Berta M. Geller

Individual and Combined Effects of Age, Breast Density, and Hormone Replacement Therapy Use on the Accuracy of Screening Mammography

Context High breast density increases breast cancer risk and the difficulty of reading mammograms. Breast density decreases with age and increases with postmenopausal hormone therapy use. The interplay of breast density, age, and hormone therapy use on the accuracy of mammography is uncertain. Contribution For women with fatty breasts, the sensitivity of mammography was 87% and the specificity was 96.9%. For women with extremely dense breasts, the sensitivity of mammography was 62.9% and the specificity was 89.1%. Sensitivity increased with age. Hormone therapy use was not an independent predictor of accuracy. Implications The accuracy of screening mammography is best in older women and in women with fatty breasts. Postmenopausal hormone therapy affects mammography accuracy only through its effects on breast density. The Editors Mammographic breast density may be the most undervalued and underused risk factor in studies investigating breast cancer occurrence (1). The risk for breast cancer is four to six times higher in women with dense breasts (2, 3). Breast density may also decrease the sensitivity and, thus, the accuracy of mammography. Radiographically dense breast tissue may obscure tumors, which increases the difficulty of detecting breast cancer. In addition, dense breast tissue may mimic breast cancer on mammography (4), which increases recall rates (4-12), reduces specificity, and compromises the benefit of screening in women with dense breasts (such as women who use HRT or who are premenopausal) (6, 8, 13). Breast density is affected by age, use of hormone replacement therapy (HRT), menstrual cycle phase, parity, body mass index, and familial or genetic tendency (4, 5, 14-21). Studies show that the sensitivity of mammography increases with age (6-8), especially in postmenopausal women whose breasts are less dense (8). Earlier research has examined the individual effect of each factor we have described, but most studies could not adequately examine the interaction of these factors because of insufficient sample size (4-15). Studies conducted in the 1970s with data from the Breast Cancer Detection Demonstration Project (22) and New York Health Insurance Plan (23) are based on mammographic examinations that are very different from those performed using current technology. The Mammography Quality Standards Act (24) and the standardized reporting efforts of the American College of Radiology (25) have resulted in important improvements in mammography that necessitate reexamination. We used data from the National Cancer Institutes Breast Cancer Surveillance Consortium (BCSC) (26) on 329 495 women in the United States who had 463 372 screening mammograms, which were linked to 2223 cases of breast cancer. Our goal was to examine the individual and combined effects of age, breast density, and HRT use on mammographic accuracy. This large data set provides a unique opportunity to examine these issues in women undergoing screening mammography in the United States, especially women younger than 50 years of age and older than 80 years of age. We chose to study a sample that had been recently screened (within the previous 2 years) so that the risk for breast cancer would be similar to that in women who receive routine mammographic screening. Methods Data Collection Initially, we included data on women 40 to 89 years of age who underwent screening mammography between 1996 and 1998, as submitted by seven registries in the BCSC (North Carolina; New Mexico; New Hampshire; Vermont; Colorado; Seattle, Washington; and San Francisco, California). We included women who reported having previous mammography or who had a previous mammographic examination recorded in a registry within 2 years of the index mammogram. Women with breast implants or a personal history of breast cancer were excluded. In addition, women with missing data for age (<1%), breast density (27%), or HRT use (21%) were excluded (36% of all data). Demographic characteristics, clinical characteristics, and accuracy measures for women missing any of this information were very similar to those for women with complete data. All registries obtained institutional review board approval for data collection and linkage procedures, and careful data management, processing, and security procedures were followed (27). Consortium mammography registries and data collection procedures are described elsewhere (26). Briefly, seven institutions in seven states receive funding from the National Cancer Institute to maintain mammography registries that cover complete or contiguous portions of each state. Data are collected similarly at each registry. Demographic and history information is collected from women at the time of mammography by using a self-administered survey or face-to-face interview methods. Variables include date of birth, history of previous mammography, race or ethnicity, current use of