Current Guidelines and Gaps in Breast Cancer Screening

Breast cancer is the most common nonskin cancer in women and the second leading cause of cancer death for women in the United States. Mammography screening is proven to significantly decrease breast cancer mortality, with a 40% or more reduction expected with annual use starting at age 40 for women of average risk. However, less than half of all eligible women have a mammogram annually. The elimination of cost sharing for screening made possible by the Affordable Care Act (2010) encouraged screening but mainly for those already insured. The United States Preventive Services Task Force 2009 guidelines recommended against screening those 40 to 49 years old and have left women over 74 years of age vulnerable to coverage loss. Other populations for whom significant gaps in risk information or screening use exist, including women of lower socioeconomic status, black women, men at higher than average risk of breast cancer, and sexual and gender minorities. Further work is needed to achieve higher rates of screening acceptance for all appropriate individuals so that the full mortality and treatment benefits of mammography screening can be realized.     

Breast cancer screening—Does it fulfil the criteria for medical screening?

Almost a decade ago, in 1986 the Forrest Report advocated that breast screening by single medio-lateral oblique mammography should be offered at 3-yearly intervals, by invitation to women between 50 and 64 years and on request to older women. The Government accepted these recommendations and set up the National Breast Screening Programme (NHSBSP). This article critically reviews the extent to which the breast cancer screening programme fulfils the criteria for mass screening.     

Digital Breast Tomosynthesis: A Decade of Practice in Review

Digital breast tomosynthesis (DBT), introduced in 2011, was thought to be a further evolution of full-field digital mammography (DM). Assessing DBT presents unique challenges. The widely variable settings in which DBT has been applied affect outcomes. In initial studies comparing DM-DBT with DM, outcomes for cancer detection rates (CDRs) and recall rates have been mixed. CDR improves most in biennial screening settings, with little or no improvement in annual screening. Recall rates improve most where rates are highest; no improvement is seen in European prospective trials. Adoption of synthesized mammography (SM), derived from the tomosynthesis acquisition and intended to avoid the DM exposure, has been slow because of inferior image quality. Despite this, SM-DBT has shown equivalent outcomes measures to DM-DBT. An important exception is the To-Be randomized controlled trial, which showed that SM-DBT was equivalent to DM in CDR, not better. To date, interval cancer rate, a surrogate for mortality reduction, has not been shown to be improved by DBT. We may have reached the limit of morphological assessment in x-ray technique. Its use may evolve with advancements in technology as use of contrast agents expands, algorithms for SM progress, and tomosynthesis-guided biopsy proliferates. Our expectations of the contributions of DBT will evolve as well.     

United States Preventive Services Task Force screening mammography recommendations: science ignored

OBJECTIVE: The purpose of this article is to examine the scientific evidence considered by the United States Preventive Services Task Force (USPSTF) in recommending against screening mammography in women 40-49 years old and against annual screening mammography in women 50 and older. We use evidence made available to the USPSTF to estimate the benefits and "harms" of screening mammography in women 40 years old and older. We use Cancer Intervention and Surveillance Modeling Network modeling to compare lives saved by different screening scenarios and the summary of evidence prepared for the USPSTF to estimate the frequency of harms of screening mammography by age. CONCLUSION: Averaged over the six Cancer Intervention and Surveillance Modeling Network models of benefit, screening mammography shows greatest benefit--a 39.6% mortality reduction--from annual screening of women 40-84 years old. This screening regimen saves 71% more lives than the USPSTF-recommended regimen of biennial screening of women 50-74 years old, which had a 23.2% mortality reduction. For U.S. women currently 30-39 years old, annual screening mammography from ages 40-84 years would save 99,829 more lives than USPSTF recommendations if all women comply, and 64,889 more lives with the current 65% compliance rate. The potential harms of a screening examination in women 40-49 years old, on average, consist of the risk of a recall for diagnostic workup every 12 years, a negative biopsy every 149 years, a missed breast cancer every 1,000 years, and a fatal radiation-induced breast cancer every 76,000-97,000 years. Evidence made available to the USPSTF strongly supports the mortality benefit of annual screening mammography beginning at age 40 years, whereas potential harms of screening with this regimen are minor.     

