Breast cancer — symptoms, diagnosis, treatment

Breast cancer originates in the epithelial tissue of the breast. Women are a group particularly vulnerable to its development — this applies to the entire world population. Breast cancer can also develop in men, although such cases are rare. According to data from the International Agency for Research on Cancer (IARC), 2.26 million people worldwide were diagnosed with breast cancer in 2020. In the next 10 years, this number is to increase to 2.74 million.

What are the symptoms of breast cancer?

The most common symptoms of breast cancer include:

• Lump;
• Change in the size or shape of the breasts;
• Breast asymmetry;
• Inverted nipple;
• Nipple discharge;
• Skin hardening or tightness;
• Redness of the breast;
• Swelling of the breast;
• Breast soreness;
• Axillary lymphadenopathy.

Symptoms that appear as a result of developing breast cancer may vary — depending on the specific type of tumor. It is also possible for symptoms not to appear at all — many cancers develop asymptomatically.

Breast tumors — types

There are two main groups of breast tumors — non-invasive breast cancer and invasive breast cancer. Additional subtypes can be distinguished:

Non-invasive breast cancers:

This group includes the following types:

• Ductal carcinoma in situ;
• Lobular carcinoma in situ.

This group includes neoplasms that do not infiltrate the breast tissue and are located in the milk ducts or lobules of the breast. These “in situ” tumors classified as precancerous conditions.

Invasive ductal carcinoma:

This group includes the following types:

• Invasive lobular carcinoma;
• Paget's disease of the breast;
• Inflammatory breast cancer;
• Locally advanced breast cancer;
• Phyllodes tumor (PT);
• Metastatic breast cancer.

This group includes neoplasms that have spread beyond the breast tubules or lobules to the surrounding breast tissue.

Breast cancer — causes and risk factors

The main risk factor for developing breast cancer is gender — the vast majority of diagnosed cases concern women. This is due to higher levels of certain hormones in women (like estrogen). Another important risk factor is age — breast cancer is most often diagnosed among people between 50 and 70 years of age.

Risk factors may also be genetic. According to Mayo Clinic, this applies to approximately 5-10% of diagnosed cases. This group includes people with a family history of breast cancer. Mutations of specific genes — most often BRCA1 and BRCA2 — are responsible for the appearance of the disease.

Risk factors that are hormonal in nature can be divided into two types:

• Endogenous, i.e., coming from within the body. For example in women with an eraly onset of menstruation (before the age of 12) and the late menopause (after the age of 55).
• Exogenous, i.e., coming from outside the body — hormone replacement therapy and long-term use of oral hormonal contraception.

In addition, lifestyle factors can have an impact on the development of breast cancer. Factors increasing the risk of developing the disease include obesity, unhealthy diet, low levels of physical activity, smoking, and alcohol abuse.

Breast cancer — screening and diagnosis

The most basic screening tool is breast self-examination. It is recommended to perform this type of examination at least once a month. If a lump is detected, you should see a doctor who will examine you refer for appropriate diagnostic tests. The primary method of diagnosing breast cancer is mammography. Usually, an ultrasound is also performed, which allows for more accurate identification of changes in the breast — determining whether they are cystic or solid, examining their size and location. In some cases, more advanced studies are needed, like magnetic resonance imaging or PET-CT. Finally, a reliable diagnosis is obtained by performing a histological examination, e.g., a biopsy.

Breast cancer — treatment

Choosing the right treatment method can be difficult and is based on various factors, including stage of the disease and type of breast cancer. Surgery is the most common form of treatment. There are two types of breast cancer surgery:

• Lumpectomy — it includes removal of the tumor along with the surrounding tissues, but preserves the mammary gland; it can cause change in the size of the breast, therefore it is often possible to perform a breast reconstruction or a healthy breast size reduction procedure.
• Mastectomy — it includes removal of the entire breast gland along with the tumor; it is performed when the tumor is large, multifocal, or located in a hard-to-reach place.

Breast reconstructive surgery may be offered after both lumpectomy or mastectomy. In addition, chemotherapy, radiotherapy and hormone therapy are also used. Some of these treatments can be implemented before surgery (like chemotherapy to reduce tumor size) or after surgery (like radiotherapy to minimize disease recurrence risk).