HRT (prescription medication used to treat perimenopausal and postmenopausal symptoms), and menopausal status. We assumed that women 55 years of age and older were perimenopausal or postmenopausal. For women 40 to 54 years of age, premenopausal status was defined as having regular menstrual periods with no HRT use; perimenopausal or postmenopausal status was defined as either removal of both ovaries or uncertainty about whether periods had stopped permanently. This latter category was further classified into HRT users and nonusers. These definitions recognize that HRT users with intact uteri may have menstrual-like bleeding. Additional data, including mammographic breast density, mammographic assessment, and recommended follow-up (based on the American College of Radiology Breast Imaging Reporting and Data System [BI-RADS]), are collected from the technologist and radiologist at the time of mammography (25). Pathology data are collected from one or more sources: regional Surveillance, Epidemiology, and End Results (SEER) programs, state cancer registries, or pathology laboratories. Design We included all screening examinations for women who met the described criteria and who had at least one screening mammogram in 1996, 1997, or 1998. These years were chosen to ensure 1-year follow-up for cancer reporting and to account for routine reporting schedules in obtaining data from SEER and state cancer registries. We classified mammography as screening if a radiologist indicated that the examination was a bilateral, two-view (craniocaudal and mediolateral) examination. To avoid including diagnostic examinations, we excluded any breast imaging study performed within the previous 9 months. Because our goal was to study routine screening, mammographic accuracy was calculated on the basis of the initial assessment of the screening views alone (only 6% required supplemental imaging). Interpretation codes included BI-RADS assessments of 0 (incomplete), 1 (negative), 2 (negative, benign), 3 (probably benign), 4 (suspicious abnormality), or 5 (highly suggestive of malignancy). In cases in which the initial screening visit included both a screening examination and additional imaging to determine an assessment, the initial screening assessment was assigned a 0 (incomplete assessment) for analysis. When a woman had different assessments by breast, we chose the highest-level assessment for the woman as a whole (woman-level assessment) on the basis of the following hierarchy of overall level of radiologic concern: 1 < 2 < 3 < 0 < 4 < 5. We defined a screening examination as positive if it was assigned a BI-RADS assessment code of 0, 4, or 5. An assessment code of 3 associated with a recommendation for immediate additional imaging, biopsy, or surgical evaluation was also classified as positive. Although the BI-RADS recommendation for a code 3 (probably benign) is short-interval follow-up, immediate work-up was recommended in 37% of code 3s in the pooled BCSC data; therefore, this assessment is more consistent with a BI-RADS code of 0 (incomplete assessment) (28). We defined a screening examination as negative if it received a BI-RADS assessment code of 1, 2, or 3 when associated with short-interval follow-up only or routine follow-up. We classified breast pathology outcomes as cancer if pathology or cancer registry data identified a diagnosis of invasive or ductal carcinoma in situ. Lobular carcinoma in situ (<0.01% of cancer cases in our pooled data) was not considered a diagnosis of cancer in our analyses because it cannot be detected by mammography and is not treated. Examinations were classified as false-positive when the assessment was positive and breast cancer was not diagnosed within the follow-up period (365 days after the index screening examination or until the next examination, whichever occurred first). Examinations were classified as true-positive when the assessment was positive and cancer was diagnosed. A false-negative examination was a negative assessment with a diagnosis of cancer within the follow-up period. A true-negative examination was a negative assessment with no subsequent diagnosis of cancer within the follow-up period. Radiographic breast density was defined according to BI-RADS as follows: 1) almost entirely fatty, 2) scattered fibroglandular tissue, 3) heterogeneously dense, and 4) extremely dense (25). We excluded one registry that collects two categories of breast density (dense or not dense) at some facilities. Statistical Analysis For age, breast density, and HRT groups, we calculated rates of incident breast cancer, rates of breast cancer detected by mammography, and rates of missed cancer. To examine the nonlinear effects of age, we categorized age into 10-year groups, except for ages 40 to 59, which were divided into 5-year groups to explore changes around menopause. Accuracy indices included sensitivity and specificity. Sensitivity was calculated as true-positive/(true-positive + false-negative). Specificity was calculated as true-negative/(true-negative + false

