Three-dimensional tumor visualization of invasive breast carcinomas using whole-mount serial section histopathology: implications for tumor size assessment.

PURPOSE: Linear tumor size (T-size) estimated with conventional histology informs breast cancer management. Previously we demonstrated significant differences in margin and focality estimates using conventional histology versus digital whole-mount serial sections (WMSS). Using WMSS we can measure T-size or volume. Here, we compare WMSS T-size with volume, and with T-size measured conventionally. We also compare the ellipsoid model for calculating tumor volume to direct, WMSS measurement. METHODS: Two pathologists contoured regions of invasive carcinoma and measured T-size from both WMSS and (simulated) conventional sections in 55 consecutive lumpectomy specimens. Volume was measured directly from the contours. Measurements were compared using the paired t-test or Spearman's rank-order correlation. A five-point 'border index' was devised and assigned to each case to parametrize tumor shape considering 'compactness' or cellularity. Tumor volumes calculated assuming ellipsoid geometry were compared with direct, WMSS measurements. RESULTS: WMSS reported significantly larger T-size than conventional histology in the majority of cases [61.8%, 34/55; means = (2.34 cm; 1.99 cm), p < 0.001], with a 16.4% (9/55) rate of 'upstaging'. The majority of discordances were due to undersampling. T-size and volume were strongly correlated (r = 0.838, p < 0.001). Significantly lower volume was obtained with WMSS versus ellipsoid modeling [means = (1.18 cm3; 1.45 cm3), p < 0.001]. CONCLUSIONS: Significantly larger T-size is measured with WMSS than conventionally, due primarily to undersampling in the latter. Volume and linear size are highly correlated. Diffuse tumors interspersed with normal or non-invasive elements may be sampled less extensively than more localized masses. The ellipsoid model overestimates tumor volume.

Factors influencing survival among patients with HER2-positive metastatic breast cancer treated with trastuzumab.

PURPOSE: We have limited capability to predict survival among patients treated for metastatic HER2-positive breast cancer. Further research is warranted to identify significant prognostic and predictive factors. METHODS: We identified all HER2-positive metastatic breast cancer patients receiving trastuzumab at the Sunnybrook Odette Cancer Centre (SOCC) from 1999 to 2013 through the Cancer Care Ontario (CCO) Registry (n = 256) and selected patients with available pathology reports (n = 154). A retrospective review was completed documenting clinical, pathologic, and laboratory characteristics at the time of first trastuzumab therapy and survival outcomes. Cox proportional hazards regression models were used to identify prognostic factors for overall survival (OS) (primary endpoint) and failure-free survival (FFS), adjusted for the known prognostic factors of the presence of CNS metastases and the presence of ≥ 2 distant metastatic sites. RESULTS: A multivariable model identified older age [hazard ratio (HR) 1.18/decade, 95% confidence interval (CI) 1.02-1.37)], increased platelet-to-lymphocyte ratio (PLR) (HR 1.75/log-unit, 95% CI 1.25-2.46), increased serum alkaline phosphatase (ALP) (HR 1.87/log-unit, 95% CI 1.41-2.49), and ER positivity (HR 0.63, 95% CI 0.42-0.96) as significant prognostic factors for OS after adjusting for the presence of CNS metastasis (HR 3.19, 95% CI 1.59-6.38) and the presence of ≥ 2 distant metastatic sites (HR 2.10, 95% CI 1.19-3.70). PLR (HR 1.54/log-unit, 95% CI 1.12-2.12) was the only prognostic factor associated with FFS after adjusting for CNS and ≥ 2 distant metastatic sites. CONCLUSION: Older age, increased PLR, and ALP were identified as poor prognostic factors and ER positivity as a favorable prognostic factor for OS after adjusting for the presence of CNS metastasis and the presence of number of ≥ 2 distant metastatic sites. Increased PLR was a poor prognostic factor for both OS and FFS, and warrants further investigation into its prognostic ability amongst patients with HER2-positive metastatic breast cancer.

Cost-effectiveness analysis of whole-mount pathology processing for patients with early breast cancer undergoing breast conservation.

