Screening with magnetic resonance imaging and mammography of a UK population at high familial risk of breast cancer: a prospective multicentre cohort study (MARIBS)

The management of lobular carcinoma in situ (LCIS). Is LCIS the same as ductal carcinoma in situ (DCIS)?

Lobular carcinoma in situ was first described over 60 years ago. Despite the long history, it continues to pose significant difficulties in screening, diagnosis, management and treatment. This is partly due its multi-focal and bilateral presentation, an incomplete understanding of its biology and natural history and perpetuation of misconceptions gathered over the last decades. In this review, the working group on behalf of EUSOMA has attempted to summarise the current thinking and management of this interesting lesion.

Breast cancer screening in women at increased risk according to different family histories: an update of the Modena Study Group experience

BACKGROUND

Breast cancer (BC) detection in women with a genetic susceptibility or strong family history is considered mandatory compared with BC screening in the general population. However, screening modalities depend on the level of risk. Here we present an update of our screening programs based on risk classification.

METHODS

We defined different risk categories and surveillance strategies to identify early BC in 1325 healthy women recruited by the Modena Study Group for familial breast and ovarian cancer. Four BC risk categories included BRCA1/2 carriers, increased, intermediate, and slightly increased risk. Women who developed BC from January 1, 1994, through December 31, 2005 (N = 44) were compared with the number of expected cases matched for age and period. BRCA1/2 carriers were identified by mutational analysis. Other risk groups were defined by different levels of family history for breast or ovarian cancer (OC). The standardized incidence ratio (SIR) was used to evaluate the observed and expected ratio among groups. All statistical tests were two-sided.

RESULTS

After a median follow-up of 55 months, there was a statistically significant difference between observed and expected incidence [SIR = 4.9; 95% confidence interval (CI) = 1.6 to 7.6; p < 0.001]. The incidence observed among BRCA carriers (SIR = 20.3; 95% CI = 3.1 to 83.9; P < 0.001), women at increased (SIR = 4.5; 95% CI = 1.5 to 8.3; P < 0.001) or intermediate risk (SIR = 7.0, 95% CI = 2.0 to 17.1; P = 0.0018) was higher than expected, while the difference between observed and expected among women at slightly increased risk was not statistically significant (SIR = 2.4, 95% CI = 0.9 to 8.3; P = .74).

CONCLUSION

The rate of cancers detected in women at high risk according to BRCA status or strong family history, as defined according to our operational criteria, was significantly higher than expected in an age-matched general population. However, we failed to identify a greater incidence of BC in the slightly increased risk group. These results support the effectiveness of the proposed program to identify and monitor individuals at high risk, whereas prospective trials are needed for women belonging to families with sporadic BC or OC.

Student nurses' knowledge and attitudes toward CAM therapies

Hessig et al (2004) highlight that nurses value complementary and alternative therapies (CAM) but lack the knowledge regarding their application. They suggest that education can affect knowledge and application of CAM in nursing practice. Complementary and alternative therapy input into the pre-registration nursing curriculum is sporadic and higher education institutions need to incorporate CAM therapies more fully into professional education (Department of Health, 2003). This study investigated the knowledge and attitudes student nurses have to CAM therapies and their use in cancer and palliative care. Ethical approval was sought from the ethics committee at the University of Hull. A quantitative evaluative study using a convenience sample of student nurses in their final semester of pre-registration nurse education was used. Data were collected via a questionnaire; the findings demonstrate the respondents' acknowledgement of their limited knowledge of CAM therapies and the study has highlighted the need to continue working towards integrated CAM education into the pre-registration nursing curriculum.

MR Imaging for Surveillance of Women at High Familial Risk for Breast Cancer

The adequate management of individuals who carry a high lifetime risk for breast cancer is still an unsettled issue. This holds especially true for subjects with documented or suspected germline mutation of a breast cancer susceptibility gene. These women face a lifetime risk for breast cancer of up to 80%, which is, of course, significant. Still, this means that approximately one fifth of women never develop the disease. The perceived mutilating effects of preventive mastectomy make the decision for surgical prevention difficult for most women. Secondary prevention aims at identifying familial breast cancer at the earliest possible stage. During recent years, considerable evidence has been accumulated that breast MR imaging is substantially more sensitive than mammography and breast ultrasound regarding the identification of familial breast cancer. It should be considered an integral part of a surveillance program for women at increased familial risk for breast cancer, be it with or without documented mutation of a breast cancer susceptibility gene.

