted OR = 1.92, CI 0.824–4.5162) were positively associated with risk. The association with preeclampsia was stronger when the analysis was restricted to invasive breast cancer (OR = 2.87, CI 1.08–7.59). We also used case-only analyses to assess etiologic heterogeneity for estrogen receptor (ER)-positive versus estrogen receptor-negative cancer. Women who were born to a preeclamptic pregnancy and later developed young-onset breast cancer were at increased odds for the ER-negative type (OR = 2.27; CI 1.05–4.92).

Conclusion

These results suggest that being born to a preeclamptic pregnancy may increase risk for young-onset breast cancer, especially for the ER-negative subtype.

Polymorphisms in the Tumor Necrosis Factor Genes Are Associated with Breast Cancer in the Moroccan Population

Background: The multifunctional cytokines of the tumor necrosis factor (TNF) family have been found to be involved in the promotion of inflammatory responses, and to play critical roles in the pathogenesis of inflammatory, autoimmune, and malignant diseases. The aim of the present study was to assess the associations among the TNFα -238 G > A (rs361525), TNFα -308 G > A (rs1800629), and TNFβ +252 A>G (rs909253) polymorphisms, and the breast cancer (BC) susceptibility in the Moroccan population. Materials and Methods: We conducted a case-control study, including 492 participants made up of 264 pathologically confirmed BC subjects, and 228 healthy women as controls. The samples were genotyped by means of polymerase chain reaction-restriction fragment length polymorphism analyses. Results: The TNFα -238 G > A and TNFα -308 G > A polymorphisms were significantly associated with increased risk of BC for the AA genotype, while, the AG genotype of TNFβ +252 A>G may offer a protective effect in this population. Haplotypic analyses showed that the GAA and AAG haplotypes increased the risk significantly for BC. Moreover, a significant association was observed between polymorphisms at the TNFα -238 A>G locus and the clinical profiles of the patients with regard to their estrogen-and progesterone-positive receptor status. Conclusion: These findings indicate that TNF gene polymorphisms are linked with the risk of BC in the Moroccan population. Further studies implementing a larger sample size are needed to support our findings.

Collaborative Molecular Epidemiology Study of Metabolic Dysregulation, DNA Methylation, and Breast Cancer Risk Among Nigerian Women: MEND Study Objectives and Design

PURPOSE

To elucidate the role of metabolic dysregulation and associated DNA methylation changes on breast cancer risk and aggressive subtypes among Nigerian women. We describe the design and methods of a collaborative molecular epidemiology study of breast cancer in Nigerian hospitals.

METHODS

The Mechanisms for Novel and Established Risk Factors for Breast Cancer in Women of Nigerian Descent (MEND) study was designed as a matched case-control study of 350 patients, age 18 to 75 years, with newly diagnosed, treatment-naïve breast cancer and 350 age-matched healthy controls from surrounding geographic areas. Patients with breast cancer seen for initial diagnosis at four large tertiary hospitals in southwest Nigeria and one affiliated private hospital were recruited. Healthy female controls were selected from a cohort of 4,000 healthy women recruited as part of the Human Heredity and Health (H3) in Africa Chronic Kidney Disease Case-Control Study in Nigeria. Tumor and adjacent normal tissue, and blood and saliva samples were collected for molecular and epigenetic assays.

RESULTS

Although recruitment is ongoing, a total of 416 patients have been recruited to date, with tumor and blood samples obtained from at least 310 patients. Data on age-matched (± 6 months) controls have also been obtained and harmonized. Lipid assays for 350 pathologically verified cases and 350 age-matched controls is underway, and pathologic characterization of tumors (including immunohistochemistry for subtyping) is ongoing. Data on DNA methylation for tumors and adjacent normal tissue are expected by the end of the study period.

CONCLUSION

The MEND study will provide a unique, high-quality source of data to evaluate the contribution of metabolic dysregulation such as obesity, diabetes, hypertension, and metabolic syndrome to the biology of breast cancer among Nigerian women and foster collaborative studies relevant for women of African descent globally.

Obesity and Cancer Treatment Outcomes: Interpreting the Complex Evidence

A wealth of epidemiological evidence, combined with plausible biological mechanisms, present a convincing argument for a causal relationship between excess adiposity, commonly approximated as body mass index (BMI, kg/m²), and incident cancer risk. Beyond this relationship, there are a number of challenges posed in the context of interpreting whether being overweight (BMI 25.0-29.9 kg/m²) or obese (BMI ≥ 30.0 kg/m²) adversely influences disease progression, cancer mortality and survival. Elevated BMI (≥ 25.0 kg/m²) may influence treatment selection of, for example, the approach to surgery; the choice of chemotherapy dosing; the inclusion of patients into randomised clinical trials. Furthermore, the technical challenges posed by an elevated BMI may adversely affect surgical outcomes, for example, morbidity (increasing the risk of surgical site infections), reduced lymph node harvest (and subsequent risk of under-staging and under-treatment) and increased risk of margin positivity. Suboptimal chemotherapy dosing, associated with capping chemotherapy in obese patients as an attempt to avoid excess toxicity, might be a driver of poor prognostic outcomes. By contrast, the efficacy of immune checkpoint inhibition may be enhanced in patients who are obese, although in turn, this observation might be due to reverse causality. So, a central research question is whether being overweight or obese adversely affects outcomes either directly through effects of cancer biology or whether adverse outcomes are mediated through indirect pathways. A further dimension to this complex relationship is the obesity paradox, a phenomenon where being overweight or obese is associated with improved survival where the reverse is expected. In this overview, we describe a framework for evaluating methodological problems such as selection bias, confounding and reverse causality, which may contribute to spurious interpretations. Future studies will need to focus on prospective studies with well-considered methodology in order to improve the interpretation of causality.

