HER-2 positive breast cancer is a subtype of breast cancer characterized by excessive expression of the HER-2 (human epidermal growth factor receptor 2) protein on the surface of tumor cells. This protein belongs to the epidermal growth factor receptor family and is actively involved in the processes of cell growth and division. Increased quantitative expression of HER-2 is observed in approximately 20–30% patients with breast cancer and is associated with a more aggressive course of the disease, which is important to consider when choosing a treatment strategy and prognostic assessments. A scientifically based approach to the treatment of HER-2 positive cancer includes the use of specific targeted therapies, such as trastuzumab, which radically changes outcomes compared to traditional methods.
History of the disease and interesting historical facts
Breast cancer has been known since ancient times. The first mentions of breast diseases can be found in the texts of Ancient Egypt and Greece. However, the specific classification of breast cancer as HER-2 positive began to form only at the end of the 20th century. In the 1980s, scientists first described molecules associated with HER-2 and established their role in the pathogenesis of the disease. The advent of immunohistochemistry methods made it possible to detect and measure HER-2 levels in tumors, which significantly improved diagnostic capabilities. Since 1998, when trastuzumab was approved for the treatment of patients with HER-2 positive breast cancer, a new era in oncology began, opening the door to targeted treatment strategies and increased survival.
Epidemiology
According to statistics, breast cancer is one of the most common cancers among women worldwide. According to WHO, approximately 2.3 million cases of the disease were registered on the planet in 2020. Of these, about 20–30% are HER-2 positive tumors, indicating a global population of more than 400,000 women potentially susceptible to this subtype of cancer. Survival for HER-2 positive cancer significantly depends on the stage of the disease at the time of diagnosis and the treatment strategy. In recent decades, there has been a decrease in the incidence rate, which is associated with the strengthening of screening programs and improvement of treatment methods.
Genetic predisposition to this disease
HER-2 positive breast cancer is associated with mutations and abnormalities in certain genes. The focus is on the ERBB2 gene, which codes for the HER-2 protein. Increased copy number of this gene and its chromosomal abnormalities directly lead to increased signals responsible for cell growth. There are also links to mutations in other genes, such as TP53 and PIK3CA, which may increase the risk of cancer development. Genetic changes in these regions can be identified using molecular profiling of tumors, opening up opportunities for personalized treatment approaches.
Risk factors for the development of this disease
There are both physical and chemical risk factors that contribute to the development of HER-2 positive breast cancer. These include:
- Age: The risk increases with age, especially after 50 years.
- Heredity: Having first-degree relatives diagnosed with breast or ovarian cancer increases the likelihood of developing the disease.
- Obesity: A higher body mass index (BMI) is associated with a greater risk of developing the disease.
- Hormonal factors: Long-term exposure to estrogens and progestins, as in the case of hormone replacement therapy.
- Ethnicity: Some research suggests a higher risk in women from certain ethnic groups.
In addition to the factors listed above, there are also environmental factors, such as exposure to chemical carcinogens, ultraviolet radiation and other lifestyle factors.
Diagnosis of this disease
Diagnosis of HER-2 positive breast cancer involves several steps and methods. The main symptoms to look out for include:
- Formation of nodules or tumors in the mammary gland area.
- Change in the size or shape of the breasts.
- Discharge from the nipples.
- Skin changes on the breast, such as redness or lumpiness.
To confirm the diagnosis, a variety of laboratory and radiological studies are performed, including:
- Mammography and breast ultrasound to visualize changes.
- Breast biopsy for histological analysis.
- Immunochemical test to determine the level of HER-2.
- Molecular analysis to detect specific mutations.
Particular attention is paid to differential diagnosis, since it is necessary to exclude other pathologies of the mammary gland, such as benign tumors and other forms of cancer.
Treatment
Treatment of HER-2 positive breast cancer requires a comprehensive approach and may include:
- Surgery: mastectomy or lumpectomy depending on the stage of the disease.
- Chemotherapy: The use of cytotoxic drugs to kill tumor cells.
- Targeted therapy: trastuzumab and other drugs that specifically target HER-2.
- Radiotherapy: May be used after surgery to reduce the chance of recurrence.
- Hormonal therapy: may be prescribed depending on the status of hormone receptors.
Successful treatment requires a multidisciplinary approach, including oncologists, surgeons, radiologists, pathologists and other specialists to optimize disease management.
List of medications used to treat this disease
The main drugs used to treat HER-2 positive breast cancer include:
- Trastuzumab (Herceptin)
- Pertuzumab (Perjeta)
- Lapatinib (Tykerb)
- Tucotinib (Tukysa)
- Eramutik (Ibrance) and other CDK4/6 inhibitors
These drugs are used depending on the specific clinical case and treatment regimen, which allows achieving higher survival rates.
Disease monitoring
Monitoring of HER-2 positive breast cancer involves regular check-ups and assessment of patients' health after treatment. Key milestones may include:
- Regular visits to the oncologist to evaluate the condition and symptoms.
- Mammography and other imaging tests to check for possible recurrence.
- Laboratory tests to assess possible side effects of treatment.
The prognosis in this case depends on many factors, including the stage at diagnosis, response to treatment, and the presence of concomitant diseases. A certain group of patients has the possibility of relapse or metastasis, which requires a careful approach to examination.
Age-related features of the disease
HER-2 positive breast cancer manifests differently depending on the age group of patients. Women over 50 have a higher risk of developing aggressive forms of the disease, while younger patients often face unique diagnostic and treatment challenges. Younger women also have higher levels of stress and social pressure, which can impact treatment outcomes and quality of life. Follow-up studies are ongoing to better understand and address age-related factors in disease management.
Questions and Answers
- What is the risk of developing HER-2 positive breast cancer? The risk increases with age and if there is a family history of breast cancer, especially if there is a family history of breast cancer.
- How is this cancer diagnosed? It can be diagnosed with mammography, ultrasound, biopsy, and specialized tests for HER-2 levels.
- What are the main treatment methods? Treatment includes surgery, chemotherapy, radiation therapy, and targeted therapy using drugs that target HER-2.
- What is the role of genetic testing? Genetic testing can help identify the presence of specific mutations and select the most appropriate treatment, including targeted drugs.
- What is the prognosis for patients with HER-2 positive cancer? The prognosis depends on the stage at diagnosis, but with proper treatment, the chance of long-term survival increases significantly.
Advice from Dr. Oleg Korzhikov: “When diagnosing HER-2 positive breast cancer, it is extremely important not to waste time. Immediately contact specialists to create an individual treatment plan. Regular examinations and following doctor’s recommendations play a key role in achieving positive results. Remember that modern treatment methods can significantly increase the chances of a full recovery. Also, be sure to pay attention to your psychological state, since the support of loved ones and timely psychological help can significantly improve the quality of life.”
