Cigarette smoking and mammographic density in the Danish Diet,Cancer and Health cohort

Purpose

Smoking before first childbirth increases breast cancer risk, but the biological mechanism remains unknown and may involve mammographic density (MD), one of the strongest biomarkers of breast cancer risk. We aimed to examine whether active smoking and passive smoking were associated with MD.

Methods

For the 5,356 women (4,489 postmenopausal) from the Danish Diet, Cancer and Health cohort (1993–1997) who attended mammographic screening in Copenhagen (1993–2001), we used MD (mixed/dense or fatty) assessed at the first screening after cohort entry. Active smoking (status, duration, and intensity) and passive smoking were assessed at cohort baseline (1993–1997) via questionnaire, together with other breast cancer risk factors. Logistic regression was used to estimate associations (odds ratios, 95 % confidence intervals) between smoking and MD, adjusting for confounders.

Results

Two thousand and twenty-six (56.5 %) women had mixed/dense MD, 2,214 (41.4 %) were current, and 1,175 (21.9 %) former smokers. Current smokers had significantly lower odds (0.86, 0.75–0.99) of having mixed/dense MD compared to never smokers, while former smoking was not associated with MD. Inverse association between smoking and MD was strongest in women who initiated smoking before age of 16 years (0.79, 0.64–0.96), smoked ≥15 cigarettes/day (0.83, 0.71–0.98), smoked ≥5 pack-years (0.62, 0.43–0.89), smoked >30 years (0.86, 0.75–0.99), and smoked ≥11 years before first childbirth (0.70, 0.51–0.96). Association between smoking and MD diminished after smoking cessation, with increased odds of having mixed/dense breasts in women who quit smoking >20 years ago as compared to current smokers (1.37, 1.01–1.67). There was no association between passive smoking and MD.

Conclusions

We found an inverse association between active smoking and MD.

     

Diabetes,diabetes treatment,and mammographic density in Danish Diet,Cancer, and Health cohort

Purpose

We examined whether diabetes and diabetes treatment are associated with MD in a cohort study of Danish women above age of 50 years.

Methods

Study cohort consisted of 5,644 women (4,500 postmenopausal) who participated in the Danish Diet, Cancer, and Health cohort (1993–1997) and subsequently attended mammographic screening in Copenhagen (1993–2001). We used MD assessed at the first screening after the cohort entry, defined as mixed/dense or fatty. Diabetes diagnoses and diabetes treatments (diet, insulin, or oral antidiabetic agents) were self-reported at the time of recruitment (1993–1997). The association between MD and diabetes was analyzed by logistic regression adjusted for potential confounders. Effect modification by menopausal status and body mass index (BMI) was performed by introducing an interaction term into the model and tested by Wald test.

Results

Of 5,644 women with mean age of 56 years, 137 (2.4%) had diabetes and 3,180 (56.3%) had mixed/dense breasts. Having diabetes was significantly inversely associated with having mixed/dense breasts, in both, the crude model (odds ratio; 95% confidence interval: 0.33; 0.23–0.48), and after adjustment for adiposity and other risk factors (0.61; 0.40–0.92). Similar inverse associations were observed for 44 women who controlled diabetes by diet only and did not receive any medication (0.56; 0.27–1.14), and 62 who took oral antidiabetic agents only for diabetes (0.59; 0.32–1.09), while women taking insulin had increased odds of mixed/dense breasts (2.08; 0.68–6.35). There was no effect modification of these associations by menopausal status or BMI.

Conclusions

Having diabetes controlled by diet or oral antidiabetic agents is associated with a decrease in MD, whereas taking insulin is associated with an increase in MD.

     

Regular physical activity and mammographic density: a cohort study

Purpose

Physical activity is a modifiable lifestyle risk factor in prevention of breast cancer. Mammographic density (MD) is a strong risk factor for breast cancer. We investigate the association of regular physical activity with MD.

Methods

For 5,703 women who participated in the Danish Diet, Cancer and Health cohort (1993–1997) and attended mammographic screening in Copenhagen (1993–2001), MD was assessed at the first screening after cohort entry. MD was defined as a binary measure equivalent to Breast Imaging Report and Data System (BI-RADS) to either mixed/dense or fatty. Participation and duration in physical activities (hours/week) and confounders were assessed by questionnaire at cohort baseline. Logistic regression was used to estimate associations [odds ratios (OR), 95% confidence intervals (CI)] between physical activities and MD.