Design,implementation, and pitfalls of TMIST

The early detection of breast cancer has been shown to reduce deaths through randomized, controlled trials. Numerous observational studies, failure analyses, and “incidence of death” studies have confirmed that screening reduces deaths in the general population. Digital Breast Tomosynthesis (DBT) which collects mammographic images from different angles and uses them to synthesize planes through the breast is simply another advance in mammography among others that have been made over the years. DBT “absolutely” detects more cancers at a time when cure is more likely while also having the advantage of reducing recall rates. The Tomosynthesis Mammographic Imaging Screening Trial (TMIST) has been designed to compare DBT with 2-Dimensional Full Field Digital Mammography (FFDM), but it's major design issues may provide misleading results. Instead of using a reduction in deaths as the endpoint, benefit in TMIST is predicated on a reduction in advanced cancers in the DBT group. This is a questionable “endpoint” (a reduction in advanced cancers is not necessary as proof of benefit). In addition, the trial may be underpowered so that even if DBT shows a benefit it may not be able to achieve “statistical significance”. The six CISNET models of the National Cancer Institute have shown that annual mammography beginning at the age of 40 will save the most lives. Yet TMIST will only include women ages 45 and over and will screen postmenopausal women every two years instead of annually. Consequently, TMIST results may be used, inappropriately, to limit access to breast cancer screening starting at the age of 45, and only offer biennial screening for post-menopausal women.     

A case-control study to estimate the impact of the Icelandic population-based mammography screening program on breast cancer death

Background: The Icelandic breast cancer screening program, initiated November 1987 in Reykjavik and covering the whole country from December 1989, comprises biennial invitation to mammography for women aged 40-69 years old.

Purpose: To estimate the impact of mammography service screening in Iceland on deaths from breast cancer.

Material and Methods: Cases were deaths from breast cancer from 1990 onwards in women aged 40 and over at diagnosis, during the period November 1987 to December 31, 2002. Age- and screening-area-matched, population-based controls were women who had also been invited to screening but were alive at the time their case died.

Results: Using conditional logistic regression on the data from 226 cases and 902 controls, the odds ratio for the risk of death from breast cancer in those attending at least one screen compared to those never screened was 0.59 (95% CI 0.41-0.84). After adjustment for healthy-volunteer bias and screening-opportunity bias, the odds ratio was 0.65 (95% CI 0.39-1.09).

Conclusion: These results indicate a 35-40% reduction in breast cancer deaths by attending the Icelandic breast cancer screening program. These results are consistent with the overall evidence from other observational evaluations of mammography-based programs.     

Digital Mammography: Are There Advantages in Screening for Breast Cancer?

The clinical trials to date have demonstrated the overall diagnostic accuracy of DM is equivalent to that of SFM for breast cancer screening. However, DM has higher diagnostic accuracy in specific patient populations (ie, women younger than 50 years of age and those with heterogeneously dense or extremely dense breasts). Whether this would result in an improvement in long-term outcomes for patients has yet to be determined. The US studies did not demonstrate a statistically significant difference in recall rates. However, the two European trials did demonstrate higher recall rates for DM. The overall recall rates for both DM and SFM were higher in the US studies than in the European trials, which likely reflect a difference in the medico-legal environments. However, despite a lack of substantially improved diagnostic accuracy in the screening population, DM has much potential for advanced applications. Some of the applications, such as telemammography, may improve the ability to deliver expert interpretation and care to underserved populations. Contrast-enhanced DM and tomosynthesis may improve diagnosis of breast cancer.     

Guidelines for screening for breast cancer. Is a revision in order?