Performance of Screening Mammography among Women with and without a First-Degree Relative with Breast Cancer

Many guidelines recommend that women at high risk for breast cancer undergo regular screening mammography at a younger age than those at average risk (1). However, few studies have evaluated the performance of screening mammography among younger women at increased risk for breast cancer. One group reported that the positive predictive value of mammography was two- to threefold higher (2) but the sensitivity was slightly lower (3) in women who had at least one first-degree relative with a history of breast cancer compared with those who did not. No randomized, controlled trials or subgroup analyses of data from existing randomized, controlled trials of screening mammography have evaluated the efficacy of the test in women with a family history of breast cancer. Understanding whether a family history of breast cancer influences the test performance characteristics of mammography may be important in developing screening strategies. This may be especially true for younger women, in whom the positive predictive value of mammography is low and the likelihood of associated diagnostic procedures to evaluate an abnormal result is high (2, 4, 5). We pooled data from seven mammography registries in order to provide a more stable estimate of the accuracy of screening mammography among women with a first-degree family history of breast cancer. We also compared the accuracy of the test in these women and in women of similar age without a family history. In this study, we report the rate of cancer, cancer yield per breast biopsy, and positive predictive value and sensitivity of mammography according to family history and decade of age. Methods Participants and Data Sources Our study sample included women 30 to 69 years of age who underwent screening mammography from April 1985 to November 1997. Data were pooled from seven mammography registries that participate in the National Cancer Institute Breast Cancer Surveillance Consortium (BCSC) (6). The seven registries, which are funded by the National Cancer Institute or the Department of Defense, are the San Francisco Mammography Registry (SFMR), San Francisco, California; Group Health Cooperative (GHC), Seattle, Washington; Fred Hutchinson Cancer Research Center (FHCRC), Seattle, Washington; New Mexico Mammography Project (NMMP), Albuquerque, New Mexico; Vermont Mammography Registry (VMR), Burlington, Vermont; Colorado Mammography Advocacy Project (CMAP), Denver, Colorado; and New Hampshire Mammography Network (NHMN), Hanover, New Hampshire. The SFMR provided data from April 1985 to December 1993, the GHC provided data from January 1986 to December 1993, the FHCRC provided data from December 1987 to December 1996, the NMMP provided data from June 1992 to December 1995, the VMR provided data from January 1994 to December 1996, the CMAP provided data from August 1994 to December 1996, and the NHMN provided data from May 1996 to November 1997. One mammographic examination per woman was included in the pooled analysis. If a woman had more than one mammographic examination in a mammography registry, results from her earliest dated examination were included and results from any subsequent screening examinations were excluded. We excluded women with a previous diagnosis of breast cancer and those with a palpable breast mass by history or on physical examination. Women whose ZIP codes were outside the catchment areas of their regional Surveillance, Epidemiology, and End Results (SEER) program or state tumor registry were also excluded to minimize incomplete follow-up information. The University of California, San Francisco, Committee on Human Research approved the study. Measurements We obtained a self-reported risk profile for breast cancer for each woman, as well as a mammographic assessment of two standard screening views per breast. The risk profile for breast cancer included questions about family history of breast cancer in a first-degree relative. Women were considered to have a family history of breast cancer if they reported having at least one first-degree relative (mother, sister, or daughter) with breast cancer. Results of initial screening examinations were classified as normal or abnormal. In mammography registries that used the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) (7) or terminology consistent with BI-RADS to assign mammographic assessment categories (SFMR, FHCRC, NMMP, VMR, NHMN, and CMAP), findings considered negative (category 1) or benign (category 2) were classified as normal. Examinations reported with any of the following BI-RADS assessments were categorized as abnormal: 1) probably benign (category 3); 2) incomplete, needs additional imaging evaluation (category 0), 3) suspicious (category 4), and 4) highly suggestive of malignancy (category 5). Before using BI-RADS, GHC used three mammographic assessment codes: negative, indeterminate, and positive. Negative and indeterminate