Results

56.3% of women had mixed/dense MD and 47.6% participated in sports. We found a significant positive association between participation in sports (OR 1.15; 95% CI 1.03–1.28) and do-it-yourself work (1.17; 1.05–1.31) and odds of having mixed/dense MD, which attenuated (1.08; 0.96–1.22 and 1.11; 0.98–1.25, respectively) in a fully adjusted model. No associations were found for time spent on physical activities or total metabolic equivalent of task scores with MD, in fully adjusted models. There was no effect modification of association between any physical activities and MD by obesity (BMI?≥?30 kg/m²) and menopause status.

Conclusions

Physical activity is not a determinant of MD.

     

Residential traffic noise and mammographic breast density in the Diet,Cancer, and Health cohort

Objectives

Traffic is the most important source of community noise, and it has been proposed to be associated with a range of disease outcomes, including breast cancer. As mammographic breast density (MD) is one of the strongest risk factors for developing breast cancer, the present study investigated whether there is an association between residential exposure to traffic noise and MD in a Danish cohort.

Methods

We included women with reproductive and lifestyle information available from the Diet, Cancer, and Health cohort, who also participated in the Copenhagen Mammography Screening Programme (n?=?5,260). Present and historical addresses from 1987 to 2011 were found in national registries, and traffic noise was modeled 5 years before mammogram. Analyses between residential traffic noise and MD were performed using logistic regression.

Results

We found no association between residential road and railway noise exposure 5 years before mammogram, and having a mixed/dense versus a fatty mammogram, and no interaction with menopausal status, BMI, HRT use, and railway noise exposure, for analyses on road traffic noise.

Conclusion

The present study does not suggest an association between residential traffic noise exposure and subsequent MD in a cohort of middle-aged Danish women.

     

Digital volumetric measurement of mammographic density and the risk of overlooking cancer in Japanese women

Background

Breast density often affects cancer detection via mammography (MMG). Because of this, additional tests are recommended for women with dense breasts. This study aimed to reveal trends in breast density among Japanese women and determine whether differences in breast density differentially affected the detection of abnormalities via MMG.

Methods

We retrospectively analyzed 397 control women who underwent MMG screening as well as 269 patients who underwent surgery for breast cancer for whom preoperative MMG data were available. VolparaDensity? (Volpara), a three-dimensional image analysis software with high reproducibility, was used to calculate breast density. Breasts were categorized according to the volumetric density grade (VDG), a measure of the percentage of dense tissue. The associations between age, VDG, and MMG density categories were analyzed.

Results

In the control group, 78% of women had dense breasts, while in the breast cancer group, 87% of patients had dense breasts. One of 36 patients with non-dense breasts (2.7%) was classified as category 1 or 2 (C-1 or C-2), indicating that abnormal findings could not be detected by MMG. The proportion of patients with breast cancer who had dense breasts and were classified as C-1 or C-2 was as high as 22.3%.

Conclusions

The proportions of Japanese women with dense breasts were high. In addition, the false-negative rate for women with dense breasts was also high. Owing to this, Japanese women with dense breasts may need to commonly undergo additional tests to ensure detection of breast cancer in the screening MMG.

     

Does mammographic density mediate risk factor associations with breast cancer? An analysis by tumor characteristics

Background

Though mammographic density (MD) has been proposed as an intermediate marker of breast cancer risk, few studies have examined whether the associations between breast cancer risk factors and risk are mediated by MD, particularly by tumor characteristics.

Methods

Our study population included 3392 cases (1105 premenopausal) and 8882 (3192 premenopausal) controls from four case–control studies. For established risk factors, we estimated the percent of the total risk factor association with breast cancer that was mediated by percent MD (secondarily, by dense area and non-dense area) for invasive breast cancer as well as for subtypes defined by the estrogen receptor (ER+/ER?), progesterone receptor (PR+/PR?), and HER2 (HER2+/HER2?). Analyses were conducted separately in pre- and postmenopausal women.

