Breast Cancer Risk Factors: what really matters?

Breast cancer is the most common neoplasia among women worldwide, representing a significant public health challenge. In Brazil, tens of thousands of new cases are estimated to arise each year, reinforcing the need for effective strategies for prevention, early diagnosis, and proper treatment.

Breast cancer and its relevance in public health

Breast cancer is the most common neoplasia among women worldwide, representing a significant public health challenge.
In Brazil, it is estimated that tens of thousands of new cases arise each year, reinforcing the need for effective strategies for prevention, early diagnosis, and proper treatment.

During Breast Cancer Awareness Month, awareness campaigns draw attention to the importance of screening and women’s health care. However, along with the dissemination of information, myths and doubts about the true risk factors for breast cancer also arise.

What really increases the risk of breast cancer?

It is essential for doctors to be well informed to safely guide their patients, differentiating proven risk factors — such as smoking, alcohol, obesity, and physical inactivity — from those that are often mistakenly associated, such as hormone replacement therapy (HRT) during menopause.

For years, HRT was pointed out as one of the main causes of breast cancer. However, new scientific evidence has revised this perspective.
In a recent panel by the FDA (Food and Drug Administration), specialists highlighted that the relationship between HRT and breast cancer is much more complex than previously thought.

The main conclusion was clear:

HRT, when well indicated and monitored, should not be considered a villain.
The risk is modest and variable, depending on the type of formulation, duration of use, and, most importantly, the genetic and clinical profile of the patient.

The impact of lifestyle habits on breast cancer

When analyzing population data, it is evident that lifestyle habits have a much greater influence on the risk of breast cancer than HRT.

• Smoking: responsible for about 30% of cases of various types of cancer, including breast cancer.
• Obesity in adulthood: increases risk by approximately 30%, especially in postmenopause.
• Physical inactivity: contributes around 5%, but is directly related to obesity and insulin resistance.
• Alcohol consumption: a proven risk factor, impacting even with moderate consumption.

These factors are modifiable and should be the main focus of prevention strategies.

The role of the physician: information and individualization

More than restricting hormonal therapies that improve quality of life, it is essential that the physician acts as an educator, helping the patient understand her real risks and adopt healthy habits.

Moreover, the risk of developing breast cancer is not the same for all women. It varies according to family history, genetic predisposition, environment, and lifestyle.
Therefore, individualized genetic assessment has become an essential ally in modern medical practice.

Genetics and personalized medicine: the future of prevention

Personalized medicine allows for a better understanding of each patient’s individual risk.
Through specific genetic tests, it is possible to identify variants associated with breast cancer predisposition, such as BRCA1, BRCA2, TP53, PALB2, ATM, and CHEK2.

The MyHormoDNA Breast and Ovarian Cancer Panel is an advanced tool that offers:

• Increased safety in the prescription of HRT, avoiding unnecessary risks in patients with genetic mutations;
• Early screening and establishment of preventive behaviors;
• Clinical, ethical, and legal support in accordance with international guidelines from NCCN, ESMO, and ASCO.

This approach promotes a personalized, safe, and evidence-based medical practice.

Conclusion: it’s time to update the debate

The debate on HRT and breast cancer needs to be revised in light of current science.
Hormonal replacement, when well indicated and monitored, should not be seen as a cause of breast cancer.
The real focus should be on modifiable risk factors — such as lifestyle habits — and on individualized genetic assessment.

Do you want to better understand how to assess your patients’ individual risk?
Contact us and learn about the MyHormoDNA genetic tests, designed to offer security, personalization, and clinical precision.

References

• NCCN Guidelines – Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic (v.2.2024).
• ESMO Clinical Practice Guidelines – Hereditary Breast and Ovarian Cancer Syndromes (2023).
• ASCO Statement – Genetic Testing and Cancer Susceptibility (2022).
• Richards S. et al. Genetics in Medicine, 2015.
• Brazilian Society of Medical Genetics and Genomics (2024).
• Daly MB et al., J Natl Compr Canc Netw, 2024.
• Kurian AW et al., J Clin Oncol, 2014.
• Domchek SM et al., JAMA, 2010.
• Tung N et al., Cancer, 2015.
• Desmond A et al., JAMA Oncol, 2015.

Prepared by Dr. Francisco Tostes, Scientific Director at Renewal