Mammographic screening: evidence from randomised controlled trials

Considerations for using potential surrogate endpoints in cancer screening trials

The requirement of large-scale expensive cancer screening trials spanning decades creates considerable barriers to the development, commercialisation, and implementation of novel screening tests. One way to address these problems is to use surrogate endpoints for the ultimate endpoint of interest, cancer mortality, at an earlier timepoint. This Review aims to highlight the issues underlying the choice and use of surrogate endpoints for cancer screening trials, to propose criteria for when and how we might use such endpoints, and to suggest possible candidates. We present the current landscape and challenges, and discuss lessons and shortcomings from the therapeutic trial setting. It is hugely challenging to validate a surrogate endpoint, even with carefully designed clinical studies. Nevertheless, we consider whether there are candidates that might satisfy the requirements defined by research and regulatory bodies.

Breast cancer risk prediction using Tyrer-Cuzick algorithm with an 18-SNPs polygenic risk score in a European population with below-average breast cancer incidence

GOALS

To determine whether an 18 single nucleotide polymorphisms (SNPs) polygenic risk score (PRS18) improves breast cancer (BC) risk prediction for women at above-average risk of BC, aged 40-49, in a Central European population with BC incidence below EU average.

METHODS

502 women aged 40-49 years at the time of BC diagnosis completed a questionnaire on BC risk factors (as per Tyrer-Cuzick algorithm) with data known at age 40 and before BC diagnosis. Blood samples were collected for DNA isolation. 250 DNA samples from healthy women aged 50 served as a control cohort. 18 BC-associated SNPs were genotyped in both groups and PRS18 was calculated. The predictive power of PRS18 to detect BC was evaluated using a ROC curve. 10-year BC risk was calculated using the Tyrer-Cuzick algorithm adapted to the Slovenian incidence rate (S-IBIS): first based on questionnaire-based risk factors and, second, including PRS18.

RESULTS

The AUC for PRS18 was 0.613 (95 % CI 0.570-0.657). 83.3 % of women were classified at above-average risk for BC with S-IBIS without PRS18 and 80.7 % when PRS18 was included.

CONCLUSION

BC risk prediction models and SNPs panels should not be automatically used in clinical practice in different populations without prior population-based validation. In our population the addition of an 18SNPs PRS to questionnaire-based risk factors in the Tyrer-Cuzick algorithm in general did not improve BC risk stratification, however, some improvements were observed at higher BC risk scores and could be valuable in distinguishing women at intermediate and high risk of BC.

Breast cancer risk stratification using genetic and non-genetic risk assessment tools for 246,142 women in the UK Biobank

PURPOSE

The benefit of using individual risk prediction tools to identify high-risk individuals for breast cancer (BC) screening is uncertain, despite the personalized approach of risk-based screening.

METHODS

We studied the overlap of predicted high-risk individuals among 246,142 women enrolled in the UK Biobank. Risk predictors assessed include the Gail model (Gail), BC family history (FH, binary), BC polygenic risk score (PRS), and presence of loss-of-function (LoF) variants in BC predisposition genes. Youden J-index was used to select optimal thresholds for defining high-risk.

RESULTS

In total, 147,399 were considered at high risk for developing BC within the next 2 years by at least 1 of the 4 risk prediction tools examined (Gail2-year > 0.5%: 47%, PRS2-yea r > 0.7%: 30%, FH: 6%, and LoF: 1%); 92,851 (38%) were flagged by only 1 risk predictor. The overlap between individuals flagged as high-risk because of genetic (PRS) and Gail model risk factors was 30%. The best-performing combinatorial model comprises a union of high-risk women identified by PRS, FH, and, LoF (AUC2-year [95% CI]: 62.2 [60.8 to 63.6]). Assigning individual weights to each risk prediction tool increased discriminatory ability.

CONCLUSION

Risk-based BC screening may require a multipronged approach that includes PRS, predisposition genes, FH, and other recognized risk factors.

Evidence for reducing cancer-specific mortality due to screening for breast cancer in Europe: A systematic review

BACKGROUND

The aim of this study was to quantify the impact of organised mammography screening on breast cancer mortality across European regions. Therefore, a systematic review was performed including different types of studies from all European regions and stringently used clearly defined quality appraisal to summarise the best evidence.

METHODS

Six databases were searched including Embase, Medline and Web of Science from inception to March 2018. To identify all eligible studies which assessed the effect of organised screening on breast cancer mortality, two reviewers independently applied predefined inclusion and exclusion criteria. Original studies in English with a minimum follow-up of five years that were randomised controlled trials (RCTs) or observational studies were included. The Cochrane risk of bias instrument and the Newcastle-Ottawa Scale were used to assess the risk of bias.

RESULTS

Of the 5015 references initially retrieved, 60 were included in the final analysis. Those comprised 36 cohort studies, 17 case-control studies and 7 RCTs. None were from Eastern Europe. The quality of the included studies varied: Nineteen of these studies were of very good or good quality. Of those, the reduction in breast cancer mortality in attenders versus non-attenders ranged between 33% and 43% (Northern Europe), 43%-45% (Southern Europe) and 12%-58% (Western Europe). The estimates ranged between 4% and 31% in invited versus non-invited.

CONCLUSION

This systematic review provides evidence that organised screening reduces breast cancer mortality in all European regions where screening was implemented and monitored, while quantification is still lacking for Eastern Europe. The wide range of estimates indicates large differences in the evaluation designs between studies, rather than in the effectiveness of screening.

Abbreviated Magnetic Resonance Imaging for Breast Cancer Screening: Concept, Early Results, and Considerations

Breast magnetic resonance imaging (MRI) has been increasingly utilized, especially in screening for high-risk cases, because of its high sensitivity and superior ability to detect cancers as compared with mammography and ultrasound. Several limitations such as higher cost, longer examination time, longer interpretation time, and low availability have hindered the wider application of MRI, especially for screening of average-risk women. To overcome some of these limitations and increase access to MRI screening, an abbreviated breast MRI protocol has been introduced. Abbreviated breast MRI is becoming popular and challenges the status quo. This review aims to present an overview of abbreviated MRI, discuss the current findings, and introduce ongoing prospective trials.