Results

Positive associations between prior breast biopsy and risk of invasive breast cancer as well as all subtypes were partially mediated by percent MD in pre- and postmenopausal women (percent mediated?=?11–27%, p?≤?0.02). In postmenopausal women, nulliparity and hormone therapy use were positively associated with invasive, ER+?, PR+?, and HER2? breast cancer; percent MD partially mediated these associations (percent mediated?≥?31%, p?≤?0.02). Further, among postmenopausal women, percent MD partially mediated the positive association between later age at first birth and invasive as well as ER+?breast cancer (percent mediated?=?16%, p?≤?0.05).

Conclusion

Percent MD partially mediated the associations between breast biopsy, nulliparity, age at first birth, and hormone therapy with risk of breast cancer, particularly among postmenopausal women, suggesting that these risk factors at least partially influence breast cancer risk through changes in breast tissue composition.

     

Association between lifestyle,menstrual/reproductive history,and histological factors and risk of breast cancer in women biopsied for benign breast disease

Purpose

Women with benign breast disease (BBD) have an increased risk of subsequent breast cancer. However, whether conventional breast cancer risk factors influence risk of breast cancer among women with BBD is unclear. In this study, we investigated the associations of lifestyle, menstrual/reproductive, and histological factors with risk of breast cancer among women biopsied for BBD.

Methods

We conducted a case–control study, nested within a cohort of 15,395 women biopsied for BBD at Kaiser Permanente Northwest between 1971 and 2006. Cases were women who developed a subsequent invasive breast cancer during follow-up; controls were individually matched to cases on age at BBD diagnosis. A total of 526 case–control pairs were included in the study. We calculated crude and multivariable OR and 95% CI for the associations between lifestyle, menstrual/reproductive, and histological factors and breast cancer risk using conditional logistic regression.

Results

Compared to premenopausal women, postmenopausal women had reduced risk of subsequent breast cancer (OR 0.60; 95% CI 0.39–0.94), whereas women who ever used hormone replacement therapy (HRT) had increased risk (OR 3.61; 95% CI 1.68–7.75), as did women whose BBD lesion showed atypical hyperplasia (OR 5.56; 95% CI 2.05–15.06). Smoking, BMI, early menarche, multiparity (≥4), history of oophorectomy, and extent of lobular involution were not associated with risk of breast cancer.

Conclusion

This study suggests that use of HRT and having atypical hyperplasia are associated with increased risk of breast cancer among women with BBD, while postmenopausal women with BBD have a reduced risk.

     

Alcohol consumption and mammographic density in the Danish Diet,Cancer and Health cohort

Purpose

We examined the association between alcohol consumption and mammographic density (MD) considering in detail the time of exposure and the type of alcohol.

Methods

Of 5,356 women (4,489 post-menopausal) from the Danish Diet, Cancer and Health cohort (1993–1997) who attended mammographic screening in Copenhagen (1993–2001), we used MD (mixed/dense or fatty) assessed at the first screening after cohort entry. Alcohol consumption was assessed at the time of recruitment. Logistic regression was used to estimate associations [odds ratios (OR), 95% confidence intervals (CI)] between alcohol consumption and MD.

Results

The mean age was 56.2 years, 56.5% of women had mixed/dense MD, and 91.8% were alcohol consumers. There was no association between current alcohol consumption and MD at baseline (age 50–65, on average 1 year before MD assessment) neither between age at drinking initiation and MD, in the fully adjusted model. There was a borderline statistically significantly increased OR of having mixed/dense MD in women who consumed?>?7 drinks/week at age 20–29 (1.31, 95% CI 1.00–1.72) compared to non-drinkers in this age group, and no effect of drinking at age 30–39, 40–49 or after >?50 years, when adjusting for current drinking. However, when considering different types of alcohol, drinking spirits at age 20–29 was positively associated with mixed/dense breast (3–7 drinks/week: OR 1.74, 95% CI 1.12–2.72); >7 drinks/week: (OR 1.76, 95% CI 0.73–4.23). No consistent pattern was found with beer, wine, or fortified wine.

Conclusions

We found higher MD among women with high alcohol consumption in early adulthood (ages 20–29), in those drinking spirits.

