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

Who Should Have Breast Magnetic Resonance Imaging Evaluation?

During the last two decades, tremendous advances have been made in the performance and interpretation of breast magnetic resonance imaging (MRI) examinations. Technical requirements for optimal breast imaging including the requirement for a breast MRI biopsy system are now being defined as part of a voluntary American College of Radiology (ACR) breast MRI accreditation program. The ACR BI-RADS (Breast Imaging Reporting and Data System) lexicon for breast MRI has brought uniformity to the interpretation of breast MRI examinations. With these advances in imaging technique, interpretation guidelines, and increasing availability of MR-compatible breast biopsy systems, MRI of the breast is rapidly gaining popularity in clinical practice in both the diagnostic setting and, more recently, in the screening setting. The clinical indications for breast MRI, however, remain to be defined. There are clinical indications that have emerged where MRI, as an adjunct to mammography, seems to be the imaging study of choice. There are other indications, specifically breast cancer staging, in which MRI is being utilized with increasing frequency, but in which controversy persists.

Cancer surveillance based on imaging techniques in carriers of BRCA1/2 gene mutations: a systematic review

We have systematically reviewed the literature focusing on the performance of surveillance programmes and imaging techniques for the early diagnosis of breast and ovarian cancer in women carrying mutations in BRCA1/2 genes. A search for relevant articles published between 1996 and 2005 (inclusive) was run on Medline, Embase and other databases. Of the 749 articles retrieved, only 13 met the inclusion criteria. Of these, 12 provided information on breast cancer surveillance, 1 on ovarian cancer surveillance and a further study addressed both cancer types. A critical appraisal of the studies was performed using a tool for the quality assessment of diagnostic accuracy studies (QUADAS). The synthesis of results is qualitative. All studies on imaging techniques for the diagnosis of breast cancer indicated that screening MRI had the highest sensitivity (between 77% and 100%). Breast cancer surveillance programmes, including MRI, achieved the highest diagnostic performance (between 83% and 95%) for all women. However, it must be taken into account that biases that may affect the validity of the outcomes were seen in the evaluated studies. Also, MRI is an expensive test with a low positive predictive value and, to date, MRI screening has not been proven to reduce mortality rates in women carrying BRCA1/2 gene mutations. As a result of the scant information and low quality of the papers reviewed, no definitive conclusion could be drawn on the performance of ovarian cancer surveillance in women carrying BRCA1/2 mutations.

Relationship of Breast Magnetic Resonance Imaging to Outcome After Breast-Conservation Treatment With Radiation for Women With Early-Stage Invasive Breast Carcinoma or Ductal Carcinoma in Situ

Purpose

To determine the relationship of breast magnetic resonance imaging (MRI) to outcome after breast-conservation treatment (BCT) with radiation for women with early-stage invasive breast carcinoma or ductal carcinoma in situ.

Patients and Methods

A total of 756 women with early stage invasive breast carcinoma or ductal carcinoma in situ underwent BCT including definitive breast irradiation during 1992 to 2001. At the time of initial diagnosis and evaluation, routine breast imaging included conventional mammography. Of the 756 women, 215 women (28%) had also undergone a breast MRI study, and 541 women (72%) had not undergone a breast MRI study. The median follow-up after treatment was 4.6 years (range, 0.1 to 13.5 years).

Results

For the women with a breast MRI study compared with the women without a breast MRI study, there were no differences in the 8-year rates of any local failure (3% v 4%, respectively; P = .51) or local-only first failure (3% v 4%, respectively; P = .32). There were also no differences between the two groups for the 8-year rates of overall survival (86% v 87%, respectively; P = .51), cause-specific survival (94% v 95%, respectively; P = .63), freedom from distant metastases (89% v 92%, respectively; P = .16), or contralateral breast cancer (6% v 6%, respectively; P = .39).

Conclusion

The use of a breast MRI study at the time of initial diagnosis and evaluation was not associated with an improvement in outcome after BCT with radiation.

Treatment of hereditary breast cancer

Mutations in BRCA1 and BRCA2 are well-established causes of hereditary breast cancer. As genetic testing becomes more widespread, increasing numbers of women are known to have mutations at or shortly after their breast cancer diagnosis. Current evidence is insufficient to mandate different local or systemic treatment based upon the presence of a germline mutation. The well-documented increased risk of contralateral second primary breast cancer and possibly of late ipsilateral second primary breast cancers may influence patient decision-making with regard to breast-conserving treatment.

Screening for hereditary breast cancer

Most women at risk for hereditary breast cancer opt for intensive breast screening rather than risk-reducing mastectomy. For this to be a rational choice, the vast majority of tumors must be detected either while still in situ or at a very early stage of invasion. Annual screening mammography has low sensitivity in this population, in part due to the greater breast density of younger women, resulting in cancers being detected at a suboptimal stage. In six prospective comparative studies, the addition of annual contrast-enhanced magnetic resonance imaging (MRI) of the breast to mammography demonstrated greater than 90% sensitivity, more than twice that of mammography alone. In those studies that included ultrasound and clinical breast examination, additional cancers were rarely detected by these modalities. False positive rates were higher with the addition of MRI, but specificity improved on successive rounds of screening. Although long-term survival data are still lacking, there is mounting evidence that the addition of screening MRI to mammography detects hereditary breast cancers at an earlier stage and is thus estimated to be cost-effective, at least for women with BRCA mutations. This review will examine the literature and current screening recommendations.

Meta-analysis of MR imaging in the diagnosis of breast lesions

PURPOSE

To determine, in a meta-analysis, the diagnostic performance of contrast material-enhanced magnetic resonance (MR) imaging in patients with breast lesions.

MATERIALS AND METHODS

Studies to assess the diagnostic performance of MR imaging in patients suspected of having breast cancer who underwent MR imaging and biopsy from January 1985 through March 2005 were reviewed for inclusion. A summary receiver operating characteristic curve was constructed, and pooled weighted estimates of sensitivity and specificity were calculated by using the recently developed bivariate approach for diagnostic meta-analysis.

RESULTS

Of 251 eligible studies, 44 were included in the meta-analysis (sample size range, 14-821; cancer prevalence, 23%-84%). Pooled weighted estimates of sensitivity and specificity were 0.90 (95% confidence interval: 0.88, 0.92) and 0.72 (95% confidence interval: 0.67, 0.77), respectively. The performance of breast MR imaging was influenced by the prevalence of cancer in the studied population (P = .05) and by whether two criteria (ie, morphology, enhancement, and kinetic enhancement pattern)--versus one or three criteria--were used to differentiate benign from malignant lesions (P = .02).

