Breast cancer: Why It Occurs and How It Manifests Itself - Self-examination As A Way Of Prevention

Breast cancer: Why It Occurs and How It Manifests Itself - Self-examination As A Way Of Prevention
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Breast cancer is the most common cancer globally and is also the leading cause of death among cancers in women. Worldwide, breast cancer is the leading type of cancer in women, accounting for 25% of all cases. In 2018, it resulted in 2 million new cases and 627,000 deaths. It affects women, but rarely men. Breast cancer mortality is declining due to regular preventive check-ups.


Breast cancer is the most common cancer in women. Its proportion among malignant cancers is about 20-30 percent.

It mainly affects women.
Men are rarely affected. The incidence rate for men is 1:100 cases.

The incidence of breast cancer is increasing worldwide. In the past, the disease was most often diagnosed in women over 60 years of age. However, in recent years, it has also increasingly affected women between the ages of 25 and 45.

Early diagnosis and timely treatment have a direct impact on mortality. Screening, regular preventive examinations, and breast self-exams help.

The exact cause of cancer is not known, but we do know some of the risk factors involved in its development.

There are warning signs that should not be ignored. Everything women should know about the disease is presented in this article.

Why does breast cancer appear and how long does it progress?
How does it manifest? 
How is it treated? 
What is the role of breast self-exams in prevention?

Not All Breast Lumps are Tumours or Cancer

Not all breast lumps and masses indicate cancer.

But that does not mean that it can be ignored.

A tumour is something that does not follow the rules of the body and lives on its own. It can affect any cell in the body. We do not know the exact cause.

Tumour is defined as excessive growth of tissue, which is uncoordinated with that of the normal surrounding tissue.

It is characterized by features such as:

  1. excessive growth
  2. uncoordinated growth
  3. and growth that is independent of the environment and the organism as a whole, i.e. it is autonomous

DNA damage and genetic alterations, the formation of pathological proteins, which interfere with the normal processes of cell division, the proper differentiation (classification of function, diversity), and cell death. They are all involved in the development of a tumour.

Substances called oncogenes are present in the process of tumour formation.

The growth of pathological cells and tissues is also characterized by a suppressed function of anticancer genes, or anti-oncogenes. These are responsible for regulating normal cell growth and division. Their task is also to prevent the erroneous proliferation of cells with incorrect genetic information.

Whether a tumour begins to form is affected by various internal as well as external factors. Internal factors include, for example, genetic predisposition, hormonal influences or human immunity. External factors are, for example, chemicals, physical influences and viruses.

Table: Some Risk Factors that Affect the Development of Tumours

Internal factors External factors
Genetic predisposition Chemical factors
heredity, such as breast cancer
if the mother has breast cancer, there is a high probability of developing the disease in the daughter
heavy metals
products of imperfect combustion
aromatic hydrocarbons
Hormonal influence Physical influence
after hormonal treatment, after menopause, hormonal influence on the development of prostate cancer in older men ionizing, radiation, UV, X-ray
to a certain extent
Immunity Viruses
higher incidence of oncological diseases in long-term diseases, in AIDS, after transplants, due to weakened immunity hepatitis virus and liver cancer
HPV virus and cervical cancer
Epstein-Barr virus (EBV) - lymphoma or Burkitt lymphoma

TIP: Learn more about liver cancer and cervical cancer prevention.

Tumours can be benign, i.e. non-cancerous, and malignant, or cancerous.

Although benign tumours are not life-threatening, some of them may pose an increased risk of cancer. For example, benign masses are cysts that are palpable, well demarcated and may hurt. Another types is a fibroadenoma and other proliferative conditions.

The human breast is affected by various changes throughout the person's life, such as fluctuations in hormonal levels due to estrogens and progestogens. These changes are intended to prepare the mammary gland for pregnancy and breastfeeding. The mammary gland enlarges, the breast may become painful, and if the released egg does not fertilize, the changes subside.

Different nodules may appear in the breast during the cycle. They are referred to as, for example, fibrocystic changes or fibrocystic mastopathy. It is similar when taking hormonal drugs.

Breast Cancer is...

Breast cancer is a malignant disease that most commonly develops in cells from the lining of milk ducts and the lobules that supply these ducts with milk. Other forms are called carcinoma in situ and invasive cancerous forms.

There are two kinds of carcinoma in situ: lobular and ductal.

The lobular form indicates the involvement of the mammary gland, the lobes or the smaller lobules. The breast consists of approximately 15-20 glands, each forming a separate lobe. The designation ductal means that it affects the glandular ducts.