     

Aspirin use is associated with lower mammographic density in a large screening cohort

Background

Observational and biologic studies suggest that aspirin is a promising prevention therapy for breast cancer. However, clinical trials to date have not corroborated this evidence, potentially due to study design. We evaluated the effect of aspirin on mammographic density (MD), an established modifiable risk factor for breast cancer.

Methods

Electronic medical records from the University of Pennsylvania were evaluated for women who underwent screening mammography, saw their primary care provider, and had a confirmed list of medications during 2012–2013. Logistic regression was performed to test for associations between clinically recorded MD and aspirin use, after adjusting for age, body mass index (BMI), and ethnicity.

Results

We identified 26,000 eligible women. Mean age was 57.3, mean BMI was 28.9 kg/m², 41% were African American, and 19.7% reported current aspirin use. Aspirin users were significantly older and had higher BMI. There was an independent, inverse association between aspirin use and MD (P _trend < 0.001). Women with extremely dense breasts were less likely to be aspirin users than women with scattered fibroglandular density (OR 0.73; 95% CI 0.57–0.93). This association was stronger for younger women (P = 0.0002) and for African Americans (P = 0.011). The likelihood of having dense breasts decreased with aspirin dose (P _trend = 0.007), suggesting a dose response.

Conclusions

We demonstrate an independent association between aspirin use and lower MD in a large, diverse screening cohort. This association was stronger for younger and African American women: two groups at greater risk for ER? breast cancer. These results contribute to the importance of investigating aspirin for breast cancer prevention.

     

Assessing within-woman changes in mammographic density: a comparison of fully versus semi-automated area-based approaches

Background

Mammographic density (MD) varies throughout a woman’s life. We compared the performance of a fully automated (ImageJ-based) method to the observer-dependent Cumulus approach in the assessment of within-woman changes in MD over time.

Methods

MD was assessed in annual pre-diagnostic films (from age 40 to early 50s) from 313 breast cancer cases and 452 matched controls using Cumulus (left medio-lateral oblique (MLO) readings) and the ImageJ-based method (mean left–right MLO readings). Linear mixed models were used to compare within-woman changes in MD among controls. Associations between individual-specific MD trajectories and breast cancer were examined using conditional logistic regression.

Results

The age-related trajectories predicted by Cumulus and the ImageJ-based method were similar for all MD measures, except that the ImageJ-based method yielded slightly higher (by 2.54 %, 95 % CI 2.07 %, 3.00 %) estimates for percent MD. For both methods, the yearly rate of change in percent MD was twice faster after menopause than before, and higher BMI was associated with lower mean percent MD, but not associated with rate of change. Both methods yielded similar associations of individual-specific MD trajectories with breast cancer risk.

Conclusions

The ImageJ-based method is a valid fully automated alternative to Cumulus for measuring within-woman changes in MD in digitized films. The Age Trial is registered as an International Standard Randomized Controlled Trial, number ISRCTN24647151.

     

Diagnostic accuracy of contrast-enhanced spectral mammography in comparison to conventional full-field digital mammography in a population of women with dense breasts

Background

Contrast-enhanced spectral mammography to compare clinical efficacy of contrast-enhanced spectral mammography (CESM) and conventional digital mammography (MMG) with histopathology as gold standard in dense breasts.

Patients and methods

A total of 143 breasts of 72 women who underwent CESM and MMG between 2011 and 2014 at Showa University Hospital were analyzed.

Results

129 (90.2 %) of 143 breasts revealed dense breasts on MMG. 58 (40.6 %) of 143 breasts were diagnosed with breast cancer at histopathology. The remaining 85 breasts were diagnosed with benign findings after image assessments and/or core needle biopsy. CESM revealed 8 false-negative cases among 58 breast cancer cases (sensitivity 86.2 %) and 5 false-positive cases (specificity 94.1 %). Accuracy was 90.9 %. Conventional MMG was assessed true positive in 31 of 58 breast cancer cases (sensitivity 53.4 %) and false positive in 12 cases (specificity 85.9 %). Accuracy was 72.7 %. Sensitivity (p < 0.001), specificity (p = 0.016) and accuracy (p < 0.001) were significantly higher on CESM compared to MMG. MMG missed malignancy in 27 breasts. Of these, 25 were dense breasts. Of these 25, 20 (80.0 %) breasts were positive on CESM.