BACKGROUND: Obtaining accurate histopathologic detail for breast lumpectomy specimens is challenging because of sampling and loss of three-dimensional conformational features with conventional processing. The whole-mount (wm) technique is a novel method of serial pathologic sectioning designed to optimize cross-sectional visualization of resected specimens and determination of margin status. METHODS: Using a Markov chain cohort simulation cost-effectiveness model, we compared conventional processing with wm technique for breast lumpectomies. Cost-effectiveness was evaluated from the perspective of the Canadian health care system and compared using incremental cost-effectiveness ratios (icers) for cost per quality-adjusted life-year (qaly) over a 10-year time horizon. Deterministic and probabilistic sensitivity analyses were performed to test the robustness of the model with willingness-to-pay (wtp) thresholds of $0-$100,000. Costs are reported in adjusted 2014 Canadian dollars, discounted at a rate of 3%. RESULTS: Compared with conventional processing, wm processing is more costly ($19,989 vs. $18,427) but generates 0.03 more qalys over 10 years. The icer is $45,414, indicating that this additional amount is required for each additional qaly obtained. The model was robust to all variance in parameters, with the prevalence of positive margins accounting for most of the model's variability. CONCLUSIONS: After a wtp threshold of $45,414, wm processing becomes cost-effective and ultimately generates fewer recurrences and marginally more qalys over time. Excellent baseline outcomes for the current treatment of breast cancer mean that incremental differences in survival are small. However, the overall benefit of the wm technique should be considered in the context of achieving improved accuracy and not just enhancements in clinical effectiveness.

A task-based quality control metric for digital mammography.

A reader study was conducted to tune the parameters of an observer model used to predict the detectability index (dʹ ) of test objects as a task-based quality control (QC) metric for digital mammography. A simple test phantom was imaged to measure the model parameters, namely, noise power spectrum,modulation transfer function and test-object contrast. These are then used ina non-prewhitening observer model, incorporating an eye-filter and internal noise, to predict dʹ. The model was tuned by measuring dʹ of discs in a four-alternative forced choice reader study. For each disc diameter, dʹ was used to estimate the threshold thicknesses for detectability. Data were obtained for six types of digital mammography systems using varying detector technologies and x-ray spectra. A strong correlation was found between measured and modeled values of dʹ, with Pearson correlation coefficient of 0.96. Repeated measurements from separate images of the test phantom show an average coefficient of variation in dʹ for different systems between 0.07 and 0.10. Standard deviations in the threshold thickness ranged between 0.001 and 0.017 mm. The model is robust and the results are relatively system independent, suggesting that observer model dʹ shows promise as a cross platform QC metric for digital mammography.

Volumetric breast density characteristics as determined from digital mammograms.

In this paper we present the results of an automated and entirely reproducible algorithm that estimates the breast volume, dense tissue volume and the volumetric breast density from digital mammograms. The algorithm was applied to 55, 087 digital images (CC view only) from 15 351 individual women, acquired between 2008 and 2011 at the Sunnybrook Health Sciences Centre in Toronto, Canada. The algorithm is based on a prior calibration of the digital image signal versus tissue thickness and composition, and the thickness of the compressed breast is estimated using an empirical model that corrects the thickness readout of the mammography system as a function of compression force. The mean volumetric density and breast volumes for our study group were 30% and 687 cm(3), respectively. The left and right volumetric density and breast volume were strongly correlated, with a Pearson correlation of 0.92 and 0.91, respectively. The volumetric density decreased from 45% to 25% as age increased from 35 to 75 years, with an increase to 30% at 80 years. For a given woman, the volumetric density decreased at an average rate of -2 density percentage points per year while the breast volume increased by 2% per year.

Long-term results of screening with magnetic resonance imaging in women with BRCA mutations.

BACKGROUND: The addition of breast magnetic resonance imaging (MRI) to screening mammography for women with BRCA mutations significantly increases sensitivity, but there is little data on clinical outcomes. We report screening performance, cancer stage, distant recurrence rate, and breast cancer-specific mortality in our screening study. METHODS: From 1997 to 2009, 496 women aged 25 to 65 years with a known BRCA1/2 mutation, of whom 380 had no previous cancer history, were enrolled in a prospective screening trial that included annual MRI and mammography. RESULTS: In 1847 screening rounds, 57 cancers were identified (53 screen-detected, 1 interval, and 3 incidental at prophylactic mastectomy), of which 37 (65%) were invasive. Sensitivity of MRI vs mammography was 86% vs 19% over the entire study period (P<0.0001), but was 74% vs 35% from 1997 to 2002 (P=0.02) and 94% vs 9% from 2003 to 2009 (P<0.0001), respectively. The relative sensitivities of MRI and mammography did not differ by mutation, age, or invasive vs non-invasive disease. Of the incident cancers, 97% were Stage 0 or 1. Of 28 previously unaffected women diagnosed with invasive cancer, 1 BRCA1 mutation carrier died following relapse of a 3 cm, node-positive breast cancer diagnosed on her first screen at age 48 (annual breast cancer mortality rate=0.5%). Three patients died of other causes. None of the 24 survivors has had a distant recurrence at a median follow-up of 8.4 years since diagnosis. CONCLUSION: Magnetic resonance imaging surveillance of women with BRCA1/2 mutations will detect the majority of breast cancers at a very early stage. The absence of distant recurrences of incident cancers to date is encouraging. However, longer follow-up is needed to confirm the safety of breast surveillance.