Effect of screening mammography on breast cancer mortality: Quasi-experimental evidence from rollout of the Dutch population-based program with 17-year follow-up of a cohort

There is uncertainty about the magnitude of the effect of screening mammography on breast cancer mortality. The relevance and validity of evidence from dated randomized controlled trials has been questioned, whereas observational studies often lack a valid comparison group. There is no estimate of the effect of one screening invitation only. We exploited the geographic rollout of the Dutch screening mammography program across municipalities to estimate the effects of one additional biennial screening invitation on breast cancer and all‐cause mortality. Population administrative data provided vital status and cause of death of a cohort of women aged 49–63 in 1995 over 17 years. Linear probability models were used to estimate the mortality effects. We estimated 154 fewer breast cancer deaths (95% confidence interval: 40–267; p = 0.01) over 17 years in a population of 100,000 women aged 49–63 who received one additional biennial screening invitation, which corresponds to an 9.6% risk reduction for a woman of age 56. The estimated effect on all‐cause mortality was negative but not close to statistical significance. Our study shows that one single invitation for breast cancer screening is effective in reducing breast cancer mortality, which is important for health policy. The effect is smaller than previous estimates of the effect of invitation for multiple screens, which further emphasizes the importance of achieving regular participation.

What's new?

To date, there is still uncertainty about the magnitude of the effect of screening mammography on breast cancer mortality. Here, the authors exploited the geographic rollout of the Dutch screening mammography program and high‐quality national population, cancer, and death registries to avoid limitations of observational research by comparing breast cancer mortality across groups of women of the same age who joined the mammography program at different dates. The analysis provides a unique estimate of the effect of one additional invitation for screening mammography on breast cancer mortality (around 10%) and delivers evidence in favour of the effectiveness of such screening.

Value of whole breast magnetic resonance elastography added to MRI for lesion characterization

The purpose of this work was to assess the diagnostic value of magnetic resonance elastography (MRE) in addition to MRI to differentiate malignant from benign breast tumors, and the feasibility of performing MRE on the whole breast. MRE quantified biomechanical properties within the entire breast (50 slices) using an 11 min acquisition protocol at an isotropic image acquisition resolution of 2 × 2 × 2 mm³ . Fifty patients were included. Finally, 43 patients (median age 52) with a suspect breast lesion detected by mammography and/or ultrasound were examined by MRI and MRE at 1.5 T. The viscoelastic parameters, i.e. elasticity (G_d ), viscosity (G_l ), the magnitude of the complex shear modulus Gd2+Gl2, and the phase angle y=2πatanGlGd, were measured via MRE and correlated with MRI Breast Imaging-Reporting and Data System (BI-RADS) score, histological type, and histological grade. Stroma component and angiogenesis were also correlated with viscoelastic properties. In the 43 lesions, G_d decreased and y increased with the MRI BI-RADS score (p_Gd  = 0.02, p_y  = 0.002), whereas (G_l ) and y were increased in malignant lesions (p_Gl  = 0.045, p_y  = 0.0004). The area under the curve increased from 0.84 for MRI BI-RADS alone to 0.92 with the MRI BI-RADS and y (AUC increase +0.08; 95% CI (-0.003; 0.16)). Lesion characterization using the y parameter increased the diagnostic accuracy. The phase angle y was found to have a significant role (p = 0.01) in predicting malignancy independently of the MRI BI-RADS. Interestingly, histological analysis showed no correlation between viscoelastic parameters and percentage and type of stroma, CD34 quantification of vessels, or histological grade. The combination of MRE and MRI improves the diagnostic accuracy for breast lesions in the studied cohort. In particular, the phase angle y was found to have a significant role in predicting malignancy in addition to BI-RADS.

Breast cancer screening in developing countries

Developing countries have limited healthcare resources and use different strategies to diagnose breast cancer. Most of the population depends on the public healthcare system, which affects the diagnosis of the tumor. Thus, the indicators observed in developed countries cannot be directly compared with those observed in developing countries because the healthcare infrastructures in developing countries are deficient. The aim of this study was to evaluate breast cancer screening strategies and indicators in developing countries. A systematic review and the Population, Intervention, Comparison, Outcomes, Timing, and Setting methodology were performed to identify possible indicators of presentation at diagnosis and the methodologies used in developing countries. We searched PubMed for the terms "Breast Cancer" or "Breast Cancer Screening" and "Developing Country" or "Developing Countries". In all, 1,149 articles were identified. Of these articles, 45 full articles were selected, which allowed us to identify indicators related to epidemiology, diagnostic intervention (diagnostic strategy, diagnostic infrastructure, percentage of women undergoing mammography), quality of intervention (presentation of symptoms at diagnosis, time to diagnosis, early stage disease), comparisons (trend curves, subpopulations at risk) and survival among different countries. The identification of these indicators will improve the reporting of methodologies used in developing countries and will allow us to evaluate improvements in public health related to breast cancer.

Self concepts, health locus of control and cognitive functioning associated with health-promoting lifestyles in schizophrenia

PURPOSE

The study aimed to investigate the relationship among self concepts, health locus of control, cognitive functioning and health-promoting lifestyles in patients diagnosed with schizophrenia. We examined health-promoting lifestyles through self-efficacy, self-esteem, health locus of control and neurocognitive factors.

METHOD

Fifty-six people with schizophrenia were enrolled in the study group. All subjects participated in the self-esteem (Rosenberg Self-Esteem Scale), self-efficacy (General Self-Efficacy Scale), health locus of control (The Multidimensional Health Locus of Control Scales), health-promoting lifestyles (Health Promotion Life-style Profile-II) and a series of neurocognitive measures.

FINDINGS

Stepwise regression analysis revealed that self-efficacy, internal health locus of control and attentional set-shifting accounted for 42% of the variance in total health-promoting lifestyles scores. Self-efficacy, self-esteem, internal and powerful others health locus of control and attentional set-shifting were significant predictors for domains of health-promoting lifestyles, respectively.

CONCLUSION

Study findings can help mental health professionals maintain and improve health-promoting behaviors through a better understanding of self-esteem, self-efficacy, health locus of control and neurocognitive functioning among people with schizophrenia.

Predictive Factors of the Survival of Women With Invasive Breast Cancer in French Guiana: The Burden of Health Inequalities

BACKGROUND

The prognosis of patients with breast cancer in French Guiana is worse than in France, with 23 deaths per 100 incident cases versus 17 per 100 in metropolitan France. This study aimed to compare the relative survival of patients with invasive breast cancer (IBC) between women from French Guiana and metropolitan France and to determine risk factors influencing breast cancer survival in French Guiana.

