One in eight cases of breast cancer in Spain affects women who, in many cases, do not have a genetic predisposition. Among the modifiable risk factors, the use of hormonal contraceptives – pills, patches or intrauterine devices – has once again come under scientific scrutiny. The most recent evidence confirms a small but significant increase in risk, which requires reevaluation of its use from an individualized medical perspective.
A link that science cannot fully close
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The Spanish Society of Medical Oncology (SEOM) remembers that breast cancer has a multifactorial origin: only 10% is due to hereditary causes. The rest responds to environmental and hormonal factors.
In this context, hormonal contraceptives—which act by blocking ovulation using synthetic estrogens and progestogens—have always generated debate.
The International Agency for Research on Cancer (IARC) classified them in 2005 as “carcinogenic to humans”, especially in relation to breast, cervical and liver cancers. However, the same compounds are associated with a reduced risk of ovarian and endometrial cancer.
What the latest research says
A joint study by the universities of Navarra and Harvard, published in Maturitas, analyzed 20 cohorts and more than 5.5 million women.
Their results are the most conclusive so far:
- Using hormonal contraceptives for five years or more increases the risk of breast cancer by 20%.
- The risk increases in the first five years, stabilizes and rises again after a decade.
- In young women, the increase is even greater: a 41% increased risk before menopause.
The researchers highlight that, although the individual increase is low, its global impact is important given the number of female users around the world.
Why hormones influence breast tissue
The effect of contraceptives is explained by the proliferative action of estrogens and progestins on breast tissue.
These hormones stimulate cell growth and can promote mutations in breast cells over time.
The risk increases the longer the use lasts, although it gradually decreases after stopping treatment.
A balance of risks and benefits
Hormonal contraceptives remain an effective and safe method for millions of women.
The increased risk of breast cancer must be weighed against its advantages: prevention of unwanted pregnancies, regulation of menstrual cycles and reduction of other types of cancer.
Specialists recommend individualized medical advice, which takes into account:
- Family history and genetics.
- Duration of use of the method.
- Age and reproductive history.
The final decision should be based on complete information, not fear.
Next steps of the investigation
Experts emphasize the need to evaluate new hormonal formulations, less powerful and with safer combinations, as well as to study the effect on different subtypes of breast cancer.
It is also being investigated whether alternative routes of administration – such as patches or hormonal IUDs – present a lower risk than traditional pills.
Informed prevention, not alarmism
The risk associated with the use of hormonal contraceptives exists, but should not be interpreted as a condemnation.
The increase is relative and depends on multiple factors.
The key is in personalized prevention, regular check-ups and doctor-patient communication.
Ultimately, understanding how hormones act in the body is essential to making free and well-informed decisions about reproductive health.
Source: Infobae.