DDT and Breast Cancer: Prospective Study of Induction Time and Susceptibility Windows

BACKGROUND

In a previous Child Health and Development Studies report, p, p'-DDT was associated with a fivefold increased risk of premenopausal (before age 50 years) breast cancer for women first exposed before puberty. Here we extend our observation to breast cancer diagnosed during early postmenopause (ages 50-54 years) to determine whether age at diagnosis modifies the interaction of DDT with age at exposure.

METHODS

We conducted a second prospective, nested case-control study in the Child Health and Development Studies (153 incident breast cancer cases diagnosed at ages 50-54 years and 432 controls matched to cases on birth year). These were analyzed separately and pooled with our previous study (129 breast cancer cases diagnosed at ages 31-49 years and 129 controls matched on birth year). Blood samples were obtained during pregnancy (median age, 26 years), 1-3 days after delivery from 1959 to 1967 in Oakland, California. Serum was assayed for p, p'-DDT, o, p'-DDT, and p, p'-DDE. Odds ratios (ORs) below are given for doubling of serum p, p'-DDT. All statistical tests were two-sided.

RESULTS

For early postmenopausal breast cancer, p, p'-DDT was associated with risk for all women (ORDDT 50-54 = 1.99, 95% CI = 1.48 to 2.67). This association was accounted for by women first exposed to DDT after infancy (ORDDT 50-54 for first exposure after infancy = 2.83, 95% CI = 1.96 to 4.10 vs ORDDT 50-54 for first exposure during infancy = 0.56, 95% CI = 0.26 to 1.19; Pinteraction DDT x age at first exposure = .01). In contrast, for premenopausal breast cancer, p, p'-DDT was associated with risk among women first exposed during infancy through puberty, but not after (ORDDT<50 for first exposure during infancy = 3.70, 95% CI = 1.22 to 11.26, Pinteraction DDT x age at first exposure x age at diagnosis = .03).

CONCLUSIONS

p, p'-DDT was associated with breast cancer through age 54 years. Risk depended on timing of first exposure and diagnosis age, suggesting susceptibility windows and an induction period beginning in early life. DDT appears to be an endocrine disruptor with responsive breast targets from in utero to menopause.

Role of aldehyde dehydrogenases, alcohol dehydrogenase 1B genotype, alcohol consumption, and their combination in breast cancer in East-Asian women

The associations between genetic polymorphisms in ADH1B (rs1229984) and ALDH2 (rs671), alcohol consumption, the effect of a combination of the two polymorphisms, and breast cancer risk were studied in a population of East-Asian women. In this study, 623 breast cancer cases and 1845 controls, aged 40 or above, were included. The association between ALDH2 polymorphism and breast cancer risk was validated in 2143 breast cancer cases and 3977 controls. Alcohol consumption increased the risk of breast cancer regardless of ADH1B and ALDH2 genotypes. The rs671 polymorphism of ALDH2 was independently associated with increased breast cancer risk (OR = 1.27, 95% CI = 1.02–1.58 per increment of A). The ADH1B rs1229984 polymorphism, and combined effects of the rs671 and rs1229984 polymorphisms, did not reveal any significant association with breast cancer. Stratification by menopausal status revealed that rs671 gene polymorphisms were significantly associated with breast cancer only in postmenopausal women (OR = 1.45, 95% CI = 1.03–2.05 per increment of A). This is the first study to demonstrate an independent association between ALDH2 gene variants and breast cancer in Asian women. Further studies are warranted to further elucidate the etiology of breast cancer as it relates to alcohol consumption in Asian women.

Uterine cancer in breast cancer survivors: a systematic review

PURPOSE

Epidemiological evidence on the risk factors for uterine/endometrial cancer in breast cancer (BCa) survivors is limited and inconsistent. Therefore, we critically reviewed and summarized available evidence related to the risk factors for uterine/endometrial cancer in BCa survivors.

METHODS

We conducted a literature search through PubMed, Web of Science Core Collection/Cited Reference Search, as well as through manual searches of the bibliographies of the articles identified in electronic searches. We included in this review studies that were published up to November 30, 2018 that were accessible in full-text format and were published in English.

RESULTS

Of the 27 eligible studies, 96% had > 700 participants, 74% were prospective cohorts, 70% originated outside of the US, 44% reported as having pre-/postmenopausal women, and 26% reported having racially heterogeneous populations. Risk factors positively associated with uterine/endometrial cancer risk among BCa survivors included age at BCa diagnosis > 50 years, African American race, greater BMI/weight gain, and Tamoxifen treatment. For other lifestyle, reproductive and clinical factors, associations were either not significant (parity) or inconsistent (HRT use, menopausal status, smoking status) or had limited evidence (alcohol intake, family history of cancer, age at first birth, oral contraceptive use, age at menopause, comorbidities).