MATERIALS AND METHODS

Data were collected from the Cancer Registry of French Guiana. We compared the relative survival of women with IBC between French Guiana and metropolitan France. We used the Cox proportional hazard regression to evaluate the effect of prognostic factors on cancer-specific mortality in French Guiana.

RESULTS

We included all 269 cases of IBC in women diagnosed in French Guiana between 2003 and 2009. The overall 5-year relative survival rate of patients with IBC was 79% in French Guiana and 86% in metropolitan France. The place of birth (foreign country vs. French territory), the tumor stage at the time of diagnosis, the mode of diagnosis (symptoms vs. screening), the presence of hormone receptors in the tumor, and the histologic type were the variables associated with survival differences. None of the other study variables were significantly associated with prognosis.

CONCLUSION

Access to care for migrants is challenging, which leads to health inequalities. Early detection through prevention programs is crucial to increase IBC survival, notably for foreign-born patients.

A comparison of clinical-pathological characteristics between symptomatic and interval breast cancer

BACKGROUND

An association between interval breast cancers (cancer detected after a normal mammogram and before the next scheduled mammogram) and tumour aggressiveness has been postulated which may reflect their relatively poor overall prognosis. The aim of this study was to evaluate known prognostic features of screen detected breast cancers compared to interval breast cancers.

METHODS

Patients diagnosed with breast cancer between January 2010 and 2013 at a single unit of the National Breast Screening Program (NBSP) in Ireland and those between the ages of 50 and 65 diagnosed at a symptomatic breast clinic were included in the study. Patients who had not had a screening mammogram within the proceeding two years or had a previous history of breast cancer were excluded. Data were retrospectively collected on patient demographics, tumour type, grade, hormone receptor status and stage of disease at presentation.

RESULTS

There were 915 patients included in the study, with 92% (n = 844) diagnosed through the NBSP. Ductal carcinoma in-situ accounted for 19% (n = 160) of screen-detected breast cancers but only 2.8% of interval cancers (p < 0.05). The most common type of invasive cancer was invasive ductal carcinoma. Tumour grade was significantly higher in interval breast cancers (p < 0.05). Interval cancers were identified at a significantly higher stage (Stage 1 versus 2; p < 0.001) than screen-detected cancers. Interval breast cancers were less likely to be ER positive (76% versus 81%; p < 0.05) and significantly more likely to over-express HER2 (20% vs 10%, p < 0.05) than screen-detected cancers.

CONCLUSION

This study highlights the fact that interval cancers appear to have a number of adverse prognostic markers for overall breast cancer survival when compared to women with screen-detected breast cancers. Interval cancers were more likely to be invasive, of a higher grade and stage and with a greater predominance of HER2 and triple negative molecular subtypes. Therefore this heterogeneous group of tumours may be biologically more aggressive and account disproportionately to overall breast cancer mortality.

Recommendations for breast cancer surveillance for female survivors of childhood, adolescent, and young adult cancer given chest radiation: a report from the International Late Effects of Childhood Cancer Guideline Harmonization Group

Female survivors of childhood, adolescent, and young adult (CAYA) cancer who were given radiation to fields that include breast tissue (ie, chest radiation) have an increased risk of breast cancer. Clinical practice guidelines are essential to ensure that these individuals receive optimum care and to reduce the detrimental consequences of cancer treatment; however, surveillance recommendations vary among the existing long-term follow-up guidelines. We applied evidence-based methods to develop international, harmonised recommendations for breast cancer surveillance among female survivors of CAYA cancer who were given chest radiation before age 30 years. The recommendations were formulated by an international, multidisciplinary panel and are graded according to the strength of the underlying evidence.

Nuclear imaging of the breast: translating achievements in instrumentation into clinical use

Approaches to imaging the breast with nuclear medicine and∕or molecular imaging methods have been under investigation since the late 1980s when a technique called scintimammography was first introduced. This review charts the progress of nuclear imaging of the breast over the last 20 years, covering the development of newer techniques such as breast specific gamma imaging, molecular breast imaging, and positron emission mammography. Key issues critical to the adoption of these technologies in the clinical environment are discussed, including the current status of clinical studies, the efforts at reducing the radiation dose from procedures associated with these technologies, and the relevant radiopharmaceuticals that are available or under development. The necessary steps required to move these technologies from bench to bedside are also discussed.

Breast cancer causes and treatment: where are we going wrong?

This discussion paper seeks to provoke thoughts about cancer research in general, and why breast cancer in particular is not yet "curable". It asks the question - are we looking at the disease in the right way? Should we regard cancer as a progressive state, which is part of aging? Should we tailor treatment to "reset" the system or slow progression rather than try using toxic and aggressive therapy to kill every cancer cell (and sometimes also the patient)? The thesis is presented that we need to revisit our fundamental beliefs about the disease and then ask why we cling to beliefs that clearly are no longer valid. The paper also questions the role of ethics boards in hampering research and discusses the concept that breast cancer is an industry with vested interests involving profiteering by preventive, diagnostic, and therapeutic players. Finally, the paper suggests some ways forward based on emerging concepts in system biology and epigenetics.

What factors explain disparities in mammography rates among Asian-American immigrant women? A population-based study in California

BACKGROUND

The purpose of this study was to compare rates of screening mammography among immigrant women in five Asian-American ethnic groups in California, and ascertain the extent to which differences in mammography rates among these groups are attributable to differences in known correlates of cancer screening.

METHODS

Using 2009 data from the California Health Interview Survey, we compared the rates of mammography among Chinese, Filipino, Japanese, Korean, and Vietnamese immigrants 40 years and older. To assess the impact of Asian ethnicity on participation in screening, we performed multiple logistic regression analysis with models that progressively adjusted for acculturation, sociodemographic characteristics, access to health care, and breast cancer risk factors, and examined the predicted probabilities of screening after adjusting for these factors.

FINDINGS

Participation in screening mammography differed according to ethnicity, with Filipina and Vietnamese Americans having the highest rates and Korean Americans having the lowest rates of lifetime and recent (past 2 years) screening. These differences decreased substantially after adjusting for acculturation, sociodemographic factors, and risk factors of breast cancer, but differences remained, most notably for Korean Americans, who continued to have the lowest predicted probability of screening even after adjustment for these factors.

CONCLUSIONS

This analysis draws attention to low mammography screening rates among Asian-American immigrants, especially recent immigrants who lack health insurance. Given that their breast cancer incidence is rising with length of stay in the United States, it is important to increase regular mammography screening in these groups.

