Breast cancer risk reduction: strategies for women at increased risk

Economic evaluation of germline genetic testing for breast cancer in low- and middle-income countries: a systematic review

BACKGROUND

Breast cancer (BC) is the most common cancer affecting women globally. Genetic testing serves as a prevention and treatment strategy for managing BC. This study aims to systematically review economic evaluations and the quality of selected studies involving genetic screening strategies for BC in low and middle-income countries (LMICs).

METHODS

A search was performed to identify related articles that were published up to April 2023 on PubMed, Embase, CINAHL, Web of Science, and the Centre for Reviews and Dissemination. Only English-language LMIC studies were included. Synthesis of studies characteristics, methodological and data input variations, incremental cost-effectiveness ratios (ICERs), and reporting quality (Consolidated Health Economic Evaluation Reporting Standards (CHEERS) 2022 checklist) were performed.

RESULTS

This review found five pertinent studies, mainly focusing on economic evaluations of germline genetic testing in upper-middle-income countries (Upper MICs) like Malaysia, China, and Brazil. Only one study covered multiple countries with varying incomes, including lower-middle-income nations (Lower MICs) like India. The ICERs values in various screening scenarios for early-stage BC, HER2 negative BC patients, and healthy women with clinical or family history criteria were ranging from USD 2214/QALY to USD 36,342/QALY. Multigene testing for all breast cancer patients with cascade testing was at USD 7729/QALY compared to BRCA alone. Most studies adhered to the CHEERS 2022 criteria, signifying high methodological quality.

CONCLUSIONS

Germline testing could be considered as cost-effective compared to no testing in Upper MICs (e.g., Malaysia, China, Brazil) but not in Lower MICs (e.g., India) based on the willingness-to-pay (WTP) threshold set by each respective study. Limitations prevent a definite conclusion about cost-effectiveness across LMICs. More high-quality studies are crucial for informed decision-making and improved healthcare practices in these regions.

Weight, physical activity and breast cancer survival

Weight, weight change and physical activity may affect prognosis among women who are diagnosed with breast cancer. Observational studies show associations between overweight/obesity and weight gain with several measures of reduced prognosis in women with breast cancer, and some suggestions of lower survival in women who are underweight or who experience unexplained weight loss after diagnosis. Observational studies have also shown an association between higher levels of physical activity and reduced breast cancer-specific and all-cause mortality, although a dose–response relationship has not been established. The effects of purposive dietary weight loss and increase in physical activity on survival or recurrence in breast cancer are not yet established, and randomised controlled trials are needed for definitive data. This paper presents the epidemiologic evidence on weight status, weight change, and physical activity and breast cancer survival; suggests potential mediating mechanisms; summarises evidence on weight loss interventions in breast cancer survivors; describes ongoing randomised clinical trials designed to test the effects of weight loss or physical activity on breast cancer survival; and provides information on available guidelines on weight and physical activity for cancer survivors.

Pilot study demonstrating potential association between breast cancer image-based risk phenotypes and genomic biomarkers

PURPOSE

In this pilot study, the authors examined associations between image-based phenotypes and genomic biomarkers. The potential genetic contribution of UGT2B genes to interindividual variation in breast density and mammographic parenchymal patterns is demonstrated by performing an association study between image-based phenotypes and genomic biomarkers [single-nucleotide polymorphism (SNP) genotypes].

METHODS

This candidate-gene approach study included 179 subjects for whom both mammograms and blood DNA samples had been obtained. The full-field digital mammograms were acquired using a GE Senographe 2000D FFDM system (12-bit; 0.1 mm-pixel size). Regions-of-interest, 256 × 256 pixels in size, selected from the central breast region behind the nipple underwent computerized image analysis to yield image-based phenotypes of mammographic density and parenchymal texture patterns. SNP genotyping was performed using a Sequenom MassArray System. One hundred twenty three SNPs with minor allele frequency above 5% were genotyped for the UGT2B gene clusters, and used in the study. The association between the image-based phenotypes and genomic biomarkers was assessed with the Pearson correlation coefficient via thePLINK software, and included permutation and correction for multiple SNP comparisons.