Screening women over the age of 50 for breast cancer has clearly been proven to be capable of reducing population mortality from breast cancer. Population based screening for women aged 40 to 49 has not been shown to be effective, and in several trials there is an early excess breast cancer mortality in the screened population. Because tumors tend to grow more rapidly in younger women than in older women, those trials performed at biannual intervals will detect only the intermediate and slower growing lesions. The more rapidly growing tumors will occur between screens. Furthermore, maintaining a high positive predictive value will lead to a lower sensitivity rate. If the screening interval is too long or the positive predictive value too high, the reassuring effect of a false-negative screening examination may contribute to delay in diagnosis beyond even the usual clinical detection threshold. This may cause more deaths in the study population than in the control population. Guidelines that take the various factors into account have been proposed.     

A retrospective audit of the first screening round of the Maltese breast screening programme

PurposeTo analyse whether the screening performance parameters of the Maltese National Breast Screening Programme first screening round met requirements set by European standards. The association between screening age and results of screening performance parameters was also investigated.MethodQuantitative methodology was used to review examinations of women who were recalled for a technical recall or further assessment rates. All accessible members of the population recalled during the first round were retrospectively reviewed resulting in a sample of 2300 recalled examinations.ResultsMalta's first screening round met the European Guidelines recommendations for technical repeat rate (0.26%), early recall rate (0.45%), breast cancer detection rate (13.77 per 1000 women) and Positive Predictive Value of screening test (7.58%). However, local recall rate (18.53%) and further assessment rate (18.27%) were higher than recommended.The Chi square test showed a statistically significant difference (p ≤ 0.05) in recall rates between the compared age groups, as younger women (51–55 years) were more likely to have a negative diagnosis after the initial mammogram whereas older women (56–60 years) were more likely to be recalled. There was no age discrepancy (p ≥ 0.05) in local breast cancer detection rate and positive predictive value of screening test.ConclusionAlthough the Maltese first screening round performed well, this study found deficiencies in recall and further assessment rates, which according to literature may result in psychological morbidity and inefficient use of screening resources. This study also concluded that when a cohort is analysed, age is not as significant as the screening round itself (first/subsequent).     

Facility Variability in Examination Indication Among Women With Prior Breast Cancer: Implications and the Need for Standardization

ObjectiveWe sought to identify and characterize examinations in women with a personal history of breast cancer likely performed for asymptomatic surveillance.MethodsWe included surveillance mammograms (1997-2017) in asymptomatic women with a personal history of breast cancer diagnosed at age ≥18 years (1996-2016) from 103 Breast Cancer Surveillance Consortium facilities. We examined facility-level variability in examination indication. We modeled the relative risk (RR) and 95% confidence intervals (CIs) at the examination level of a (1) nonscreening indication and (2) surveillance interval ≤9 months using Poisson regression with fixed effects for facility, stage, diagnosis age, surgery, examination year, and time since diagnosis.ResultsAmong 244,855 surveillance mammograms, 69.5% were coded with a screening indication, 12.7% short-interval follow-up, and 15.3% as evaluation of a breast problem. Within a facility, the proportion of examinations with a screening indication ranged from 6% to 100% (median 86%, interquartile range 79%-92%). Facilities varied the most for examinations in the first 5 years after diagnosis, with 39.4% of surveillance mammograms having a nonscreening indication. Within a facility, breast conserving surgery compared with mastectomy (RR = 1.64; 95% CI = 1.60-1.68) and less time since diagnosis (1 year versus 5 years; RR = 1.69; 95% CI = 1.66-1.72; 3 years versus 5 years = 1.20; 95% CI = 1.18-1.23) were strongly associated with a nonscreening indication with similar results for ≤9-month surveillance interval. Screening indication and >9-month surveillance intervals were more common in more recent years.ConclusionVariability in surveillance indications across facilities in the United States supports including indications beyond screening in studies evaluating surveillance mammography effectiveness and demonstrates the need for standardization.     