CONCLUSION

MR imaging of the breast has high sensitivity and lower specificity in the evaluation of breast lesions.

SUPPLEMENTAL MATERIAL

http://radiology.rsnajnls.org/cgi/content/full/2461061298/DC1.

Beyond standard mammographic screening: mammography at age extremes, ultrasound, and MR imaging

This article describes the principles and performance of screening mammography and discusses indications for screening before the age of 40 years and after the age of 69 years. Specific definitions of high risk are provided, and the rationale and performance characteristics to dare of supplemental screening with ultrasound or MR imaging are reviewed.

Perspectives for preventive screening with total body MRI

Radiology has started to increasingly recognise its potential for screening with the advent of "whole-body" imaging techniques. This article briefly reviews prerequisites for successful screening, presents a quick summary of single-organ screening with magnetic resonance (MR) imaging, and introduces how this knowledge can be integrated into whole-body MR (wb-MR) screening. MR colonography has demonstrated its potential for screening. Wb-MR in the form of wb-MR angiography has already entered both clinical and screening settings; also, the search for metastases with wb-MR has been evaluated and has performed well when compared with other imaging modalities. But screening a group of healthy subjects requires more than feasibility and high accuracy of the screening test; thus, technical and ethical considerations are also presented. Wb-MR is only at its beginning and will in the near future certainly inspire many new research activities as well as transform the radiological market.

Magnetic resonance imaging of the breast improves detection of invasive cancer, preinvasive cancer, and premalignant lesions during surveillance of women at high risk for breast cancer

PURPOSE

To assess the diagnostic accuracy of mammography, ultrasound, and magnetic resonance imaging (MRI) of the breast in the surveillance of women at high risk for breast cancer.

EXPERIMENTAL DESIGN

In this prospective comparison study, women at high risk for breast cancer were offered annual surveillance examinations, consisting of mammography, ultrasound, and MRI, at a single tertiary care breast center. The sensitivity and specificity of each modality was based on the histopathologic evaluation of suspicious findings from all modalities plus the detected interval cancers.

RESULTS

Three hundred and twenty-seven women underwent 672 complete imaging rounds. Of a total of 28 detected cancers, 14 were detected by mammography, 12 by ultrasound, and 24 by MRI, which resulted in sensitivities of 50%, 42.9%, and 85.7%, respectively (P < 0.01). MRI detected not only significantly more invasive but also significantly more preinvasive cancers (ductal carcinoma in situ). Mammography, ultrasound, and MRI led to 25, 26, and 101 false-positive findings, which resulted in specificities of 98%, 98%, and 92%, respectively (P < 0.05). Thirty-five (35%) of these false-positive findings were atypical ductal hyperplasias, lesions considered to be of premalignant character. Nine (26%) of those were detected by mammography, 2 (6%) with ultrasound, and 32 (91%) with MRI (P < 0.01).

CONCLUSION

Our results show that MRI of the breast improves the detection of invasive cancers, preinvasive cancers, and premalignant lesions in a high-risk population and should therefore become an integral part of breast cancer surveillance in these patients.

Surveillance mammography after breast conservation therapy in Hong Kong: effectiveness and feasibility of risk-adapted approach

Annual surveillance mammography is commonly recommended after breast conservation therapy (BCT). We retrospectively reviewed its effectiveness on 511 invasive and non-invasive breast cancers treated with BCT between 1994 and 2003. The median follow-up was 5.9 years. The 5-year actuarial ipsilateral breast tumour recurrence (IBTR) rate was 4.5% and contralateral breast cancer (CBC) rate was 2.0% (representing eight times increase in risk). IBTR of 43% and 62% CBC were first detected by surveillance mammography. The IBTR detection rates per 1000 mammograms were 5.2 for patients (n=349) with one or more IBTR risk factors (age 45, positive/close margins or histological grade 3) and 0.6 for patients (n=162) without. No survival difference was observed between different modes of IBTR detection (p=0.342). In conclusion, a risk-adapted approach of limiting ipsilateral surveillance to patients with IBTR risk is possible but its implementation will be complicated by the continued need of contralateral surveillance.

BRCA mutations in women with ductal carcinoma in situ

PURPOSE

The strength of the association between ductal carcinoma in situ (DCIS) and BRCA mutations has not been defined.

EXPERIMENTAL DESIGN

Mutation frequency was compared in three groups: (1) a prevalent series of women with DCIS, (2) an incident series of women with DCIS, and (3) a clinic-based series of women with DCIS referred for hereditary cancer risk assessment. In groups 1 and 2, limited to Ashkenazi Jewish (AJ) cases, mutation frequency was compared with that in age-matched AJ controls with invasive breast cancer (IBC).

RESULTS

In group 1, 3 of 62 (4.8%) women with DCIS and 15 of 130 (11.5%) controls with IBC had BRCA mutations. In group 2, 0 of 58 (0%) women with DCIS and 6 of 116 (5.2%) controls with IBC had BRCA mutations [combined odds ratios (OR) in groups 1 and 2: 3.64, 95% confidence interval (95% CI), 1.06-12.46; P=0.04]. In group 3, deleterious mutations were identified in 10 of 79 (12.7%) probands with DCIS, similar to the frequency in IBC probands. In group 3, mutations were associated with family history of ovarian cancer (OR, 13.35; 95% CI, 2.48-71.94; P=0.003) or early onset breast cancer (OR, 16.23; 95% CI, 1.68-157.01; P=0.02) but not with AJ ethnicity or age at diagnosis.

CONCLUSIONS

BRCA mutations were less frequent in women with DCIS not selected for family history or age at diagnosis than in women with IBC. Nonetheless, mutations were found in a significant proportion of women with DCIS who presented for hereditary risk assessment.

Management updates for women with a BRCA1 or BRCA2 mutation

In most cases of families with breast and ovarian cancer, the pattern of cancers in the family can be attributed to mutations in the BRCA1 and BRCA2 genes. Genetic testing for these cancer susceptibility genes typically takes place in the context of comprehensive genetic counseling. Strategies have been developed for the medical management of women at high risk of developing breast cancer, including options for screening and prophylactic surgery. BRCA1 and BRCA2 carriers are recommended to undergo prophylactic bilateral salpingo-oophorectomy by age 35-40 years or when childbearing is complete. This surgery significantly reduces the risk of ovarian cancer and also reduces the risk of breast cancer when performed in premenopausal mutation carriers. For breast cancer management, BRCA1 and BRCA2 carriers are offered the options of increased surveillance, with or without chemoprevention, or prophylactic surgery. Currently, BRCA carrier status is not used as an independent prognostic factor regarding systemic treatment options.