RESULTS

From the phenotype-genotype association analysis, a parenchyma texture coarseness feature was found to be correlated with SNP rs451632 after multiple test correction for the multiple SNPs (p = 0.022). The power law β, which is used to characterize the frequency component of texture patterns, was found to be correlated with SNP rs4148298 (p = 0.035).

CONCLUSIONS

The authors' results indicate that UGT2B gene variation may contribute to interindividual variation in mammographic parenchymal patterns and breast density. Understanding the relationship between image-based phenotypes and genomic biomarkers may help understand the biologic mechanism for image-based biomarkers and yield a future role in personalized medicine.

Mammographic image denoising and enhancement using the Anscombe transformation, adaptive wiener filtering, and the modulation transfer function

A new restoration methodology is proposed to enhance mammographic images through the improvement of contrast features and the simultaneous suppression of noise. Denoising is performed in the first step using the Anscombe transformation to convert the signal-dependent quantum noise into an approximately signal-independent Gaussian additive noise. In the Anscombe domain, noise is filtered through an adaptive Wiener filter, whose parameters are obtained by considering local image statistics. In the second step, a filter based on the modulation transfer function of the imaging system in the whole radiation field is applied for image enhancement. This methodology can be used as a preprocessing module for computer-aided detection (CAD) systems to improve the performance of breast cancer screening. A preliminary assessment of the restoration algorithm was performed using synthetic images with different levels of quantum noise. Afterward, we evaluated the effect of the preprocessing on the performance of a previously developed CAD system for clustered microcalcification detection in mammographic images. The results from the synthetic images showed an increase of up to 11.5 dB (p = 0.002) in the peak signal-to-noise ratio. Moreover, the mean structural similarity index increased up to 8.3 % (p < 0.001). Regarding CAD performance, the results suggested that the preprocessing increased the detectability of microcalcifications in mammographic images without increasing the false-positive rates. Receiver operating characteristic analysis revealed an average increase of 14.1 % (p = 0.01) in overall CAD performance when restored image sets were used.

Risk-reducing salpingectomy as preventative strategy for pelvic serous cancer

The systemic failure to detect early-stage ovarian cancer may be attributed to a significant amount of pelvic serous cancers arising from the fallopian tube rather than the ovarian surface epithelium. This article reviews the possibility of applying risk-reducing salpingectomy as a new paradigm for the prevention of pelvic serous cancer in both high- and low-risk women.

Willingness to use tamoxifen to prevent breast cancer among diverse women

Use of chemoprevention to prevent development of breast cancer among high-risk women has been limited despite clinical evidence of its benefit. Our goals were to determine whether knowledge of the benefits and risks of tamoxifen affects a woman's willingness to take it to prevent breast cancer, to define factors associated with willingness to take tamoxifen, and to evaluate race/ethnic differences. Women, ages 50-80, who identified as African American, Asian, Latina, or White, and who had at least one visit to a primary care physician in the previous 2 years, were recruited from ambulatory practices. After a screening telephone survey, women completed an in-person interview in their preferred language. Multivariate regression models were constructed to examine the associations of demographic characteristics, numeracy, breast cancer history, and health knowledge with willingness to take tamoxifen. Over 40% of the women reported they would likely take tamoxifen if determined to be at high risk, and 31% would be somewhat likely to do so. Asian women, those with no insurance, and those with less than high school education were significantly more likely to be willing to take tamoxifen. Higher scores on numeracy and on breast cancer knowledge were also associated with willingness to take tamoxifen. A higher tamoxifen knowledge score was inversely related to willingness to take the drug. Factors affecting women's willingness to take breast cancer chemoprevention drugs vary and are not determined solely by knowledge of risk/benefit or risk perception.