Outcomes by Race in Breast Cancer Screening With Digital Breast Tomosynthesis Versus Digital Mammography

PurposeDigital breast tomosynthesis (DBT) in conjunction with digital mammography (DM) is becoming the preferred imaging modality for breast cancer screening compared with DM alone, on the basis of improved recall rates (RR) and cancer detection rates (CDRs). The aim of this study was to investigate racial differences in the utilization and performance of screening modality.MethodsRetrospective data from 63 US breast imaging facilities from 2015 to 2019 were reviewed. Screening outcomes were linked to cancer registries. RR, CDR per 1,000 examinations, and positive predictive value for recall (cancers/recalled patients) were compared.ResultsA total of 385,503 women contributed 542,945 DBT and 261,359 DM screens. A lower proportion of screenings for Black women were performed using DBT plus DM (referred to as DBT) (44% for Black, 48% for other, 63% for Asian, and 61% for White). Non-White women were less likely to undergo more than one mammographic examination. RRs were lower for DBT among all women (8.74 versus 10.06, P < .05) and lower across all races and within age categories. RRs were significantly higher for women with only one mammogram. CDRs were similar or higher in women undergoing DBT compared with DM, overall (4.73 versus 4.60, adjusted P = .0005) and by age and race. Positive predictive value for recall was greater for DBT overall (5.29 versus 4.45, adjusted P < .0001) and by age, race, and screening frequency.ConclusionsAll racial groups had improved outcomes with DBT screening, but disparities were observed in DBT utilization. These data suggest that reducing inequities in DBT utilization may improve the effectiveness of breast cancer screening.     

Bahcesehir long-term population-based screening compared to National Breast Cancer Registry Data: effectiveness of screening in an emerging country

PURPOSEWe aimed to show the effects of long-term screening on clinical, pathologic, and survival outcomes in patients with screen-detected breast cancer and compare these findings with breast cancer patients registered in the National Breast Cancer Registry Data (NBCRD).METHODSWomen aged 40–69 years, living in Bahcesehir county, Istanbul, Turkey, were screened every 2 years using bilateral mammography. The Bahcesehir National Breast Cancer Registry Data (BMSP) data were collected during a 10-year screening period (five rounds of screening). BMSP data were compared with the NBCRD regarding age, cancer stage, types of surgery, tumor size, lymph node status, molecular subtypes, and survival rates.RESULTSDuring the 10-year screening period, 8758 women were screened with 22621 mammograms. Breast cancer was detected in 130 patients; 51 (39.2%) were aged 40–49 years. The comparison of breast cancer patients in the two programs revealed that BMSP patients had earlier stages, higher breast-conserving surgery rates, smaller tumor size, more frequent negative axillary nodal status, lower histologic grade, and higher ductal carcinoma in situ rates than NBCRD patients (p = 0.001, for all).CONCLUSIONThese results indicate the feasibility of successful population-based screening in middle-income countries.

Breast cancer is the most frequent cancer and cause of cancer-related deaths among Turkish women, as well as globally (1–5). Although the incidence of breast cancer increases every year, mortality rates are decreasing in developed countries because of nationwide screening programs and modern treatment options (5, 6). An invited mammography screening program for women aged between 40 and 69 years revealed a 60% reduction in cancer-related 10-year mortality in a landmark study (7). A systematic review of Myers et al. (8) showed that breast cancer screening reduced mortality by 20% in average-risk women of all age groups. However, this review did not evaluate the differences between annual and biannual mammographic screening.In 2004, the Cancer Control Department of Turkey recommended biannual mammographic screening for women aged 50–69 years, based on European Guidelines. The population of Turkey is relatively young, and almost half of all breast cancer patients in Turkey are younger than 50 years. According to and National Breast Cancer Registry Data (NBCRD) reports, the starting age for mammography screening was set as 40 years. The Bahcesehir Mammographic Screening Program (BMSP) was the first organized population-based 10-year (2009–2019) mammography screening program in Turkey, a middle-income country.Turkish Federation of Breast Diseases Societies started a voluntary data registry program that was provided by breast surgeons working in secondary or tertiary hospitals. This program aimed to collect detailed information of breast cancer patients and to pool comprehensive country-specific breast cancer data. This registry, namely the NBCRD, was the first specified database on breast cancer in the country and was started in 2005, before the BMSP (9). Data from 36 centers were collected for 10 years. However, the cancer registry is a standard database containing general information as defined by the International Agency for Research on Cancer standards.The aim of this study was to show the feasibility of a population-based breast cancer screening program in an emerging, middle-income country, Turkey. The objective of our study was to evaluate the effectiveness of a population-based breast cancer screening program by comparing it with NBCRD data.     