Cancer yield of mammography, MR, and US in high-risk women: prospective multi-institution breast cancer screening study

PURPOSE

To prospectively determine cancer yield, callback and biopsy rates, and positive predictive value (PPV) of mammography, magnetic resonance (MR) imaging, and ultrasonography (US) in women at high risk for breast cancer.

MATERIALS AND METHODS

The study was approved by the institutional review board and was HIPAA compliant, and informed consent was obtained. We conducted a prospective pilot study of screening mammography, MR, and US in asymptomatic women 25 years of age or older who were genetically at high risk, defined as BRCA1/BRCA2 carriers or with at least a 20% probability of carrying a BRCA1/BRCA2 mutation. All imaging modalities were performed within 90 days of each other. Data were analyzed by using exact confidence intervals (CIs) and the McNemar test.

RESULTS

A total of 195 women were enrolled in this study over a 6-month period, and 171 completed all study examinations (mammography, US, and MR). Average age of the 171 participants was 46 years +/- 10.2 (standard deviation). Sixteen biopsies were performed and six cancers were detected, for an overall 3.5% cancer yield. MR enabled detection of all six cancers; mammography, two; and US, one. The diagnostic yields for each test were 3.5% for MR, 0.6% for US, and 1.2% for mammography. MR, US, and mammography findings prompted biopsy in 8.2%, 2.3%, and 2.3% of patients, respectively. None of the pairwise comparisons were statistically significant. The PPV of biopsies performed as a result of MR was 43%.

CONCLUSION

Screening MR imaging had a higher biopsy rate but helped detect more cancers than either mammography or US. US had the highest false-negative rate compared with mammography and MR, enabling detection of only one in six cancers in high-risk women.

Current Status of Breast MR Imaging Part 2. Clinical Applications

Magnetic resonance (MR) imaging is emerging as the most sensitive modality that is currently available for the detection of primary or recurrent breast cancer. Although this technique has been shown to be an extremely powerful diagnostic tool, it is still relatively rarely used in clinical practice, as compared with other applications of MR imaging such as for musculoskeletal or brain and spine imaging. This is the second of a two-part series on the current status of breast MR. Part two provides an overview of the use of breast MR imaging in clinical patient care, the body of evidence that supports its use. A discussion is provided on the many controversies that exist regarding breast MR imaging for preoperative staging and for screening.

Diagnostic Breast MR Imaging: Current Status and Future Directions

Breast MRI has become an integral component in breast imaging. Indications have become clearer and better defined. Guidelines and recommendations are evolving and many are recognized and published. Future applications are exciting and may possibly improve our ability to diagnose breast cancer, improving the patient's treatment options and ultimately patient outcome.

The GRAIDS Trial: a cluster randomised controlled trial of computer decision support for the management of familial cancer risk in primary care

The objective was to evaluate the effect of an assessment strategy using the computer decision support system (the GRAIDS software), on the management of familial cancer risk in British general practice in comparison with best current practice. The design included cluster randomised controlled trial, and involved forty-five general practice teams in East Anglia, UK. Randomised to GRAIDS (Genetic Risk Assessment on the Internet with Decision Support) support (intervention n=23) or comparison (n=22). Training in the new assessment strategy and access to the GRAIDS software (GRAIDS arm) was conducted, compared with an educational session and guidelines about managing familial breast and colorectal cancer risk (comparison) were mailed. Outcomes were measured at practice, practitioner and patient levels. The primary outcome measure, at practice level, was the proportion of referrals made to the Regional Genetics Clinic for familial breast or colorectal cancer that were consistent with referral guidelines. Other measures included practitioner confidence in managing familial cancer (GRAIDS arm only) and, in patients: cancer worry, risk perception and knowledge about familial cancer. There were more referrals to the Regional Genetics Clinic from GRAIDS than comparison practices (mean 6.2 and 3.2 referrals per 10 000 registered patients per year; mean difference 3.0 referrals; 95% confidence interval (CI) 1.2–4.8; P=0.001); referrals from GRAIDS practices were more likely to be consistent with referral guidelines (odds ratio (OR)=5.2; 95% CI 1.7–15.8, P=0.006). Patients referred from GRAIDS practices had lower cancer worry scores at the point of referral (mean difference −1.44 95% CI −2.64 to −0.23, P=0.02). There were no differences in patient knowledge about familial cancer. The intervention increased GPs' confidence in managing familial cancer. Compared with education and mailed guidelines, assessment including computer decision support increased the number and quality of referrals to the Regional Genetics Clinic for familial cancer risk, improved practitioner confidence and had no adverse psychological effects in patients. Trials are registered under N0181144343 in the UK National Research Register.

MRI for diagnosis of pure ductal carcinoma in situ: a prospective observational study

BACKGROUND

Diagnosing breast cancer in its intraductal stage might be helpful to prevent the development of invasive cancer. Our aim was to investigate the sensitivity with which ductal carcinoma in situ (DCIS) is diagnosed by mammography and by breast MRI.

METHODS

During a 5-year period, 7319 women who were referred to an academic national breast centre received MRI in addition to mammography for diagnostic assessment and screening. Mammograms and breast MRI studies were assessed independently by different radiologists. We investigated the sensitivity of each method of detection and compared the biological profiles of mammography-diagnosed DCIS versus DCIS detected by MRI alone. We also compared the risk profiles of women with mammography-detected DCIS with those of MRI-detected DCIS.

FINDINGS

193 women received a final surgical pathology diagnosis of pure DCIS. Of those, 167 had undergone both imaging tests preoperatively. 93 (56%) of these cases were diagnosed by mammography and 153 (92%) by MRI (p<0.0001). Of the 89 high-grade DCIS, 43 (48%) were missed by mammography, but diagnosed by MRI alone; all 43 cases missed by mammography were detected by MRI. By contrast, MRI detected 87 (98%) of these lesions; the two cases missed by MRI were detected by mammography. Age, menopausal status, personal or family history of breast cancer or of benign breast disease, and breast density of women with MRI-only diagnosed DCIS did not differ significantly from those of women with mammography-diagnosed DCIS.