Weight, physical activity, diet, and prognosis in breast and gynecologic cancers

Diet, physical activity, and weight may affect prognosis among women who are diagnosed with breast or gynecologic cancer. Observational studies show associations between being overweight or obese and weight gain with several measures of reduced prognosis in women with breast cancer and some suggestion of poor prognosis in underweight women. Observational studies have shown an association between higher levels of physical activity and improved breast cancer-specific and all-cause mortality, although a dose-response relationship has not been established. One large randomized controlled trial reported increased disease-free survival after a mean of 5 years in patients with breast cancer randomly assigned to a low-fat diet versus control. However, another trial of similar size found no effect from a high vegetable/fruit, low-fat diet on breast cancer prognosis. The few reported studies suggest that obesity negatively affects endometrial cancer survival, while the limited data are mixed for associations of weight with ovarian cancer prognosis. Insufficient data exist for assessing associations of weight, physical activity, or diet with prognosis in other gynecologic cancers. Associations of particular micronutrient intake and alcohol use with prognosis are not defined for any of these cancers. The effects of dietary weight loss and increase in physical activity on survival or recurrence in breast and gynecologic cancers are not yet established, and randomized controlled trials are needed for definitive data.

Evaluation of computer-aided diagnosis on a large clinical full-field digital mammographic dataset

RATIONALE AND OBJECTIVES

To convert and optimize our previously developed computerized analysis methods for use with images from full-field digital mammography (FFDM) for breast mass classification to aid in the diagnosis of breast cancer.

MATERIALS AND METHODS

An institutional review board approved protocol was obtained, with waiver of consent for retrospective use of mammograms and pathology data. Seven hundred thirty-nine FFDM images, which contained 287 biopsy-proven breast mass lesions, of which 148 lesions were malignant and 139 lesions were benign, were retrospectively collected. Lesion margins were delineated by an expert breast radiologist and were used as the truth for lesion-segmentation evaluation. Our computerized image analysis method consisted of several steps: 1) identified lesions were automatically extracted from the parenchymal background using computerized segmentation methods; 2) a set of image characteristics (mathematic descriptors) were automatically extracted from image data of the lesions and surrounding tissues; and 3) selected features were merged into an estimate of the probability of malignancy using a Bayesian artificial neural network classifier. Performance of the analyses was evaluated at various stages of the conversion using receiver-operating characteristic analysis.

RESULTS

An area under the curve value of 0.81 was obtained in the task of distinguishing between malignant and benign mass lesions in a round-robin by case evaluation on the entire FFDM dataset. We failed to show a statistically significant difference (P = .83) compared to results from our previous study in which the computerized classification was performed on digitized screen-film mammograms.

CONCLUSIONS

Our computerized analysis methods developed on digitized screen-film mammography can be converted for use with FFDM. Results show that the computerized analysis methods for the diagnosis of breast mass lesions on FFDM are promising, and can potentially be used to aid clinicians in the diagnostic interpretation of FFDM.

CANCER RISKS FOR AUSTRALIAN WOMEN WITH A BRCA1 OR A BRCA2 MUTATION

One of the primary purposes of genetic testing for mutations in the BRCA1 and BRCA2 genes in patients with familial breast/ovarian cancer has been to provide accurate advice to at-risk relatives. The provision of such advice has been hampered by a lack of appropriate data regarding the cancer risks. Chen and colleagues recently provided precise estimates of the relative risks of breast and ovarian cancer in almost 2000 kindreds with such mutations ascertained through familial cancer clinics across USA. The baseline incidence of breast cancer is lower in Australia than in North America. The relative risks derived from the study have been combined with Australian baseline incidence data to estimate the absolute short-term and long-term risks of breast and ovarian cancers for Australian carriers of different ages. The results are presented as a series of graphs that may be useful in counselling an unaffected carrier of a specified age. It is of note that the incidence of breast cancer in carriers is high in premenopausal women, but approaches the population incidence in postmenopausal women. Conversely, the incidence of ovarian cancer continues to increase from the age of 40 years. Among carriers of BRCA1 or BRCA2 mutations, the cumulative lifetime risk of developing breast cancer is 50-60% and the equivalent risk of ovarian cancer is 20-40%. An unaffected carrier aged 60 years is at greater risk of developing ovarian cancer than breast cancer. These observations have important implications for genetic counselling and decisions regarding prophylactic surgery.