Cost-effectiveness of screening women with familial risk for breast cancer with magnetic resonance imaging

BACKGROUND

To reduce mortality, women with a family history of breast cancer are often screened with mammography before age 50 years. Additional magnetic resonance imaging (MRI) improves sensitivity and is cost-effective for BRCA1/2 mutation carriers. However, for women with a family history without a proven mutation, cost-effectiveness is unclear.

METHODS

We evaluated data of the largest prospective MRI screening study (MRISC). Between 1999 and 2007, 1597 women (8370 woman-years at risk) aged 25 to 70 years with an estimated cumulative lifetime risk of 15% to 50% for breast cancer were screened with clinical breast examination every 6 months and with annual mammography and MRI. We calculated the cost per detected and treated breast cancer. After incorporating MRISC data into a microsimulation screening analysis model (MISCAN), different schemes were evaluated, and cost per life-year gained (LYG) was estimated in comparison with the Dutch nationwide breast cancer screening program (biennial mammography from age 50 to 75 years). All statistical tests were two-sided.

RESULTS

Forty-seven breast cancers (9 ductal carcinoma in situ) were detected. Screening with additional MRI costs $123 672 (€93 639) per detected breast cancer. In increasing age-cohorts, costs per detected and treated breast cancer decreased, but, unexpectedly, the percentage of MRI-only detected cancers increased. Screening under the MRISC-scheme from age 35 to 50 years was estimated to reduce breast cancer mortality by 25% at $134 932 (€102 164) per LYG (3.5% discounting) compared with 17% mortality reduction at $54 665 (€41 390) per LYG with mammography only.

CONCLUSIONS

Screening with MRI may improve survival for women with familial risk for breast cancer but is expensive, especially in the youngest age categories.

Breast density as indicator for the use of mammography or MRI to screen women with familial risk for breast cancer (FaMRIsc): a multicentre randomized controlled trial

BACKGROUND

To reduce mortality, women with a family history of breast cancer often start mammography screening at a younger age than the general population. Breast density is high in over 50% of women younger than 50 years. With high breast density, breast cancer incidence increases, but sensitivity of mammography decreases. Therefore, mammography might not be the optimal method for breast cancer screening in young women. Adding MRI increases sensitivity, but also the risk of false-positive results. The limitation of all previous MRI screening studies is that they do not contain a comparison group; all participants received both MRI and mammography. Therefore, we cannot empirically assess in which stage tumours would have been detected by either test.The aim of the Familial MRI Screening Study (FaMRIsc) is to compare the efficacy of MRI screening to mammography for women with a familial risk. Furthermore, we will assess the influence of breast density.

METHODS/DESIGN

This Dutch multicentre, randomized controlled trial, with balanced randomisation (1:1) has a parallel grouped design. Women with a cumulative lifetime risk for breast cancer due to their family history of ≥20%, aged 30-55 years are eligible. Identified BRCA1/2 mutation carriers or women with 50% risk of carrying a mutation are excluded. Group 1 receives yearly mammography and clinical breast examination (n = 1000), and group 2 yearly MRI and clinical breast examination, and mammography biennially (n = 1000).Primary endpoints are the number and stage of the detected breast cancers in each arm. Secondary endpoints are the number of false-positive results in both screening arms. Furthermore, sensitivity and positive predictive value of both screening strategies will be assessed. Cost-effectiveness of both strategies will be assessed. Analyses will also be performed with mammographic density as stratification factor.

DISCUSSION

Personalized breast cancer screening might optimize mortality reduction with less over diagnosis. Breast density may be a key discriminator for selecting the optimal screening strategy for women < 55 years with familial breast cancer risk; mammography or MRI. These issues are addressed in the FaMRIsc study including high risk women due to a familial predisposition.

TRIAL REGISTRATION

Netherland Trial Register NTR2789.

The demographic, system, and psychosocial origins of mammographic screening disparities: prediction of initiation versus maintenance screening among immigrant and non-immigrant women

Disparities in breast screening are well documented. Less clear are differences within groups of immigrant and non-immigrant minority women or differences in adherence to mammography guidelines over time. A sample of 1,364 immigrant and non-immigrant women (African American, English Caribbean, Haitian, Dominican, Eastern European, and European American) were recruited using a stratified cluster-sampling plan. In addition to measuring established predictors of screening, women reported mammography frequency in the last 10 years and were (per ACS guidelines at the time) categorized as never, sub-optimal (<1 screen/year), or adherent (1+ screens/year) screeners. Multinomial logistic regression showed that while ethnicity infrequently predicted the never versus sub-optimal comparison, English Caribbean, Haitian, and Eastern European women were less likely to screen systematically over time. Demographics did not predict the never versus sub-optimal distinction; only regular physician, annual exam, physician recommendation, and cancer worry showed effects. However, the adherent categorization was predicted by demographics, was less likely among women without insurance, a regular physician, or an annual exam, and more likely among women reporting certain patterns of emotion (low embarrassment and greater worry). Because regular screening is crucial to breast health, there is a clear need to consider patterns of screening among immigrant and non-immigrant women as well as whether the variables predicting the initiation of screening are distinct from those predicting systematic screening over time.

Mammography: EUSOBI recommendations for women's information

This paper summarises the basic information to be offered to women who undergo mammography. After a delineation of the general aim of early diagnosis of breast cancer, the main difference between screening mammography and diagnostic mammography is explained. The best time for scheduling mammography in fertile women is defined. The need to bring images and reports from the previous mammogram (and from other recent breast imaging examinations) is highlighted. The technique and procedure of mammography are briefly described with particular attention to discomfort and pain experienced by a fraction of women who undergo the test. Information is given on the recall during a screening program and on the request for further work-up after a diagnostic mammography. The logic of the diagnostic mammography report and of classification systems such as BI-RADS and R1-R5 is illustrated, and brief but clear information is given about the diagnostic performance of the test, with particular reference to interval cancers. Moreover, the breast cancer risk due to radiation exposure from mammography is compared to the reduction in mortality obtained with the test, and the concept of overdiagnosis is presented. Finally, five frequently asked questions are answered.

