Is it your age, your lifestyle, or your genetics? If you have a fibroadenoma, you may be wondering, “Why did I develop this?”

Fibroadenomas are solid, benign (noncancerous) breast lumps. Most don’t cause pain, although some may feel tender or uncomfortable. Many fibroadenomas don’t need treatment. Some shrink or disappear over time, while others may be removed with surgery if they grow or cause bothersome symptoms.

About 1 in 10 females worldwide experiences a fibroadenoma at some point, according to StatPearls. You’re hardly alone if you develop one. The good news is that having a fibroadenoma doesn’t mean you did anything wrong.

Researchers don’t know exactly why some people develop fibroadenomas. Here are some factors that may affect your risk.

Age and Menopause

Fibroadenomas most often occur in females between the ages of 15 and 35, according to Cleveland Clinic. They become less common after menopause (when menstrual periods permanently stop).

Because estimates vary among studies and populations, it’s difficult to say exactly how many people in this age group develop fibroadenomas. A reported estimate in the journal Cureus suggests that 27.6 percent of women ages 18 to 40 develop fibroadenomas.

So why does a younger age make some people more prone to fibroadenomas? Researchers think some people may be more sensitive to the effects of estrogen. As a result, they tend to develop fibroadenomas during life stages associated with high estrogen or hormonal changes.

For adolescents, fibroadenomas disappear spontaneously 10 percent to 40 percent of the time. Fibroadenomas may also shrink after menopause as hormone levels change.

Family History of Adenomas or Breast Cancer

If you have a family history of fibroadenomas, there’s a higher chance that you’ll develop them as well. In one study published in JNCI Cancer Spectrum, a family history of breast cancer was associated with a higher risk of biopsy-confirmed fibroadenoma. A biopsy entails removing a tissue sample for examination under a microscope.

This family connection suggests possible genetic links. Eventually, research may paint a clearer genetic picture to help predict the risk. For now, there’s no way to test a person’s likelihood of developing fibroadenomas.

Your Reproductive Health History

Starting menstrual cycles at a younger age may make a person more likely to develop fibroadenomas compared to those who start menstruating later. The same is true for developing breast cancer, and this is because breast tissue begins to be stimulated by estrogen at an earlier age.

The breast cells that can become fibroadenomas have estrogen and progesterone receptors. These hormones are both high during pregnancy, which could be what drives the growth of fibroadenomas in pregnancy.

Women who have more children during their lifetime may also be less likely to develop fibroadenomas than those who have fewer children, according to the JNCI Cancer Spectrum study.

Birth Control and Hormone Replacement Therapy

Taking birth control pills (oral contraceptives) before the age of 20 may put you at a higher risk of fibroadenomas.

Fibroadenomas are also more common in women who are undergoing hormone replacement therapy (HRT), according to another study published in Cureus. This effect may be related to how the breast cells respond to estrogen and progesterone.

Body Size

Researchers have studied whether body weight affects the risk of fibroadenomas, but the results aren’t clear.

Some studies have found a link between body size or obesity and fibroadenomas, while others have not. Excess body fat releases hormones that may impact fibroadenoma development.

It’s not clear exactly why or even if body weight truly leads to fibroadenomas. As with most risk factors, the data points to an association. Associations are different from cause-and-effect relationships. There’s a chance the connection could be a coincidence.

Breast Injuries

Although breast trauma isn’t considered a direct cause of fibroadenomas, some research suggests it may trigger their development or growth. This hasn’t been proven, however, and more research is needed.

Many people develop fibroadenomas with no history of physical trauma to the breast. While injuries could be relevant for some, they’re not necessarily a factor.

Is It Possible To Prevent Fibroadenomas?

From what’s known so far, fibroadenoma prevention isn’t really possible. There’s no way to predict how different risk factors may affect you and more research is needed to know exactly how risk factors play a role in fibroadenomas.

In addition, most of the suspected risk factors aren’t factors you can change. You can’t change your age, the year you get your first period, or your family history. While you may have some control over others, such as which birth control you use and how you manage your weight, there’s no way to know if adjusting them would reduce your risk.

When To See Your Doctor

If you notice a new lump, always tell your healthcare provider. If you were diagnosed with a fibroadenoma before but have noticed changes in its size, shape, or how it feels, let your doctor know right away. They’ll likely want to do some testing to ensure it’s a benign breast condition.

A breast exam and imaging, such as an ultrasound or mammogram, can help evaluate whether a breast lump is something benign, such as a fibroadenoma or a cyst, or possibly breast cancer. A biopsy may be needed to confirm the diagnosis.

Some research suggests that a history of biopsy may raise the risk of breast cancer later. So it’s important to stay vigilant and follow up on any concerns.

Join the Conversation

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What potential risk factors matter most to you? Let others know in the comments below.