Update on hereditary breast cancer

Women with BRCA1 or BRCA2 mutations are at substantial risk for breast and ovarian cancer. This review describes recent developments in the approach to hereditary breast cancer. Risk-reducing surgeries remain the most effective means of preventing breast cancer in mutation carriers. For women with breast tissue at risk, magnetic resonance imaging is rapidly becoming incorporated into screening programs. For affected women, management does not currently differ from that of women with sporadic breast cancer, although women may choose to undergo bilateral mastectomy. Preclinical data suggest that BRCA mutation-associated breast cancers may benefit from specific targeted therapeutic approaches.

Differences between first and subsequent rounds of the MRISC breast cancer screening program for women with a familial or genetic predisposition

BACKGROUND

Within the Dutch MRI Screening (MRISC) study, a Dutch multicenter screening study for hereditary breast cancer, the authors investigated whether previously reported increased diagnostic accuracy of magnetic resonance imaging (MRI) compared with mammography would be maintained during subsequent screening rounds.

METHODS

From November 1999 to October 2003, 1909 eligible women were included in the study. Screening parameters and tumor characteristics of different rounds were calculated and compared. The authors defined 3 different types of imaging screening rounds: first round in women never screened by imaging before, first round in women screened by imaging (mainly mammography) before, and subsequent rounds.

RESULTS

The difference in sensitivity for invasive cancers between mammography and MRI was largest in the first round of women previously screened with mammography (20.0 vs. 93.3%; P=.003), but also in subsequent rounds, there was a significant difference in favor of MRI (29.4 vs. 76.5%; P=.02). The difference in false-positive rate between mammography and MRI was also largest in the first round of women previously screened with mammography (5.5 vs. 14.0%; P<.001), and it remained significant in subsequent rounds (4.6 vs. 8.2%; P<.001). Screen-detected tumors were smaller and more often lymph node negative than symptomatic tumors in age-matched control patients, but no major differences in tumor stage were found between tumors detected at subsequent rounds compared with those in the first round.

CONCLUSIONS

In subsequent rounds, a significantly higher sensitivity and better discriminating capacity of MRI compared with mammography was maintained, and a favorable tumor stage compared with age-matched symptomatic controls. As results of these subsequent screening rounds were most predictive for long-term effects, the authors expect that this screening program will contribute to a decrease of breast cancer mortality in these high-risk women.

A meta-analysis of scintimammography: an evidence-based approach to its clinical utility

BACKGROUND

Scintimammography using (99m)Tc-labelled isonitriles, sestamibi and tetrofosmin, has become a mature technique in the adjunctive setting for the diagnosis of primary breast cancer. To establish an evidence base for its use, clinically, a meta-analysis was performed on both single-site and multi-centre trials performed since January 1997.

METHODS

Using an on-line literature search all such trials containing 100 or more studies were identified. To prevent double counting of patients only the last published report from any centre was used.

RESULTS

A total of 2424 patients were identified in the single-site trial group, the smallest study having 105 patients and the largest 353 patients. The overall sensitivity was 85% and the specificity was 84%. In the multi-centre trial studies, published data from 3049 patients were included. The overall sensitivity in this group was also 85% and the specificity was 83%.

CONCLUSION

There is evidence that this is a robust imaging technique delivering high sensitivities and specificities in patients studied in both single-centre and multi-centre trials and, as such, can be relied on as an adjunctive method for the investigation of primary breast cancer.

Radiotherapy and genetic predisposition to breast cancer

Cancer genetics is becoming increasingly integrated into oncological care; particularly in breast cancer management. The recognition of monogenic breast cancer predisposition syndromes, such as BRCA, is critical as there is also a risk of other cancers in addition to a markedly elevated risk of contralateral breast cancer. In individuals with breast cancer due to some predisposition genes, radiation should be avoided, e.g. the ATM and TP53 genes, but there is still controversy as to whether radiation should be used in BRCA1/2 mutation carriers and more follow-up is needed. There are some radiation-sensitive genetic conditions where, if breast cancer occurs (as it may occur in any individual, not necessarily due to an increased risk associated with the condition), radiation should be avoided. These conditions are often associated with dysmorphic features. If such features are noticed then the advice of a geneticist should be sought urgently prior to giving radiation.