CONCLUSION

We identified several methodological concerns and limitations across epidemiological studies on potential risk factors for uterine/endometrial cancer in BCa survivors, including lack of details on uterine/endometrial cancer case ascertainment, varying and imprecise definitions of important covariates, insufficient adjustment for potential confounders, and small numbers of uterine/endometrial cancer cases in the overall as well as stratified analyses. Based on the available evidence, older age and higher body weight measures appear to be a shared risk factor for uterine/endometrial cancer in the general population as well as in BCa survivors. In addition, there is suggestive evidence that African American BCa survivors have a higher risk of uterine/endometrial cancer as compared to their White counterparts. There is also evidence that Tamoxifen contributes to uterine/endometrial cancer in BCa survivors. Given limitations of existing studies, more thorough investigation of these associations is warranted to identify additional preventive strategies needed for BCa survivors to reduce uterine/endometrial cancer risk and improve overall survival.

A retrospective study on breast cancer presentation, risk factors, and protective factors in patients with a positive family history of breast cancer

Women with a positive family history of breast cancer are greatly predisposed to breast cancer development. From January 2007 to December 2016, 1101 patients with a histologically confirmed breast cancer were divided into two groups: patients with and without a positive family history of breast cancer. Variables including age at presentation, ethnicity, tumor size, age at menarche, age at menopause, oral contraceptive pill (OCP) use, hormone replacement therapy (HRT), alcohol intake, smoking, body mass index (BMI), diabetes mellitus, parity, and breastfeeding were recorded. One hundred and fifty-nine out of 1101 (14.4%) of the patients had a family history of breast cancer. There was no significant difference in the incidence of breast cancer among Malays, Chinese, and Indians. Both patient groups presented at a mean age of about 60 years (+FH 60; -FH 61.2 P-value = .218). Significantly higher prevalence of history of benign breast disease (11.3%, P .018), nulliparity (13.2%, P .014), tumor size at presentation of more than 5 cm (47.3%, P 0.001), and bilateral site presentation (3.1%, P 0.029) were noted among respondents with a positive family history of breast cancer compared to those with a negative family history of breast cancer. The odds of having a tumor size larger than 5cm at presentation were almost two times higher in patients with a positive family history as compared to those without a family history (adjusted OR = 1.786, 95% CI 1.211-2.484) (P-value .003). Women in Malaysia, despite having a positive family history of breast cancer, still present late at a mean age of 60 with a large tumor size of more than 5 cm, reflecting a lack of awareness. Breastfeeding does not protect women with a family history from developing breast cancer.

Adult Physical Activity and Breast Cancer Risk in Women with a Family History of Breast Cancer

BACKGROUND

Recreational physical activity has been consistently associated with reduced breast cancer risk. Less is known about how family history of breast cancer affects the association and whether it varies by menopausal status.

METHODS

The Sister Study is a cohort of 50,884 women who had a sister with breast cancer but no prior breast cancer themselves at enrollment. Women reported all recreational sport/exercise activities they participated in over the past 12 months. Hours/week and MET-hours/week of physical activity were considered in association with breast cancer risk. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated with Cox regression. Extent of family history, examined as a modifier, was characterized by a Bayesian score incorporating characteristics of the family structure.

RESULTS

During follow-up (average 8.4 years), 3,023 cases were diagnosed. Higher hours/week (HR_≥7vs<1 = 0.77; 95% CI, 0.66-0.90) and MET-hours/week (HR_quartile4vs1 = 0.75; 95% CI, 0.67-0.85) of physical activity were associated with reduced postmenopausal breast cancer risk. Hours/week and MET-hours/week were associated with suggestively increased premenopausal breast cancer risk (MET-hours/week HR_quartile4vs1 = 1.25; 95% CI, 0.98-1.60). Associations did not vary with extent of family history. However, the increased risk in premenopausal women may be limited to those with stronger family history.

CONCLUSIONS

In women with a family history of breast cancer, physical activity was associated with reduced postmenopausal, but not premenopausal, breast cancer risk and was not modified by extent of family history.

IMPACT

This was the first study to examine the association between physical activity and breast cancer risk in a large population with a family history of breast cancer.