Conclusion

These findings suggest that CESM offers superior clinical performance compared to MMG. Use of CESM may decrease false negatives especially for women with dense breasts.

     

Breast Density and the Importance of Supplemental Screening

Purpose of Review

Mammographically dense breast tissue raises the risk of developing breast cancer and makes detection of breast cancer more difficult using standard of care mammography. This paper seeks to outline the evidence behind these risks and highlight the importance of informing patients, and their clinicians, of their density status. Solutions are also offered for improved detection in cancer screening in this population.

Recent Findings

Many states now require density information be conveyed to the patient. When performed in addition to screening mammography, supplemental screening methods (including tomosynthesis, ultrasound, and especially MRI) have demonstrated markedly improved rates of cancer detection in the dense screening population. However, only six states mandate insurance coverage for supplemental screening.

Summary

Increased breast density inherently raises the risk of breast cancer and reduces mammographic sensitivity. It is essential that women with dense breasts are notified of these hazards and provided with additional screening methods to aid in early detection.

     

Quantification of masking risk in screening mammography with volumetric breast density maps

Purpose

Fibroglandular tissue may mask breast cancers, thereby reducing the sensitivity of mammography. Here, we investigate methods for identification of women at high risk of a masked tumor, who could benefit from additional imaging.

Methods

The last negative screening mammograms of 111 women with interval cancer (IC) within 12 months after the examination and 1110 selected normal screening exams from women without cancer were used. From the mammograms, volumetric breast density maps were computed, which provide the dense tissue thickness for each pixel location. With these maps, three measurements were derived: (1) percent dense volume (PDV), (2) percent area where dense tissue thickness exceeds 1 cm (PDA), and (3) dense tissue masking model (DTMM). Breast density was scored by a breast radiologist using BI-RADS. Women with heterogeneously and extremely dense breasts were considered at high masking risk. For each masking measure, mammograms were divided into a high- and low-risk category such that the same proportion of the controls is at high masking risk as with BI-RADS.

Results

Of the women with IC, 66.1, 71.9, 69.2, and 63.0% were categorized to be at high masking risk with PDV, PDA, DTMM, and BI-RADS, respectively, against 38.5% of the controls. The proportion of IC at high masking risk is statistically significantly different between BI-RADS and PDA (p-value 0.022). Differences between BI-RADS and PDV, or BI-RADS and DTMM, are not statistically significant.

Conclusion

Measures based on density maps, and in particular PDA, are promising tools to identify women at high risk for a masked cancer.

     

Gestational diabetes,type II diabetes,and mammographic breast density in a U.S. racially diverse population screened for breast cancer

Purpose

Type II diabetes mellitus (T2DM) has consistently been associated with an increased risk of breast cancer, but the association of gestational diabetes mellitus (GDM) with breast cancer is less clear. T2DM and GDM may influence breast cancer risk through mammographic breast density, a strong risk factor for breast cancer. We examined whether T2DM and GDM are associated with higher mammographic breast density in a largely racial/ethnic minority sample.

Methods

We collected digital mammograms, anthropometric measures, and interview data from 511 racially diverse women recruited during screening mammography appointments between 2012 and 2016 (mean age 51 years; 70% Hispanic). We examined the associations of self-reported GDM, T2DM, and medication use (metformin and insulin) with mammographic breast density, measured as percent and area of dense tissue using Cumulus software.

Results

In multivariable linear regression models, history of T2DM and/or GDM and length of time since diagnosis were not associated with percent density or dense breast area, either before or after adjustment for current BMI. Use of metformin in diabetic women was associated with lower percent density (β?=???5.73, 95% CI ??10.27, ??1.19), only before adjusting for BMI. These associations were not modified by menopausal status.

Conclusions

Our results do not support associations between T2DM and/or GDM and higher amount of mammographically dense breast tissue, suggesting that the mechanism linking diabetes with breast cancer risk may not include mammographic breast density in midlife.

     

A population-based audit of ethnicity and breast cancer risk in one general practice catchment area in North London,UK: implications for practice

Objectives

To conduct a pilot population-based study within a general practice catchment area to determine whether the incidence of breast cancer was increased in the Ashkenazi population.