assessments (for which follow-up in 1 year was recommended) were classified as normal; indeterminate assessments (for which 6-month follow-up examinations, additional imaging, or biopsy was recommended) and all positive assessments were classified as abnormal. Follow-up Breast biopsies performed to evaluate an abnormal mammography result were identified by contacting the womans personal physician, performing data linkage with a pathology database, or performing data linkage with a radiology database, depending on the study site. Breast biopsies included excisional and core biopsies. Women who had screening examinations were linked by computer to a pathology database (VMR, NHMN), to SEER (GHC, SFMR, NMMP, FHCRC), or to a state tumor registry (VMR, NHMN, CMAP) that collects population-based cancer data. To maintain participant confidentiality, procedures for linkage were performed according to protocols for human subjects research. Women were linked by using their full names, birth dates, addresses, ZIP codes, and Social Security numbers, when available, by using a probability-matching software program (Automatch, Vality Technology, Inc., Boston, Massachusetts) (VMR, NHMN, SFMR) or a comparable software program developed for linkage by a mammography registry (GHC, FHCRC, NMMP, CMAP). To allow adequate time for breast cancer to be reported to a tumor registry after a normal mammography result, we included only women who were screened through November 1997. Women were considered to have breast cancer if reports from a breast pathology database, SEER program, or state tumor registry showed any invasive carcinoma or ductal carcinoma in situ. Women with lobular carcinoma in situ only were excluded. Results for all cases of breast cancer and results for invasive cancer are presented separately. Definitions If breast cancer was diagnosed within 12 months of a normal mammography result, the examination was considered to be a false negative. If breast cancer was not diagnosed within 12 months of a normal mammography result, the examination was considered to be a true negative. If breast cancer was diagnosed within 12 months of an abnormal mammography result, the examination was considered to be a true positive. If breast cancer was not diagnosed within 12 months of an abnormal mammography result, the examination was considered to be a false positive. The diagnosis date was the date reported by a SEER program, the date reported by a state tumor registry, or the biopsy date recorded in a pathology database. Statistical Analysis The positive predictive value of screening mammography was calculated as the percentage of women with abnormal screening examinations who received a diagnosis of breast cancer within 12 months of the screening examination. Since the positive predictive value of mammography is influenced by the criteria used to define an examination as abnormal, we also reported the number of cases of breast cancer detected per 1000 screening examinations (normal and abnormal combined) when breast cancer was diagnosed within 1 year of the screening examination. The cancer yield per breast biopsy was calculated as the percentage of women who had a breast biopsy and received a diagnosis of breast cancer within 12 months of the screening examination. The sensitivity of mammography was calculated as the number of true-positive examinations divided by the number of true-positive examinations plus the number of false-negative examinations. The specificity of mammography was calculated as the number of true-negative examinations divided by the number of false-positive examinations plus the number of true-negative examinations. The chi-square test and the Fisher exact test were used for comparison of proportions. The chi-square test for trend and the chi-square test for homogeneity were used to compare proportions stratified by age. All Pvalues were two sided. Role of the Funding Sources The funding sources had no role in the collection, analysis, or interpretation of the data or in the decision to submit the paper for publication. Results A total of 389 533 screening examinations were performed among seven mammography registries. Of these, 50 834 (13.0%) were performed in women with a family history of breast cancer. Five registries record self-reported previous use of mammography. In data from these registries, previous use was similar among women with a family history of breast cancer (81.7% [28 574 of 34 973]) and among those without (80.2% [170 505 of 212 729]). Abnormal Mammography Results Among women without a family history of breast cancer, the overall frequency of abnormal examination results was 10.8% (95% CI, 10.7% to 11.0%). The frequency of abnormal results ranged from 8.8% to 11.3% across age groups and was lowest for women 30 to 39 years of age (Table 1). The frequency of abnormal examination results was higher among women with a family history of breast cancer than among those without (12.7% vs. 10.8%; P<0.001 [chi-square test]); these differe

