Breast Cancer Awareness Month brings a lot of familiar messages every October. But awareness is more useful when it helps you understand the details that are easy to miss.

Breast cancer can affect people differently, and there is no single sign, family history or risk profile that tells the whole story. Here are a few things worth knowing.

No family history doesn’t mean no risk

Family history matters, but it is only one part of breast cancer risk. Most women diagnosed with breast cancer do not have a known family history of the disease. WHO estimates that around 80% of breast cancers occur in women with no specific risk factors other than sex and age.

That means “breast cancer doesn’t run in my family” shouldn’t be treated as reassurance that screening or breast changes are irrelevant.

Family history can still provide useful information. Breast and ovarian cancers on either side of the family may be relevant, and some inherited genetic changes, including BRCA1 and BRCA2, can substantially increase risk.

A lump is only one possible sign

A new lump in the breast or underarm is probably the symptom most people associate with breast cancer. There are other changes that may warrant attention too.

These can include swelling or thickening, changes in the size or shape of a breast, dimpling or irritation of the skin, redness or flaky skin around the breast or nipple, a nipple that begins pulling inward, nipple discharge other than breast milk, or persistent breast pain. Some people with breast cancer have no noticeable symptoms at all.

Many breast changes are caused by conditions other than cancer. The useful habit is simply knowing what is normal for your body and bringing an unexplained change to a healthcare professional rather than trying to diagnose it yourself.

Breast density is something more people are hearing about

You may have noticed the term breast density on a mammogram report without knowing what it means.

Breasts contain different amounts of fatty, glandular and connective tissue. Dense breast tissue can make some cancers harder to see on a mammogram, and having dense breasts is itself associated with increased breast cancer risk. You cannot tell whether your breasts are dense by looking at or feeling them; density is identified through mammography.

How breast density is reported and used in screening decisions varies between countries and health systems.

In the United States, for example, federal regulations have required mammography facilities since September 2024 to tell patients whether their breast tissue is dense as part of their mammogram results. Approximately half of U.S. women over 40 have dense breast tissue.

If your mammogram report mentions breast density, it is worth reading that information rather than treating the result as simply “normal” or “abnormal.” A healthcare professional can explain what the finding means in the context of your individual risk.

Screening recommendations have changed

There is no single breast cancer screening schedule used everywhere. Recommendations can differ by country, health authority, age, individual risk and access to screening programs.

For example, in the United States, the U.S. Preventive Services Task Force recommends mammography every two years from ages 40 through 74 for women at average risk. Its recommendation also applies to other people assigned female at birth who meet its criteria.

Other countries and medical organizations use different age ranges and screening intervals. People with certain inherited genetic changes, previous breast cancer, prior chest radiation or other higher-risk circumstances may also receive different recommendations.

That is why a screening age you heard online, or the schedule followed by a friend or family member in another country, may not apply to you. Check the current guidance from your local health authority or speak with a healthcare professional about what’s appropriate for you.

Men get breast cancer too

Breast cancer is much less common in men, which can also make it easier to overlook.

Globally, WHO estimates that approximately 0.5-1% of breast cancers occur in men. In the United States, the CDC puts it similarly: about 1 in every 100 breast cancers diagnosed is found in a man.

Possible signs can include a lump or swelling, changes to the breast skin, nipple discharge or a nipple that begins pulling inward.

Family history and inherited genetic changes can matter for men as well. Breast Cancer Awareness Month therefore has relevance beyond women alone.

There can be a long period between “something showed up” and an answer

Cancer awareness campaigns tend to talk about screening and diagnosis as though one follows neatly after the other. Real life can involve more uncertainty.

A mammogram may lead to additional images or other testing. Screening itself can also produce false-positive results, which means something appears concerning but ultimately turns out not to be cancer.

For employees, that can mean attending appointments, waiting for results or trying to work while wondering what a test means. Someone going through that process may not have a diagnosis to share, and they may not want to explain the details.

If a colleague does tell you they are dealing with a breast health concern, you don’t need to find the perfect thing to say. Respect their privacy, avoid asking for information they have not offered, and follow their lead on how much they want to talk about it.

A few useful things you can do with this information

• Learn whether breast cancer screening is recommended for you based on your age and individual circumstances
• Know relevant cancer history on both sides of your family where possible
• If you have had a mammogram, read the full result, including any information about breast density
• Pay attention to new or unexplained breast changes rather than waiting specifically for a lump
• Give coworkers dealing with screening, testing, treatment or caregiving the space and flexibility you would want in the same situation

Awareness can’t tell any individual person whether they will develop breast cancer. What it can do is make important information easier to recognize, understand and act on.

This resource is provided for general educational purposes and does not replace medical advice, diagnosis or individualized screening recommendations. Questions about personal risk, symptoms or screening should be discussed with a qualified healthcare professional.