Interpreting overdiagnosis estimates in population-based mammography screening

Estimates of overdiagnosis in mammography screening range from 1% to 54%. This review explains such variations using gradual implementation of mammography screening in the Netherlands as an example. Breast cancer incidence without screening was predicted with a micro-simulation model. Observed breast cancer incidence (including ductal carcinoma in situ and invasive breast cancer) was modeled and compared with predicted incidence without screening during various phases of screening program implementation. Overdiagnosis was calculated as the difference between the modeled number of breast cancers with and the predicted number of breast cancers without screening. Estimating overdiagnosis annually between 1990 and 2006 illustrated the importance of the time at which overdiagnosis is measured. Overdiagnosis was also calculated using several estimators identified from the literature. The estimated overdiagnosis rate peaked during the implementation phase of screening, at 11.4% of all predicted cancers in women aged 0–100 years in the absence of screening. At steady-state screening, in 2006, this estimate had decreased to 2.8%. When different estimators were used, the overdiagnosis rate in 2006 ranged from 3.6% (screening age or older) to 9.7% (screening age only). The authors concluded that the estimated overdiagnosis rate in 2006 could vary by a factor of 3.5 when different denominators were used. Calculations based on earlier screening program phases may overestimate overdiagnosis by a factor 4. Sufficient follow-up and agreement regarding the chosen estimator are needed to obtain reliable estimates.

Multicenter surveillance of women at high genetic breast cancer risk using mammography, ultrasonography, and contrast-enhanced magnetic resonance imaging (the high breast cancer risk italian 1 study): final results

OBJECTIVES

: To prospectively compare clinical breast examination, mammography, ultrasonography, and contrast-enhanced magnetic resonance imaging (MRI) in a multicenter surveillance of high-risk women.

MATERIALS AND METHODS

: We enrolled asymptomatic women aged ≥ 25: BRCA mutation carriers; first-degree relatives of BRCA mutation carriers, and women with strong family history of breast/ovarian cancer, including those with previous personal breast cancer.

RESULTS

: A total of 18 centers enrolled 501 women and performed 1592 rounds (3.2 rounds/woman). Forty-nine screen-detected and 3 interval cancers were diagnosed: 44 invasive, 8 ductal carcinoma in situ; only 4 pT2 stage; 32 G3 grade. Of 39 patients explored for nodal status, 28 (72%) were negative. Incidence per year-woman resulted 3.3% overall, 2.1% <50, and 5.4% ≥ 50 years (P < 0.001), 4.3% in women with previous personal breast cancer and 2.5% in those without (P = 0.045). MRI was more sensitive (91%) than clinical breast examination (18%), mammography (50%), ultrasonography (52%), or mammography plus ultrasonography (63%) (P < 0.001). Specificity ranged 96% to 99%, positive predictive value 53% to 71%, positive likelihood ratio 24 to 52 (P not significant). MRI showed significantly better negative predictive value (99.6) and negative likelihood ratio (0.09) than those of the other modalities. At receiver operating characteristic analysis, the area under the curve of MRI (0.97) was significantly higher than that of mammography (0.83) or ultrasonography (0.82) and not significantly increased when MRI was combined with mammography and/or ultrasonography. Of 52 cancers, 16 (31%) were diagnosed only by MRI, 8 of 21 (38%) in women <50, and 8 of 31 (26%) in women ≥ 50 years of age.

CONCLUSION

: MRI largely outperformed mammography, ultrasonography, and their combination for screening high-risk women below and over 50.

Independent prognostic value of screen detection in invasive breast cancer

BACKGROUND

Mammographic screening has led to a proportional shift toward earlier-stage breast cancers at presentation. We assessed whether the method of detection provides prognostic information above and beyond standard prognostic factors and investigated the accuracy of predicted overall and breast cancer-specific survival by the computer tool Adjuvant! among patients with screen-detected, interval, and nonscreening-related carcinomas.

METHODS

We studied 2592 patients with invasive breast cancer who were treated at the Netherlands Cancer Institute from January 1, 1990, through December 31, 2000. Overall and breast cancer-specific survival probabilities among patients with mammographically screen-detected (n = 958), interval (n = 417), and nonscreening-related (n = 1217) breast carcinomas were compared. Analyses were adjusted for clinicopathologic characteristics and adjuvant systemic therapy. Because of gradual implementation of population-based screening in the Netherlands, analyses were stratified a priori according to two periods of diagnosis. All statistical tests were two-sided.

RESULTS

Screen detection was associated with reduced mortality (adjusted hazard ratio for all-cause mortality = 0.74, 95% confidence interval = 0.63 to 0.87, P < .001, and adjusted hazard ratio for breast cancer-specific mortality = 0.62, 95% confidence interval = 0.50 to 0.78, P < .001, respectively) compared with nonscreening-related detection. The absolute adjusted reduction in breast cancer-specific mortality was 7% at 10 years. The prognostic value of the method of detection was independent of the period of diagnosis and was similar across tumor size and lymph node status categories, indicating its prognostic value beyond stage migration. Adjuvant! underestimated breast cancer-specific survival in patients with screen-detected (-3.2%) and interval carcinomas (-5.4%).

CONCLUSIONS

Screen detection was found to be independently associated with better prognosis for overall and breast cancer-specific survival and to provide prognostic information beyond stage migration among patients with invasive breast cancer. We propose that the method of detection should be taken into account when estimating individual prognosis.

A community peer-volunteer telephone reminder call to increase breast cancer-screening attendance

PURPOSE/OBJECTIVES

To assess the effect of a tailored telephone reminder call by community peer volunteers on mammography rates in women who do not attend a breast cancer-screening program.

DESIGN

Individual-level randomized trial.

SETTING

Four semirural communities in Belgium.

SAMPLE

Women aged 50-69 years who had not had a mammogram.

METHODS

Women in the usual care (control) arm received an invitation letter for screening mammography and an information leaflet; women in the intervention arm received usual care as well as a telephone reminder call. The call was tailored on four variables: individual mammography history, mailing of the invitation letter, mammography appointment date, and type of mammography facility in the area (e.g., mobile unit versus fixed site). Community peer volunteers made up to three attempts to call the women in the intervention arm.

MAIN RESEARCH VARIABLES

Mammography rates verified by screening registration review and adverse events identified in contacts with peer volunteers, radiologists, and community workers of local authorities.

FINDINGS

A total of 3,880 women were included in the study and individually randomized into control and intervention groups. Phone numbers were identified for 79% of the women in the intervention group, and 69% were contacted. Twenty-two percent had screening mammography, which was 4% higher than controls (relative risk = 1.22). No adverse effects were identified. An additional mammogram came at an average cost of 17 phone conversations and two hours of volunteer work.

CONCLUSIONS

The tested telephone reminder call is suitable for Belgian women.