The University of Wisconsin Breast Cancer Epidemiology Simulation Model: An Update

The University of Wisconsin Breast Cancer Epidemiology Simulation Model (UWBCS), also referred to as Model W, is a discrete-event microsimulation model that uses a systems engineering approach to replicate breast cancer epidemiology in the US over time. This population-based model simulates the lifetimes of individual women through 4 main model components: breast cancer natural history, detection, treatment, and mortality. A key feature of the UWBCS is that, in addition to specifying a population distribution in tumor growth rates, the model allows for heterogeneity in tumor behavior, with some tumors having limited malignant potential (i.e., would never become fatal in a woman's lifetime if left untreated) and some tumors being very aggressive based on metastatic spread early in their onset. The model is calibrated to Surveillance, Epidemiology, and End Results (SEER) breast cancer incidence and mortality data from 1975 to 2010, and cross-validated against data from the Wisconsin cancer reporting system. The UWBCS model generates detailed outputs including underlying disease states and observed clinical outcomes by age and calendar year, as well as costs, resource usage, and quality of life associated with screening and treatment. The UWBCS has been recently updated to account for differences in breast cancer detection, treatment, and survival by molecular subtypes (defined by ER/HER2 status), to reflect the recent advances in screening and treatment, and to consider a range of breast cancer risk factors, including breast density, race, body-mass-index, and the use of postmenopausal hormone therapy. Therefore, the model can evaluate novel screening strategies, such as risk-based screening, and can assess breast cancer outcomes by breast cancer molecular subtype. In this article, we describe the most up-to-date version of the UWBCS.

Common Model Inputs Used in CISNET Collaborative Breast Cancer Modeling

BACKGROUND

Since their inception in 2000, the Cancer Intervention and Surveillance Network (CISNET) breast cancer models have collaborated to use a nationally representative core of common input parameters to represent key components of breast cancer control in each model. Employment of common inputs permits greater ability to compare model output than when each model begins with different input parameters. The use of common inputs also enhances inferences about the results, and provides a range of reasonable results based on variations in model structure, assumptions, and methods of use of the input values. The common input data are updated for each analysis to ensure that they reflect the most current practice and knowledge about breast cancer. The common core of parameters includes population rates of births and deaths; age- and cohort-specific temporal rates of breast cancer incidence in the absence of screening and treatment; effects of risk factors on incidence trends; dissemination of plain film and digital mammography; screening test performance characteristics; stage or size distribution of screen-, interval-, and clinically- detected tumors by age; the joint distribution of ER/HER2 by age and stage; survival in the absence of screening and treatment by stage and molecular subtype; age-, stage-, and molecular subtype-specific therapy; dissemination and effectiveness of therapies over time; and competing non-breast cancer mortality.

METHOD AND RESULTS

In this paper, we summarize the methods and results for the common input values presently used in the CISNET breast cancer models, note assumptions made because of unobservable phenomena and/or unavailable data, and highlight plans for the development of future parameters.

CONCLUSION

These data are intended to enhance the transparency of the breast CISNET models.

Polymorphisms of long non-coding RNA HOTAIR with breast cancer susceptibility and clinical outcomes for a southeast Chinese Han population

Hox transcript antisense intergenic RNA (HOTAIR) is a well-known long non-coding RNA (lncRNA) which participates in tumorigenesis and progress of multiple cancers. However, the associations among polymorphisms on HOTAIR, breast cancer (BC) susceptibility and clinical outcomes have remained obscure. In this case-control study, we assessed the interaction between three lncRNA HOTAIR single nucleotide polymorphisms (SNPs) (rs1899663, rs4759314 and rs7958904) on the risk and clinical outcome of breast cancer in a Chinese Han population. In total, 969 breast cancer cases and 970 healthy controls were enrolled in this study. Associations among genotypes, BC risk and survival were evaluated by univariate and multivariate logistic regression to estimate the odds ratio (OR), hazard ratio (HR) and its 95% confidence interval (CI). The disease-free survival (DFS) and overall survival (OS) was calculated by the Kaplan–Meier method. We found that the T allele of rs1899663 and C allele of rs7958904 both achieved significant differences between cases and controls in the single locus analyses (P = 0.017 and 0.010, respectively). Multivariate analyses also revealed the rs1899663 TT genotype and rs7958904 CC genotype were both at higher risk of breast cancer compared with the GG homozygotes (OR = 2.08, 95% CI = 1.20–3.60 and OR = 1.45, 95% CI = 1.01–2.08, respectively). In survival analysis, we observed that the T allele of rs1899663 presented significant differences for both DFS (HR = 1.64, 95% CI = 1.12–2.40) and OS (HR = 2.10, 95% CI = 1.29–3.42) in younger subjects (age ≤ 40). Our findings may provide new insights into the associations among the genetic susceptibility, the fine classifications and the prognosis of breast cancer. Further studies with larger sample size and functional research should also be conducted to validate our findings and better elucidate the underlying biological mechanisms.

Alcohol and oestrogen metabolites in postmenopausal women in the Women's Health Initiative Observational Study

Background:

Alcohol consumption is associated with an increased risk of several cancers. Potential mechanisms include altered oestrogen metabolism. Parent oestrogens metabolise into alternate pathways of oestrogen metabolites that may have variable effects on cancer pathogenesis. We examined associations of alcohol consumption with circulating oestrogen/oestrogen metabolites in postmenopausal women in the Women’s Health Initiative (WHI)-Observational Study (OS).

Methods:

We conducted a cross-sectional analysis of prediagnosis ovarian/endometrial cancer case-control data within WHI-OS (N=1864). Alcohol consumption was measured by validated food frequency questionnaire. Fasting serum parent oestrogens/oestrogen metabolites were assayed using liquid chromatography tandem mass-spectrometry. Geometric mean analyte concentrations (GM, pmol l⁻¹) were calculated by alcohol category using inverse-probability weighted linear regression, adjusting for venepuncture age/year, race, smoking, body mass index, years since menopause, oral contraceptive duration, caffeine intake, and physical activity.

