In industrialized countries, breast cancer is the most commonly diagnosed malignant tumour in women. The number of newly diagnosed cases is  increasing steadily, while at the same time mortality is decreasing – thanks to rapidly developing therapies and screening. In 2019, more than 8,000 new cases were reported in Hungary, every sixth malignant disease in women originated from the breast. Nowadays, the 5-year survival rate is close to 90%.

Genetic predisposition (most often mutations in the BRCA1 and BRCA2 genes) can be detected in only 10% of the diagnosed breast cancers. Factors that increase the risk of its development include early menarche, late menopause, hormone replacement, high-fat diet, overweight, obesity, sedentary lifestyle, alcohol consumption, and the incidence increases with age, with the highest frequency of occurence in the 50-64 age group.

The most common symptom is a painless lump in the breast, but other symptoms, among others, may include indentation of the breast skin, abnormal (often bloody) discharge from the nipple, and differences in the size of the two breasts.

Diagnosis consists of physical examination, complex breast examination (mammography, breast ultrasound) and sampling.

There are several histological subtypes of breast cancer, the most common is the invasive ductal carcinoma. The histological examination of the tumour includes assessment of hormone receptor status (estrogen and progesterone receptor expression), approximately 60-75% of breast tumours are estrogen receptor positive, in which case they are sensitive to hormone therapy. Similarly, HER-2 (human epidermal growth factor) receptor determination is routinely carried out from histology, and if positive, it is considered a HER-2 positive breast tumour that responds well to biological therapy (e.g. Herceptin/Trastuzumab). If the tumour is negative for both the hormone receptor and the HER-2 receptor, it is considered a triple negative breast cancer. Triple negative breast cancer has worse five-year survival.

In addition, the factor determining the prognosis is the presence of local or distant metastasis. Local tumour spread means the presence of axillary lymph node metastasis. Distant metastasis cases (bone, lung, liver, brain metastasis) have the worst prognosis.

The treatment strategy may vary depending on the histology (tissue type), but it most often consists of surgery, chemotherapy, radiotherapy, and sometimes hormone therapy and biological therapy.

Surgical treatment depends on the extent and histological subtype of the tumour. The type of surgery may include, among others, breast conservation surgery, where only the tumour tissue is removed (lumpectomy), keeping the remaining breast tissue, or mastectomy, with the removal of the entire breast tissue, which can be followed by breast reconstruction, the two most common methods of this reconstruction are breast augmentation with the patient’s own tissue or with foreign material. As part of the operation, axillary lymph node removal is also performed, if no lymph node metastasis are proven, only the sentinel lymph node (performed by isotope labeling, this is the first lymph node in the armpit where the lymphatic circulation of the breast tissue leads) is biopsied from the affected side of the armpit, but it happens that all axillary lymph nodes are removed.

Chemotherapy is often used as part of the treatment and can be given before surgery (neoadjuvant treatment) or after surgery (adjuvant treatment).

Radiotherapy is given before surgery or if chemotherapy is needed, after the chemotherapy process.

In the case of a histologically confirmed hormone receptor-positive tumour, hormone therapy is also necessary to reduce the risk of recurrence. Tamoxifen or aromatase inhibitor tablets (Letrozole, Anastrozole) are usually used as hormone therapy for 5-10 years. Hormone therapy is carried out to reduce the levels of estrogen and progesterone normally produced in the patient’s body (produced by the ovaries before menopause and by the adrenal glands in smaller quantities after menopause). This can lead to side effects such as night sweats, heat flushes, reduced libido, vaginal dryness, weight gain, all of which can impair the quality of life of patients.

The side effects caused by chemotherapy range widely and can vary from patient to patient, depending on the patient’s tolerance and the treatment used.