Breast cancer is the most commonly diagnosed cancer among women worldwide, accounting for 25% of all cases, and it is one of the leading causes of death (14%). Women diagnosed with breast cancer represent 36% of all cancer patients. In 2022, approximately 2.3 million women were diagnosed with breast cancer and 670,000 deaths were recorded globally. Breast cancer occurs in every country in the world among women of any age after puberty, with increasing rates later in life. Global estimates reveal striking inequalities in the burden of breast cancer according to human development. For example, in countries with a very high Human Development Index (HDI), 1 in 12 women will be diagnosed with breast cancer during their lifetime, and 1 in 71 women will die from the disease. These countries include Belgium, Denmark, the Netherlands, Germany, and the United Kingdom. The lowest rates are observed in regions of Africa and Southeast Asia. In these regions, 1 in 27 women is diagnosed with breast cancer during her lifetime, while 1 in 48 women dies from it. For example, Japanese women who migrate to the United States begin to have breast cancer risks approaching those observed in their new place of residence, indicating that environmental factors also play a key role.

What is breast cancer?

Breast cancer is a malignant disease that occurs when normal breast cells change their properties and begin to grow uncontrollably, multiply, and destroy surrounding healthy tissue. These altered cells can then travel through the lymphatic and/or blood vessels, spreading the disease to other parts of the body. Breast cancer is the most common type of cancer among women and an important public health issue. It is the third leading cause of cancer-related death among women, after lung cancer and colorectal cancer.

Who can get breast cancer?

Breast cancer most often affects women over the age of 50, but it can also occur in younger women in their forties, thirties, and twenties. Men can also develop breast cancer, but much less frequently than women. One percent of all registered breast cancer cases occur in men. Numerous epidemiological studies show that several known risk factors are clearly associated with the development of breast cancer.

Who is at risk?

The greatest risk factor for breast cancer is sex. Approximately 99% of cases occur in women, and only 0.5–1% in men. Treatment of breast cancer in men follows the same treatment principles as in women.

Factors that increase the risk of breast cancer include:

• older age
• genetic predisposition to breast cancer
• first menstruation before the age of 12
• menopause after the age of 50
• having no children or giving birth after the age of 30
• use of hormone therapy
• dense breast tissue
• occurrence of breast and/or ovarian cancer in close relatives
• previous breast disease

An increased risk of breast cancer is also associated with certain unhealthy and preventable habits and lifestyle factors:

• unhealthy diet (high intake of fats and sugars)
• obesity
• excessive alcohol consumption
• smoking
• physical inactivity
• exposure to ionizing radiation

When should mammography and breast ultrasound be performed?

Mammography is an X-ray examination of the breasts that detects tumors and other breast changes that are too small to be felt. It has been proven that mammography can detect breast changes approximately two years earlier than clinical examination based on symptoms or palpable lumps. Mammography is performed in women with menstruation between the 5th and 10th day of the cycle, counting from the first day of the last menstrual period. Although mammography is an extremely valuable and irreplaceable test for detecting disease at an early stage, it should be emphasized that mammography cannot detect 15–20% of breast cancers, especially in breasts with dense glandular tissue. Every woman should have her first mammogram between the ages of 38 and 40, and then once a year or every two years. For women with a family history of breast cancer among blood relatives, regular screening is recommended at an earlier age.

Ultrasound, in addition to mammography, significantly increases the accuracy of diagnosing benign and malignant breast diseases. It is the method of choice for breast imaging in younger women and an important complementary method to mammography. In women under 40 years of age, mammography is generally not recommended as a routine examination. In this age group, breast ultrasound can be performed once a year. However, in women with suspected malignant breast disease, mammography should also be performed at a younger age.

Although these tests are valuable, their accuracy is often lower than that of modern techniques such as PET/CT or PET/MR, which offer greater sensitivity and specificity. PET/MR allows simultaneous evaluation of the entire body with a lower dose of ionizing radiation compared to PET/CT.

What is breast self-examination?

Breast self-examination is a procedure that allows a woman to examine her own breasts. During self-examination, special attention should be paid to the following signs: detection of a lump on palpation, breast thickening, enlargement of one breast, any changes in the skin of the nipples and breasts, nipple discharge, breast pain, and changes in the underarm area. If a woman notices any of these symptoms, she should mandatory consult a doctor.

When should breast self-examination be performed?

Breast self-examination is recommended once a month, preferably a few days after the end of the menstrual cycle. If a woman no longer has a menstrual cycle, it is best to choose a specific day of the month for the examination. Regularity is very important, so choosing a fixed date each month helps maintain consistency and makes it easier to notice changes in the breasts.

It is recommended to begin breast self-examination from the time of the first menstruation, so that during breast development, girls become familiar with their anatomy and can later monitor any changes. Early detection of breast cancer plays a crucial role in successful treatment. Combining regular self-examination with other screening methods such as ultrasound, mammography, clinical examination, and magnetic resonance imaging increases the chances of early detection. The earlier breast cancer is detected, the greater the chances of faster and more successful treatment.

Breast self-examination should become an integral part of every woman’s routine. Through self-examination, women can notice changes in breast size and shape, as well as lumps or other symptoms. In short, breast self-examination is key to detecting breast cancer at an early stage and plays an important role in maintaining breast health and reducing the risk of complications.

Breast self-examination in five steps

1. Visual inspection in front of a mirror
Begin the self-examination in front of a mirror to visually inspect the external appearance of the breasts. Stand with your arms at your sides and observe the size, shape, and color of your breasts. With regular practice, you will become familiar with your breast anatomy and notice any irregularities. Pay attention to the following signs:

• breasts should not be thickened or wrinkled, and the skin should not resemble an orange peel
• nipples should not be inverted or flattened
• the skin should not have rashes, visible lumps, or color changes
• breasts should not be painful, except during the menstrual cycle

If you notice any of these signs, it is important to consult your doctor.

2. Visual inspection with raised arms
Raise your arms and carefully examine the breasts for the same changes as in the first step, including shape, size, skin texture, and other signs.

3. Nipple examination
Standing in front of the mirror, gently squeeze the nipple and check for any discharge. The discharge may be watery, milky, yellow, or bloody.

4. Examination while lying down
Examine the breasts while lying down to detect lumps or abnormalities not previously noticed. Use your right hand to examine the left breast and your left hand to examine the right breast. Begin with gentle, superficial movements and continue with firmer, deeper movements using the pads of the middle three fingers, keeping them flat and together. Place the arm on the side being examined under your head. Examine the breast in circular motions, starting from the upper area below the collarbone, moving through the outer (axillary) area, the lower part, and the inner area toward the cleavage. Make circles around the edge of the breast and gradually move toward the nipple, which should also be examined. Be sure to examine the entire breast.

5. Examination while standing or sitting
At the end of the self-examination, palpate your breasts while standing or sitting. Examine the entire breast using the same hand movements and techniques described in the previous step. If it is easier, you may apply oil or body lotion to your breasts, or perform the examination in the shower using soap lather.

Early diagnosis of breast cancer provides better chances for successful treatment and improves quality of life.