INTERPRETATION

MRI could help improve the ability to diagnose DCIS, especially DCIS with high nuclear grade.

A systematic review of the effectiveness of magnetic resonance imaging (MRI) as an addition to mammography and ultrasound in screening young women at high risk of breast cancer

Breast magnetic resonance imaging (MRI) has been proposed as an additional screening test for young women at high risk of breast cancer in whom mammography alone has poor sensitivity. We conducted a systematic review to assess the effectiveness of adding MRI to mammography with or without breast ultrasound and clinical breast examination (CBE) in screening this population. We found consistent evidence in 5 studies that adding MRI provides a highly sensitive screening strategy (sensitivity range: 93-100%) compared to mammography alone (25-59%) or mammography plus ultrasound+/-CBE (49-67%). Meta-analysis of the three studies that compared MRI plus mammography versus mammography alone showed the sensitivity of MRI plus mammography as 94% (95%CI 86-98%) and the incremental sensitivity of MRI as 58% (95%CI 47-70%). Incremental sensitivity of MRI was lower when added to mammography plus ultrasound (44%, 95%CI 27-61%) or to the combination of mammography, ultrasound plus CBE (31-33%). Estimates of screening specificity with MRI were less consistent but suggested a 3-5-fold higher risk of patient recall for investigation of false positive results. No studies assessed as to whether adding MRI reduces patient mortality, interval or advanced breast cancer rates, and we did not find strong evidence that MRI leads to the detection of earlier stage disease. Conclusions about the effectiveness of MRI therefore depend on assumptions about the benefits of early detection from trials of mammographic screening in older average risk populations. The extent to which high risk younger women receive the same benefits from early detection and treatment of MRI-detected cancers has not yet been established.

Sensitivity of MRI versus conventional screening in the diagnosis of BRCA-associated breast cancer in a national prospective series

We wanted to compare the sensitivities of breast magnetic resonance imaging (MRI) and the conventional screening programme consisting of mammography (XRM) +/- ultrasound for early diagnosis of breast cancer in BRCA1/2 mutation carriers. BRCA1/2 mutation carriers were examined prospectively by both breast MRI and XRM +/- ultrasound. Eight hundred and sixty-seven MRI examinations were carried out in 445 BRCA1 and 46 BRCA2 mutation carriers. A total of 25 cancers were observed, five (20%) as interval cancers. At the time of diagnosis, sensitivity to detect cancer was 19/22=86% for MRI and 12/24=50% for XRM. Twenty-one were examined by both methods at the time of diagnosis. In the19 BRCA1 mutation carriers among them, MRI had a sensitivity of 1/3(33%) to diagnose DCIS and 15/16 (94%) among the invasive cancers. For XRM the sensitivities were 1/3(33%) for DCIS, 3/7(42%) for pT1b, 3/6(50%) for pT1c, and 3/3/100%) for pT2. In the two BRCA2 mutation carriers, both were demonstrated by breast MRI, neither was detected by XRM. Breast MRI had increased sensitivity compared to XRM to diagnose all cancers staged less than pT2.

Clinical management recommendations for surveillance and risk-reduction strategies for hereditary breast and ovarian cancer among individuals carrying a deleterious BRCA1 or BRCA2 mutation

BACKGROUND

In Canada, there are wide variations in services for patients at risk for hereditary breast and ovarian cancer (HBOC), and clinical interventions and recommendations differ between regions and/or provinces. National strategies for the clinical management of HBOC exist in the United Kingdom, France, and Australia, and clinical programs in Canada would benefit from similar national recommendations and a consistent approach to clinical management. The National Hereditary Cancer Task Force developed recommendations to address the clinical management of patients at high risk of HBOC and related cancers. These recommendations are based on current practice in high-risk cancer clinics that provide care for individuals with known BRCA1 or BRCA2 mutations.

METHODS

Canadian consensus recommendations were generated by the National Hereditary Cancer Task Force and compared mainly with two recently published guidance documents on the clinical management of women with increased risk of HBOC, one from the United Kingdom and the other from France. After review of these documents and the associated supporting scientific evidence, the Canadian consensus recommendations were modified and rated using predefined criteria.

CONCLUSIONS

These recommendations pertain to (1) surveillance options including breast self-examination, clinical breast examination, breast surveillance by imaging, ovarian cancer surveillance, and surveillance for men; (2) risk-reduction strategies including prophylactic mastectomy, prophylactic salpingo-oophorectomy, and pharmacoprevention; and (3) the use of exogenous hormones. Regular updates should occur as new evidence becomes available.

Ovarian cancer screening with annual transvaginal sonography: findings of 25,000 women screened

BACKGROUND

Ovarian cancer has the highest mortality rate of all gynecologic malignancies, and most women present with advanced-stage disease. The current investigation was performed to determine the efficacy of annual transvaginal sonography (TVS) as a screening method for ovarian cancer.

METHODS

Annual TVS screening was performed on 25,327 women from 1987 to 2005. Asymptomatic women aged>or=50 years and women aged>or=25 years who had a family history of ovarian cancer were eligible for participation in this trial.

RESULTS

Among 364 patients (1.4%) with a persisting ovarian tumor on TVS who underwent exploratory laparoscopy or laparotomy with tumor removal, 35 primary invasive ovarian cancers, 9 serous ovarian tumors of low malignant potential, and 7 cancers metastatic to the ovary were detected. Stage distribution was as follows: 28 patients had stage I disease, 8 patients had stage II disease, and 8 patients had stage III disease. Four patients died of disease, 2 patients died of other causes, and 38 patients were alive and well from 0.5 years to 15.8 years after diagnosis (mean, 5.3 years). Nine women developed ovarian cancer within 12 months of a negative screen (false-negative results), and 3 of these patients died of disease. TVS screening had a sensitivity of 85.0%, specificity of 98.7%, positive predictive value of 14.01%, and negative predictive value of 99.9%. After 107,276 screening years, there have been 7 ovarian cancer deaths in the annually screened population and 3 ovarian cancer deaths among women who were noncompliant. Excluding patients with nonepithelial or borderline ovarian malignancies, the survival of patients with ovarian cancer in the annually screened population was 89.9%+/-10.1% at 2 years and 77.2%+/-22.8% at 5 years.