Design

Population-based cohort study.

Setting

A single general practice catchment area in North London.

Participants

1947 women over the age of 16 who responded to a questionnaire about ethnicity and breast cancer.

Main outcome measures

Incidence of breast cancer, ethnicity.

Results

This study showed a 1.5-fold (95% CI 0.93–2.39) increase in breast cancer risk in the Ashkenazim compared with the non-Ashkenazi white population. The increased incidence was for both premenopausal and postmenopausal breast cancer (expected incidence pre:post is 1:4 whereas in the Ashkenazim it was 1:1; 51 and 52% of cases respectively). This increase was not shown in the Sephardim. Asians had a reduction in incidence (OR = 0.44; 95% CI 0.10–1.89). Results were adjusted for other risk factors for breast cancer.

Conclusion

This study showed a 1.5-fold increase in breast cancer rates in Ashkenazim compared with the non-Jewish white population when adjusted for age (i.e. corrections were made to allow comparison of age groups) and this is not observed in the Sephardic population. The proportion of premenopausal breast cancer was just over double that of the general population. This is the first general practice population-based study in the UK to address this issue and has implications for general practitioners who care for patients from the Ashkenazi community.

     

The need for supplemental breast cancer screening modalities: a perspective of population-based breast cancer screening programs in Japan

Purpose

This article discusses possible supplemental breast cancer screening modalities for younger women with dense breasts from a perspective of population-based breast cancer screening program in Japan.

Conclusion

Supplemental breast cancer screening modalities have been proposed to increase the sensitivity and detection rates of early stage breast cancer in women with dense breasts; however, there are no global guidelines that recommend the use of supplemental breast cancer screening modalities in such women. Also, no criterion standard exists for breast density assessment. Based on the current situation of breast imaging in Japan, the possible supplemental breast cancer screening modalities are ultrasonography, digital breast tomosynthesis, and breast magnetic resonance imaging. An appropriate population-based breast cancer screening program based on the balance between cost and benefit should be a high priority. Further research based on evidence-based medicine is encouraged. It is very important that the ethnicity, workforce, workflow, and resources for breast cancer screening in each country should be considered when considering supplemental breast cancer screening modalities for women with dense breasts.

     

Active smoking and risk of Luminal and Basal-like breast cancer subtypes in the Carolina Breast Cancer Study

Purpose

Growing evidence suggests an association between active cigarette smoking and increased breast cancer risk. However, the weak magnitude of association and conflicting results have yielded uncertainty and it is unknown whether associations differ by breast cancer subtype.

Methods

Using population-based case–control data from phases I and II of the Carolina Breast Cancer Study, we examined associations between self-reported measures of smoking and risk of Luminal and Basal-like breast cancers. We used logistic regression models to estimate case–control odds ratios (OR) and 95 % confidence intervals (CI).

Results

Ever smoking (current and former) was associated with a weakly increased risk of Luminal breast cancer (OR 1.12, 95 % CI 0.92–1.36) and was not associated with risk of Basal-like breast cancer (OR 0.96, 95 % CI 0.69–1.32). Similarly, smoking duration of more than 20 years was associated with increased risk of Luminal (OR 1.51, 95 % CI 1.19–1.93), but not Basal-like breast cancer (OR 0.90, 95 % CI 0.57–1.43). When stratified by race, elevated odds ratios between smoking and Luminal breast cancer risk were found among black women across multiple exposure measures (ever smoking, duration, and dose); conversely, among white women odds ratios were attenuated or null.

Conclusions

Results from our study demonstrate a positive association between smoking and Luminal breast cancer risk, particularly among black women and women with long smoking histories. Addressing breast cancer heterogeneity in studies of smoking and breast cancer risk may elucidate associations masked in prior studies.

     

Predictors associated with MRI surveillance screening in women with a personal history of unilateral breast cancer but without a genetic predisposition for future contralateral breast cancer

Purpose

For women with a personal history of breast cancer (PHBC), no validated mechanisms exist to calculate future contralateral breast cancer (CBC) risk. The Manchester risk stratification guidelines were developed to evaluate CBC risk in women with a PHBC, primarily for surgical decision making. This tool may be informative for the use of MRI screening, as CBC risk is an assumed consideration for high-risk surveillance.