3D Pathology Volumetric Technique: A Method for Calculating Breast Tumour Volume from Whole-Mount Serial Section Images.

Tumour size, most commonly measured by maximum linear extent, remains a strong predictor of survival in breast cancer. Tumour volume, proportional to the number of tumour cells, may be a more accurate surrogate for size. We describe a novel "3D pathology volumetric technique" for lumpectomies and compare it with 2D measurements. Volume renderings and total tumour volume are computed from digitized whole-mount serial sections using custom software tools. Results are presented for two lumpectomy specimens selected for tumour features which may challenge accurate measurement of tumour burden with conventional, sampling-based pathology: (1) an infiltrative pattern admixed with normal breast elements; (2) a localized invasive mass separated from the in situ component by benign tissue. Spatial relationships between key features (tumour foci, close or involved margins) are clearly visualized in volume renderings. Invasive tumour burden can be underestimated using conventional pathology, compared to the volumetric technique (infiltrative pattern: 30% underestimation; localized mass: 3% underestimation for invasive tumour, 44% for in situ component). Tumour volume approximated from 2D measurements (i.e., maximum linear extent), assuming elliptical geometry, was seen to overestimate volume compared to the 3D volumetric calculation (by a factor of 7x for the infiltrative pattern; 1.5x for the localized invasive mass).

Optimization of exposure parameters for cone beam computed tomography sialography.

OBJECTIVES: The assessment of image quality is a crucial step in the development of a new imaging protocol. Having proposed and reported on a preliminary protocol for sialography using cone beam CT (CBCT), the purpose of this study was to further optimize this protocol by maximizing the image signal difference-to-noise ratio (SDNR) and to relate these new data to previously published dosimetric data for CBCT sialography. METHODS: An imaging phantom was constructed using samples with different concentrations of iodine and a water-immersed mandible. The CB MercuRay (Hitachi Medical Systems, Tokyo, Japan) was used to image the phantom using different peak kilovoltage (kVp) and milliamperage (mA) settings. SDNR was then calculated using the raw images based on mean pixel values (MPV) measured in selected regions of interest (ROI). Finally, a figure of merit (FOM) was calculated to examine the trade-off between image SDNR and effective radiation dose. RESULTS: The SDNR demonstrated an expected increase as the kVp increased from 60 to 120. Also, images made with the higher mA setting (15) had greater SDNR. The iodine concentration also influenced the image quality such that SDNR increased with increased amounts of iodine. The calculated FOM was greatest for the technique using 80 kVp, with equivalent results for 10 mA and 15 mA. CONCLUSION: An optimized protocol for CBCT sialography using CB MercuRay entails a 6 inch field of view with 80 kVp and 10 mA.

A randomized, placebo-controlled trial (NCIC CTG MAP.2) examining the effects of exemestane on mammographic breast density, bone density, markers of bone metabolism and serum lipid levels in postmenopausal women.

We hypothesized that exemestane (EXE) would reduce mammographic breast density and have unique effects on biomarkers of bone and lipid metabolism. Healthy postmenopausal women were randomized to EXE (25 mg daily) or placebo (PLAC) for 12 months and followed for a total of 24 months. The primary endpoint was change in percent breast density (PD) between the baseline and 12-month mammograms and secondary endpoints were changes in serum lipid levels, bone biomarkers, and bone mineral density (BMD). Ninety-eight women were randomized (49 to EXE; 49 to PLAC) and 65 had PD data at baseline and 12 months. Among women treated with EXE, PD was not significantly changed from baseline at 6, 12, or 24 months and was not different from PLAC. EXE was associated with significant percentage increase from baseline in N-telopeptide at 12 months compared with PLAC. No differences in percent change from baseline in BMD (lumbar spine and femoral neck) were observed between EXE and PLAC at either 12 or 24 months. Patients on EXE had a significantly larger percent decrease in total cholesterol than in the PLAC arm at 6 months and in HDL cholesterol at 3, 6, and 12 months. No significant differences in percent change in LDL or triglycerides were noted at any time point between the two treatment arms. EXE administered for 1 year to healthy postmenopausal women did not result in significant changes in mammographic density. A reversible increase in the bone resorption marker N-telopeptide without significant change in bone specific alkaline phosphatase or BMD during the 12 months treatment period and 1 year later was noted. Changes in lipid parameters on this trial were modest and reversible.