CONCLUSIONS

TVS screening, when it was performed annually, was associated with a decrease in disease stage at detection and with case-specific ovarian cancer mortality, but it was not effective in detecting ovarian cancers in women who had normal ovarian volume.

Effect of mammography on breast cancer risk in women with mutations in BRCA1 or BRCA2

Women who carry mutations in either the BRCA1 or BRCA2 genes are at risk for early-onset breast cancer and are recommended to begin screening mammography at age 25 to 30 years. Results of in vitro and animal studies suggest that BRCA1/BRCA2 mutation carriers are hypersensitive to ionizing radiation and possibly to radiation-induced breast cancer. This study was undertaken to investigate the association of low-dose radiation exposure from mammograms with breast cancer status in BRCA mutation carriers. One hundred sixty-two female mutation carriers provided information at time of genetic testing about exposure to mammograms before enrollment. Using unconditional logistic regression, breast cancer status was not associated with number of mammograms received before diagnosis (affected women) or ascertainment [unaffected women; adjusted odds ratio (OR), 0.94; P = not significant]. A larger group of 213 women provided information about lifetime number of mammograms. There was no association between mammogram exposure and risk in the group as a whole (adjusted OR, 1.04; P = not significant), although there was a modest association in BRCA1 carriers (adjusted OR, 1.08; P = 0.03). These findings indicate that screening mammography is unlikely to be associated with a large increase in breast cancer risk in this population.

Follow-up after treatment for breast cancer in young women

The majority (80%) of breast cancers are diagnosed in women over the age of 50; only 5% will be in their 20s and 30s. These women have specific needs that include genetic counselling, psychological support, advice with regard to fertility and pregnancy issues and information on coping with treatment-related morbidity. The primary purpose of follow-up is often regarded as the early detection of recurrence as well as the detection of second primary tumours. Rather than concentrating solely on detecting cancer recurrence, clinicians need to be more susceptive to symptoms related to treatment morbidity and to the information needs of their patients. This paper outlines the specific issues listed above that need to be addressed in follow-up clinics and highlights interventions that may help improve the value of follow-up appointments and quality of life for young women with breast cancer.

Multidisciplinary frontiers in breast cancer management: a surgeon's perspective

The current paradigm of breast cancer management may be altered significantly over the coming years by the adoption of new treatment schema and devices outside of the surgical arena. New advances in breast cancer imaging will improve our ability to detect early-stage disease but also will assist in monitoring treatment outcomes and support the development of nonsurgical ablation techniques. These advances, some already in use, include a 3-dimensional adaptation of digital mammography, color Doppler ultrasonography that can visualize neovascularization in growing tumors, contrast-enhanced magnetic resonance imaging with improved accuracy for the detection of occult cancers, a specialized approach to positron emission tomography designed for use on the breast, and the development of nanoparticle contrast agents that can be visualized with near-infrared light. Systemic therapy, which revolutionized breast cancer management in the last half of the 20th century, is being reconceptualized, with attention turning to adjusting the timing of chemotherapy. Dose-dense regimens are being tested, and there also is interest in so-called metronomic chemotherapy in which very low doses are given on a very frequent schedule, resulting in reduced toxicity and treatment outcomes that reflect an antiangiogenic mode of action. Finally, the possibility of a breast cancer vaccine continues to intrigue and excite physicians and patients alike, with the promise of enlisting the body's own immune system to seek out and destroy cancer cells and/or prevent the development of future disease. It will be important for surgeons to stay aware of all developments that may improve the care of their patients and to be true surgical oncologists rather than merely surgical technicians.

Gene promoter hypermethylation in ductal lavage fluid from healthy BRCA gene mutation carriers and mutation-negative controls

Introduction

Female germline BRCA gene mutation carriers are at increased risk for developing breast cancer. The purpose of our study was to establish whether healthy BRCA mutation carriers demonstrate an increased frequency of aberrant gene promoter hypermethylation in ductal lavage (DL) fluid, compared with predictive genetic test negative controls, that might serve as a surrogate marker of BRCA1/2 mutation status and/or breast cancer risk.

Methods

The pattern of CpG island hypermethylation within the promoter region of a panel of four genes (RAR-β, HIN-1, Twist and Cyclin D2) was assessed by methylation-specific polymerase chain reaction using free DNA extracted from DL fluid.

Results

Fifty-one DL samples from 24 healthy women of known BRCA mutation status (7 BRCA1 mutation carriers, 12 BRCA2 mutation carriers and 5 controls) were available for methylation analysis. Eight of 19 (42.1%) BRCA mutation carriers were found to have at least one hypermethylated gene in the four-gene panel. Two BRCA mutation carriers, in whom aberrant methylation was found, also had duct epithelial cell atypia identified. No hypermethylation was found in DL samples from 5 negative controls(p = 0.13).

Conclusion

We found substantial levels of aberrant methylation, with the use of a four-gene panel, in the fluid from the breasts of healthy BRCA mutation carriers compared with controls. Methylation analysis of free DNA in DL fluid may offer a useful surrogate marker for BRCA1/2 mutation status and/or breast cancer risk. Further studies are required for the evaluation of the specificity and predictive value of aberrant methylation in DL fluid for future breast cancer development in BRCA1/2 mutation carriers.

[Indications of MRI in the initial local staging of early-stage breast cancer]

MR Imaging is the most sensitive technique for detecting breast cancer. In patients with breast cancer, the additional value of MRI is validated in patients candidates for a breast-conserving surgery and when: cancer is occult, size evaluation is difficult at standard imaging, parietal involvement is suspected, and before neoadjuvant chemotherapy. In fatty breasts, MRI is not routinely recommended, because of same performances as in standard imaging. In dense breasts, MRI becomes significantly more sensitive than mammography for detecting multifocality and multicentricity with a positive predictive value of 60% for detected additional foci. Thus, a decision of mastectomy should not be made solely on the basis of MRI and may require additional tissue sampling of areas of concern identified by breast MRI. The additional value of breast MRI is particularly useful in patients with dense breasts and high risk factors for local recurrence: young age (< 40 years), familial high risk, or because of a high-grade invasive cancer greater than 2 cm in size. Performing breast MRI in such patients underlies requirements: an expert breast imaging team, optimal MRI protocols, and radiologists working in concert with the multidisciplinary treatment team.

