Certain changes in the breast may be early signs of breast cancer. Knowing what these changes look like can help people access the right treatment, as soon as possible.

Understanding the different parts of the breast and their functions can help people be more aware of any changes or abnormalities.

This article explores breast anatomy and explains more about the different tissue, lobes, lobules and milk ducts that make up the breast.

It also highlights what warning signs to look for that may indicate breast cancer, and what people should do if they spot them.

Breast anatomy and breast cancer signs

It's important to learn about the parts of the breast in order to better understand how cancer forms and what the signs of it might be.

A female breast is made up of many parts, including:

• body fat (adipose tissue)
• lobes
• lobules
• milk ducts
• lymph nodes
• blood vessels

Adipose tissue

Most of the female breast is made of adipose tissue, more commonly known as body fat. Not only in the breast itself, adipose tissue stretches from the collarbone, down to the underarm, and across to the ribcage.

Adipose tissue also contains nerve cells and blood vessels. It is important for storing and releasing energy.

Lobes, lobules, and milk ducts

A female breast will generally have between 12 and 20 sections known as lobes. Each of these is made up of smaller areas called lobules, which are milk glands.

Lobes and lobules are connected by milk ducts, which carry milk to the nipple. It is among the lobes, lobules, and milk ducts were cancer is most likely to form.

Lymphatic and vascular system

There is a lymphatic and vascular network inside the breast. The vascular system is a network of blood vessels, while the network of lymph channels is called the lymphatic system. This network helps carry blood and fluid to and from the breast tissue to the rest of the body.

Breast cancer can enter these systems through the blood vessels or lymph channels. This increases the chance of the cancer spreading throughout the body or coming back.

Clusters of bean-shaped cells called lymph nodes are found throughout the lymphatic system. These are immune cells that act as filters. These nodes are the first place breast cancer is likely to spread to.

Early symptoms and warning signs

Warning signs and symptoms can vary greatly from person to person, but there are some common signs:

• lumps inside the breast or underarm area
• change in breast size and shape
• pain in a specific area that does not go away
• prominent veins on the surface of the breast
• nipple discharge that starts suddenly
• sore or rash on the nipple
• swelling, redness, or darkening of the breast
• dimpling of the skin on the breast
• pulling in of the nipple or other parts of the breast

However, if any of these symptoms do occur, it does not necessarily mean that cancer is present. The changes can often be the result of benign breast conditions.

Benign means it is not cancer and changes in the breast can be caused by a variety of factors throughout a woman's life.

For example, puberty, pregnancy, and menopause may cause changes in the breast because of varying levels of the hormones estrogen and progesterone in the body.

Other warning signs can signify other benign conditions.

Nipple discharge

While nipple discharge can be troubling and unpleasant, again, it is usually nothing to worry about. It may simply be caused by the nipples being squeezed, or may be the result of an infection.

More serious signs include:

• discharge that occurs without squeezing the nipple
• discharge in one breast and not the other
• discharge that has blood in it

Anybody that notices nipple discharge should seek medical advice.

Lumps

Many women may find their breasts are lumpy. This is often because the breast is made up of tissue, which is lumpy in texture.

Lumpiness can vary widely in women's breasts. Usually it is nothing to worry about, particularly if it feels the same throughout both breasts.

There are other situations when it is best to get the lump checked out: These include:

• a harder lump that feels different from the rest of the breast
• a lump that feels different from the other breast
• something that feels different to how it felt before

Often these can be benign conditions, such as a cyst or fibroadenoma, which is a tumor made up of glandular and connective tissue. Fibroadenomas are most common in women in their 20s and 30s.

What to do if you spot symptoms

The American Cancer Society offers guidelines on cancer screening in adults. The majority of breast cancers in the United States (U.S.) are found in their early stages, before symptoms appear, thanks in part to the use of mammograms. A mammogram is an X-ray of the breast that checks for cancer.

The guidelines are as follows:

• Women aged 40 to 44 can start having mammograms if they wish.
• Women aged 45 to 54 should have a mammogram every year.
• Women over 55 should have a mammogram every two years, but can have one annually if they wish.

However, mammography does not find all breast cancers. So individuals should talk to a doctor to identify the best screening process for them.

Anyone who has any concern that they might have breast cancer should go and see their doctor.

What the doctor will do

Adult women of all ages are encouraged to conduct breast self-examinations. These should be done at least once a month to search for anything unusual.

If someone has any concerns, they should go to their doctor who will carry out a clinical breast exam.

Clinical breast exam

A doctor, who is trained in how to identify abnormalities or warning signs of cancer in the breast, will conduct the examination in their office. The person being examined will be asked to remove the clothing from their top half. The doctor will then perform a number of checks to see if there are any problems. These include:

• Visual check: The individual will be asked to raise their arms, put them by their sides, and press their hands against their hips. This can show differences in the size and shape of the breasts. The doctor will also look for any rashes, dimpling, or nipple discharge.
• Manual check: The doctor will use the pads of their fingers to check the entire breast, underarm, and collarbone for any abnormalities and suspicious lumps. They will also check the lymph nodes if they are enlarged.
• Assessment: If a lump is discovered, its size, shape, and texture will be noted down. The doctor will check to see if it has traits of cancer, or whether it is more likely to be a benign tumor or cyst. Either way further tests will be required.

Other tests

If a lump is discovered the person will undergo further diagnostic methods, which include:

• Mammogram: An X-ray of the breast.
• Ultrasound: Sound waves that do not damage or affect the body.
• MRI: Inside a machine, a magnet will transmit magnetic energy and radio waves to make a detailed picture of the breast.
• Biopsy: Tissue or fluid from the suspicious area is removed and sent for further tests.