Evaluation of a Prospective Scoring System Designed for a Multicenter Breast MR Imaging Screening Study

PURPOSE

To evaluate prospectively the accuracy of a lesion classification system designed for use in a magnetic resonance (MR) imaging high-breast-cancer-risk screening study.

MATERIALS AND METHODS

All participating patients provided written informed consent. Ethics committee approval was obtained. The results of 1541 contrast material-enhanced breast MR imaging examinations were analyzed; 1441 screening examinations were performed in 638 women aged 24-51 years at high risk for breast cancer, and 100 examinations were performed in 100 women aged 23-81 years. Lesion analysis was performed in 991 breasts, which were divided into design (491 breasts) and testing (500 breasts) sets. The reference standard was histologic analysis of biopsy samples, fine-needle aspiration cytology, or minimal follow-up of 24 months. The scoring system involved the use of five features: morphology (MOR), pattern of enhancement (POE), percentage of maximal focal enhancement (PMFE), maximal signal intensity-time ratio (MITR), and pattern of contrast material washout (POCW). The system was evaluated by means of (a) assessment of interreader agreement, as expressed in kappa statistics, for 315 breasts in which both readers analyzed the same lesion, (b) assessment of the diagnostic accuracy of the scored components with receiver operating characteristic curve analysis, and (c) logistic regression analysis to determine which components of the scoring system were critical to the final score. A new simplified scoring system developed with the design set was applied to the testing set.

RESULTS

There was moderate reader agreement regarding overall lesion outcome (ie, malignant, suspicious, or benign) (kappa=0.58) and less agreement regarding the scored components. The area under the receiver operating characteristic curve (AUC) for the overall lesion score, 0.88, was higher than the AUC for any one component. The components MOR, POE, and POCW yielded the best overall result. PMFE and MITR did not contribute to diagnostic utility. Applying a simplified scoring system to the testing set yielded a nonsignificantly (P=.2) higher AUC than did applying the original scoring system (sensitivity, 84%; specificity, 86.0%).

CONCLUSION

Good diagnostic accuracy can be achieved by using simple qualitative descriptors of lesion enhancement, including POCW. In the context of screening, quantitative enhancement parameters appear to be less useful for lesion characterization.

Breast CT: potential for breast cancer screening and diagnosis

Although screening mammography has been shown to be effective in reducing breast cancer mortality, a new technique called breast computed tomography (CT) is being studied in the hope that breast cancer can be detected even earlier. A prototype unit has been designed, fabricated and tested at the University of California, Davis, USA, and is currently being used in a Phase II clinical trial to study the feasibility of breast CT for breast cancer detection and diagnosis. A total of 46 volunteers and patients have been imaged, and the breast CT images show impressive anatomical detail of the breast that is not appreciated in mammography. The radiation dose levels needed to produce excellent image quality are equal to two-view mammography. Further study of breast CT is needed to better understand its potential role in breast cancer screening and diagnosis.

A test of performance of breast MRI interpretation in a multicentre screening study

OBJECTIVES

The aim of this study was to assess the consistency and performance of radiologists interpreting breast magnetic resonance imaging (MRI) examinations.

MATERIALS AND METHODS

Two test sets of eight cases comprising cancers, benign disease, technical problems and parenchymal enhancement were prepared from two manufacturers' equipment (X and Y) and reported by 15 radiologists using the recording form and scoring system of the UK MRI breast screening study [(MAgnetic Resonance Imaging in Breast Screening (MARIBS)]. Variations in assessments of morphology, kinetic scores and diagnosis were measured by assessing intraobserver and interobserver variability and agreement. The sensitivity and specificity of reporting performances was determined using receiver operating characteristic (ROC) curve analysis.

RESULTS

Intraobserver variation was seen in 13 (27.7%) of 47 of the radiologists' conclusions (four technical and seven pathological differences). Substantial interobserver variation was observed in the scores recorded for morphology, pattern of enhancement, quantification of enhancement and washout pattern. The overall sensitivity of breast MRI was high [88.6%, 95% confidence interval (CI) 77.4-94.7%], combined with a specificity of 69.2% (95% CI 60.5-76.7%). The sensitivities were similar for the two test sets (P=.3), but the specificity was significantly higher for the Manufacturer X dataset (P<.001). ROC curve analysis gave an area under the curve of 0.85 (95% CI 0.79-0.92)

CONCLUSIONS

Substantial variation in all elements of the scoring system and in the overall diagnostic conclusions was observed between radiologists participating in MARIBS. High overall sensitivity was achieved with moderate specificity. Manufacturer-related differences in specificities possibly occurred because the numerical thresholds set for the scoring system were not optimised for both equipment manufacturers. Scoring systems developed on one equipment software may not be transferable to other manufacturers.