IMPLICATIONS FOR NURSING

The telephone reminder call may be implemented in settings similar to the studied context.

Increasing breast examinations among arab women using a tailored culture-based intervention

This study aimed to assess outcomes of a culture-specific intervention devised to reduce barriers to breast cancer screening among Arab women in Israel. Women in intervention (n = 42) and control (n = 24) groups answered breast examination performance and Arab culture-specific barriers and health beliefs questionnaires at pre- and postintervention. Women in the study group received tailored telephone intervention between the 2 interviews. Although the study and control groups did not differ in rate of attending clinical examinations and mammography at pre-intervention, at post-intervention, almost 48% of the intervention group and 12.5% of the control group scheduled or attended a clinical examination, and 38.5% of women in the intervention group and 21.4% of the control group attended or scheduled a mammography. Of the cultural barriers, a significant group x time effect was found for the cultural barriers of exposure, social barriers, and self-uneasiness with body, with a higher decrease in the intervention group. Of the health beliefs, a group x time effect was found for perceived vulnerability and perceived barriers to clinical examination and mammography, which significantly decreased in the intervention group, but not in the control group. The preliminary results showed that the culture-based intervention was effective in reducing barriers and increasing the rate of breast cancer examinations.

Screening and prevention of breast cancer in primary care

Mammography remains the mainstay of breast cancer screening. There is little controversy that mammography reduces the risk of dying from breast cancer by about 23% among women between the ages of 50 and 69 years, although the harms associated with false-positive results and overdiagnosis limit the net benefit of mammography. Women in their 70s may have a small benefit from screening mammography, but overdiagnosis increases in this age group as do competing causes of death. While new data support a 16% reduction in breast cancer mortality for 40- to 49-year-old women after 10 years of screening, the net benefit is less compelling in part because of the lower incidence of breast cancer in this age group and because mammography is less sensitive and specific in women younger than 50 years. Digital mammography is more sensitive than film mammography in young women with similar specificity, but no improvements in breast cancer outcomes have been demonstrated. Magnetic resonance imaging may benefit the highest risk women. Randomized trials suggest that self-breast examination does more harm than good. Primary prevention with currently approved medications will have a negligible effect on breast cancer incidence. Public health efforts aimed at increasing mammography screening rates, promoting regular exercise in all women, maintaining a healthy weight, limiting alcohol intake, and limiting postmenopausal hormone therapy may help to continue the recent trend of lower breast cancer incidence and mortality among American women.

Effectiveness of early detection on breast cancer mortality reduction in Catalonia (Spain)

Background

At present, it is complicated to use screening trials to determine the optimal age intervals and periodicities of breast cancer early detection. Mathematical models are an alternative that has been widely used. The aim of this study was to estimate the effect of different breast cancer early detection strategies in Catalonia (Spain), in terms of breast cancer mortality reduction (MR) and years of life gained (YLG), using the stochastic models developed by Lee and Zelen (LZ).

Methods

We used the LZ model to estimate the cumulative probability of death for a cohort exposed to different screening strategies after T years of follow-up. We also obtained the cumulative probability of death for a cohort with no screening. These probabilities were used to estimate the possible breast cancer MR and YLG by age, period and cohort of birth. The inputs of the model were: incidence of, mortality from and survival after breast cancer, mortality from other causes, distribution of breast cancer stages at diagnosis and sensitivity of mammography. The outputs were relative breast cancer MR and YLG.

Results

Relative breast cancer MR varied from 20% for biennial exams in the 50 to 69 age interval to 30% for annual exams in the 40 to 74 age interval. When strategies differ in periodicity but not in the age interval of exams, biennial screening achieved almost 80% of the annual screening MR. In contrast to MR, the effect on YLG of extending screening from 69 to 74 years of age was smaller than the effect of extending the screening from 50 to 45 or 40 years.

Conclusion

In this study we have obtained a measure of the effect of breast cancer screening in terms of mortality and years of life gained. The Lee and Zelen mathematical models have been very useful for assessing the impact of different modalities of early detection on MR and YLG in Catalonia (Spain).

Developing and testing an instrument for identifying culture-specific barriers to breast cancer screening in Israeli Arab women

AIMS

To develop and assess an instrument for studying culture-specific barriers to performing examinations for early detection of breast cancer.

METHODS

A three-step design: (a) content analysis of five focus groups (n=51); (b) constructing and initial testing of the Arab culture-specific barriers (ACSB) instrument in a pilot study (n=79); (c) testing for validity and reliability of the revised ACSB instrument (n=300, of these 200 Muslim and 100 Christian, mean age 48). Construct validity was examined using factor analysis. Performance of screenings (mammography and clinical and self breast examination) was used to test criterion validity by logistic regression and receiver operating characteristic (ROC) curve; convergent validity was tested by the barriers subscale of the health beliefs questionnaire. Internal consistency reliability was tested by Cronbach's alpha coefficients.

RESULTS

Factor analysis revealed five subscales: social barriers, exposure barriers, environmental barriers, uneasiness with own body, and traditional beliefs concerning cancer. The factors accounted for 54.6% of cumulative variance. Twelve items not meeting item-scale criteria were removed, resulting in a 21-item instrument. Convergent validity was confirmed for all subscales except traditional beliefs. ACSB mean score explained between 0.79 (95% CI .72-.86) and 0.85 (95% CI .79-.94) of the area under the ROC curve of the screening procedures. Internal consistency of the subscales ranged from 0.76 to 0.90.

CONCLUSIONS

The study showed initial satisfactory reliability of the ACSB. Validity was approved for social barriers, exposure barriers, environmental barriers and uneasiness with own body subscales, and only partially for traditional beliefs. Further examination of the instrument with different populations of Arab women is needed.

Impressive time-related influence of the Dutch screening programme on breast cancer incidence and mortality, 1975-2006

The aim of this study was to assess changes in the trends in breast cancer mortality and incidence from 1975 to 2006 among Dutch women, in relation to the implementation of the national breast cancer screening programme. Screening started in 1989 for women aged 50-69 and was extended to women aged 70-75 years in 1998 (attendance rate approximately >80%). A joinpoint Poisson regression analysis was used to identify significant changes in rates over time. Breast cancer mortality rates increased until 1994 (age group 35-84), but thereafter showed a marked decline of 2.3-2.8% per annum for the age groups 55-64 and 65-74 years, respectively. For the age group of 75-84 years, a decrease started in the year 2001. In women aged 45-54, an early decline in breast cancer mortality rates was noted (1971-1980), which is ongoing from 1992. For all ages, breast cancer incidence rates showed an increase between 1989 and 1993, mainly caused by the age group 50-69, and thereafter, a moderate increase caused by age group 70-74 years. This increase can partly be explained by the introduction of screening. The results indicate an impressive decrease in breast cancer mortality in the age group invited for breast cancer screening, starting to show quite soon after implementation.