Endogenous Steroid Hormone Concentrations and Risk of Breast Cancer Among Premenopausal Women

BACKGROUND

Higher levels of endogenous sex steroid hormones are associated with increased risks of breast cancer in postmenopausal women. Data for premenopausal women are sparse, in part because of the complexity of measuring hormone levels that vary cyclically. We prospectively evaluated associations between plasma sex hormone levels and breast cancer risk among premenopausal women in a case-control study nested within the Nurses' Health Study II.

METHODS

From 1996 to 1999, blood samples were collected from 18,521 premenopausal women during the early follicular and midluteal phases of their menstrual cycles. A total of 197 cases of breast cancer were diagnosed among these women after blood collection and before June 1, 2003; these case subjects were matched to 394 control subjects. Logistic regression models, controlling for breast cancer risk factors, were used to calculate relative risks (RRs) and 95% confidence intervals (CIs). All statistical tests were two-sided.

RESULTS

Women in the highest (versus the lowest) quartiles of follicular total and free estradiol levels had statistically significantly increased risks of breast cancer (RR = 2.1 [95% CI = 1.1 to 4.1], P(trend) = .08, and RR = 2.4 [95% CI = 1.3 to 4.5], P(trend) = .01, respectively); the associations were stronger for invasive breast cancer and for estrogen and progesterone receptor-positive (ER+/PR+) tumors. Luteal estradiol levels were not associated with breast cancer risk. Higher levels of total and free testosterone and androstenedione in both menstrual cycle phases were associated with modest, non-statistically significant increases in overall risk of breast cancer and with stronger, statistically significant increases in risks of invasive and ER+/PR+ cancers (e.g., RR of invasive cancers for the top [versus bottom] quartile of luteal total testosterone levels = 2.0 [95% CI = 1.1 to 3.6], P(trend) = .05, and RR of ER+/PR+ cancers = 2.9 [95% CI = 1.4 to 6.0], P(trend) = .02). Levels of estrone, estrone sulfate, progesterone, and sex hormone-binding globulin were not associated with breast cancer risk. The absolute number of cases observed over 3 years were 30 among women in the lowest 25% of follicular total estradiol levels and 50 among women in the highest 25%.

CONCLUSIONS

Levels of circulating estrogens and androgens may be important in the etiology of premenopausal breast cancer.

Breast Cancer Risk Assessment and Prevention: A Framework for Shared Decision-Making Consultations

Options for breast cancer prevention, used in combination with screening and surveillance, include lifestyle modifications, chemoprevention with tamoxifen, and prophylactic surgery. Preventive health decisions are often preference driven: patients typically must choose whether to initiate effective treatments that hold the possibility of side effects that can negatively impact quality of life. This situation demands that patients be well informed and have a full understanding of the risks associated with each option. Investigators have developed a comprehensive decision-making framework designed to support breast cancer prevention consultations within a shared decision-making setting. The framework integrates predictive information from current risk models within the context of a woman's general health to appropriately frame breast cancer risk management consultations and outlines the application of available treatments and emerging biomarker information to individual patient decisions. Using an evidence-based approach, specialized risk-benefit projections can be provided in the clinical setting. A more comprehensive individualized risk profile allows for tailored medical management plans and can better prepare patients to make informed decisions. The framework is intended to encourage a shared decision-making approach to prevention consultations, a method for researchers to increase accrual to trials, and to more quickly incorporate new findings into the routine of practice.

Women's posttraumatic stress responses to maternal breast cancer

Levels of posttraumatic stress disorder (PTSD) symptoms and their relationships to demographic and psychosocial variables and maternal medical history were examined among 31 women with maternal histories of breast cancer. The results indicate that 19.4% of these women were likely to merit a PTSD diagnosis related to maternal breast cancer, particularly those who reported greater negative affect. In addition, PTSD symptom severity was positively associated with the mother's cancer stage at diagnosis and was inversely associated with participant age. These results suggest that maternal breast cancer is an emotionally traumatic event for many women and point to the potential influence of psychological factors and stressor characteristics on daughters' PTSD responses.

Computerized texture analysis of mammographic parenchymal patterns of digitized mammograms

RATIONALE AND OBJECTIVES

Mammographic density and parenchymal patterns have been shown to be related to the risk of developing breast cancer. Thus, computerized texture analysis of breast parenchymal patterns on mammograms may be useful in assessing breast cancer risk.

