Understanding and Reducing Breast Cancer Risk Through Individualized Screening and Prevention – Erin Rurak, ND

Understanding and Reducing Breast Cancer Risk Through Individualized Screening and Prevention

Erin Rurak, ND

Breast cancer remains one of the most prevalent cancers among women, with a widely cited statistic that 1 in 8 women will develop the disease in their lifetime.1 However, this figure is a population-level estimate and not reflective of a woman’s risk. Personal factors such as genetics, lifestyle, reproductive history, and environmental exposures can significantly influence an individual’s likelihood of developing breast cancer.2,3 Currently, breast cancer screening guidelines are largely age-based and fail to account for these individual variations in risk.

Women generally fall into four broad categories of breast cancer risk: average risk (<15% lifetime risk), moderate risk (15-20% lifetime risk), high risk (>20% lifetime risk), and those carrying hereditary breast cancer mutations.1 Despite this classification, most women are unaware of their risk. Increased awareness and individualized risk assessments could enable more effective prevention strategies and tailored screening protocols. This article highlights key breast cancer risk factors, tools for risk calculation, and appropriate screening techniques based on individual risk, advocating for a shift from age-based to risk-based screening models as the latter approach should help reduce breast cancer diagnosis and lower breast cancer mortality.

Non-Modifiable Risk Factors

Hereditary Breast Cancer Mutations

Certain genetic mutations significantly increase breast cancer risk.2 These include BRCA1, BRCA2, PALB2, CHEK2, and ATM, among others.2 Unfortunately, only about 10% of women with hereditary cancer mutations have been identified, highlighting a critical gap in genetic screening.2 Expanding access to multigene cancer panels is essential for identifying women at high genetic risk and improving early detection efforts.

Age and Ethnicity

Advancing age is a well-established risk factor for breast cancer.3 However, incidence rates are rising among younger women, with disparities across ethnic groups. Non-Hispanic white women have the highest breast cancer incidence overall, but non-Hispanic Black women experience the highest mortality rates.4 Additionally, Black women are more likely to develop aggressive triple-negative breast cancer and have higher incidence rates before age 40.4 Given that screening often begins at age 40 or later, these disparities underscore the need for earlier and more tailored screening protocols for at-risk populations.

Reproductive Factors

Reproductive factors such as early menarche (before age 12) and late menopause (after age 55) are associated with increased breast cancer risk5. Early menarche, in particular, has become more common, with the average onset age decreasing from 17 to 12 years since the mid-19th century.3,12 Factors such as childhood obesity, exposure to endocrine disruptors, and psychological stress are likely contributing to this trend.6,7 Helping young women maintain a healthy body weight through a whole foods diet high in plant protein and fiber, as well as physical activity, are ways in which clinicians can empower women as early as in childhood to lower their risk of future breast cancer.8 

Childbearing also influences breast cancer risk. While parity offers long-term protection if the first full-term pregnancy occurs before age 35, the risk of breast cancer temporarily increases in the years following childbirth.9 This is known as pregnancy-associated breast cancer and is likely due to hormonal and inflammatory changes during breast remodeling to its pre-pregnant state.9,10 Reproductive factors in breast cancer occurrence are essential, as is present society. Women are undergoing menarche earlier, going through menopause later, bearing fewer children, and beginning their families later than ever, all likely factors contributing to the increased incidence of breast cancer worldwide. 

Breast Density

Breast density, categorized by the BIRADS scoring system, plays a critical role in stratifying women’s risk of breast cancer.11 Dense breast tissue, classified as a BIRADS C or D, is found in 50% of women.11 Dense breast tissue poses two significant concerns. Denser breast tissue is a known risk for breast cancer, with a BIRADS D increasing the risk of breast cancer by twofold.12 Density also impacts mammographic sensitivity, with mammograms being less sensitive in identifying abnormalities in denser breast tissue.11,12 

Breast density highlights the need for tailored breast screening. Mammography remains the gold standard for reducing breast cancer mortality, performing well in women with fatty breast tissue but less effectively in women with dense tissue.13 Individualized approaches, such as breast tomosynthesis, contrast-enhanced mammograms, or MRIs, will benefit women less suited to mammographic screening alone.13 

Some women seek breast thermography for its non-invasive nature, avoiding compression and radiation.14 Unfortunately, it lacks the specificity and sensitivity required for effective screening and is not endorsed by any significant breast screening authority.14,15 It is up to clinicians to educate women on its limitations and guide them towards more evidence-based breast screening options. 