Outcomes among women younger than age 40 in a state breast cancer screening program

BACKGROUND

The value of entering women younger than age 40 in breast cancer screening programs (SPs) remains unclear.

METHODS

Data from the Oregon Breast and Cervical Cancer Program (BCCP) for the period December 31, 2000 through July 1, 2003 were reviewed with a focus on women 39 years of age or younger. Information on cancers detected in this group was extracted from The Oregon State Cancer Registry.

RESULTS

Of the 13,636 women screened, 797 (5.8%) were younger than 40 (mean age 31.9 years). A total of 20.6% of the women were asymptomatic and therefore represented true incidence screening, while 79.4% were referred to the program for symptoms (prevalence screen). A total of 125 biopsies were done out of 797 women, which yielded 5 cancers. All 5 of these patients were symptomatic at presentation and had a negative family history.

CONCLUSIONS

There are as yet no data in our state breast cancer SP to support screening of asymptomatic women younger than 40.

Computed tomography for imaging the breast

Despite the success of screening mammography contributing to the reduction of cancer mortality, a number of other imaging techniques are being studied for breast cancer screening. In our laboratory, a dedicated breast computed tomography (CT) system has been developed and is currently undergoing patient testing. The breast CT system is capable of scanning the breast with the woman lying prone on a tabletop, with the breast in the pendant position. A 360 degrees scan currently requires 16.6 s, and a second scanner with a 9-second scan time is nearly operational. Extensive effort was placed on computing the radiation dose to the breast under CT geometry, and the scan parameters are selected to utilize the same radiation dose levels as two-view mammography. A total of 55 women have been scanned, ten healthy volunteers in a Phase I trial, and 45 women with a high likelihood of having breast cancer in a Phase II trial. The breast CT process leads to the production of approximately three hundred 512 x 512 images for each breast. Subjective evaluation of the breast CT images reveals excellent anatomical detail, good depiction of microcalcifications, and exquisite visualization of the soft tissue components of the tumor when contrasted against adipose tissues. The use of iodine contrast injection dramatically enhances the visualization of tumors. While a thorough scientific investigation based upon observer performance studies is in progress, initial breast CT images do appear promising and it is likely that breast CT will play some role in breast cancer imaging.

Radiological surveillance of interval breast cancers in screening programmes

Interval breast cancers-those diagnosed after a negative mammographic screen and before the next scheduled screen-are an important indicator of the potential effectiveness of population screening for breast cancer. Although the incidence of interval cancers is usually monitored, radiological surveillance is not undertaken routinely in most screening programmes. Here, we describe radiological surveillance of interval breast cancers and discuss methodological difficulties in the radiological review process and in the categorisation of interval cancers as false-negative, true, or occult. Furthermore, we identify methods that affect whether an interval cancer is classified as a false-negative (missed) or a true interval cancer. For all radiological categories of interval cancers, we outline possible changes to screening programmes that might improve cancer detection. Standardised radiological surveillance of interval cancers might allow within-programme comparisons and has the potential to guide practice and improve quality.

Women's acceptance of MRI in breast cancer surveillance because of a familial or genetic predisposition

Magnetic resonance imaging (MRI) of the breasts is a promising screening modality for early detection in women at increased breast cancer risk. We investigated the subjective experiences with MRI and the preferences for MRI, mammography or clinical breast examination in 178 high-risk women adhering to a breast cancer surveillance programme. MRI was reported to cause limited discomfort. About 44% preferred MRI as a screening test (mammography: 14%). MRI provided the most reassurance of breast cancer being absent in case of a favourable test result. MRI seems to be acceptable as a screening test for women at increased breast cancer risk and is preferred by them over mammography.