A survey of preventive measures among BRCA1 mutation carriers from Poland

Among women with a BRCA1 mutation, the lifetime risks of breast and ovarian cancer are elevated. Several measures for reducing cancer risk in carriers of BRCA1 mutations have been proposed, including prophylactic surgery and tamoxifen chemoprevention. It is not yet known to what extent women with mutations have adopted these various preventive measures. We surveyed 414 Polish women with a BRCA1 mutation who had received counseling about various preventive strategies. Each woman completed a survey for a minimum of 18 months after receiving her genetic result. A high proportion of women reported having had an oophorectomy to reduce breast and ovarian cancer risk (49.1%). In contrast, only 11% had taken tamoxifen and only 5% had undergone a preventive mastectomy. Most of the women (81%) had a screening mammogram during the follow-up period. Oral contraceptives and breastfeeding are believed to protect against ovarian cancer, but only 9% of women had taken the birth control pill for 3 years or more and 27% had breastfed for 1 year or more. In summary, approximately one-half of Polish women with a BRCA1 mutation had taken an active step to reduce their risk of breast cancer within 18 months of receiving a positive result. A greater effort should be made to promote breastfeeding and use of oral contraceptive as risk-reducing measures.

Mammographic breast density and race

OBJECTIVE

Women with increased mammographic breast density are known to be at higher risk of developing breast cancer. Reports of differences in breast density by race have implied that genetic and environmental factors may in part determine breast density. We first compared breast density among white, African American, and Asian women and then correlated breast density and race with age, body mass index (BMI), and breast or cup size.

MATERIALS AND METHODS

A retrospective review of data collected from 15,292 women was conducted. A stepwise multiple regression for an ordered response (breast density) was used to test for a relationship between race or ethnicity and breast density. We then determined whether differences in breast density by race might be caused by differences among races and ethnic groups in the age at imaging and BMI. We informally assessed the strength of the contribution of each term by means of the incremental change in the percent concordance. We also compared models using bra and cup sizes and age with models using BMI and age to try to determine whether the effects of breast size are local or systemic.

RESULTS

We did not find evidence that mammographic breast density differences exist across racial groups (p < 0.0001) other than those associated with BMI and age at screening. Ignoring age and BMI, breast density depends on race for all comparisons (p < 0.0001). To generalize, we found that breast density appears to be greater in Asian women and least in African American women. However, when controlling for BMI and age, breast density differences by race disappeared in all groups except Asians (p < 0.0001). In all racial groups, bra and cup size in addition to age correlated with breast density after controlling for BMI (p < 0.0001). Except in Asian women, in women of any racial group, age and any of the following parameters accounted for all of the breast density differences: BMI, bra size, and cup size.

CONCLUSION

Although breast density is associated with breast cancer risk, our results indicate that innate mammographic breast density differences across racial groups do not explain the risk differences known for the development of breast cancer. Age and BMI or age, bra size, and cup size can account for the reported density differences except among Asians. There may be no innate racial differences in breast density beyond those associated with racial differences in age and body habitus.

[Hereditary breast and ovarian cancer: primary and secondary prevention for BRCA1 and BRCA2 mutation carriers]

Ten years after the identification of the breast and ovarian cancer predisposition genes, BRCA1 and BRCA2, an emerging literature has explored the efficacy of strategies for primary as well as secondary prevention of breast and ovarian cancer in BRCA1 and BRCA2 mutations carriers. The integration of magnetic resonance imaging for breast cancer screening in BRCA carriers has achieved a higher sensibility of the screening, and an early detection of breast cancer. However, we don't have yet enough level of evidence that magnetic resonance imaging could reduce mortality in BRCA carriers. Because of the limitations of screening for ovarian cancer, bilateral prophylactic salpingo-oophorectomy has been established as one of the most effective strategies to prevent ovarian cancer in BRCA1 and BRCA2 mutation carriers. This strategy also has a favorable effect on the reduction of risk of breast cancer if is performed before the age of 50. The management of this patients must be individualized and multidisciplinary.

Multicenter comparative multimodality surveillance of women at genetic-familial high risk for breast cancer (HIBCRIT study): interim results

PURPOSE

To prospectively compare clinical breast examination (CBE), mammography, ultrasonography (US), and contrast material-enhanced magnetic resonance (MR) imaging for screening women at genetic-familial high risk for breast cancer and report interim results, with pathologic findings as standard.

MATERIALS AND METHODS

Institutional review board of each center approved the research; informed written consent was obtained. CBE, mammography, US, and MR imaging were performed for yearly screening of BRCA1 or BRCA2 mutation carriers, first-degree relatives of BRCA1 or BRCA2 mutation carriers, or women enrolled because of a strong family history of breast or ovarian cancer (three or more events in first- or second-degree relatives in either maternal or paternal line; these included breast cancer in women younger than 60 years, ovarian cancer at any age, and male breast cancer at any age).

RESULTS

Two hundred seventy-eight women (mean age, 46 years +/- 12 [standard deviation]) were enrolled. Breast cancer was found in 11 of 278 women at first round and seven of 99 at second round (14 invasive, four intraductal; eight were <or=10 mm in diameter). Detection rate per year was 4.8% (18 of 377) overall; 4.3% (11 of 258) in BRCA1 or BRCA2 mutation carriers and first-degree relatives of BRCA1 or BRCA2 mutation carriers versus 5.9% (seven of 119) in women enrolled because of strong family history; and 5.3% (nine of 169) in women with previous personal breast and/or ovarian cancer versus 4.3% (nine of 208) in those without. In six (33%) of 18 patients, cancer was detected only with MR imaging. Sensitivity was as follows: CBE, 50% (95% confidence interval [CI]: 29%, 71%); mammography, 59% (95% CI: 36%, 78%); US, 65% (95% CI: 41%, 83%); and MR imaging, 94% (95% CI: 82%, 99%). Positive predictive value was as follows: CBE, 82% (95% CI: 52%, 95%); mammography, 77% (95% CI: 50%, 92%); US, 65% (95% CI: 41%, 83%); and MR imaging, 63% (95% CI: 43%, 79%).

CONCLUSION

Addition of MR imaging to the screening regimen for high-risk women may enable detection of otherwise unsuspected breast cancers.

Results of MRI screening for breast cancer in high-risk patients with LCIS and atypical hyperplasia

BACKGROUND

Magnetic resonance imaging (MRI) can detect breast cancer in high-risk patients, but is associated with a significant false-positive rate resulting in unnecessary breast biopsies. More data are needed to define the role of MRI screening for specific high-risk groups. We describe our experience with MRI screening in patients with atypical hyperplasia (AH) and lobular carcinoma in situ (LCIS).

