Management of women who have a genetic predisposition for breast cancer

Complication rates among women undergoing preventive mastectomy: An Austrian registry

Germline variations in the BRCA-1 and BRCA-2 genes are associated with an increased risk of breast cancer. These variants are found in 5% of all breast cancer cases. Prophylactic mastectomy is the most effective risk-reducing method and shows high rates of patient satisfaction and acceptance. We established a registry of Austrian BRCA-1 and BRCA-2 mutation carriers who had undergone mastectomy for oncologic or prophylactic reasons. Data were collected on the type of operation, complications, and type of reconstructive surgery for patients between 2014 and 2017. The complication rate in patients with nipple-sparing mastectomy was significantly lower (23.1%) than in those with other types of mastectomies (60.7%; P = .005). In patients with implant-based breast reconstruction, subpectoral placement was associated with a significantly higher rate of complications than prepectoral placement (P = .025). Median implant volume was 350 cc (range: 155-650 cc), and a 100-cc increase was associated with doubling of the odds of a complication (regression coefficient = 0.007); based on this finding, some surgeons may decide on using smaller implants. In summary, we identified significant associations between the risk of complications and surgical characteristics, and found host factors like diabetes, BMI, and smoking among Austrian patients with BRCA-1 and BRCA-2 variants.

Risk-Reducing Options for Women with a Hereditary Breast Cancer Predisposition

Genetic testing is now widely utilized to identify women with a hereditary predisposition for breast cancer. Women who carry mutations that increase breast cancer risk may consider three options to reduce risk: screening, chemoprevention, and prophylactic surgery. Yet, no randomized trials have specifically assessed the efficacy of these options in mutation carriers. In many developed countries, mammography is regarded as the optimal means of screening for breast cancer in the general population. However, breast MRI is a more sensitive screening tool, and for mutation carriers, any breast cancer screening strategy should incorporate screening with MRI. In randomized trials of women at high risk for developing breast cancer, chemoprevention reduces that risk, but it has not been shown to reduce mortality. Finally, observational studies suggest that, in mutation carriers, prophylactic surgery may reduce the risk of developing breast cancer by 90-95%. There are several prophylactic mastectomy procedures to choose from, and these are generally done in conjunction with breast reconstruction. In this article, we discuss management of women who carry mutations that have been associated with an increased breast cancer risk. Mutation carriers should be informed of the potential risks and benefits of the three available options to reduce breast cancer risk.

Practical consensus recommendation on when to do BRCA testing

BRCA-mutation associated breast cancer and to future cancer risks and sensitivity to systemic therapies. Now that rapid genetic testing for BRCA1 and BRCA2 mutations is available, BRCA mutation status can be considered when making treatment and prevention decisions for BRCA testing, BRCA mutation carriers with breast cancer. Expert group used data from published literature, practical experience, and opinion of a large group of academic oncologists, to arrive at practical consensus recommendations for use by the community oncologists.

Clinical Practice Guideline for the prevention and early detection of breast and ovarian cancer in women from HBOC (hereditary breast and ovarian cancer) families

An estimated 10% of breast cancer cases exhibit a higher familial incidence, and functional mutations in BRCA (breast cancer-gene) 1 or 2 are responsible for the development of malignant tumors in approximately half of these cases. Women with a germline mutation in either of the two genes have a lifetime risk of up to 85% to develop breast cancer, and of up to 60% risk to develop ovarian cancer. This clinical practice guideline defines the individual and familial tumor constellations that represent an indication for BRCA germline testing. It also describes the therapeutic options (early detection programme vs prophylactic surgery) that arise from the result of a BRCA mutational analysis. This guideline further includes recommendations regarding the use of multigene panels and therapeutic aspects that arise from the selective use of poly ADP ribose polymerase (PARP) inhibitors in patients with known BRCA1 or 2 mutations. It replaces the previous version of the "Clinical Practice Guideline for the Prevention and Early Detection of Breast- and Ovarian Cancer in women from HBOC (hereditary breast and ovarian cancer) families" which was published in 2012.

Breast cancer risk assessment, prevention, and the future

Today breast cancer remains a major public health problem, although reducing its risk is now an achievable medical objective. Risk-assessment models may be used in estimating a woman's risk for developing breast cancer and to direct suitable candidates for preventive therapy. Researchers are attempting to enhance individualized risk assessment through incorporation of phenotypic biomarkers. Individual selective estrogen receptor modulators have been approved for breast cancer risk reduction, and other drug categories are being studied. It is critical that obstetrician-gynecologists be familiar with the evolving science of the risk assessment of breast cancer as well as interventional and surveillance strategies.