Results:

There was evidence for a positive association between alcohol consumption and oestrone, oestradiol and 2-hydroxylation oestrogen metabolite concentrations among menopausal hormone therapy (MHT) users. We observed an association between liquor consumption and parent oestrogens among non-MHT users, who consumed larger doses of liquor than MHT users.

Conclusions:

Among postmenopausal women, the association between alcohol intake and parent oestrogen, but not oestrogen metabolite concentrations, may be influenced by MHT and type of alcohol.

Age-Specific Indicators of a Healthy Lifestyle and Postmenopausal Breast Cancer

INTRODUCTION

Modifiable lifestyle factors have been consistently associated with breast cancer, and risk may vary by menopausal status. However, whether these associations vary according to age among postmenopausal women remains unresolved.

METHODS

Using postmenopausal women from a population-based case-control study (990 cases and 1006 frequency-matched controls), we conducted multivariable-adjusted unconditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for lifestyle factors (lifetime alcohol intake, body mass index [BMI] in the year before diagnosis, lifetime recreational physical activity [RPA], and nonsteroidal anti-inflammatory drug use) in association with breast cancer stratified by age (<65 vs. 65+). We examined estrogen-related subgroups by (1) further stratifying by hormone replacement therapy (HRT) use and (2) restricting cases to estrogen receptor (ER)+/progesterone receptor (PR)+ cancers.

RESULTS

Postmenopausal breast cancer incidence in women 65 years and older was positively associated with alcohol intake (OR = 1.79 for 15-30 g/day vs. nondrinkers, 95% CI: 1.03-3.12) and BMI (OR = 1.83 for BMI ≥30 vs. <25, 95% CI: 1.29-2.60), and inversely with RPA (OR = 0.69 for fourth quartile vs. inactive, 95% CI: 0.47-1.03). For postmenopausal women younger than 65, ORs were closer to the null. Tests for heterogeneity by age were significant at the p < 0.10 level for BMI and RPA, but not alcohol. Among older women, associations were stronger among never users of HRT and for those with ER+/PR+ cancers. The inverse associations with aspirin use did not differ by age.

CONCLUSIONS

Interventions targeting modifiable lifestyle factors may reduce the burden of postmenopausal breast cancer among older women.

Breastfeeding: a reproductive factor able to reduce the risk of luminal B breast cancer in premenopausal White women

In the medical literature, the role of breastfeeding and reproductive factors in the risk of breast carcinoma is still an open debate in premenopausal women. We highlight the role of breastfeeding and reproductive factors in luminal A and luminal B, the most frequent breast cancers. This case-control study analyzes a White premenopausal population of 286 breast cancer patients, divided into molecular subtypes, and 578 controls matched by age. Multivariate logistic regression models were used to assess the relationships of breastfeeding and other reproductive factors (age at menarche, parity, age at first pregnancy, number of children) with the risk of breast cancers. Among the variables examined, reproductive factors did not alter the risk of cancer, whereas breastfeeding up to 12 months was a significant protective factor against luminal B breast cancer (multivariate odds ratio: 0.22, 95% confidence interval: 0.09-0.59, P=0.002). In contrast, luminal A cases did not significantly correlate with breastfeeding or other reproductive factors. Breastfeeding up to 12 months is strongly protective against the more aggressive luminal B, but not against the less aggressive luminal A breast cancer in premenopausal White women.

Breast cancer in Mongolia: an increasingly important health policy issue

Breast cancer is a leading cause of cancer-related death for women in both developed and developing countries. The incidence and mortality of breast cancer in Mongolia, while low compared with other counties, has been increasing on an annual basis. In addition, in Mongolia, approximately 90% of the patients are diagnosed at a late stage, resulting in high mortality, with the majority of individuals diagnosed with breast cancer dying within 5 years of diagnosis. Breast cancer screening plays an important role in reducing mortality in Western countries and has been adopted by a number of Asian countries; however, no such approach exists in Mongolia. In a country of limited resources, implementation of expensive health strategies such as screening requires effective allocations of resources and the identification of the most effective imaging methods. This requirement relies on recent accurate data; however, at this time, there is a paucity of information around breast cancer in Mongolia. Until data around features of the disease are available, effective strategies to diagnose breast cancer that recognize the economic climate in Mongolia cannot be implemented and the impact of breast cancer is likely to increase.

Previous GWAS hits in relation to young-onset breast cancer

PURPOSE

Genome-wide association studies (GWAS) have identified dozens of single-nucleotide polymorphisms (SNPs) associated with breast cancer. Few studies focused on young-onset breast cancer, which exhibits etiologic and tumor-type differences from older-onset disease. Possible confounding by prenatal effects of the maternal genome has also not been considered.

METHODS

Using a family-based design for breast cancer before age 50, we assessed the relationship between breast cancer and 77 GWAS-identified breast cancer risk SNPs. We estimated relative risks (RR) for inherited and maternally mediated genetic effects. We also used published RR estimates to calculate genetic risk scores and model joint effects.