METHODS

We retrospectively reviewed data from our high-risk screening program prospective database for the period from April 1999 (when screening MRI was first performed at our institution) to July 2005. Patients with AH or LCIS demonstrated on previous surgical biopsy were identified. All patients underwent yearly mammography and twice yearly clinical breast examination. Additional screening MRI was performed at the discretion of the physician and patient.

RESULTS

We identified 378 patients; 126 had AH and 252 had LCIS. Of these, 182 (48%) underwent one or more screening MRIs (mean, 2.6 MRIs; range, 1-8) during this period, whereas 196 (52%) did not. Those who had MRIs were younger (P < 0.001) with stronger family histories of breast cancer (P = 0.02). In MRI-screened patients, 55 biopsies were recommended in 46/182 (25%) patients, with 46/55 (84%) biopsies based on MRI findings alone. Cancer was detected in 6/46 (13%) MRI-generated biopsies. None of the six cancers detected on MRI were seen on recent mammogram. All six cancers were detected in five patients (one with bilateral breast cancer) with LCIS; none were detected by MRI in the AH group. Thus, cancer was detected in 5/135 (4%) of patients with LCIS undergoing MRI. The yield of MRI screening overall was cancer detection in 6/46 (13%) biopsies, 5/182 (3%) MRI-screened patients and 5/478 (1%) total MRIs done. In two additional MRI-screened patients, cancer was detected by a palpable mass in one, and on prophylactic surgery in the other and missed by all recent imaging studies. For 196 non-MRI-screened patients, 21 (11%) underwent 22 biopsies during the same period. Eight of 22 (36%) biopsies yielded cancer in seven patients. All MRI-detected cancers were stage 0-I, whereas all non-MRI cancers were stage I-II.

CONCLUSION

Patients with AH and LCIS selected to undergo MRI screening were younger with stronger family histories of breast cancer. MRI screening generated more biopsies for a large proportion of patients, and facilitated detection of cancer in only a small highly selected group of patients with LCIS.

Management of the BRCA Mutation Carrier or High-Risk Patient

Women who are at high risk of breast cancer are eligible for several risk management strategies including intensified surveillance, chemoprevention, and prophylactic surgery. This article reviews and summarizes the risk factors associated with breast cancer, the different risk calculation models available, and risk management strategies.

Breast imaging and reporting data system (BIRADS): magnetic resonance imaging

This article reviews the technical aspects and interpretation criteria in breast MR imaging based on the first edition of breast imaging and reporting data system (BIRADS) published by the American College of Radiology (ACR) in 2003. In a second article, practical cases will be proposed for training the readers. The major aims of using this lexicon are: first to use a logical and standardized description of MR lesions, secondly to obtain a structured MR report with a clear final impression (BIRADS assessment categories), and thirdly to help comparison between different clinical studies based on similar breast MRI terminology.

Screening MRI for women at high risk for breast cancer

Recognition of the limitations of mammography in screening women at high risk for breast cancer stimulated clinical trials to evaluate magnetic resonance imaging (MRI) as an adjunct to mammography. Based on the results of these trials, there is increased interest in offering screening MRI to high-risk women after discussion of the potential benefits and risks. The benefits include increased cancer detection with MRI and significantly more cancers detected prior to nodal metastases. The risks include false-positive exams, which lead to additional imaging and/or benign biopsies. This article will review the findings from published clinical trials and provide guidelines for implementation of an MRI screening program.

The diagnostic impact of contrast-enhanced MRI in management of breast disease

For effective use, the diagnostic impact of contrast-enhanced breast MRI (CE MRI) needs to be quantified. This is a retrospective study of 441 women who have undergone CE MRI of the breast from 1 July 1997 to 25 March 2002. Indications for CE MRI studies were diagnostic in 176, monitoring chemotherapy in 126 and study of MRI screening for breast cancer (MARIBS) cases in 139. CE MRI results were confusing or incorrect in 6% of the diagnostic group, 13% of the chemotherapy group and 9% of the MARIBS group. In 18 of 38 of these cases CE MRI stimulated further tests to clarify a clinical query. CE MRI resulted in an increase in confidence or change in clinical plan in 46% of the diagnostic group, 72% of the chemotherapy group and 80% of the MARIBS group. In 44 of 283 of these, CE MRI caused a beneficial change in the clinical plan based on conventional radiology. CE MRI results in a positive diagnostic impact above conventional imaging in a clinically important proportion of patients, but gives some false calls in a smaller proportion (8.6%).

Loss of heterozygosity at the BRCA1 and BRCA2 loci detected in ductal lavage fluid from BRCA gene mutation carriers and controls

Female BRCA gene mutation carriers are at increased risk for developing breast cancer. Ductal lavage is a novel method for sampling breast ductal fluid, providing epithelial cells for cytologic assessment and a source of free DNA for molecular analyses. Loss of heterozygosity (LOH) at the BRCA loci in ductal lavage fluid is a potential biomarker of breast cancer risk. The LOH rate was measured at the BRCA1/2 loci and compared with that at a control locus (APC) using free DNA from the ductal lavage fluid of BRCA carriers and predictive test negative controls. We evaluated the reproducibility of these analyses. Free DNA sufficient for PCR amplification was obtained from 33 ductal lavage samples of 17 healthy women of known BRCA status (14 BRCA carriers and 3 controls). LOH rates of 36.4% to 56.3% at the BRCA1 locus and 45% to 61.5% at the BRCA2 locus were found among BRCA carriers. The LOH rate at the APC locus was lower (18.5%). The interaliquot reproducibility for the D17S855 marker of the BRCA1 locus was 66.7%. Intraaliquot reproducibility was 90%. Although we successfully isolated sufficient free DNA from ductal lavage fluid for PCR amplification, the degree of reproducibility of these LOH studies raises questions about the robustness of this technique as a risk assessment tool in the evaluation of high-risk women. Further studies are required to evaluate the specificity and predictive value of LOH in ductal lavage fluid for breast cancer development.