Adiposity changes after a 1-year aerobic exercise intervention among postmenopausal women: a randomized controlled trial.

OBJECTIVE: We examined the effects of an aerobic exercise intervention on adiposity outcomes that may be involved in the association between physical activity and breast cancer risk. DESIGN: This study was a two-centre, two-armed, randomized controlled trial. The 1-year-long exercise intervention included 45 min of moderate-to-vigorous aerobic exercise five times per week, with at least three of the sessions being facility based. The control group was asked not to change their activity and both groups were asked not to change their diet. SUBJECTS: A total of 320 postmenopausal, sedentary, normal weight-to-obese women aged 50-74 years who were cancer-free, nondiabetic and nonhormone replacement therapy users were included in this study. MEASUREMENTS: Anthropometric measurements of height, weight and waist and hip circumferences; dual energy X-ray absorptiometry measurements of total body fat; and computerized tomography measurements of abdominal adiposity were carried out. RESULTS: Women in the exercise group exercised a mean of 3.6 days (s.d.=1.3) per week and 178.5 min (s.d.=76.1) per week. Changes in all measures of adiposity favored exercisers relative to controls (P<0.001). The mean difference between groups was: -1.8 kg for body weight; -2.0 kg for total body fat; -14.9 cm(2) for intra-abdominal fat area; and -24.1 cm(2) for subcutaneous abdominal fat area. A linear trend of greater body fat loss with increasing volume of exercise was also observed. CONCLUSION: A 1-year aerobic exercise program consistent with current public health guidelines resulted in reduced adiposity levels in previously sedentary postmenopausal women at higher risk of breast cancer.

A comparative study of the effective radiation doses from cone beam computed tomography and plain radiography for sialography.

OBJECTIVES: As a first step in developing a protocol for multidimensional sialography using cone beam CT (CBCT), the objective of this study was to compare the effective radiation doses from sialography of the parotid and submandibular glands using plain radiography and CBCT. METHODS: The effective doses were calculated from dose measurements made at 25 selected locations in the head and neck of a radiation analogue dosimeter (RANDO) phantom, using International Commission on Radiological Protection 2007 tissue weighting factors. RESULTS: The effective dose (E) changed in relationship to changes in CBCT field of view (FOV), peak kilovoltage (kVp) and milliamperage (mA). Specifically, E decreased from a maximum of 932 microSv (30 cm FOV, 120 kVp, 15 mA) to 60 microSv (15 cm FOV, 80 kVp, 10 mA) for a parotid gland study and to 148 microSv (15 cm FOV, 80 kVp, 10 mA) for a submandibular study. The collective series of plain radiographs made during sialography of the parotid and submandibular glands yielded effective doses of 65 microSv and 156 microSv, respectively. The plain parotid gland series included one panoramic, two anterior-posterior skull and four lateral skull radiographs, whereas the submandibular gland series included one panoramic, one standard mandibular occlusal and four lateral skull radiographs. CONCLUSION: The effective doses from CBCT examinations centred on the parotid and submandibular glands were similar to those calculated for plain radiograph sialography when a 15 cm FOV was chosen in combination with exposure conditions of 80 kVp and 10 mA.

Validation of a method for measuring the volumetric breast density from digital mammograms.

The purpose of this study was to evaluate the performance of an algorithm used to measure the volumetric breast density (VBD) from digital mammograms. The algorithm is based on the calibration of the detector signal versus the thickness and composition of breast-equivalent phantoms. The baseline error in the density from the algorithm was found to be 1.25 +/- 2.3% VBD units (PVBD) when tested against a set of calibration phantoms, of thicknesses 3-8 cm, with compositions equivalent to fibroglandular content (breast density) between 0% and 100% and under x-ray beams between 26 kVp and 32 kVp with a Rh/Rh anode/filter. The algorithm was also tested against images from a dedicated breast computed tomography (CT) scanner acquired on 26 volunteers. The CT images were segmented into regions representing adipose, fibroglandular and skin tissues, and then deformed using a finite-element algorithm to simulate the effects of compression in mammography. The mean volume, VBD and thickness of the compressed breast for these deformed images were respectively 558 cm(3), 23.6% and 62 mm. The displaced CT images were then used to generate simulated digital mammograms, considering the effects of the polychromatic x-ray spectrum, the primary and scattered energy transmitted through the breast, the anti-scatter grid and the detector efficiency. The simulated mammograms were analyzed with the VBD algorithm and compared with the deformed CT volumes. With the Rh/Rh anode filter, the root mean square difference between the VBD from CT and from the algorithm was 2.6 PVBD, and a linear regression between the two gave a slope of 0.992 with an intercept of -1.4 PVBD and a correlation with R(2) = 0.963. The results with the Mo/Mo and Mo/Rh anode/filter were similar.