MATERIALS AND METHODS

A comparative evaluation was conducted of various computer-extracted texture features of mammographic parenchymal patterns of women with BRCA1/BRCA2 gene mutations and those of women at low risk of developing breast cancer. Mammograms from 172 subjects (30 women with either the BRCA1 or BRCA2 gene mutation and 142 low-risk women) were analyzed. Computerized texture features were extracted from regions-of-interest to assess the mammographic parenchymal patterns in the images. Receiver operating characteristic analysis was used to assess the performance of these features in the task of distinguishing between the two groups of women.

RESULTS

Quantitative texture analysis on digitized mammograms demonstrated that gene-mutation carriers and low-risk women have different mammographic parenchymal patterns. Gene-mutation carriers presented with parenchymal patterns that were denser, coarser, and lower in contrast than those of the low-risk group. For the gene-mutation carriers, their mammographic patterns appear to contain less high-frequency component as indicated by higher coarseness values, lower fractal dimensions, and smaller edge gradients, which yielded corresponding A(z) values of 0.79, 0.84, and 0.78, respectively, in the task of distinguishing between gene-mutation carriers and the low-risk group with the entire dataset. The contrast measure calculated from co-occurrence matrix method, which describes local image variation, yielded an A(z) value of 0.86 in distinguishing between the two groups of women.

CONCLUSION

Computerized texture analysis of mammograms provides radiographic descriptors of mammographic parenchymal patterns. The computer-extracted features may be useful for identifying women at high risk for breast cancer and for monitoring the treatment of breast cancer patients.

Promotion of mammary cancer development by tamoxifen in a mouse model of Brca1-mutation-related breast cancer

Loss of full-length Brca1 in mammary epithelial cells of the mouse mammary tumor virus (MMTV)-Cre Brca1 conditional exon 11 deletion mouse model results in the development of mammary adenocarcinomas with similar genetic changes to those found in human BRCA1-mutation-related breast cancers. We used this experimental model to evaluate the chemopreventive effect of tamoxifen on the development of mammary preneoplasia and adenocarcinoma. No protective effects of tamoxifen administration on mammary cancer development were found. Instead, tamoxifen treatment significantly increased rates of mammary epithelial cell proliferation and the prevalence of mammary hyperplasia at 6 months of age. Tamoxifen-exposed mice developed adenocarcinomas at younger ages than control mice and a higher percentage of mice developed adenocarcinomas by 12 months of age. Both whole mouse and tissue culture cell models were used to test if loss of full-length Brca1 was associated with a relative increase in the agonist activity of tamoxifen. Tamoxifen induced increased ductal growth in MMTV-Cre Brca1 conditional mice compared to wild type. Estrogen receptor alpha (ERalpha) expression was downregulated in the tamoxifen-induced hyperplasias. Reducing BRCA1 levels in MCF-7 cells using siRNA resulted in a relative increase in the agonist activity of tamoxifen. Results suggest a model of mammary cancer progression in which loss of full-length Brca1 altered the agonist/antagonist activity of tamoxifen, resulting in tamoxifen-induced mammary epithelial cell proliferation with subsequent loss of ERalpha expression and development of ERalpha-negative hyperplasias and adenocarcinomas.