Increased level of chromosomal damage after irradiation of lymphocytes from BRCA1 mutation carriers

Deleterious mutations in the BRCA1 gene predispose women to an increased risk of breast and ovarian cancer. Many functional studies have suggested that BRCA1 has a role in DNA damage repair and failure in the DNA damage response pathway often leads to the accumulation of chromosomal aberrations. Here, we have compared normal lymphocytes with those heterozygous for a BRCA1 mutation. Short-term cultures were irradiated (8Gy) using a high dose rate and subsequently metaphases were analysed by 24-colour chromosome painting (M-FISH). We scored the chromosomal rearrangements in the metaphases from five BRCA1 mutation carriers and from five noncarrier control samples 6 days after irradiation. A significantly higher level of chromosomal damage was detected in the lymphocytes heterozygous for BRCA1 mutations compared with normal controls; the average number of aberrations per mitosis was 3.48 compared with 1.62 in controls (P=0.0001). This provides new evidence that heterozygous mutation carriers have a different response to DNA damage compared with noncarriers and that BRCA1 has a role in DNA damage surveillance. Our finding has implications for treatment and screening of BRCA1 mutation carriers using modalities that involve irradiation.

The prevention, detection, and management of breast cancer

The reduction in the incidence of contralateral breast cancer in women treated with adjuvant tamoxifen provided a model for prevention using endocrine agents. Oestrogen-receptor-positive cancer can be prevented with tamoxifen, but side effects limit its clinical utility, and the risk-benefit ratio is not sufficiently high to routinely recommend tamoxifen as a preventive agent. Agents being evaluated in prevention trials include raloxifene and the aromatase inhibitors; these are expected to be at least as effective as tamoxifen and to have fewer side effects. Core needle biopsy (providing histological information) and high-resolution breast ultrasound enhance preoperative assessment of breast cancer. Mammography remains the only screening test shown to reduce breast cancer deaths in randomised trials. Magnetic resonance imaging may have a role in screening women with inherited mutations of the breast cancer genes. Sentinel lymph node biopsy accurately assesses lymph node status and is associated with less morbidity than axillary dissection. Where the biopsy is negative (no histologic evidence of metastases), no further axillary treatment is necessary. Breast reconstruction after mastectomy can produce good cosmetic results, especially where autologous tissue is used. Myocutaneous flaps using latissimus dorsi or transverse rectus abdominus muscles are increasingly popular. Adjuvant trastuzumab therapy in patients whose tumours overexpress HER2 (growth factor receptor) can reduce recurrence rates and improve survival. Neoadjuvant endocrine therapy (as an initial treatment before surgery) is an underutilised treatment in postmenopausal women with oestrogen-receptor-positive large operable or locally advanced cancers. It makes more patients suitable for surgery and offers others the choice of breast conservation.

Risk-reducing surgery in women with familial susceptibility for breast and/or ovarian cancer

This multicentre study examined uptake of bilateral risk-reducing mastectomy (BRRM) and bilateral risk-reducing oophorectomy (BRRO) in women at increased risk for breast and/or ovarian cancer who had attended a familial cancer clinic (FCC) between January 1999 and June 2000. Eligible women (N=396), were mailed a questionnaire assessing: BRRM and BRRO details; risk perception; and anxiety. Family history, genetic testing and risk assessment were abstracted from medical records. Surgery was cross-tabulated with demographics, risk perception and anxiety with either Fisher's exact test or the exact form of the Mantel-Haenszel test (for ordinal factors) used to investigate for associations. Ordinal logistic regression was used with continuous-scale covariates. In total, 130 women were lost to follow-up leaving 266; of these 182 (68.4%) responded. Mean follow-up time was 3.73 years. The BRRM rate was 4.4%; with no difference found between moderate and high-risk groups. BRRM was associated with increasing numbers of affected relatives (P=0.025). BRRO was undertaken by 17.3%, more commonly in women older than 40 years of age (P=0.023) and with a BRCA1/2 mutation (P=0.017). Women who underwent BRRM (P=0.052) or BRRO (P<0.001) had a lower post-procedure risk perception than those who did not. During the timeframe of this study, risk-reducing surgery was undertaken by a small percentage of Australian women at increased risk for breast and/or ovarian cancer who attended FCCs. Family cancer history and mutation status were associated with uptake.