Methods

Three hundred twenty-two women with a PHBC were treated with unilateral surgery within our multidisciplinary breast clinic. We calculated lifetime CBC risk using the Manchester tool, which incorporates age at diagnosis, family history, genetic mutation status, estrogen receptor positivity, and endocrine therapy use. Univariate and multivariate logistic regression analyses (UVA/MVA) were performed, evaluating whether CBC risk predicted MRI surveillance.

Results

For women with invasive disease undergoing MRI surveillance, 66% had low, 23% above-average, and 11% moderate/high risk for CBC. On MVA, previous mammography-occult breast cancer [odds ratio (OR) 18.95, p < 0.0001], endocrine therapy use (OR 3.89, p = 0.009), dense breast tissue (OR 3.69, p = 0.0007), mastectomy versus lumpectomy (OR 3.12, p = 0.0041), and CBC risk (OR 3.17 for every 10% increase, p = 0.0002) were associated with MRI surveillance. No pathologic factors increasing ipsilateral breast cancer recurrence were significant on MVA.

Conclusions

Although CBC risk predicted MRI surveillance, 89% with invasive disease undergoing MRI had <20% calculated CBC risk. Concerns related to future breast cancer detectability (dense breasts and/or previous mammography-occult disease) predominate decision making. Pathologic factors important for determining ipsilateral recurrence risk, aside from age, were not associated with MRI surveillance.

     

Percent mammographic density prediction: development of a model in the nurses’ health studies

Purpose

To develop a model to predict percent mammographic density (MD) using questionnaire data and mammograms from controls in the Nurses’ Health Studies’ nested breast cancer case–control studies. Further, we assessed the association between both measured and predicted percent MD and breast cancer risk.

Methods

Using data from 2,955 controls, we assessed several variables as potential predictors. We randomly divided our dataset into a training dataset (two-thirds of the dataset) and a testing dataset (one-third of the dataset). We used stepwise linear regression to identify the subset of variables that were most predictive. Next, we examined the correlation between measured and predicted percent MD in the testing dataset and computed the r ² in the total dataset. We used logistic regression to examine the association between measured and predicted percent MD and breast cancer risk.

Results

In the training dataset, several variables were selected for inclusion, including age, body mass index, and parity, among others. In the testing dataset, the Spearman correlation coefficient between predicted and measured percent MD was 0.61. As the prediction model performed well in the testing dataset, we developed the final model in the total dataset. The final prediction model explained 41% of the variability in percent MD. Both measured and predicted percent MD were similarly associated with breast cancer risk adjusting for age, menopausal status, and hormone use (OR per five unit increase = 1.09 for both).

Conclusion

These results suggest that predicted percent MD may be useful for research studies in which mammograms are unavailable.

     

Tree nut,peanut, and peanut butter intake and risk of postmenopausal breast cancer: The Netherlands Cohort Study

Purpose

Nut intake has been associated with reduced mortality and risk of cardiovascular diseases, but there is only limited evidence on cancer. We investigated the relationship between nut intake and risk of postmenopausal breast cancer, and estrogen/progesterone receptor (ER/PR) subtypes.

Methods

In The Netherlands Cohort Study, 62,573 women aged 55–69 years provided information on dietary and lifestyle habits in 1986. After 20.3 years of follow-up, 2,321 incident breast cancer cases and 1,665 subcohort members were eligible for multivariate case-cohort analyses.

Results

Total nut intake was significantly inversely related to ER negative (ER??) breast cancer risk, with HR 0.55 (95% CI 0.33–0.93) for those consuming at least 10 g nuts/day versus non-consumers (p trend?=?0.025). There were no significant inverse associations with ER?+?or total breast cancer. While there was no variation between PR subtypes, the ER–PR- subtype was also significantly inversely associated with nut intake, with HR 0.53 (95% CI 0.29–0.99), p trend?=?0.037. Intake of peanuts and tree nuts separately was also inversely related to ER?? breast cancer subtypes, while no associations were found with peanut butter intake.

Conclusions

Our findings suggest an inverse association between nut intake and ER?? breast cancer, and no association with total or hormone receptor-positive subtypes.