A randomized, placebo-controlled trial (NCIC CTG MAP1) examining the effects of letrozole on mammographic breast density and other end organs in postmenopausal women.

Mammographically detected breast density has been correlated with breast cancer risk. Breast density appears to be influenced by hormonal factors including increasing age, postmenopausal status, number of pregnancies, lower body weight, hormone replacement therapy, and tamoxifen therapy. The aromatase inhibitor letrozole profoundly reduces breast and circulating estrogen levels in postmenopausal women. We hypothesize that letrozole may reduce breast density and report here on its effects on mammographic breast density, bone mineral density (BMD), bone biomarkers, plasma hormone, and serum lipid levels. MAP1 was a multicenter, randomized, double-blind, placebo-controlled, feasibility trial in which postmenopausal women with or without prior invasive breast cancer were randomized in a 2:1 ratio of letrozole (2.5 mg daily) or placebo for 12 months and followed for a total of 24 months. Eligible women had an estimated >25% breast density on baseline mammogram. The primary endpoint was change in percent breast density (PD) between the baseline and 12-month mammograms as estimated by a computer-assisted thresholding program. Baseline and 12-month mammographic density was also assessed in a blinded manner by visual inspection. Secondary endpoints included changes in serum hormones, plasma lipid levels, bone biomarkers, and BMD. Data are available for 67 women (44 on letrozole and 23 on placebo). No significant changes in PD were noted between the treatment arms at either 12 or 24 months. No distinguishable difference in density measurements by visual inspection were noted between baseline and 12-month mammograms. A significant decrease in percentage change in T-score of the femoral neck at 12 months was noted in the letrozole arm without other significant changes in BMD parameters. Lipid values did not differ between treatment groups except for a borderline significant decrease in total cholesterol at 3 months among women treated with letrozole. Letrozole therapy was associated with a significant reduction in mean serum estradiol, estrone, and estrone sulfate levels at 12 months, but not at 24 months. A significant increase in serum IGF-1 levels was also noted in the letrozole group compared to the placebo group at both 12 and 24 months. To conclude, compared with placebo, 12 months of letrozole therapy does not appear to have a significant effect on mammographic PD. Twelve months of letrozole was associated with a decrease of uncertain clinical significance in the T-score of the femoral neck at 12 months which was reversible at 24 months with recovery of estrogen levels. Letrozole therapy was found to increase IGF-1 levels at 12 and 24 months.

The myth of the 50-50 breast.

PURPOSE: For dosimetry and for work in optimization of x-ray imaging of the breast, it is commonly assumed that the breast is composed of 50% fibroglandular tissue and 50% fat. The purpose of this study was to assess whether this assumption was realistic. METHODS: First, data obtained from an experimental breast CT scanner were used to validate an algorithm that measures breast density from digitized film mammograms. Density results obtained from a total of 2831 women, including 191 women receiving CT and from mammograms of 2640 women from three other groups, were then used to estimate breast compositions. RESULTS: Mean compositions, expressed as percent fibroglandular tissue (including the skin), varied from 13.7% to 25.6% among the groups with an overall mean of 19.3%. The mean compressed breast thickness for the mammograms was 5.9 cm (sigma = 1.6 cm). 80% of the women in our study had volumetric breast density less than 27% and 95% were below 45%. CONCLUSIONS: Based on the results obtained from the four groups of women in our study, the "50-50" breast is not a representative model of the breast composition.

Whole-specimen histopathology: a method to produce whole-mount breast serial sections for 3-D digital histopathology imaging.