The case against routine preoperative breast MRI

In patients with primary breast cancer, preoperative MRI identifies additional foci of tumor in the ipsilateral or contralateral breast that are not evident with standard imaging. Breast cancer patients who are otherwise deemed suitable candidates for breast-conserving surgery might, therefore, be urged to undergo mastectomy or even bilateral mastectomy following staging with preoperative breast MRI. The effect of preoperative breast MRI on clinical end points (rates of ipsilateral breast tumor recurrence) and surgical end points (rates of reoperation) have been assessed in several large studies. These studies indicate that the routine use of preoperative breast MRI is not beneficial. The additional occult foci of tumor detected with preoperative breast MRI seem to either have no clinical significance, or can be adequately treated with radiotherapy and/or systemic therapy. This article reviews these studies and highlights the potential harms associated with the routine use of preoperative MRI in patients with primary breast cancer.

[Guideline for the prevention and early detection of breast and ovarian cancer in high risk patients, particularly in women from HBOC (hereditary breast and ovarian cancer) families]

The Austrian guideline for prevention and early detection of breast and ovarian cancer in high risk patients--particularly in women from hereditary breast and ovarian cancer families--were established with particular consideration of the most recent position paper of the European Society of Breast Cancer Specialists (EUSOMA) by the authors mentioned above. The guideline is aimed at facilitating and standardizing the care and early detection strategies in women with an elevated life time risk for breast and ovarian cancer.

Serum levels of IGF-I and BRCA penetrance: a case control study in breast cancer families

High serum levels of insulin-like growth factor I (IGF-I) are associated with an increased risk of sporadic breast cancer (BC). The aim of the present work is to evaluate the association between IGF-I and hereditary BC risk, using a case-control approach. The work represents an "ad interim" cross-sectional analysis of an ongoing study with a prospective design whose aim is to recruit a cohort of women belonging to high genetic risk families to test potential modulators of penetrance and prognosis. The odd of exposure to high serum IGF-I levels among women with a previous diagnosis of BC ("cases") was compared with the odd among unaffected "controls". The odds ratio (OR) and 95% confidence intervals (CIs) were estimated by unconditional logistic regression, controlling for confounders. We analysed 308 women (209 cases and 99 controls) at high genetic risk of BC. The adjusted OR of BC for the upper tertile of serum IGF-I versus the lowest one was 3.5 (95%CI 1.4-8.8). Excluding from the analysis 64 women under current Tamoxifen or GnRH analogues treatment, the adjusted OR of BC became 3.7 (95%CI 1.4-9.9). The association became stronger restricting the analysis to the 161 women (97 cases and 64 controls) with a proven BRCA mutation. If confirmed by a prospective approach, the association between IGF-I and familial BC will open further options for reducing BC risk in susceptible women.

A long AAAG repeat allele in the 5' UTR of the ERR-γ gene is correlated with breast cancer predisposition and drives promoter activity in MCF-7 breast cancer cells

We sequenced the 5' UTR of the estrogen-related receptor gamma gene (ERR-γ) in ~500 patient and volunteer samples and found that longer alleles of the (AAAG)(n) microsatellite were statistically and significantly more likely to exist in the germlines of breast cancer patients when compared to healthy volunteers. This microsatellite region contains multiple binding sites for a number of transcription factors, and we hypothesized that the polymorphic AAAG-containing sequence in the 5' UTR region of ERR-γ might modulate expression of ERR-γ. We found that the 369 bp PCR product containing the AAAG repeat drove expression of a reporter gene in estrogen receptor positive breast cancer cells. Our results support a role for the 5' UTR region in ERR-γ expression, which is potentially mediated via binding to the variable tandem AAAG repeat, the length of which correlates with breast cancer pre-disposition. Our study indicates that the AAAG tetranucleotide repeat polymorphism in ERR-γ gene 5' UTR region may be a new biomarker for genetic susceptibility to breast cancer.