Comparative Effectiveness of Digital Versus Film-Screen Mammography in Community Practice in the United States: A Cohort Study

BACKGROUND Few studies have examined the comparative effectiveness of digital versus film-screen mammography in U.S. community practice. OBJECTIVE To determine whether the interpretive performance of digital and film-screen mammography differs. DESIGN Prospective cohort study. SETTING Mammography facilities in the Breast Cancer Surveillance Consortium. PARTICIPANTS 329,261 women aged 40 to 79 years underwent 869 286 mammograms (231 034 digital; 638 252 film-screen). MEASUREMENTS Invasive cancer or ductal carcinoma in situ diagnosed within 12 months of a digital or film-screen examination and calculation of mammography sensitivity, specificity, cancer detection rates, and tumor outcomes. RESULTS Overall, cancer detection rates and tumor characteristics were similar for digital and film-screen mammography, but the sensitivity and specificity of each modality varied by age, tumor characteristics, breast density, and menopausal status. Compared with film-screen mammography, the sensitivity of digital mammography was significantly higher for women aged 60 to 69 years (89.9% vs. 83.0%; P = 0.014) and those with estrogen receptor-negative cancer (78.5% vs. 65.8%; P = 0.016); borderline significantly higher for women aged 40 to 49 years (82.4% vs. 75.6%; P = 0.071), those with extremely dense breasts (83.6% vs. 68.1%; P = 0.051), and pre- or perimenopausal women (87.1% vs. 81.7%; P = 0.057); and borderline significantly lower for women aged 50 to 59 years (80.5% vs. 85.1%; P = 0.097). The specificity of digital and film-screen mammography was similar by decade of age, except for women aged 40 to 49 years (88.0% vs. 89.7%; P < 0.001). LIMITATION Statistical power for subgroup analyses was limited. CONCLUSION Overall, cancer detection with digital or film-screen mammography is similar in U.S. women aged 50 to 79 years undergoing screening mammography. Women aged 40 to 49 years are more likely to have extremely dense breasts and estrogen receptor-negative tumors; if they are offered mammography screening, they may choose to undergo digital mammography to optimize cancer detection. PRIMARY FUNDING SOURCE National Cancer Institute.

Prognostic Characteristics of Breast Cancer Among Postmenopausal Hormone Users in a Screened Population

PURPOSE We determined the risk of breast cancer and tumor characteristics among current postmenopausal hormone therapy users compared with nonusers, by duration of use. METHODS From January 1996 to December 2000, data were collected prospectively on 374,465 postmenopausal women aged 50 to 79 years who underwent screening mammography. We calculated the relative risk (RR) of breast cancer (invasive or ductal carcinoma-in-situ) and type of breast cancer within 12 months of postmenopausal therapy use among current hormone users with a uterus (proxy for estrogen and progestin use) and without a uterus (proxy for estrogen use), compared with nonusers. RESULTS Compared with nonusers, women using estrogen and progestin for >/= 5 years were at increased risk of breast tumors of stage 0 or I (RR, 1.51; 95% CI, 1.37 to 1.66), stage II or higher (RR, 1.46; 95% CI, 1.30 to 1.63), size </= 20 mm (RR, 1.59; 95% CI, 1.43 to 1.76), size greater than 20 mm (RR, 1.24; 95% CI, 1.09 to 1.42), grade 1 or 2 (RR, 1.60; 95% CI, 1.44 to 1.77), grade 3 or 4 (RR, 1.54; 95% CI, 1.37 to 1.73), and estrogen receptor-positive (RR, 1.72; 95% CI, 1.55 to 1.90). Estrogen-only users were slightly more likely to have estrogen receptor-positive breast cancer compared with nonusers (RR, 1.14; 95% CI, 1.06 to 1.23). CONCLUSION Use of estrogen and progestin postmenopausal hormone therapy for five years or more increased the likelihood of developing breast cancer, including both tumors with favorable prognostic features and tumors with unfavorable prognostic features.