AIMS: To develop a method for preparing diagnostic-quality, whole-mount serial sections of breast specimens while preserving 3-D conformation. This required supporting the fresh specimen prior to breadloafing and refining the conventional tissue processing method. The overall goal is to use digital images of whole-specimen histopathology to improve the estimation of extent of disease. METHODS AND RESULTS: To maintain a 3-D conformation, the specimen is suspended in 3.5% agar at 55 degrees C. The block is sliced at 5-mm intervals. Sectioning is performed after extended fixation in 4% formaldehyde from paraformaldehyde in 0.1 m Millonig's buffer, followed by paraffin processing using a non-routine schedule and extended paraffin infiltration. Whole-mount serial breast sections are produced with features of equal or superior quality to that which can be achieved using conventional methods. The method is compatible with some immunohistochemical stains but requires further optimization for others. CONCLUSIONS: The technique is currently suitable for research applications. With the reduction in processing time achievable with microwave-assisted processing, there is the potential for its use as a routine clinical method. This tool may improve the accuracy of margin estimates and identification of multifocality in breast cancer; further evaluation is necessary.

Better care and better teaching. New model of postpartum care for early discharge programs.

PROBLEM BEING ADDRESSED: Rapid postpartum discharge has reduced opportunities to detect early newborn or parenting problems and to teach neonatal assessment and maternal postpartum care to medical trainees. OBJECTIVE OF PROGRAM: Development of a program to not only ensure adequate care of mothers and newborns after early hospital discharge, but also to teach outpatient assessment skills to family medicine residents. MAIN COMPONENTS OF PROGRAM: In an urban, secondary care, university-affiliated teaching hospital predominantly training family medicine residents, an interdisciplinary committee created and supervised a neonatal and maternal postpartum assessment program. Newborn infants and their mothers are seen by a family physician, a family medicine resident, and a nurse within 48 hours of discharge, after which care is assumed in the community by the child's primary care physician. An assessment protocol developed by the interdisciplinary group promotes standardized mother and child care and a structured learning experience for trainees. CONCLUSION: Rapid follow up of early discharged infants and their mothers can be facilitated by a program of standardized assessment by a roster of pooled, interacting family physicians and nurses. When this assessment occurs in a teaching milieu, a comprehensive learning experience can be combined with defined objectives that emphasize and encourage newborn and maternal assessment for ambulatory patients.

Comparison of breast magnetic resonance imaging, mammography, and ultrasound for surveillance of women at high risk for hereditary breast cancer.

PURPOSE: Recommended surveillance for BRCA1 and BRCA2 mutation carriers includes regular mammography and clinical breast examination, although the effectiveness of these screening techniques in mutation carriers has not been established. The purpose of the present study was to compare breast magnetic resonance imaging (MRI) with ultrasound, mammography, and physical examination in women at high risk for hereditary breast cancer. PATIENTS AND METHODS: A total of 196 women, aged 26 to 59 years, with proven BRCA1 or BRCA2 mutations or strong family histories of breast or ovarian cancer underwent mammography, ultrasound, MRI, and clinical breast examination on a single day. A biopsy was performed when any of the four investigations was judged to be suspicious for malignancy. RESULTS: Six invasive breast cancers and one noninvasive breast cancer were detected among the 196 high-risk women. Five of the invasive cancers occurred in mutation carriers, and the sixth occurred in a woman with a previous history of breast cancer. The prevalence of invasive or noninvasive breast cancer in the 96 mutation carriers was 6.2%. All six invasive cancers were detected by MRI, all were 1.0 cm or less in diameter, and all were node-negative. In contrast, only three invasive cancers were detected by ultrasound, two by mammography, and two by physical examination. The addition of MRI to the more commonly available triad of mammography, ultrasound, and breast examination identified two additional invasive breast cancers that would otherwise have been missed. CONCLUSION: Breast MRI may be superior to mammography and ultrasound for the screening of women at high risk for hereditary breast cancer.

Mammographic densities as a marker of human breast cancer risk and their use in chemoprevention.

Differences in the parenchymal pattern of the breast on mammography reflect differences in the amounts of stromal, epithelial, and fat tissue present in the breast. Stroma and epithelium are radiologically dense, whereas fat is lucent. Extensive areas of mammographically dense breast tissue are strongly associated with an increased risk of breast cancer. A variety of interventions, including gonadotropin-releasing hormone inhibitor, tamoxifen, stopping hormone replacement therapy (HRT), and adopting a low-fat, high-carbohydrate diet, all influence the tissue composition of the breast and reduce mammographic densities. Of the interventions examined to date, only tamoxifen has been shown to reduce the incidence of breast cancer, at least in the short term. Conversely, HRT, which increases density, also increases risk of breast cancer. These results suggest that mammographic density may be a short-term marker of the effect on the breast of potential preventive interventions for breast cancer.