RESULTS

Seventeen of the candidate SNPs were nominally associated with young-onset breast cancer in our 1296 non-Hispanic white affected families (uncorrected p value <0.05). Top-ranked SNPs included rs3803662-A (TOX3, RR = 1.39; p = 7.0 × 10-6), rs12662670-G (ESR1, RR = 1.56; p = 5.7 × 10-4), rs2981579-A (FGFR2, RR = 1.24; p = 0.002), and rs999737-G (RAD51B, RR = 1.37; p = 0.003). No maternally mediated effects were found. A risk score based on all 77 SNPs indicated that their overall relationship to young-onset breast cancer risk was more than additive (additive-fit p = 2.2 × 10-7) and consistent with a multiplicative joint effect (multiplicative-fit p = 0.27). With the multiplicative formulation, the case sister's genetic risk score exceeded that of her unaffected sister in 59% of families.

CONCLUSIONS

The results of this family-based study indicate that no effects of previously identified risk SNPs were explained by prenatal effects of maternal variants. Many of the known breast cancer risk variants were associated with young-onset breast cancer, with evidence that TOX3, ESR1, FGFR2, and RAD51B are important for young-onset disease.

Tailoring Breast Cancer Screening Intervals by Breast Density and Risk for Women Aged 50 Years or Older: Collaborative Modeling of Screening Outcomes

BACKGROUND

Biennial screening is generally recommended for average-risk women aged 50 to 74 years, but tailored screening may provide greater benefits.

OBJECTIVE

To estimate outcomes for various screening intervals after age 50 years based on breast density and risk for breast cancer.

DESIGN

Collaborative simulation modeling using national incidence, breast density, and screening performance data.

SETTING

United States.

PATIENTS

Women aged 50 years or older with various combinations of breast density and relative risk (RR) of 1.0, 1.3, 2.0, or 4.0.

INTERVENTION

Annual, biennial, or triennial digital mammography screening from ages 50 to 74 years (vs. no screening) and ages 65 to 74 years (vs. biennial digital mammography from ages 50 to 64 years).

MEASUREMENTS

Lifetime breast cancer deaths, life expectancy and quality-adjusted life-years (QALYs), false-positive mammograms, benign biopsy results, overdiagnosis, cost-effectiveness, and ratio of false-positive results to breast cancer deaths averted.

RESULTS

Screening benefits and overdiagnosis increase with breast density and RR. False-positive mammograms and benign results on biopsy decrease with increasing risk. Among women with fatty breasts or scattered fibroglandular density and an RR of 1.0 or 1.3, breast cancer deaths averted were similar for triennial versus biennial screening for both age groups (50 to 74 years, median of 3.4 to 5.1 vs. 4.1 to 6.5 deaths averted; 65 to 74 years, median of 1.5 to 2.1 vs. 1.8 to 2.6 deaths averted). Breast cancer deaths averted increased with annual versus biennial screening for women aged 50 to 74 years at all levels of breast density and an RR of 4.0, and those aged 65 to 74 years with heterogeneously or extremely dense breasts and an RR of 4.0. However, harms were almost 2-fold higher. Triennial screening for the average-risk subgroup and annual screening for the highest-risk subgroup cost less than $100 000 per QALY gained.

LIMITATION

Models did not consider women younger than 50 years, those with an RR less than 1, or other imaging methods.

CONCLUSION

Average-risk women with low breast density undergoing triennial screening and higher-risk women with high breast density receiving annual screening will maintain a similar or better balance of benefits and harms than average-risk women receiving biennial screening.

PRIMARY FUNDING SOURCE

National Cancer Institute.

Expression of MMP and TIMP mRNA in Peripheral Blood Leukocytes of Patients with Invasive Ductal Carcinoma of the Breast

Purpose

An imbalance between matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) appears critical for tumor progression and metastasis. This study aimed to determine whether gene expression of MMP1, MMP2, MMP9, TIMP1 and TIMP3 and the MMP/TIMP expression ratio in peripheral blood leukocytes (PBLs) and the MMP1 and TIMP1 contents or MMP1/TIMP1 ratio in plasma were associated with clinicopathological characteristics in invasive ductal carcinoma (IDC) of the breast.

Materials and methods

Blood samples were collected from women newly diagnosed with IDC who had not received prior treatment (n = 102). Gene expression in PBLs was analyzed by quantitative real-time polymerase chain reaction. Concentrations of MMP1 and TIMP1 in plasma were measured using ELISA.

Results

In univariate analysis the expression levels of MMP2 and TIMP1 mRNA were significantly higher in premenopausal compared to postmenopausal patients (p<0.001 and p = 0.014, respectively). MMP2 mRNA expression negatively correlated with age (p<0.001, r = -0.43). We found that the MMP2/TIMP3 expression ratio was significantly higher in women after menopause (p = 0.007). The MMP2/TIMP1 expression ratio was higher in human epidermal growth factor receptor 2 (HER2)-positive patients (p = 0.022). Low-grade tumors had significantly lower MMP1/TIMP1 and MMP2/TIMP1 expression ratios (p = 0.047 and p = 0.048, respectively). TIMP1 plasma concentration was significantly higher in small tumors compared with T2-T3 tumors (p = 0.013).