Strategies for managing breast cancer risk after the menopause

Postmenopausal women in Western societies are conscious of breast cancer as a potential cause of death and ill health, which they wish to avoid with the advice of their doctors. Yet many factors that predispose women to the development of cancer will have been laid down before the menopause, in their genetic makeup or during their adolescent years. Even in middle age it is important to take account of the intrinsic level of risk, and to give women advice tailored to their own individual risk level. This results from their family history, previous diseases such as benign breast disease, and previous treatment for breast cancer or Hodgkin's disease. For those at the highest level of risk, strategies will include regular screening, prophylactic mastectomy, and the use of chemoprevention agents, such as tamoxifen. These women should avoid hormone replacement therapy (HRT) and control their menopausal symptoms and osteoporosis through the use of other agents now available - venlafaxine for menopausal symptoms and bisphosphonates for osteoporosis. Raloxifene is an agent under trial that may be valuable for breast cancer control as well as for osteoporosis. Women at standard population risk will require less robust preventive strategies, which will include screening and lifestyle modification. Their decisions regarding HRT should now be modified by recent evidence of associated risks. Recent studies show that tibolone causes less mammographic density and has a lower relative risk of breast cancer than combined estrogen/progestogen preparations. There is limited evidence that controlling obesity, participating in exercise and adopting a diet low in fats and high in fruit and vegetables will alter risk at this age. These precautions will, however, reduce the risk of other diseases common in this age group, such as hypertension, heart disease, stroke, and type 2 diabetes mellitus. Alcohol, even in small amounts, is a risk factor for breast cancer. Given the cardioprotective effect of moderate alcohol intake, advice on alcohol must reflect the individual relative risk of cardiovascular disease and breast cancer. Personal risk assessment is relevant for all women. Screening and a healthy lifestyle are worthwhile approaches for all, with the more aggressive approaches such as chemoprevention and prophylactic surgery reserved for those who have substantially elevated levels of risk. Once the menopause has passed, screening is probably the most effective evidence-based tool for breast cancer control by early diagnosis.

Coupled mRNA stabilization and translational silencing of cyclooxygenase-2 by a novel RNA binding protein, CUGBP2

Cyclooxygenase-2 (COX-2) expression is translationally silenced in epithelial cells undergoing radiation-induced apoptosis. CUGBP2, a predominantly nuclear protein, is also rapidly induced in response to radiation and translocates to the cytoplasm. Antisense-mediated suppression of CUGBP2 renders radioprotection through a COX-2-dependent prostaglandin pathway, providing an in vivo demonstration of translation inhibition activity for CUGBP2. CUGBP2 binds to two sets of AU-rich sequences (AREs) located within the first sixty nucleotides of the COX-2 3' untranslated region (3'UTR). Upon binding, CUGBP2 stabilizes a chimeric luciferase-COX-2 3'UTR mRNA but inhibits its translation. These findings identify a novel paradigm for RNA binding proteins in facilitating opposing functions of mRNA stability and translation inhibition and reveal a mechanism for inhibiting COX-2 expression in cancer cells.

American Society of Clinical Oncology technology assessment of pharmacologic interventions for breast cancer risk reduction including tamoxifen, raloxifene, and aromatase inhibition

OBJECTIVE

To update an evidence-based technology assessment of chemoprevention strategies for breast cancer risk reduction. POTENTIAL INTERVENTIONS: Tamoxifen, raloxifene, aromatase inhibition, and fenretinide.

OUTCOMES

Outcomes of interest include breast cancer incidence, breast cancer-specific survival, overall survival, and net health benefit.

EVIDENCE

A comprehensive, formal literature review was conducted for relevant topics. Testimony was collected from invited experts and interested parties. The American Society of Clinical Oncology (ASCO) prescribed technology assessment procedure was followed.

VALUES

More weight was given to published randomized trials. BENEFITS/HARMS: A woman's decision regarding breast cancer risk reduction strategies is complex and will depend on the importance and weight attributed to information regarding both cancer- and noncancer-related risks and benefits.

CONCLUSIONS

For women with a defined 5-year projected breast cancer risk of > or= 1.66%, tamoxifen (at 20 mg/d for 5 years) may be offered to reduce their risk. Risk/benefit models suggest that greatest clinical benefit with least side effects is derived from use of tamoxifen in younger (premenopausal) women (who are less likely to have thromboembolic sequelae and uterine cancer), women without a uterus, and women at higher breast cancer risk. Data do not as yet suggest that tamoxifen provides an overall health benefit or increases survival. In all circumstances, tamoxifen use should be discussed as part of an informed decision-making process with careful consideration of individually calculated risks and benefits. Use of tamoxifen combined with hormone replacement therapy or use of raloxifene, any aromatase inhibitor or inactivator, or fenretinide to lower the risk of developing breast cancer is not recommended outside of a clinical trial setting. This technology assessment represents an ongoing process and recommendations will be updated in a timely matter.

VALIDATION

The conclusions were endorsed by the ASCO Health Services Research Committee and the ASCO Board of Directors.