Outcomes of Screening Mammography by Frequency, Breast Density, and Postmenopausal Hormone Therapy

IMPORTANCE Controversy exists about the frequency women should undergo screening mammography and whether screening interval should vary according to risk factors beyond age. OBJECTIVE To compare the benefits and harms of screening mammography frequencies according to age, breast density, and postmenopausal hormone therapy (HT) use. DESIGN Prospective cohort. SETTING Data collected January 1994 to December 2008 from mammography facilities in community practice that participate in the Breast Cancer Surveillance Consortium (BCSC) mammography registries. PARTICIPANTS Data were collected prospectively on 11,474 women with breast cancer and 922,624 without breast cancer who underwent mammography at facilities that participate in the BCSC. MAIN OUTCOMES AND MEASURES We used logistic regression to calculate the odds of advanced stage (IIb, III, or IV) and large tumors (>20 mm in diameter) and 10-year cumulative probability of a false-positive mammography result by screening frequency, age, breast density, and HT use. The main predictor was screening mammography interval. RESULTS Mammography biennially vs annually for women aged 50 to 74 years does not increase risk of tumors with advanced stage or large size regardless of womens breast density or HT use. Among women aged 40 to 49 years with extremely dense breasts, biennial mammography vs annual is associated with increased risk of advanced-stage cancer (odds ratio [OR], 1.89; 95% CI, 1.06-3.39) and large tumors (OR, 2.39; 95% CI, 1.37-4.18). Cumulative probability of a false-positive mammography result was high among women undergoing annual mammography with extremely dense breasts who were either aged 40 to 49 years (65.5%) or used estrogen plus progestogen (65.8%) and was lower among women aged 50 to 74 years who underwent biennial or triennial mammography with scattered fibroglandular densities (30.7% and 21.9%, respectively) or fatty breasts (17.4% and 12.1%, respectively). CONCLUSIONS AND RELEVANCE Women aged 50 to 74 years, even those with high breast density or HT use, who undergo biennial screening mammography have similar risk of advanced-stage disease and lower cumulative risk of false-positive results than those who undergo annual mammography. When deciding whether to undergo mammography, women aged 40 to 49 years who have extremely dense breasts should be informed that annual mammography may minimize their risk of advanced-stage disease but the cumulative risk of false-positive results is high.

The association of increased weight, body mass index, and tissue density with the risk of breast carcinoma in Vermont.

Etiologic studies of breast carcinoma have indicated that weight, body mass index (BMI), and breast tissue density are important determinants of a womans risk for the disease. This study looked at the independent effects of these risk factors.