Breast Density Knowledge in a Screening Mammography Population Exposed to Density Notification

ObjectiveWomen are increasingly informed about their breast density due to state density reporting laws. However, accuracy of personal breast density knowledge remains unclear. We compared self-reported with clinically assessed breast density and assessed knowledge of density implications and feelings about future screening.MethodsFrom December 2017 to January 2020, we surveyed women aged 40 to 74 years without prior breast cancer, with a normal screening mammogram in the prior year, and ≥1 recorded breast density measures in four Breast Cancer Surveillance Consortium registries with density reporting laws. We measured agreement between self-reported and BI-RADS breast density categorized as “ever-dense” if heterogeneously or extremely dense within the past 5 years or “never-dense” otherwise, knowledge of dense breast implications, and feelings about future screening.ResultsSurvey participation was 28% (1,528 of 5,408), and 59% (896 of 1,528) of participants had ever-dense breasts. Concordance between self-report versus clinical density was 76% (677 of 896) among women with ever-dense breasts and 14% (89 of 632) among women with never-dense breasts, and 34% (217 of 632) with never-dense breasts reported being told they had dense breasts. Desire for supplemental screening was more frequent among those who reported having dense breasts 29% (256 of 893) or asked to imagine having dense breasts 30% (152 of 513) versus those reporting nondense breasts 15% (15 of 102) (P = .003, P = .002, respectively). Women with never-dense breasts had 6.3-fold higher odds (95% confidence interval:3.39-11.80) of accurate knowledge in states reporting density to all compared to states reporting only to women with dense breasts.DiscussionStandardized communications of breast density results to all women may increase density knowledge and are needed to support informed screening decisions.     

Risk-Based Screening Mammography for Women Aged <40: Outcomes From the National Mammography Database

ObjectiveThere is insufficient large-scale evidence for screening mammography in women <40 years at elevated risk. This study compares risk-based screening of women aged 30 to 39 with risk factors versus women aged 40 to 49 without risk factors in the National Mammography Database (NMD).MethodsThis retrospective, HIPAA-compliant, institutional review board–exempt study analyzed data from 150 NMD mammography facilities in 31 states. Patients were stratified by 5-year age intervals, availability of prior mammograms, and specific risk factors for breast cancer: family history of breast cancer, personal history of breast cancer, and dense breasts. Four screening performance metrics were calculated for each age and risk group: recall rate (RR), cancer detection rate (CDR), and positive predictive values for biopsy recommended (PPV₂) and biopsy performed (PPV₃).ResultsData from 5,986,131 screening mammograms performed between January 2008 and December 2015 in 2,647,315 women were evaluated. Overall, mean CDR was 3.69 of 1,000 (95% confidence interval: 3.64-3.74), RR was 9.89% (9.87%-9.92%), PPV₂ was 20.1% (19.9%-20.4%), and PPV₃ was 28.2% (27.0%-28.5%). Women aged 30 to 34 and 35 to 39 had similar CDR, RR, and PPVs, with the presence of the three evaluated risk factors associated with significantly higher CDR. Moreover, compared with a population currently recommended for screening mammography in the United States (aged 40-49 at average risk), incidence screening (at least one prior screening examination) of women aged 30 to 39 with the three evaluated risk factors has similar cancer detection rates and recall rates.DiscussionWomen with one or more of these three specific risk factors likely benefit from screening commencing at age 30 instead of age 40.     