Conclusions

These findings reveal an important association between tumor characteristics and expression ratios of MMP1/TIMP1 and MMP2/TIMP1 in PBLs and TIMP1 concentration in plasma. Menopausal status may influence the mRNA expression levels of MMP2 and TIMP1 as well as the MMP2/TIMP3 expression ratio in IDC of the breast.

The impact of breast cancer-specific birth cohort effects among younger and older Chinese populations

Historically low breast cancer incidence rates among Asian women have risen worldwide; purportedly due to the adoption of a "Western" life style among younger generations (i.e., the more recent birth cohorts). However, no study has simultaneously compared birth cohort effects between both younger and older women in different Asian and Western populations. Using cancer registry data from rural and urban China, Singapore and the United States (1990-2008), we estimated age-standardized incidence rates (ASR), annual percentage change (EAPC) in the ASR, net drifts, birth cohort specific incidence rates and cohort rate ratios (CRR). Younger (30-49 years, 1943-1977 birth cohorts) and older women (50-79 years; 1913-1957 birth cohorts) were assessed separately. CRRs among Chinese populations were estimated using birth cohort specific rates with US non-Hispanic white women (NHW) serving as the reference population with an assigned CRR of 1.0. We observed higher EAPCs and net drifts among those Chinese populations with lower ASRs. Similarly, we observed the most rapidly increasing cohort-specific incidence rates among those Chinese populations with the lowest baseline CRRs. Both trends were more significant among older than younger women. Average CRRs were 0.06-0.44 among older and 0.18-0.81 among younger women. Rapidly rising cohort specific rates have narrowed the historic disparity between Chinese and US NHW breast cancer populations particularly in regions with the lowest baseline rates and among older women. Future analytic studies are needed to investigate risk factors accounting for the rapid increase of breast cancer among older and younger women separately in Asian populations.

Collaborative Modeling of the Benefits and Harms Associated With Different U.S. Breast Cancer Screening Strategies

BACKGROUND

Controversy persists about optimal mammography screening strategies.

OBJECTIVE

To evaluate screening outcomes, taking into account advances in mammography and treatment of breast cancer.

DESIGN

Collaboration of 6 simulation models using national data on incidence, digital mammography performance, treatment effects, and other-cause mortality.

SETTING

United States.

PATIENTS

Average-risk U.S. female population and subgroups with varying risk, breast density, or comorbidity.

INTERVENTION

Eight strategies differing by age at which screening starts (40, 45, or 50 years) and screening interval (annual, biennial, and hybrid [annual for women in their 40s and biennial thereafter]). All strategies assumed 100% adherence and stopped at age 74 years.

MEASUREMENTS

Benefits (breast cancer-specific mortality reduction, breast cancer deaths averted, life-years, and quality-adjusted life-years); number of mammograms used; harms (false-positive results, benign biopsies, and overdiagnosis); and ratios of harms (or use) and benefits (efficiency) per 1000 screens.

RESULTS

Biennial strategies were consistently the most efficient for average-risk women. Biennial screening from age 50 to 74 years avoided a median of 7 breast cancer deaths versus no screening; annual screening from age 40 to 74 years avoided an additional 3 deaths, but yielded 1988 more false-positive results and 11 more overdiagnoses per 1000 women screened. Annual screening from age 50 to 74 years was inefficient (similar benefits, but more harms than other strategies). For groups with a 2- to 4-fold increased risk, annual screening from age 40 years had similar harms and benefits as screening average-risk women biennially from 50 to 74 years. For groups with moderate or severe comorbidity, screening could stop at age 66 to 68 years.

LIMITATION

Other imaging technologies, polygenic risk, and nonadherence were not considered.

CONCLUSION

Biennial screening for breast cancer is efficient for average-risk populations. Decisions about starting ages and intervals will depend on population characteristics and the decision makers' weight given to the harms and benefits of screening.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Lifetime use of nonsteroidal anti-inflammatory drugs and breast cancer risk: results from a prospective study of women with a sister with breast cancer

Background

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to inhibit several pathways in experimental models of breast carcinogenesis, but epidemiological evidence remains insufficient to support their use for breast cancer prevention. We examined the association between use of NSAIDs and breast cancer risk in a prospective cohort.

Methods

The Sister Study is a prospective cohort study of women who had a sister(s) with breast cancer. As of December 2013, 2118 incident breast cancers were ascertained from 50,884 women enrolled between 2003 and 2009. Lifetime history of NSAID use was estimated from self-reported data in pill-years, with 1 pill per week for a year equivalent to 1 pill-year. Cox regression models were used to estimate hazard ratios (HRs) of breast cancer in relation to pill-years of use for different NSAIDs, with adjustment for potential confounders.

Results

In the full cohort, although there was some evidence that use of non-aspirin, non-COXib NSAIDs was associated with lower breast cancer risk, there was little evidence of overall association for most categories of NSAID use. Among postmenopausal women NSAID use was not associated with reduced risk of breast cancer. However, among premenopausal women there was significantly reduced risk for any NSAID (HR_4vs1 = 0.66, 95 % CI: 0.50–0.87) and specifically for aspirin (HR_4vs1 = 0.57, 95 % CI: 0.33–0.98), with small, but non-significant reductions in risk for other drug classes.