Breast cancer screening policies in developing countries: a cost-effectiveness analysis for India

BACKGROUND

India, the largest developing country, has a steadily rising incidence of breast cancer. Estimates and comparisons of the cost-effectiveness of feasible breast cancer screening policies in developing countries and identification of the determinants of cost and efficacy are needed.

METHODS

A Microsimulation Screening Analysis model of breast cancer was calibrated to available data on breast cancer incidence, stage distribution, and mortality in India. The model was used to estimate the costs of screening for breast cancer in India, its effects on mortality, and its cost-effectiveness (ie, costs of screening per life-year gained or life saved). Screening using clinical breast examination (CBE) or mammography among different age groups and at various frequencies was analyzed. Costs were expressed in international dollars (Int.$), the currency used by the World Health Organization, which has the same purchasing power in India as the US dollar has in the United States. To determine which factors influenced cost-effectiveness, sensitivity analyses were performed.

RESULTS

The estimated mortality reduction was the greatest for programs targeting women between age 40 and 60 years. Using a 3% discount rate, a single CBE at age 50 had an estimated cost-effectiveness ratio of Int.$793 per life year gained and a breast cancer mortality reduction of 2%. The cost-effectiveness ratio increased to Int.$1135 per life year gained for every-5-year CBE (age 40-60 years) and to Int.$1341 for biennial CBE (age 40-60 years); the corresponding reductions in breast cancer mortality were 8.2% and 16.3%, respectively. CBE performed annually from ages 40 to 60 was predicted to be nearly as efficacious as biennial mammography screening for reducing breast cancer mortality while incurring only half the net costs. The main factors affecting cost-effectiveness were breast cancer incidence, stage distribution, and cost savings on prevented palliative care.

CONCLUSION

The estimated cost-effectiveness of CBE screening for breast cancer in India compares favorably with that of mammography in developed countries. However, in view of competing priorities and economic conditions, the introduction of screening in India represents a greater challenge than it has been in more developed countries.

Health beliefs and rates of breast cancer screening among Arab women

OBJECTIVES

To examine the relationship between health beliefs and participation in breast cancer screening among Arab women in Israel.

METHODS

A random sample of 568 Arab women, aged 20-60, belonging to three religious groups, Muslim, Christian, and Druze, was recruited. Participants answered a telephone questionnaire regarding attendance for mammography screening and clinical breast examination (CBE) and health beliefs.

RESULTS

Christian women had undergone more mammography screening and CBE than Druze and Muslim women. They perceived more benefits and fewer barriers to screening practices and had greater perception of the severity of breast cancer. Perception of susceptibility was similar across groups. The barriers that were significant for the Druze and Muslim women were feelings of discomfort and embarrassment, the belief that there was no cure in the case of a positive finding, perceiving mammography as hazardous to health, and perceiving CBE as painful. Logistic regression revealed that age, group, and having a first-degree relative with breast cancer predicted participation in early detection screening. Physician's recommendation predicted mammography, and level of participants' religiosity predicted CBE.

CONCLUSIONS

Diversity in health beliefs and behaviors exists in religious subgroups. Health communications should be modified to suit women in different groups in order to increase participation in screening. In addition, physicians have to be made keenly aware of their pivotal role in motivating women to participate in early detection screening.

Breast cancer screening, outside the population-screening program, of women from breast cancer families without proven BRCA1/BRCA2 mutations: a simulation study

PURPOSE

We assessed the cost-effectiveness of mammography screening for women under the age of 50, from breast cancer families without proven BRCA1/BRCA2 mutations, because current criteria for screening healthy women from breast cancer families are not evidence-based.

METHODS

We did simulation studies with mathematical models on the cost-effectiveness of mammography screening of women under the age of 50 with breast cancer family histories. Breast cancer screening was simulated with varying screening intervals (6, 12, 18, and 24 months) and screening cohorts (starting at ages 30, 35, 40, and 45, and continuing to age 50). Incremental costs of screening were compared with those of women ages 50 to 52 years, the youngest age group currently routinely screened in the nationwide screening program of the Netherlands, to determine cost-effectiveness. Sensitivity analyses were done to explore the effects of model assumptions. The cost-effectiveness of breast cancer screening for women over the age of 50 was not debated.

RESULTS

The most effective screening interval was found to be 12 months, which, however, seems only to be cost-effective in a small group of women under the age of 50 with at least two affected relatives, including at least one affected in the first degree diagnosed under the age of 50. Significantly, early breast cancer screening never seemed to be cost-effective in women with only one affected first-degree or second-degree relative.

CONCLUSION

Annual breast cancer screening with mammography for women under the age of 50 seems to be cost-effective in women with strong family histories of breast cancer, even when no BRCA1/BRCA2 mutation was found in affected family members.

Screening in women's health, with emphasis on fetal Down's syndrome, breast cancer and osteoporosis

Screening tests have become increasingly popular in women's health care over the last two decades. The initiative for screening is typically generated by either an agency or the health care professional being consulted for some reason. In many instances, however, the demand for screening tests is patient driven with the health care provider being poorly prepared to determine the usefulness of screening. This review illustrates the complexity of screening using three disorders where early detection and treatment have the potential to improve the quality and longevity of life. Prenatal diagnosis of Down's syndrome does not offer the parents the opportunity for cure but does offer the opportunity for education and rational choice as the impact of the diagnosis on the family is weighed. The evidence for breast cancer screening is more persuasive for older than younger women, but even in older women, there is a balance of risks and benefits. Treatment options for osteoporosis have improved in terms of reductions in fracture risk as well as beneficial effects on bone density, but evidence of the effectiveness of a screening programme for this condition in an unselected population is lacking. Ultimately, it is crucial that women be provided with clear and comprehensive information about the screening programme, in terms of possible gains but also costs of various kinds: physical, economic and psychological.

Cancer Screening in Older Adults in an Era of Genomics and Longevity

OBJECTIVES

To provide an overview of cancer genomics and cancer screening in older adults with a focus on breast, prostate, and colon cancers.

