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Breast cancer risk factors: What you can and can’t change

Discover key breast cancer risk factors you can and can’t control. Know what you can do to reduce your risk and how health insurance can help protect you.

8 min to read

Breast cancer is the most common cancer affecting women in New Zealand, with over 3,500 diagnoses and more than 600 deaths every year. Men aren’t exempt either, with about 25 men diagnosed with breast cancer annually.

While those numbers are concerning, understanding the symptoms and risk factors of the disease plus the value of early detection and prompt treatment all contribute significantly to good breast cancer outcomes.  

This article explains modifiable and nonmodifiable breast cancer risk factors, and how private medical insurance can help. Note that having risk factors does not mean you will have breast cancer, and likewise, the absence of these risk factors does not guarantee you won’t develop the disease.

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Breast cancer risk factors you can’t change

Below are some nonmodifiable risk factors for breast cancer.

Age

For women, the chance of developing breast cancer increases with age, with most diagnoses occurring among those above age 50.

While less common, breast cancer in men can occur at any age, however, most cases are diagnosed after the age of 60.

Genetic mutations

Certain genetic mutations, particularly in the BRCA1 and BRCA2 genes, increase a person’s risk of developing not just breast cancer but also ovarian cancer. Mutations in these genes affect their ability to stop abnormal cell growth. Inherited faulty genes cause around 5-10% of breast cancer cases.

Family history

Your risk may be higher if you have first-degree relatives (parents, siblings, children) and/or second-degree family members who:

  • were diagnosed with breast cancer, especially at a young age (before 50)
  • had male breast cancer 
  • were diagnosed with ovarian cancer.

Dense breast tissue

Individuals with dense breasts (more glandular and fibrous connective tissue than fatty tissue) have a higher risk of developing breast cancer. Having dense breasts also makes it more difficult to detect tumours via a mammogram. 

Previous history of breast-related issues

Your risk of developing breast cancer may be higher if you've had breast cancer or certain breast conditions in the past, such as ductal carcinoma in situ (DCIS), atypical ductal hyperplasia (ADH), or lobular carcinoma in situ (LCIS).

Hormonal and reproductive history

The length of time a woman produces oestrogen, a hormone produced mostly by the ovaries, can influence breast cancer risk.

Factors that influence your oestrogen levels include:

  • Younger age at first menstruation: Starting your period before the age of 12 can increase oestrogen exposure over your lifetime.
  • Older age at menopause: Women who go through menopause after the age of 55 have produced oestrogen for longer.
  • Late age at first childbirth: Having your first child after the age of 30 can increase your oestrogen exposure.

Radiation therapy exposure

Exposure to radiation therapy, especially treatments directed at the chest, can increase the risk of breast cancer. This risk is particularly relevant for individuals who received radiation therapy for other cancers, such as Hodgkin lymphoma, at a young age. 

Breast cancer risk factors you can change

While some breast cancer risk factors are beyond your control, several lifestyle and environmental influences are modifiable.

  • Physical inactivity: Leading a sedentary lifestyle is linked to an increased risk of breast cancer.
  • Being overweight or obese: Excess body weight, especially after menopause, is a known risk factor for breast cancer. 
  • Alcohol consumption: Drinking alcohol is directly associated with an increased risk of breast cancer as well as other types of cancers. Women who consume even small amounts of alcohol have a higher risk than non-drinkers.
  • Smoking: Smoking has been linked to a higher risk of breast cancer, especially in younger, premenopausal women and those who have smoked for over 10 years. Smoking also increases the risk of many health issues, including cancer of the lungs, pancreas, cervix, bowel, stomach, and bladder, cardiovascular diseases like stroke and heart attack, and vision loss or blindness. 
  • Hormone replacement therapy (HRT): Women who use combined HRT (oestrogen and progesterone) during menopause may have an increased risk of breast cancer. 
  • Birth control: Certain types of oral contraceptives have been linked to a slightly higher risk of breast cancer. 

What is not a risk factor for breast cancer?

There are many misconceptions and myths about breast cancer risk. The following factors have no proven link to this disease:

Wearing underwire or tight-fitting bras

This myth has been debunked by multiple studies, so rest assured, your bra style won’t affect your breast cancer risk.