Here are the various names given to forms of breast cancer:

  • ductal carcinoma in situ, which affects the glandular duct, it is an early stage of the disease
  • invasive ductal carcinoma, which grows out of the milk duct and behaves aggressively towards the surrounding tissue
  • lobular carcinoma, affects the mammary gland and accounts for about 10%, mostly forming metastases to the ovaries or meninges
  • ductal carcinoma is the most common form, about 75% and forms MTS in the bones, lungs and liver
  • inflammatory carcinoma is the most aggressive form, and its incidence is rarer, in the range of 1-3% of cases
  • Paget's disease of the breast, skin changes involving the nipple of the breast
  • tubular carcinoma is rare, about 1%
  • mucinous carcinoma is also rare, at approximately 2%
  • medullary carcinoma, in about 6%


The exact cause of tumours is unknown. The same goes for breast cancer. However, breast cancer susceptibility genes BRCA1 and BRCA2 are said to underlie breast cancer. This causes uncontrolled cell proliferation and cancer.

Table: Some Risk Factors for Breast Cancer

  • advanced age, above 50 years of age
  • being a woman
  • higher risk in women who did not give birth
  • even the first pregnancy after the age of 30
  • higher risk in non-breastfeeding women
  • early menarche, i.e. the first menstrual cycle, before the age of 12
  • late menopause after the age of 45
  • family history, ie the occurrence of the disease in the family, heredity
  • past breast cancer disease, risk of recurrence
  • problematic mastopathy
  • increased breast density
  • obesity
  • increased fat intake or little exercise
  • smoking and alcholism
  • chemicals, ionizing radiation
  • hormonal treatment, which is cited as a possible cause, this theory is not entirely substantiated

However, not even one or several risk factors represent a clear trigger of the disease.

Therefore, regular breast screening is necessary. Early detection and diagnosis guarantee a successful treatment. Screening, regular preventive check-ups and, of course, breast self-exams are of utmost importance.

Check with your health insurance or GP whether preventive examination is covered by your health insurance.

If a woman does not go to a gynecologist, she should be referred by a GP for an examination. Breast examinations start at 18 years of age. Ultrasound examinations are performed until 40 years of age. Women over 40 undergo a mammogram exam every two years.

Breast self-examination should be performed by every woman at least once a month, starting at the age of 18.


The symptoms of breast cancer are diverse. Some types and early-stage breast cancer do not have an obvious symptom.

They are detected at random during a gynecological examination. And that is exactly what the main task of prevention and screening is.

Benign lumps are palpable as well-defined humps and may be painful. Malignant masses are not always painful.

The development of the disease can be slow or sudden. It mainly depends on the type.

Bumps, hard lumps or enlarged breasts may also occur due to the menstrual cycle and changes in hormone levels.

It is important to note the following warning signs:

  • stiff lump in the breast
    • in up to 75% of cases, breast lumps are palpable and painless
  • skin dimpling
  • inverted nipple
  • lump in the armpits and in the area above the collarbone
    • enlargement of lymph nodes in the breast area, on the chest wall
  • discharge from the nipple which may be brownish or bloody
  • breast inflammation
  • reddening of the skin on the breast
  • eczema on the nipple
  • breast skin wrinkles, orange skin
  • breast and nipple skin discolouration
  • change in nipple sensitivity
  • breast pain occurs in approximately 5%
  • enlargement of one breast, but only in 1% of cases
  • breast reduction 
  • change in breast shape

Stages of Breast Cancer 

Classification and pathological staging of the disease are based on the clinical stage that include certain features. Palpability and regional lymph node enlargement are taken into account.

Table: Classification of Breast Cancer by Stages

Stage Description
Stage 0 carcinoma in situ
pre-malignant changes, such as ductal hyperplasia, atypical ductal or lobular hyperplasia
behaviour not invasive yet 
no metastasis and lymph node penetration is present
Stage I the tumour is less than 2 cm in size
no lymph node involvement is present
does not metastasize
Stage II
  • group A
    • if it is less than 2 cm, it affects between 1 and 3 lymph nodes
    • lymph nodes are affected but not detected in the breast
    • or if it is 2-5 cm in size but without lymph node involvement
  • group B
    • the size of the tumour is 2-5 cm, with 1 to 3 nodes being affected
    • size more than 5 cm, without affecting the nodes
Stage III
  • IIIA
    • fixation of lymph nodes with each other, without a proven breast tumour
    • the tumour is less than 2 cm and the nodes in the armpits or chest are affected
    • size 2 - 5 cm and involvement of the nodes in the armpits or chest
    • more than 5 cm of affected nodes
  • IIIB
    • different size
    • if the tumour grows into the skin or chest wall
    • inflammatory form, reddening of the skin, orange discolouration
  • IIIC
    • the tumour is of different sizes
    • affects 10 or more nodules in the armpit
    • if nodules in the collarbone are also affected
Stage IV metastasizing cancer to other parts of the body
most commonly into:
  • the lungs
  • the liver
  • the bones
  • the brain and meninges

Weight loss and bone pain are symptoms of the late stage of the disease and when it is metastasizing. Metastases of other breast cancers are less common. However, transmission of tumour metastases from breast cancer to other parts of the body is more common.

