Tumor heterogeneity is a very complex subject that has not yet been fully understood.
Breast cancer tumor heterogeneity is relatively common, which refers to the fact that during the growth process of breast tumors, after multiple proliferations, its daughter cells show molecular biological or genetic changes, so that the growth rate, invasion ability, sensitivity to drugs, prognosis and other aspects of the tumor are different.
Intratumoral heterogeneity can be divided into spatial heterogeneity (different areas of the same tumor) and temporal heterogeneity (primary tumors differ from secondary tumors).
Tumor heterogeneity can be divided into two categories: inter-tumor heterogeneity and intratumoral heterogeneity. The former refers to the differences in genes and phenotypes between cells of different tumors, and the latter refers to the differences in genes and phenotypes between different cells of the same tumor. Tumor heterogeneity is commonly referred to as intratumoral heterogeneity.
Academic theories are not easy to understand, so let's use an easy-to-understand example to illustrate them.
For example, a malignant tumor is like a bad potato, which may initially be due to a bug bite, which causes its immune barrier to be disrupted and it is susceptible to foreign infections. Suppose that the initial infection of potatoes is mold, and the mold leads to most of the invasion of potatoes, that is to say, most of the potatoes are the same type of pathogenic bacteria, but with the extension of time and the further decline of potato autoimmunity and other comprehensive factors, one or more other bacteria also take advantage of the weakness, which leads to the existence of disease variability (tumor heterogeneity) in this rotten potato. The bacteria are still there, and the remaining rotten potatoes will show a different type of lesion (pathological type) from the previous one, and it is necessary to take into account the bacterial infection before further ** or consolidation**.
From the above example, it can be seen that tumor heterogeneity is often clinically manifested in the diagnosis of breast cancer, the design of the program, the evaluation of efficacy, and the prognosis. Heterogeneity in pathological diagnosis refers to the fact that a cut breast tumor is sent to the pathology department, and the pathologist may show different pathological immunohistochemical results from different locations of the tumor, that is, there will be different molecular types of breast cancer. Heterogeneity is often manifested in differences in pathologic immunohistochemistry after surgical resection of the lesion after the design of the regimen (e.g., after neoadjuvant chemotherapy) based on the type of immunohistochemistry at the time of initial diagnosis (e.g., after neoadjuvant chemotherapy).
Clinicians need to fully consider the tumor heterogeneity of specific cases, and take into account the different heterogeneous expression types of the same tumor to design the best effect.