Identification and Management of Women With BRCA Mutations or Hereditary Predisposition for Breast and Ovarian Cancer

Women with a germline BRCA1 or BRCA2 mutation or a hereditary predisposition for breast and ovarian cancer have substantial risk of breast or ovarian cancer relative to the general US population. Health care professionals can be instrumental in identifying women at increased risk through obtaining a comprehensive family history and becoming familiar with family history characteristics associated with hereditary predisposition for breast and ovarian cancer. BRCA carriers and women at very high risk benefit from multidisciplinary, individualized medical evaluation and risk management. We conducted a search of MEDLINE from 1989 through 2010 for the terms BRCA1, BRCA2, breast cancer, ovarian cancer, risk assessment, and genetic testing. We reviewed abstracts and relevant randomized and prospective studies that included very high-risk patient groups and BRCA mutation carriers. Herein, we review the role of genetic consultation and BRCA testing and the comprehensive, multisystem recommendations for risk management. A multidisciplinary approach offers the ability to educate those at very high risk about cancer prevention, reduce cancer risk, maximize early detection of breast and ovarian cancer, and improve survival.

Risk-reducing strategies for women carrying BRCA1/2 mutations with a focus on prophylactic surgery

Background

Women who have inherited mutations in the BRCA1 or BRCA2 genes have substantially elevated risks of breast and ovarian cancer. Mutation carriers have various options, including extensive and regular surveillance, chemoprevention and risk-reducing surgery. The aim of this review is to provide an up-to-date analysis and to subsequently summarise the available literature in relation to risk-reducing strategies, with a keen focus on prophylactic surgery.

Methods

The literature review is facilitated by Medline and PubMed databases. The cross-referencing of the obtained articles was used to identify other relevant studies.

Results

Prophylactic surgery (bilateral mastectomy, bilateral salpingo-oophorectomy or a combination of both procedures) has proved to be the most effective risk-reducing strategy. There are no randomised controlled trials able to demonstrate the potential benefits or harms of prophylactic surgery; therefore, the evidence has been derived from retrospective and short follow-up prospective studies, in addition to hypothetical mathematical models.

Based on the current knowledge, it is reasonable to recommend prophylactic oophorectomy for BRCA1 or BRCA2 mutation carriers when childbearing is completed in order to reduce the risk of developing breast and ovarian cancer. In addition, women should be offered the options of rigorous breast surveillance, chemoprevention with anti-oestrogens--especially for carriers of BRCA2--or bilateral prophylactic mastectomy.

Conclusion

The selection of the most appropriate risk-reducing strategy is not a straightforward task. The impact of risk-reducing strategies on cancer risk, survival, and overall quality of life are the key criteria considered for decision-making. Notably, various other factors should be taken into consideration when evaluating individual mutation carriers' individual circumstances, namely woman's age, morbidity, type of mutation, and individual preferences and expectations.

Although prospective randomised controlled trials concerned with examining the various interventions in relation to the woman's age and type of mutation are needed, randomisation is extremely difficult and rather deemed unethical given the current available evidence from retrospective studies.

Personalized medicine: factors influencing reimbursement

OBJECTIVES

Personalized medicine (PM) has attracted tremendous interest, but yielded few marketed products. We examined factors influencing the reimbursement of existing PM technologies.

METHODS

We conducted six case studies of the following paired genetic tests and treatments: HER2/neu with trastuzumab (Herceptin); hepatitis C genotyping with ribavirin/pegylated interferon; Oncotype DX with chemotherapy; UGT1A1 with irinotecan (Camptosar); VKORC1/CYP2C9 with warfarin; BRCA1/2 with prophylactic surgical measures; and Oncotype DX with chemotherapy. We developed a framework for categorizing PM technology, and assessed factors influencing reimbursement, including quality of evidence, type of regulatory oversight, presence of clinical guidelines, and cost-effectiveness.

RESULTS

PM is not a monolithic concept, but rather encompasses different types of technology. The strength of evidence available for existing PM technology varies widely and, along with endorsement of clinical guidelines, appears to be the strongest predictor of reimbursement. In the absence of reimbursement, direct-to-consumer marketing has continued for some PM technology. The type of regulatory oversight and the results of cost-effectiveness analysis do not appear to be associated with reimbursement to date.

CONCLUSIONS

To date, the promise and hype of PM has outpaced its evidentiary support. In order to achieve favorable coverage and reimbursement and to support premium prices for PM, manufacturers will need to bring better clinical evidence to the marketplace and better establish the value of their products.

Screening and prevention of breast cancer in primary care

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