Estimated Mortality of Breast Cancer Patients Based on Stage at Diagnosis and National Screening Guideline Categorization

PurposeTo compare overall and stage I to IV mortalities of patients diagnosed with breast cancer, calculated from stage at diagnosis using the Surveillance, Epidemiology, and End Results (SEER) database stage mortality estimates, which are based on national screening guideline categorization.MethodsFrom the stage at diagnosis of new breast cancer patients between 2010 and 2014, percentages of invasive cancers, stage 0 + I of total cancers, and stage I of invasive cancers, were calculated. Five-year estimated overall and invasive mortalities were calculated based on stage at diagnosis and SEER survival data. Program categories defined included an Annual Program, based on the ACR (annual screening age 40 and above), a Biennial Program, based on the US Preventative Services Taskforce (biennial screening ages 50 to 74 years), and a Hybrid Program, based on the American Cancer Society (annual screening ages 45 to 54 years, then biennially at ages 55 and above), including respective interval cancers.ResultsIn all, 445 breast cancers met the study inclusion criteria. Comparing program categories, the Annual Program had the lowest percentage of invasive cancers (75.3%), highest percentages of stage 0 + I of total cancers (75.3%) and stage I of invasive cancers (67.1%), and the lowest 5-year estimated overall (10.1%) and stage I to IV (12.0%) mortalities. Estimated overall and stage I to IV mortalities for the Annual Program was 37.3% and 30.6% less, respectively, than the Biennial Program, and 31.8% and 26.8% less, respectively, than the Hybrid Program.ConclusionsBased on stage at diagnosis, the greatest mortality reduction is achieved with mammography utilization starting at the age of 40.     

Reviewing interval cancers: time well spent?

OBJECTIVES: To categorize interval cancers, and thus identify false-negatives, following prevalent and incident screens in the Welsh breast screening programme. SETTING: Breast Test Wales (BTW) Llandudno, Cardiff and Swansea breast screening units. METHODS: Five hundred and sixty interval breast cancers identified following negative mammographic screening between 1989 and 1997 were reviewed by eight screening radiologists. The blind review was achieved by mixing the screening films of women who subsequently developed an interval cancer with screen negative films of women who did not develop cancer, in a ratio of 4 to 1. Another radiologist used patients' symptomatic films to record a reference against which the reviewers' reports of the screening films were compared. Interval cancers were categorized as 'true', 'occult', 'false-negative' or 'unclassified' interval cancers or interval cancers with minimal signs, based on the National Health Service breast screening programme (NHSBSP) guidelines. RESULTS: Of the classifiable interval films, 32% were false-negatives, 55% were true intervals and 12% occult. The proportion of false-negatives following incident screens was half that following prevalent screens (P = 0.004). Forty percent of the seed films were recalled by the panel. CONCLUSIONS: Low false-negative interval cancer rates following incident screens (18%) versus prevalent screens (36%) suggest that lower cancer detection rates at incident screens may have resulted from fewer cancers than expected being present, rather than from a failure to detect tumours. The panel method for categorizing interval cancers has significant flaws as the results vary markedly with different protocol and is no more accurate than other, quicker and more timely methods.     

Ten years of breast screening in the Nova Scotia Breast Screening Program, 1991-2001. experience: use of an adaptable stereotactic device in the diagnosis of screening-detected abnormalities.

OBJECTIVE: To evaluate and present 10-year outcomes of the Nova Scotia Breast Screening Program (NSBSP), a population-based screening program in the province of Nova Scotia, Canada, total population 900 000. SETTING: Organized Breast Screening Program in Nova Scotia, Canada. METHODS: Rates of participation, abnormal referrals, cancer detection rates, and benign:malignant (B:M) rates for core biopsy and surgical biopsy were calculated for asymptomatic women receiving a mammogram through the NSBSP 1991-2001. RESULTS: Of 192 454 mammograms performed on 71 317 women, 33% were aged 40 to 49 years, 39% aged 50 to 59 years, 23% aged 60 to 69 years, and 5% aged 70 years and over. Cancer detection rate increased in each age group respectively: 3.7, 5.8, 9.7, and 13.5 per 1000 population on first-time screens. The positive predictive value of an abnormal screen increased with increasing age groups. Benign breast surgery decreased with increased use of needle core breast biopsy (NCBB). Open surgery decreased from 25 to 6 surgeries per 1000 screens. Of 1519 open surgical procedures (1328 women), 878 cancers were removed, with 37% 10 mm or less, and 61% 15 mm or less. In 613 women in whom the node status was assessed, 79% were negative. CONCLUSION: A quality screening program incorporating NCBB in the diagnostic work-up is effective in the early detection of breast cancer and results in less open surgery, particularly in younger women.     

