Problems of metastasis (literature review)

Despite significant successes in the development of medical sciences, the study of oncopathology issues still occupies a leading place due to the identification of a large number of advanced cases of the disease. Firstly, this may be due to the rapid growth of a malignant tumor, for example, against the background of immunodeficiency. Secondly, with late treatment of patients, when they already have distant metastases. The success of treatment of any oncological process primarily depends on the timing of the diagnosis: the earlier the tumor is diagnosed, the greater the chance of a positive outcome and an increase in the life expectancy of the cancer patient. The most formidable complication of oncopathology and the main cause of death from it is metastasis, which often reduces to zero all the effects of therapy. Metastasis remains a mystery today. So, despite the large number of various theories, the question of the spread of the tumor throughout the body has not yet been resolved. There is no definite answer to the question: do metastases metastasize? The mechanisms of the influence of hormones on the processes of metastasis have not been fully studied. Difficulties in diagnosis are associated with the lack of clinical manifestations before the appearance of metastases, the inability to track and compare changes in tissues and organs in vivo, the non-specificity of the results of available research methods, and the lack of control of the spread of metastases throughout the body. Experimental studies on laboratory animals can provide answers to these and many other questions. In a review of the literature, a study of the main issues of metastasis is conducted.