DATA SOURCES

Journal articles, research articles, and web sites.

CONCLUSION

Cancer screening in older populations is often in the context of one or more co-morbid conditions, cancer survivorship, genomic information, and competing health priorities. The field of cancer screening has outgrown the tools available to enable health care providers and older adults to make informed cancer screening decisions. Research is needed to develop clinical screening tools that integrate age, cancer risk, life expectancy, and comorbidity.

IMPLICATIONS FOR NURSING PRACTICE

Health care providers are faced with opportunities and challenges in the prevention and early detection of cancer in older Americans.

Screening for cancer: are resources being used wisely?

Cancer screening is commonly offered in order to detect tumors at an early, treatable stage. These efforts are highly advocated and widely accepted by the general public. However, there is conflicting evidence about the benefits of screening for breast cancer in pre-menopausal women, prostate cancer in older men, and colorectal cancer for both sexes. This paper examines cancer screening in relation to a disease reservoir hypothesis. There is a reservoir of undetected disease that can be found with more aggressive screening. However, much of the disease that is detected may be classified as pseudodisease because it will have no effect of life expectancy or health-related quality of life. Pseudodisease is defined as detectable disease that will never be clinically significant. A second concern about screening is that randomized clinical trials often show benefits of cancer screening for disease-specific endpoints but no benefit for total mortality. Further, screening for some cancers may significantly increase healthcare costs without enhancing population health status. Improvements in biomarkers and in screening methodologies will significantly increase the number of cancers detected. Future research is necessary in order to determine which population-based screening programs are the best use of public health resources.

Effects of Breast Cancer Risk Counseling for Sexual Minority Women

Sexual minority women (lesbian and bisexual) represent a vulnerable group regarding their breast health. The participants in this study were 150 women aged 18-74 recruited via public announcements in mainstream and sexual minority communities in the greater Seattle metropolitan area. Potential participants were recruited to participate in a randomized trial of a breast cancer risk counseling intervention for sexual minority women. The counseling intervention produced significant reductions in perceived risk of breast cancer, anxieties and fears about breast cancer at 6 and 24 months, and increases in breast screening rates at 24 months in the intervention arm, compared with the control arm participants. These data add to the growing body of knowledge on sexual minority women's health and point to areas of community action and future research.

Early breast cancer detection practices, health beliefs, and cancer worries in Jewish and Arab women

BACKGROUND

Breast examinations (BE) for the early detection of breast cancer are the principal way of increasing survival rates in breast cancer. To date, BE practices among Jewish as compared with Arab women, and the factors associated with them have not been examined in Israel.

OBJECTIVES

(1) To study differences in BE practices among Arab and Jewish women. (2) To characterize demographic, cognitive, and emotional factors related to Arab and Jewish women's BE practices.

METHOD

In 2004, 489 Jewish women and 440 Arab women, ages 20-60, and randomly sampled from the female population of Israel, answered a telephone questionnaire related to BE practices, health beliefs, and breast cancer worries.

Incidence of Invasive Breast Cancer and Ductal Carcinoma In situ in a Screening Program by Age: Should Older Women Continue Screening?

Objective: The evidence for the effectiveness of screening is strongest for women ages 50 to 69 years; however, there is variation in the target age group for screening programs between different countries. In particular, there is uncertainty over whether women should continue screening once they reach age 70. We therefore investigated incidence rates for invasive and in situ breast cancer by age as well as prognostic features of tumors within a screening program. Methods: We studied 474,808 women who attended BreastScreen Victoria from January 1, 1993 to December 31, 2000. Of these women, 5,301 were diagnosed with invasive cancer and 1,127 were diagnosed with ductal carcinoma in situ. We used generalized additive models to model age-incidence rates for invasive cancers and ductal carcinoma in situ separately by users and nonusers of hormone replacement therapy at most recent screen. Nonparametric trends for ordered groups and regression methods were used to investigate trends in size, grade, and nodal involvement for invasive tumors by type of attendance and time since previous negative screen for age group. Results: The incidence of ductal carcinoma in situ among women with a previous negative screen clearly declined after age 70 irrespective of hormone replacement therapy use. At subsequent screen, the age-incidence curve for invasive breast cancer flattened at ages 60 to 75 years and then increased only for women taking hormone replacement therapy. Tumor size at diagnosis declined with age at both first round (P = 0.15) and subsequent round (P = 0.08). The proportion of poorly differentiated tumors also decreased with age, with the smallest proportion of grade III tumors diagnosed in women ages ≥75 years (P = 0.09 for first screen and P = 0.05 for subsequent screen). The presence of positive nodes at diagnosis declined with age (P &lt; 0.001) for both first and subsequent screening rounds. Conclusion: Older age is associated with more favorable prognostic tumor features and a lower incidence of ductal carcinoma in situ among subsequent attenders of screening. When making decisions regarding continuing screening, older women and their physicians should also consider the presence of other comorbid conditions that may mitigate any impact of screening on mortality.

Diversity matters: Unique populations of women and breast cancer screening

BACKGROUND

Ethnic differences in breast cancer screening behaviors are well established. However, there is a lack of understanding regarding exactly what causes these differences and which characteristics in low-screening populations should be targeted in an effort to modify screening behavior.

METHODS

Stratified cluster sampling was used to recruit 1364 women (ages 50-70 years) from 6 ethnic groups: African-American women; U.S.-born white women; English-speaking Caribbean, Haitian, and Dominican women; and immigrant Eastern-European women. In interviews, respondents provided information concerning demographic and structural variables related to mammogram utilization (age, education, income, marital status, physician recommendation, access, and insurance) and a set of cognitive variables (fatalism, perception of personal risk, health beliefs concerning cancer) and socioemotional variables (stress, cancer worry, embarrassment, and pain).

RESULTS

For data analysis, the authors used a 2-step logistic regression with frequency of mammograms over a 10-year period (< or = 4 mammograms over 10 years or > or = 5 mammograms over 10 years) as a dependent variable. U.S.-born African-American women and Dominican women were screened as frequently as European-American women, but the remaining minority groups were screened with less frequency. With one exception, ethnicity ceased to predict screening frequency once cognitive and emotional variables were controlled.

CONCLUSIONS

Although women from clearly operationalized ethnic groups continue to screen at rates substantially below those of the majority groups, these differences appear to be explained substantially by differences in psychologic variables. This is encouraging because, rather than targeting culture for intervention, variables can be targeted that are amenable to change, such as emotions and beliefs.