What are the Patterns of Tumor Progression?
Hemoblastosis has two stages: monoclonal (benign) and polyclonal – the occurrence of subclones (malignant). However, the change of stages is carried out with an unequal frequency in different forms of hemoblastosis and with an unequal interval. The main feature of hemoblastosis is the inhibition of normal hematopoietic sprouts, in particular, the normal homolog of tumor cells. There is a pattern in the change of differentiated cells that form a tumor in chronic leukemia and lymphocytomas, which characterizes the development of either blast leukemia or hematosarcoma. An immunoglobulin secretion lymphatic or plasma tumor may lose its ability to secretion, which is accompanied by qualitative changes in the behavior of the tumor and usually its blast transformation.
Tumor cells, especially blasts, can lose the enzyme specificity of cytoplasmic inclusions and become morphologically and cytochemically unidentifiable. The shape of the nucleus and cytoplasm of blast cells may undergo abrupt or gradual changes from round to irregular in area.
All extra-cerebral hemoblastosis has the ability to leukemize and metastasize to the bone marrow. Metastases of hemoblastosis outside the blood-forming organs reflect the emergence of a new subclone adapted to this tissue, metastases behave in different organs independently, often they have different sensitivity to cytostatic combinations.
Leukemia can consistently go through different stages of progression, but in certain cases the disease begins with symptoms that are inherent in the final stage: with inhibition of normal hematopoietic sprouts, the appearance of tumor conglomerates of blast cells in different organs or with resistance to conventional cytostatic drugs. Each subsequent stage of the progression is a qualitative change in the cells, and often only some of them.
In the environment of tumor cells, there is a group of elements that are most capable of progression and growth, along with other cells that can grow, metastasize to certain tissues, but do not have the ability to progress. Tumor progression is a qualitative change in the behavior and morphology of tumor cells, resulting from the increased variability of their genetic apparatus, leading to the development of polyclone and the selection of the most autonomous subclones.