For example, breast cancer metastasizes to the following parts of the body:

  • brain and brain membranes (meninges)
  • lungs
  • live
  • ovaries
  • bones
  • lymphatic nodes


Diagnosis takes place mainly in the form of screenings and preventive examinations. Breast self-exams sre also very important. Women and girls should self-examine their breasts at least once a month.

Regular check-ups by a gynecologist are important. The doctor also examines the mammary glands.Please check whether ultrasound examination is covered by your insurance. In some countries, mammography takes place every two years and is covered after 40 years of age. If a woman notices warning signs, a professional examination is needed.

Clinical examination includes personal, family and gynecological history. Breasts and armpits are examined visually by manual palpation.

Biological material is sampled and sent to blood tests to check oncological markers, hormone receptors, HR (ER and PR) and HER/2. The tissue sample is taken by puncture, i.e. a biopsy and subsequently histology of the sample taken.

Imaging methods are another group of exams. Mammography is one of the main examinations. Ultrasound, CT, MRI, PET and ductography may also be done. Mammography is said to be the most reliable method for diagnosing the disease at an early stage.

Mammography can also reveal small features with a diametre of about 5 mm. At the same time, it can diagnose up to 90% of pre-cancerous units and conditions. Concerns about high doses of ionizing radiation have been reported in the past. However, these concerns are unfounded today.

Mammography is a special X-ray examination. People are advised to go to an entry examination after the age of 40, followed by regular examinations after the age of 49.

In addition to mammography, women should undergo an examination at least once a year after the age of 18.


The course of the disease is not uniform.

Some types of tumours grow slowly over several years. They are asymptomatic, and are detected accidentally during the examination.

Conversely, other types of tumour can grow rapidly and spread just as quickly to other parts of the body. Aggressive behaviour of this kind also means a short survival of the affected person.

It is not clear why cancer occurs in the first place.

The prerequisite is the interplay of several risk factors. However, this does not guarantee that it will happen. However, if you notice any of the warning signs, an examination is needed. Early diagnosis plays a very important role in the treatment and a good prognosis.

Remember that early detection of issues can save lives. For tumours that are smaller than 1 cm, there is a 90% chance of cure.

The likelihood of breast cancer increases with age. At the same time, there is a higher risk in women over the age of 40, which does not rule out the onset of the disease even after the age of 20. It is the most common cancer in women in Europe and North America. 

Don't forget About Breast Self-Exams

Women and girls over the age of 18 should have their breasts checked regularly every month. It is best in the period after menstruation. In the post-menopausal period, it should be one and the same day of the month. Self-investigation is an important part of early detection of a problem.

Breast self-exam procedure:

  1. you need to be shirtless and braless
  2. sit or stand in front of a mirror
    • compare your breasts, one of them might be slightly larger than the other, which is normal
    • check your skin colour
    • check the colour of the nipple and the areolae (the pigmented area on the breast around the nipple)
    • check for bulges or ridges on the skin of your breast
    • check to see if the skin is orange
    • check to see if your skin is turned in (inverted)
    • check to see if your nipples are turned in (inverted)
    • check for dimples or puckers on the skin of your breast
    • check for eczema on the skin, the nipple, the areolae
    • check for breast inflammation
  3. raise your arms raised overhead
  4. the breasts should follow the movement of your arms
  5. check to see if the nipples are the same height
  6. lying on your side
    • palpate your breast in a circular motion
    • use the pads of your fingers to examine your breasts
    • right hand - left breast and vice versa
    • palpate the area between the breast and the armpit
  7. sit or stand
    • place one hand below the breast
    • do not raise it
    • use the other hand to examine the breast
    • gentle enough nipple, check for a brownish or bloody discharge
  8. palpate the armpit
    • you can feel the lymph nodes, even under normal circumstances
    • they are soft and movable, which is the normal condition
    • in overweight and obese individuals, they are usually not palpable because they are stored in a larger layer of fat

Any change or discrepancy with a previous examination should be discussed with a physician. Not all lumps are cancerous. However, talking to your GP can save your life. Remember that early detection and timely treatment are the key to success.

How it is treated: Breast cancer

Breast cancer treatment: surgical and oncological

Show more

Breast cancer - Symptoms and treatment

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