Imaging tumour angiogenesis

The development of neovasculature via angiogenesis is a vital component of many normal physiological processes and a number of disease states. Neovascularisation is critical for the growth of malignant tumours and for the development and survival of metastases. Recently, the potential of non-invasive imaging for the functional characterisation of neovasculature has become realised. In this review we describe the process of tumour angiogenesis for radiologists and present a summary of the most available computed tomography/magnetic resonance imaging techniques that can depict the functional vascular status of human tumours.

Screening women at increased risk with MRI

Breast cancer is the most common cancer affecting women. In the screening of women for breast cancer, mammography is the most used imaging modality. Women with an increased risk for getting breast cancer can develop a malignancy at a relatively young age compared to other women. The increased risk for developing breast cancer can usually be found in a positive familial history. This positive familial history is based on a gene mutation in 5-10% of cases. The most common gene mutations are BRCA1 and BRCA2. This risk makes it necessary to start screening these women at a young age. Mammography, however, has proven to be less reliable in younger women because its sensitivity is lowered due to the dense breast tissue often present in this group. MRI has a higher sensitivity for detecting breast cancer compared to mammography. MRI is not influenced by the density of the breast tissue. This makes breast MRI the best modality available for the screening of women with an increased risk for developing breast cancer.

Reading Protocol for Dynamic Contrast-enhanced MR Images of the Breast: Sensitivity and Specificity Analysis

PURPOSE

To prospectively determine sensitivity and specificity of breast magnetic resonance (MR) imaging in a screening and symptomatic population by using independent double reading, with histologic or cytologic results or a minimum 18-month follow-up as the standard.

MATERIALS AND METHODS

Informed consent and ethical approval were obtained. Reader performance was analyzed in 44 radiologists at 18 centers from 1541 examinations, including 1441 screening examinations in 638 high-risk women aged 24-51 years (mean, 40.5 years) and 100 examinations in symptomatic women aged 23-81 years (mean, 49.2 years). A screening protocol of dynamic T1-weighted three-dimensional imaging and 0.2 mmol/kg gadolinium-based intravenous contrast agent was used. Logistic and Poisson regressions were used to analyze reader performance in relation to experience. Correlation between readers was determined with kappa statistics. Sensitivity and specificity were analyzed according to reader, field strength, machine type, and histologic results.

RESULTS

The proportion of studies with lesions analyzed reduced significantly with reader experience (odds ratio, 0.84 per 6 months; P < .001), and number of regions per lesion analyzed also diminished (incidence rate ratio, 0.98 per 6 months; P = .047). The two readers for each study agreed 87% of the time, with a moderately good kappa statistic of 0.52 (95% confidence interval [CI]: 0.45, 0.58). By taking the reading with the highest score (most likely to be malignant) from each double-read study, sensitivity was 91% (95% CI: 83%, 96%) and specificity was 81% (95% CI: 79%, 83%). Single readings had 7% lower sensitivity (95% CI: 4%, 11%) and 7% higher specificity (95% CI: 6%, 7%). Sensitivity did not differ between MR imager manufacturers or between 1.0- and 1.5-T field strength, but there were significant differences in specificity for machine type (P = .001) and for field strength adjusted for manufacturer (P = .001). Specificity, but not sensitivity, was higher in women younger than 50 years (P = .02).

CONCLUSION

Independent double reading by 44 radiologists blinded to mammography results showed sensitivity and specificity acceptable for screening; sensitivity was higher when two readings were used, at the cost of specificity. Interreader correlation was moderately good, and evidence of learning was seen. Equipment manufacturer, field strength, and age affected specificity but not sensitivity.

Familial non-BRCA1/BRCA2-associated breast cancer

Multidisciplinary breast-cancer teams commonly encounter women, both premenopausal and postmenopausal, presenting with breast cancer who also have a family history of this disease. Much of the published work on management of hereditary breast cancer focuses on women with known mutations in BRCA1 and BRCA2, in whom high-grade tumours, common second primaries, and a differential response to adjuvant chemotherapies could be relevant in finding the most effective management strategies. Extrapolation of some of these findings to all patients with familial breast cancer is tempting. However, for women in whom BRCA1 or BRCA2 mutations are unlikely or not found, what evidence is there to inform choices about the various management options? We review the published work on management issues for patients with familial breast cancer not due to a detectable mutation in BRCA1/BRCA2 and compare it with the issues for BRCA1 and BRCA2 carriers on whom more information is available.