Tumor growth and spread of
With local infiltration and distant metastasis is the ability of malignant cells specific to the nature. Patients malignancy and is a threat to the health and lives of the main reasons. Therefore, on tumor growth and spread of tumor pathology research has become an important part.

First, the growth of tumor biology

Typical of the natural growth of malignant tumors history can be divided into several stages: the cells into malignant cells cloned into → hyperplasia → → local infiltration distant metastasis. During this process, the malignant cell transformation of the internal characteristics (such as tumor cell doubling time) and the host of tumor cells or the product of the reaction (such as tumor angiogenesis) combined effect of tumor growth and evolution.

1. Tumor growth kinetics of tumor growth depends on three factors:

(1) tumor cell doubling time: the growth of malignant cells into normal cells with the same period, divided into

G0, G1, S, G2 and M phase. The majority of cancer cells by culture is not the time to imagine as a faster than normal cells, but cells with normal cells similar to or longer than normal.

(2) Score growth (growth fraction); Score refers to the growth of tumor cells in the group stage of reproduction (S + G2 phase), the proportion of cells. In the early stages of malignant transformation of cells, the vast majority of cells in a copy, so the high growth scores. However, with the continued growth of the tumor, the tumor cells are constantly dividing, leaving the stage of the cell to copy a growing number enable the majority of tumor cells in G0 phase. Even the rapid growth of the tumor growth of its points in only 20%.

(3) tumor cells and the generation of lost: the progressive tumor growth and its growth rate in its decision to generate greater than the loss of cells. Due to inadequate supply of nutrients, necrosis, as well as the body fell off the anti-tumor response, and other factors, in the process of tumor growth, a considerable portion of the tumor cells lose their vitality. Tumor cells generate and the degree of loss of the combined effect of tumor growth. Growth in the relatively high scores of tumor, the tumor cells to generate much greater than the loss of its growth faster than those cells to generate slightly more than the loss of the tumor much faster.

The dynamics of the concept of tumor cells in the tumor chemotherapy important. At present, almost all of the chemical anti-cancer drugs are targeted at the copy phase of the cell. Therefore, the high growth scores neoplasm (such as high-malignant lymphoma) are particularly sensitive to chemotherapy; common solid tumors (such as colon cancer) growth of low scores, the treatment of a relatively resistant. The clinical treatment of these tumors of the strategy is to use radiation or surgery to reduce the tumor so that the residual tumor cells from the G0 phase copy into the period after chemotherapy.

2. The tumor angiogenesis clinical and animal experiments have shown that in the absence of new blood vessels supply nutrients to reach the tumor in 1 ~ 2mm in diameter or thickness, that is, 107 or so cells will not increase. Therefore induced angiogenesis is the ability to malignant growth, invasion and the transfer of one of the prerequisites. Has now found that the tumor cells themselves and infiltration into tumor tissue in and around the inflammatory cells (mainly macrophages) to produce a class of angiogenic factors (angiogenesis factor), such as fibroblast growth factor (fibroblastic growth factor, FGF), platelet-derived endothelial growth factor (platelet-derived endothelial cell growth factor, PD-ECGF), transforming growth factor-α (transforming growth factor-α, TGF-α), tumor necrosis factor-α (TNF-α), Vascular endothelial growth factor (vascular endothelial growth factor, VEGF), and so on. One of the most characteristic is the role of angiogenesis in tumor cells generated by the FGF, it through its receptor and the combination of target cells. Endothelial cells to increase the chemical tendency to promote vascular endothelial cell division, the sprouting capillary growth, induced by soluble proteins and enzymes will help to generate endothelial cells penetrate the bud matrix functions. In addition, the macrophages produced by TNF-α also promote endothelial cell division and stimulate their migration. The new capillaries for both tumor growth provides nutrition, and to prepare for the transfer of tumor conditions. Therefore, inhibition of tumor angiogenesis research is the study of one of the hot spots.

3. The tumor evolve with the heterogeneity of the growth of malignant tumors in the process of getting rich phenomenon known as the invasive tumor evolution (progression), including growth accelerated infiltration of surrounding tissue and distant metastasis, and so on. These biological phenomena and the emergence of tumor cells in different subcloning invasion, the growth rate, hormone responses to the anti-cancer drug sensitivity in areas such as the difference - the tumor heterogeneity (heterogeneity) related. Have a reason for this phenomenon is in the process of tumor growth, there may be additional mutations (see Section XV) in the role of different tumor cells, making the tumor cells subcloning different characteristics. Such as the need for more growth factor may be the result of subcloning growth factor and not a lack of growth, and some need less of the growth factor to the growth of subcloning at this time; the body of the anti-tumor response can kill those with high antigenicity Subcloning, and the low antigenicity of subcloning can escape the body's immune surveillance. As a result of these choices, the growth of tumors in the course of those reservations can adapt to the survival, growth, invasion and metastasis subcloning. This is the heterogeneity of the tumor.