Breast Biopsies 

Previous breast biopsy incurs another risk for breast cancer.16 High-risk breast biopsies of locular cell carcinoma in situ impose a 30% lifetime risk of developing breast cancer and atypical hyperplasia of 20% lifetime risk.16 A thorough history asking patients of previous breast biopsies and ideally getting the pathology reports of these biopsies is imperative in supporting women’s breast health advocacy. 

Modifiable Risk Factors

Nutrition

Approximately one-third of breast cancers are linked to modifiable lifestyle factors, making prevention through diet and behavior crucial.17 There are roughly 350,000 new diagnoses of breast cancer annually in North America.1  It is therefore believed that over 100,000 breast cancers could be prevented through lowering modifiable risk factors. Unfortunately, many women are unaware of modifiable risk factors.17 Diets rich in plant-based proteins and fiber, alongside reduced consumption of red and processed meats, have been shown to lower breast cancer risk.18 Fiber, in particular, helps reduce intestinal estrogen reabsorption, moderates glucose release and decreases inflammation.18 Alcohol consumption is the leading modifiable risk factor for premenopausal breast cancer, contributing to an estimated 13% of cases.12 Risk increases with higher intake, making moderation a key prevention strategy. Women should be advised to limit consumption to no more than two standard drinks per week.12

Weight Management

Excess body weight, particularly after menopause, poses a significant risk for breast cancer.5 Weight gain during menopause is often accompanied by increased visceral fat, which promotes inflammation, insulin resistance, and elevated circulating estrogens—all of which are potential drivers of tumorigenesis in the breast.5,20 Helping women be proactive in maintaining their body composition through mindful whole foods, eating, and sufficient exercise are important strategies for women to lower their breast cancer risk.5

Stress

In our generation, there is what can be considered a silent pandemic of stress impacting women. Through the never-ending stressors ranging from work, parenting, finances, wars, and natural disasters, which are the latter more than ever before are available through constant access to social media, all of these factors are leading to a rise in chronic stress which appears to influence women more so than men.21 Stress through its activation of the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system can promote tumorigenesis, inflammation, and immunosuppression.22 Addressing an individual’s stress will inevitably improve health through a variety of different ways, including lowering the risk of cancer, including breast cancer.22 

Menopausal Hormone Therapy (MHT)

 MHT using a combination of both estrogen and progestogens is linked to an increased risk of breast cancer.22 This risk appears predominantly mediated through formulations containing synthetic progestins such as medroxyprogesterone acetate.22,23 When prescribing MHT considering breast cancer risk, micronized progesterone is likely the safest progestogen to prescribe.23 It is advisable to avoid progestogens in situations where they are not necessary, such as for women who have had a hysterectomy or have a levonorgestrel IUD.

Individual Risk Assessment and Screening

Risk Assessment Tools

Validated tools such as the Tyrer-Cuzick model (version 8) allow clinicians to estimate a woman’s 10-year and lifetime breast cancer risk.12 These tools integrate personal and family history, genetic factors, and reproductive data to estimate individualized risk.12 This personalized approach can guide prevention and screening strategies beyond age-based protocols.

Screening for High-Risk Women

Women with a lifetime risk more significant than 20% should consider screening beyond standard mammography.1 Options include breast ultrasound, contrast-enhanced mammography, and breast MRI.13 Education on these alternatives is vital for empowering women to advocate for appropriate screening based on their unique risk profiles.

Moving Toward Risk-Based Screening

Currently, age-based breast screening fails to address the variability in individual risk. By integrating tools for risk assessment, personalized prevention strategies, and advanced screening methods, clinicians can improve early detection and reduce mortality. While not all breast cancers can be prevented, it is estimated that one-third could be avoided through lifestyle modifications.17 For those who cannot, identifying and addressing individual risk factors will lead to earlier diagnoses and better outcomes. Transitioning to risk-based screening represents a critical step forward in breast cancer prevention and care. Through education and empowerment, we can support women in understanding and managing their risk, ultimately reducing the burden of breast cancer in our communities.

Figure 1. 

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