International Medical Journal, Vol. 23., Iss. 2, 2017, P. 65−67.
RELEVANCE THE ISSUES OF BREAST CANCER ETIOLOGY AND PATHOGENESIS
Kharkiv Medical Academy of Postgraduate Education, Ukraine
Every year dry figures of statistics demonstrate the increase in the number of newly diagnosed cases of breast cancer. Search for the mechanisms and risk factors leading to breast cancer is actively conducted by many world laboratories. Epidemiological data are accumulated with a rather high speed, however, and there is no consensus on the causes of this disease. The time period from the first cancer cell to death of the patient after the tumor has reached a critical mass is called −− «the natural history of breast cancer». In this regard, the concept of actual and potential growth rate is distinguished. Average actual doubling time of the primary tumor is 90−110 days. Rapidly growing tumors with doubling time less than 30 days, with moderate growth and doubling time of 90−100 days and slowly growing with a doubling time of 110 days can be identified. The largest percentage of patients with moderate tumor growth approximates 60 %. It is assumed that formation of metastases is a long process starting at the early stages of «natural development of history» and increasing over the time. However, it was further shown that formation of blood vessels in the tumor, angiogenesis, may begin with 100−200 cells well before the clinical onset of the tumor, within the first 20 doublings. Metastasis process is dynamic and continuous from beginning to end. B. Fisher suggested that lymphatic and hematogenous dissemination occurs simultaneously, thus metastases in regional lymph nodes are not the stage of the tumor development, and show the ability of the tumor to metastasize and are a marker of hematogenous tumor dissemination. It is suggested that breast cancer at the stage of clinical evidence is already a systemic disease.
Key words: breast cancer, epidemiology, pathogenesis, oncology.