Conclusion

Women with a sister with breast cancer are themselves at increased risk and might benefit the most from chemoprevention. Although there was little evidence of protective effect from NSAIDs in the overall cohort of women or among the subset who are postmenopausal, there is intriguing evidence that NSAID use, particularly aspirin, may reduce risk among premenopausal women.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1979-1) contains supplementary material, which is available to authorized users.

Breast cancer prevention knowledge, beliefs, and information sources between non-Hispanic and Hispanic college women for risk reduction focus

Although growing research focuses on breast cancer screenings, little is known about breast cancer prevention with risk reduction awareness for ethnic differences among college-age women. This study examined breast cancer prevention knowledge, beliefs, and information sources between non-Hispanic and Hispanic college women. Using a cross-sectional study, women at a university in the Southwest completed a 51-item survey about breast cancer risk factors, beliefs, and media and interpersonal information sources. The study was guided by McGuire's Input Output Persuasion Model. Of the 546 participants, non-Hispanic college women (n = 277) and Hispanic college women (n = 269) reported similar basic knowledge levels of modifiable breast cancer risk factors for alcohol consumption (52 %), obesity (72 %), childbearing after age 35 (63 %), and menopausal hormone therapy (68 %) using bivariate analyses. Most common information sources were Internet (75 %), magazines (69 %), provider (76 %) and friends (61 %). Least common sources were radio (44 %), newspapers (34 %), and mothers (36 %). Non-Hispanic college women with breast cancer family history were more likely to receive information from providers, friends, and mothers. Hispanic college women with a breast cancer family history were more likely to receive information from their mothers. Breast cancer prevention education for college women is needed to include risk reduction for modifiable health behavior changes as a new focus. Health professionals may target college women with more information sources including the Internet or apps.

A comparison between different prediction models for invasive breast cancer occurrence in the French E3N cohort

Breast cancer remains a global health concern with a lack of high discriminating prediction models. The k-nearest-neighbor algorithm (kNN) estimates individual risks using an intuitive tool. This study compares the performances of this approach with the Cox and the Gail models for the 5-year breast cancer risk prediction. The study included 64,995 women from the French E3N prospective cohort. The sample was divided into a learning (N = 51,821) series to learn the models using fivefold cross-validation and a validation (N = 13,174) series to evaluate them. The area under the receiver operating characteristic curve (AUC) and the expected over observed number of cases (E/O) ratio were estimated. In the two series, 393 and 78 premenopausal and 537 and 98 postmenopausal breast cancers were diagnosed. The discrimination values of the best combinations of predictors obtained from cross-validation ranged from 0.59 to 0.60. In the validation series, the AUC values in premenopausal and postmenopausal women were 0.583 [0.520; 0.646] and 0.621 [0.563; 0.679] using the kNN and 0.565 [0.500; 0.631] and 0.617 [0.561; 0.673] using the Cox model. The E/O ratios were 1.26 and 1.28 in premenopausal women and 1.44 and 1.40 in postmenopausal women. The applied Gail model provided AUC values of 0.614 [0.554; 0.675] and 0.549 [0.495; 0.604] and E/O ratios of 0.78 and 1.12. This study shows that the prediction performances differed according to menopausal status when using parametric statistical tools. The k-nearest-neighbor approach performed well, and discrimination was improved in postmenopausal women compared with the Gail model.

Predicting invasive breast cancer versus DCIS in different age groups

Background

Increasing focus on potentially unnecessary diagnosis and treatment of certain breast cancers prompted our investigation of whether clinical and mammographic features predictive of invasive breast cancer versus ductal carcinoma in situ (DCIS) differ by age.

Methods

We analyzed 1,475 malignant breast biopsies, 1,063 invasive and 412 DCIS, from 35,871 prospectively collected consecutive diagnostic mammograms interpreted at University of California, San Francisco between 1/6/1997 and 6/29/2007. We constructed three logistic regression models to predict the probability of invasive cancer versus DCIS for the following groups: women ≥ 65 (older group), women 50–64 (middle age group), and women < 50 (younger group). We identified significant predictors and measured the performance in all models using area under the receiver operating characteristic curve (AUC).

Results

The models for older and the middle age groups performed significantly better than the model for younger group (AUC = 0.848 vs, 0.778; p = 0.049 and AUC = 0.851 vs, 0.778; p = 0.022, respectively). Palpability and principal mammographic finding were significant predictors in distinguishing invasive from DCIS in all age groups. Family history of breast cancer, mass shape and mass margins were significant positive predictors of invasive cancer in the older group whereas calcification distribution was a negative predictor of invasive cancer (i.e. predicted DCIS). In the middle age group—mass margins, and in the younger group—mass size were positive predictors of invasive cancer.

Conclusions

Clinical and mammographic finding features predict invasive breast cancer versus DCIS better in older women than younger women. Specific predictive variables differ based on age.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-584) contains supplementary material, which is available to authorized users.