Management of women with a hereditary predisposition for breast cancer

Risk‐reducing mastectomy decisions among women with mutations in high‐ and moderate‐ penetrance breast cancer susceptibility genes

Background

Women harboring mutations in breast cancer susceptibility genes are at increased lifetime risk of developing breast cancer and are faced with decisions about risk management, including whether to undergo high‐risk screening or risk‐reducing mastectomy (RRM). National guidelines recommend BRCA1 or BRCA2 mutation carriers consider RRM, but that carriers of moderate penetrance mutations (e.g., ATM or CHEK2) should be managed based on family history. We aimed to investigate determinants of decision for RRM, and hypothesized that mutation status, age, family history, partner status, and breast cancer would impact RRM decision making.

Methods

We performed a retrospective study assessing RRM decisions for 279 women.

Results

Women with BRCA and moderate penetrance gene mutations, a personal history of breast cancer, or a first degree relative with a history of breast cancer were more likely to undergo RRM. Breast cancer status and age showed an interaction effect such that women with breast cancer were less likely to undergo RRM with increasing age.

Conclusion

Although national guidelines do not recommend RRM for moderate penetrance carriers, the rates of RRM for this population approached those for BRCA mutation carriers. Further insights are needed to better support RRM decision‐making in this population.

Factors associated with intentions for breast cancer risk management: Does risk group matter?

OBJECTIVE

National guidelines provide breast cancer (BC) risk management recommendations based on estimated lifetime risk. Despite this specificity, it is unclear if women's risk management intentions are or are not guideline concordant. To address this knowledge gap, women at varying risk levels reported intentions for risk-reducing behaviors. Factors associated with intentions, informed by the Health Beliefs Model, were also studied.

METHODS

Women with elevated BC risk (N = 103) were studied and categorized by risk level: moderate (15%-20%), high (greater than or equal to 20%), or very high (BRCA1/2 positive). Participants self-reported BC susceptibility, self-efficacy, and benefits, barriers, and intentions for risk-reducing mastectomy (RRM), risk-reducing salpingo-oophorectomy (RRSO), chemoprevention, improving diet or physical activity, and reducing alcohol use.

RESULTS

Groups significantly differed in RRSO intentions (P < .01); BRCA1/2 positive women had greater intentions for RRSO. Groups did not differ in intentions for RRM, chemoprevention, or lifestyle changes (Ps > .28). In hierarchical linear regression models examining Health Belief Model (HBM) factors, perceived susceptibility was associated with intentions for RRM (β = .169, P = .08). Perceived benefits was associated with intentions for RRM (β = .237, P = .02) and chemoprevention (β = .388, P < .01). Self-efficacy was associated with intentions for physical activity (β = .286, P < .01).

CONCLUSIONS

Consistent with guidelines, BRCA1/2 positive women reported greater intentions for RRSO, and risk groups did not differ in intentions for lifestyle changes. Notably, women's intentions for RRM and chemoprevention were guideline discordant; groups did not differ in intentions for these behaviors. Accounting for the effects of risk group, modifiable health beliefs were also associated with risk management intentions; these may represent targets for decision support interventions.

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.

Obesity and breast cancer - Role of estrogens and the molecular underpinnings of aromatase regulation in breast adipose tissue

One in eight women will develop breast cancer over their lifetime making it the most common female cancer. The cause of breast cancer is multifactorial and includes hormonal, genetic and environmental cues. Obesity is now an accepted risk factor for breast cancer in postmenopausal women, particularly for the hormone-dependent subtype of breast cancer. Obesity, which is characterized by an excess accumulation of body fat, is at the origin of chronic inflammation of white adipose tissue and is associated with dramatic changes in the biology of adipocytes leading to their dysfunction. Inflammatory factors found in the breast of obese women considerably impact estrogen signaling, mainly by driving changes in aromatase expression the enzyme responsible for estrogen production, and therefore promote tumor formation and progression. There is thus a strong link between adipose inflammation and estrogen biosynthesis and their signaling pathways converge in obese patients. This review describes how obesity-related factors can affect the risk of hormone-dependent breast cancer, highlighting the different molecular mechanisms and metabolic pathways involved in aromatase regulation, estrogen production and breast malignancy in the context of obesity.

Influence of vitamin D signaling on hormone receptor status and HER2 expression in breast cancer

PURPOSE

Breast cancer is a significant global public health issue. It is the leading cause of death among women around the world, with an incidence increasing annually. In recent years, there has been more and more information in the literature regarding a protective role of vitamin D in cancer. Increasingly preclinical and clinical studies suggest that vitamin D optimal levels can reduce the risk of breast cancer development and regulate cancer-related pathways.

METHOD

In this review, we focus on the importance of vitamin D in breast cancers, discussing especially the influence of vitamin D signaling on estrogen receptor and human epidermal growth factor receptor 2 (HER2), two major biomarkers of breast cancer today.

CONCLUSION

We discuss the possibility of actual and future targeted therapeutic approaches for vitamin D signaling in breast cancer.