Effectiveness of Computer-Aided Detection in Community Mammography Practice

BACKGROUND Computer-aided detection (CAD) is applied during screening mammography for millions of US women annually, although it is uncertain whether CAD improves breast cancer detection when used by community radiologists. METHODS We investigated the association between CAD use during film-screen screening mammography and specificity, sensitivity, positive predictive value, cancer detection rates, and prognostic characteristics of breast cancers (stage, size, and node involvement). Records from 684 956 women who received more than 1.6 million film-screen mammograms at Breast Cancer Surveillance Consortium facilities in seven states in the United States from 1998 to 2006 were analyzed. We used random-effects logistic regression to estimate associations between CAD and specificity (true-negative examinations among women without breast cancer), sensitivity (true-positive examinations among women with breast cancer diagnosed within 1 year of mammography), and positive predictive value (breast cancer diagnosed after positive mammograms) while adjusting for mammography registry, patient age, time since previous mammography, breast density, use of hormone replacement therapy, and year of examination (1998-2002 vs 2003-2006). All statistical tests were two-sided. RESULTS Of 90 total facilities, 25 (27.8%) adopted CAD and used it for an average of 27.5 study months. In adjusted analyses, CAD use was associated with statistically significantly lower specificity (OR = 0.87, 95% confidence interval [CI] = 0.85 to 0.89, P < .001) and positive predictive value (OR = 0.89, 95% CI = 0.80 to 0.99, P = .03). A non-statistically significant increase in overall sensitivity with CAD (OR = 1.06, 95% CI = 0.84 to 1.33, P = .62) was attributed to increased sensitivity for ductal carcinoma in situ (OR = 1.55, 95% CI = 0.83 to 2.91; P = .17), although sensitivity for invasive cancer was similar with or without CAD (OR = 0.96, 95% CI = 0.75 to 1.24; P = .77). CAD was not associated with higher breast cancer detection rates or more favorable stage, size, or lymph node status of invasive breast cancer. CONCLUSION CAD use during film-screen screening mammography in the United States is associated with decreased specificity but not with improvement in the detection rate or prognostic characteristics of invasive breast cancer.

Bias Associated With Self-Report of Prior Screening Mammography

Background: Self-reported screening behaviors from national surveys often overestimate screening use, and the amount of overestimation may vary by demographic characteristics. We examine self-report bias in mammography screening rates overall, by age, and by race/ethnicity. Methods: We use mammography registry data (1999-2000) from the Breast Cancer Surveillance Consortium to estimate the validity of self-reported mammography screening collected by two national surveys. First, we compare mammography use from 1999 to 2000 for a geographically defined population (Vermont) with self-reported rates in the prior two years from the 2000 Vermont Behavioral Risk Factor Surveillance System. We then use a screening dissemination simulation model to assess estimates of mammography screening from the 2000 National Health Interview Survey. Results: Self-report estimates of mammography use in the prior 2 years from the Vermont Behavioral Risk Factor Surveillance System are 15 to 25 percentage points higher than actual screening rates across age groups. The differences in National Health Interview Survey screening estimates from models are similar for women 40 to 49 and 50 to 59 years and greater than for those 60 to 69, or 70 to 79 (27 and 26 percentage points versus 14, and 14, respectively). Overreporting is highest among African American women (24.4 percentage points) and lowest among Hispanic women (17.9) with non-Hispanic White women in between (19.3). Values of sensitivity and specificity consistent with our results are similar to previous validation studies of mammography. Conclusion: Overestimation of self-reported mammography usage from national surveys varies by age and race/ethnicity. A more nuanced approach that accounts for demographic differences is needed when adjusting for overestimation or assessing disparities between populations. (Cancer Epidemiol Biomarkers Prev 2009;18(6):1699–705)

Accuracy and Outcomes of Screening Mammography in Women With a Personal History of Early-Stage Breast Cancer