Cost-effectiveness of screening with contrast enhanced magnetic resonance imaging vs X-ray mammography of women at a high familial risk of breast cancer

Contrast enhanced magnetic resonance imaging (CE MRI) is the most sensitive tool for screening women who are at high familial risk of breast cancer. Our aim in this study was to assess the cost-effectiveness of X-ray mammography (XRM), CE MRI or both strategies combined. In total, 649 women were enrolled in the MARIBS study and screened with both CE MRI and mammography resulting in 1881 screens and 1–7 individual annual screening events. Women aged 35–49 years at high risk of breast cancer, either because they have a strong family history of breast cancer or are tested carriers of a BRCA1, BRCA2 or TP53 mutation or are at a 50% risk of having inherited such a mutation, were recruited from 22 centres and offered annual MRI and XRM for between 2 and 7 years. Information on the number and type of further investigations was collected and specifically calculated unit costs were used to calculate the incremental cost per cancer detected. The numbers of cancer detected was 13 for mammography, 27 for CE MRI and 33 for mammography and CE MRI combined. In the subgroup of BRCA1 (BRCA2) mutation carriers or of women having a first degree relative with a mutation in BRCA1 (BRCA2) corresponding numbers were 3 (6), 12 (7) and 12 (11), respectively. For all women, the incremental cost per cancer detected with CE MRI and mammography combined was £28 284 compared to mammography. When only BRCA1 or the BRCA2 groups were considered, this cost would be reduced to £11 731 (CE MRI vs mammography) and £15 302 (CE MRI and mammography vs mammography). Results were most sensitive to the unit cost estimate for a CE MRI screening test. Contrast-enhanced MRI might be a cost-effective screening modality for women at high risk, particularly for the BRCA1 and BRCA2 subgroups. Further work is needed to assess the impact of screening on mortality and health-related quality of life.

Risk-reducing surgery, screening and chemoprevention practices of BRCA1 and BRCA2 mutation carriers: a prospective cohort study

This study prospectively evaluated the utilization of cancer risk management strategies in a multi-institutional cohort of BRCA1 and BRCA2 mutation carriers using a self-report questionnaire. Of 142 unaffected female mutation carriers, 70 (49%) had elected to receive their mutation result. Of those who knew their mutation result, 11% underwent bilateral mastectomy (BM), 29% had bilateral oophorectomy (BO), 78% performed regular breast self-examination (BSE), and 80%, 89%, 67%, and 0% had at least annual clinical breast examination (CBE), mammography, transvaginal ultrasound (TVU), and CA125, respectively. A further 20%, 7%, 0%, 21%, and 75%, respectively, reported never having had these tests. For women who elected not to receive their mutation result, 0% underwent BM, 6% underwent BO, and 77%, 42%, 56%, 7%, and 0% had regular BSE, CBE, mammography, TVU, and CA125, respectively. Only one woman used chemoprevention outside a clinical trial. Uptake of prophylactic surgery and screening was associated with knowing one's mutation status (for all behaviors except BSE), age (for BO and CBE) and residence (for mammography). In this cohort, the minority of mutation carriers utilized risk-reducing surgery or chemoprevention and a substantial minority were not undergoing regular cancer-screening tests.

Morphologic blooming in breast MRI as a characterization of margin for discriminating benign from malignant lesions

RATIONALE AND OBJECTIVES

Develop a fully automated, objective method for evaluating morphology on breast magnetic resonance (MR) images and evaluate effectiveness of the new morphologic method for detecting breast cancers.

MATERIALS AND METHODS

We present a new automated method (morphologic blooming) for identifying and classifying breast lesions on MR that measures margin sharpness, a characteristic related to blooming, defined as rapid enhancement, with a border that is initially sharp but becomes unsharp after 7 minutes. Independent training sets (98 biopsy-proven lesions) and testing sets (179 breasts, 127 patients, acquired at five institutions) were used. Morphologic blooming was evaluated as a stand-alone feature and as an adjunct to kinetics using free-response receiver operating characteristic and sensitivity analysis. Dependence of false-positive (FP) rates on acquisition times and pathologies of contralateral breasts were evaluated.

RESULTS

Sensitivity of morphologic blooming was 80% with 2.46 FP per noncancerous breast: FPs did not vary significantly by acquisition times. FPs varied significantly by pathologies of contralateral breasts (cancerous contralateral: 4.29 FP/breast; noncancerous contralateral: 0.48 FP/breast; P < .0001). Evaluation of 45 cancers showed suspicious morphologies on 10/15 (67%) cancers with benign-like kinetics and suspicious kinetics on 5/10 (50%) cancers with benign-like morphologies.

CONCLUSION

We present a new, fully automated method of identifying and classifying margin sharpness of breast lesions on MR that can be used to direct radiologists' attention to lesions with suspicious morphologies. Morphologic blooming may have important utility for assisting radiologists in identifying cancers with benign-like kinetics and discriminating normal tissues that exhibit cancer-like enhancement curves and for improving the performance of computer-aided detection systems.

American Society of Clinical Oncology 2006 Update of the Breast Cancer Follow-Up and Management Guidelines in the Adjuvant Setting

Purpose

To update the 1999 American Society of Clinical Oncology (ASCO) guideline on breast cancer follow-up and management in the adjuvant setting.

Methods

An ASCO Expert Panel reviewed pertinent information from the literature through March 2006. More weight was given to studies that tested a hypothesis directly relating testing to one of the primary outcomes in a randomized design.

Results

The evidence supports regular history, physical examination, and mammography as the cornerstone of appropriate breast cancer follow-up. All patients should have a careful history and physical examination performed by a physician experienced in the surveillance of cancer patients and in breast examination. Examinations should be performed every 3 to 6 months for the first 3 years, every 6 to 12 months for years 4 and 5, and annually thereafter. For those who have undergone breast-conserving surgery, a post-treatment mammogram should be obtained 1 year after the initial mammogram and at least 6 months after completion of radiation therapy. Thereafter, unless otherwise indicated, a yearly mammographic evaluation should be performed. Patients at high risk for familial breast cancer syndromes should be referred for genetic counseling. The use of CBCs, chemistry panels, bone scans, chest radiographs, liver ultrasounds, computed tomography scans, [18F]fluorodeoxyglucose–positron emission tomography scanning, magnetic resonance imaging, or tumor markers (carcinoembryonic antigen, CA 15-3, and CA 27.29) is not recommended for routine breast cancer follow-up in an otherwise asymptomatic patient with no specific findings on clinical examination.

Conclusion

Careful history taking, physical examination, and regular mammography are recommended for appropriate detection of breast cancer recurrence.