Using antiperspirants or deodorants

Some believe that certain antiperspirants contain chemicals which cause toxins to build up in the breast. However, most research shows no connection between the use of antiperspirants and an increased risk of breast cancer.

Breast injury

Injuries to the breast, such as bumps or bruises, do not cause breast cancer. Though an injury might make you more aware of existing lumps or abnormalities, trauma itself has no link to cancer development.

Caffeine consumption

Studies have not established a strong association between coffee and tea consumption and increased breast cancer risk. Some studies even suggest the possibility that caffeine consumption may help reduce the risk among postmenopausal women.

Breast implants

Although there are certain risks associated with breast implants, developing breast cancer isn’t one of them. Studies show no increased risk of breast cancer in women with breast implants compared to those without.

Stress

While stress can negatively impact overall health, there is no scientific proof linking stress directly to breast cancer. Managing stress is important for your general wellbeing but won’t specifically reduce or increase breast cancer risk.

How at risk are you?

Being knowledgeable about your risk of developing breast cancer means you can make informed decisions about your health. Preventive care and regular breast screenings will significantly improve your chances of catching breast cancer early when it's most treatable.

Breast cancer risk can be divided into three primary categories: sporadic, familial, and hereditary. Each carries different levels of risk and requires different levels of attention.

Risk Category

Description

Sporadic (general population risk)

  • Breast cancer with no family history or not inherited, occurring by chance or due to environmental factors
  • Accounts for 90-95% of cases

Familial (moderate risk)

Breast cancer due to genetic and environmental factors 

Hereditary (high risk)

Breast cancer linked to inherited gene mutations (BRCA1, BRCA2, TP53, PTEN, CDH1, STK11, PALB2, ATM, CHEK2)

 

Ways to lower your breast cancer risk

While some breast cancer risk factors, such as age and genetics, cannot be changed, there are several lifestyle choices which can lower your overall risk:

  • Maintain a healthy weight
  • Stay physically active. Aim for at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity activity weekly
  • Avoid or limit alcohol intake, as even small amounts can raise breast cancer risk
  • Quit smoking to lower your cancer risk and enjoy other health and financial benefits, too
  • If possible, try to breastfeed for as long as it's comfortable for you and your baby
  • Limit hormone replacement therapy (HRT): Some forms of HRT used during menopause can increase the risk of breast cancer, especially if used long-term. Discuss the pros and cons and available alternatives with your doctor.

What should I do if I’m at high risk?

If you're at moderate or high risk of developing breast cancer, here are some proactive steps to consider:

  • Have regular breast exams: Regular clinical breast exams performed by a healthcare professional can help detect any unusual changes early. Depending on your level of risk, your doctor may recommend starting mammograms early or alternating mammograms with MRI screenings every six months.
  • Discuss preventive medications: Some medications, such as selective (o)estrogen receptor modulators (SERMs) and aromatase inhibitors, may reduce the risk of breast cancer in high-risk women. Your doctor can determine if this option is appropriate for you.
  • Consider risk-reducing (prophylactic) surgery: High-risk women may opt for surgical interventions, such as prophylactic mastectomy (removal of one or both breasts) or bilateral salpingo-oophorectomy (removal of the fallopian tubes and ovaries). Note that prophylactic surgeries do not eliminate your risk of developing the disease.

The role of insurance in breast cancer prevention and treatment

The right health insurance provides you with good medical and financial support. Private health insurance can offer:

  • access to timely screening: Health insurance can expedite access to breast screenings and cover costs associated with regular mammograms, MRIs, or other advanced detection options.
  • cover for preventive medications or surgery: If your doctor recommends preventive medication or surgery, some insurance plans may help cover these often-expensive procedures.
  • financial support for treatment: Comprehensive insurance can help cover the costs of surgery, chemotherapy, and other treatments, including non-Pharmac-funded drugs.

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Disclaimer: This article is for general information only. Nothing in this blog or on this website is intended as medical, dietary, or financial advice. Although we aim to update our content regularly, you are advised to consult a Policywise adviser, health professional, or an appropriate specialist before acting on any information herein. They can factor in your personal circumstances or preferences and help guide your decision-making process.

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References

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