CONTEXT Women with a personal history of breast cancer (PHBC) are at risk of developing another breast cancer and are recommended for screening mammography. Few high-quality data exist on screening performance in PHBC women. OBJECTIVE To examine the accuracy and outcomes of mammography screening in PHBC women relative to screening of similar women without PHBC. DESIGN AND SETTING Cohort of PHBC women, mammogram matched to non-PHBC women, screened through facilities (1996-2007) affiliated with the Breast Cancer Surveillance Consortium. PARTICIPANTS There were 58,870 screening mammograms in 19,078 women with a history of early-stage (in situ or stage I-II invasive) breast cancer and 58,870 matched (breast density, age group, mammography year, and registry) screening mammograms in 55,315 non-PHBC women. MAIN OUTCOME MEASURES Mammography accuracy based on final assessment, cancer detection rate, interval cancer rate, and stage at diagnosis. RESULTS Within 1 year after screening, 655 cancers were observed in PHBC women (499 invasive, 156 in situ) and 342 cancers (285 invasive, 57 in situ) in non-PHBC women. Screening accuracy and outcomes in PHBC relative to non-PHBC women were cancer rates of 10.5 per 1000 screens (95% CI, 9.7-11.3) vs 5.8 per 1000 screens (95% CI, 5.2-6.4), cancer detection rate of 6.8 per 1000 screens (95% CI, 6.2-7.5) vs 4.4 per 1000 screens (95% CI, 3.9-5.0), interval cancer rate of 3.6 per 1000 screens (95% CI, 3.2-4.1) vs 1.4 per 1000 screens (95% CI, 1.1-1.7), sensitivity 65.4% (95% CI, 61.5%-69.0%) vs 76.5% (95% CI, 71.7%-80.7%), specificity 98.3% (95% CI, 98.2%-98.4%) vs 99.0% (95% CI, 98.9%-99.1%), abnormal mammogram results in 2.3% (95% CI, 2.2%-2.5%) vs 1.4% (95% CI, 1.3%-1.5%) (all comparisons P < .001). Screening sensitivity in PHBC women was higher for detection of in situ cancer (78.7%; 95% CI, 71.4%-84.5%) than invasive cancer (61.1%; 95% CI, 56.6%-65.4%), P < .001; lower in the initial 5 years (60.2%; 95% CI, 54.7%-65.5%) than after 5 years from first cancer (70.8%; 95% CI, 65.4%-75.6%), P = .006; and was similar for detection of ipsilateral cancer (66.3%; 95% CI, 60.3%-71.8%) and contralateral cancer (66.1%; 95% CI, 60.9%-70.9%), P = .96. Screen-detected and interval cancers in women with and without PHBC were predominantly early stage. CONCLUSION Mammography screening in PHBC women detects early-stage second breast cancers but has lower sensitivity and higher interval cancer rate, despite more evaluation and higher underlying cancer rate, relative to that in non-PHBC women.

Comparing Screening Mammography for Early Breast Cancer Detection in Vermont and Norway

BACKGROUND Most screening mammography in the United States differs from that in countries with formal screening programs by having a shorter screening interval and interpretation by a single reader vs independent double reading. We examined how these differences affect early detection of breast cancer by comparing performance measures and histopathologic outcomes in women undergoing opportunistic screening in Vermont and organized screening in Norway. METHODS We evaluated recall, screen detection, and interval cancer rates and prognostic tumor characteristics for women aged 50-69 years who underwent screening mammography in Vermont (n = 45 050) and in Norway (n = 194 430) from 1997 through 2003. Rates were directly adjusted for age by weighting the rates within 5-year age intervals to reflect the age distribution in the combined data and were compared using two-sided Z tests. RESULTS The age-adjusted recall rate was 9.8% in Vermont and 2.7% in Norway (P < .001). The age-adjusted screen detection rate per 1000 woman-years after 2 years of follow-up was 2.77 in Vermont and 2.57 in Norway (P = .12), whereas the interval cancer rate per 1000 woman-years was 1.24 and 0.86, respectively (P < .001). Larger proportions of invasive interval cancers in Vermont than in Norway were 15 mm or smaller (55.9% vs 38.2%, P < .001) and had no lymph node involvement (67.5% vs 57%, P = .01). The prognostic characteristics of all invasive cancers (screen-detected and interval cancer) were similar in Vermont and Norway. CONCLUSION Screening mammography detected cancer at about the same rate and at the same prognostic stage in Norway and Vermont, with a statistically significantly lower recall rate in Norway. The interval cancer rate was higher in Vermont than in Norway, but tumors that were diagnosed in the Vermont women tended to be at an earlier stage than those diagnosed in the Norwegian women.