Outcome analysis for women undergoing annual versus biennial screening mammography: a review of 24,211 examinations.

OBJECTIVE: Our goal was to determine differences in outcome measures between women undergoing annual versus biennial screening mammography. MATERIALS AND METHODS: A retrospective review of prospectively collected data on 24,211 consecutive screening mammography examinations was performed in women aged 40-79 years, all of whom had undergone previous normal screening mammography. Annual screening and biennial screening were defined as examinations performed 10-14 months and 22-26 months, respectively, after previous normal screening mammography. The rates of recall, biopsy, cancer detection, and interval cancer for annual and biennial screening cohorts were calculated, as were tumor size, lymph node status, and stage of invasive cancer. Interval cancer cases were identified by linkage with a regional tumor registry. RESULTS: Of the 4306 biennially screened women, 160 were recalled (3.7%), 45 were biopsied (1.0%), and cancer was detected in 19 (0.44%). Of the 19,905 annually screened women, 518 were recalled (2.6%), 150 were biopsied (0.75%), and cancer was detected in 71 (0.36%). Of the 3278 registry-linked biennially screened women, five had interval cancer (0.15%); of the 15,031 registry-linked annually screened women, 10 had interval cancer (0.07%). For biennial screening-detected cancer and interval invasive cancer combined, the median tumor size was 15 mm, 24% had lymph node metastasis, and 29% were stage 2 or higher. For annual screening-detected cancer, these measures were 11 mm, 14% positive nodes, and 17% stage 2+ cancer, respectively. CONCLUSION: Annual screening mammography results in lower recall rates than does biennial screening (p < .0001). Moreover, annual screening results in the detection of smaller tumors that have a more favorable prognosis (p = .04).     

Analysis of benefit:risk ratio and mortality reduction for the UK Breast Screening Programme

A quantitative analysis has been performed to predict the benefit:risk ratio and associated mortality reduction for the UK National Health Service Breast Screening Programme. The analysis is based on the results of an established biological simulation method coupled with dosimetric information and population statistics applicable to the UK breast screening programme. As well as the general breast screening population, the benefit:risk ratios for specific subgroups of women thought to be at higher risk are estimated. The effects of alterations in screening strategy are also investigated. The results indicate favourable benefit:risk ratios and mortality reductions for all women in the programme, with a breast cancer mortality reduction of approximately 9% over the whole UK female population, equivalent to a breast cancer mortality reduction in the region of 25% for the age range 55-69 years.     

Role of MRI in screening women at high risk for breast cancer

Breast cancer is diagnosed in over one million women worldwide every year. Until breast cancer can be prevented, early detection offers the best chance for cure. Mammographic screening is an effective method for early detection in average-risk women. However, the sensitivity of mammography is decreased in women at high risk for breast cancer. Because of its high sensitivity, multiple investigators have studied the potential role of MRI in screening women at high risk. In the past few years, results from eight major clinical trials exploring breast MRI as a screening tool have been published. Combined, the studies included 4271 patients and found 144 breast cancers detected by MRI, for an overall cancer yield of 3%. The sensitivity of MRI ranged from 71% to 100% across the studies. Although its reported specificity was variable, the call-back rates and risk of benign biopsies were within acceptable limits. In general, patients who underwent breast MRI screening had a 10% risk of being called back, and a 5% risk of having a benign biopsy. This work reviews the literature and current practices and recommendations for MRI as a screening tool for high-risk women.