In clinical pathology, we often use “tumor cell immunohistochemistry drug resistance prognostic markers”, but many units only write positive results without clinical significance, and the results are not very helpful to clinical practice because many doctors do not know the significance of these results, so it is recommended that when we produce such reports, we print the significance of “tumor cell immunohistochemistry drug resistance prognostic markers” in the report to increase the value of the report. Therefore, it is recommended to print the meaning of “tumor cell immunohistochemistry drug-resistant prognostic markers” in the report to increase the value of pathology report. 1.Immunohistochemical prognostic markers of drug resistance in malignant tumors, a full set of 4 items: P-gp, GSTπ, TOPO II, Ki-67. 2.Immunohistochemical prognostic markers of drug resistance in breast cancer, a full set of 7 items: P-gp, GSTπ, TOPO II, Ki-67, ER, PR, C-erbB-2. 3.Significance: markers – role – positive site – clinical significance P-glycoprotein (P-gp) glycoprotein (P-gp) – drug pump action – cytosolic/cytoplasmic – the higher the positive rate, the greater the resistance to the following drugs: Adriamycin, erythromycin, epi-adriamycin, mitoxantrone, vincristine, vincristine, vincristine, zybinol, tesutil. The higher the rate of glutathione S-transferase (GST π) – detoxification – cytosolic – positivity, the greater the resistance to the following drugs: adriamycin, cisplatin, azacitidine, cyclophosphamide, tumefacin. Topoisomerase II (TOPO II) – target action – cytosolic – the higher the positive rate, the more effective against the following drugs: anthracycline antibiotics and onychotoxins, such as VP-16, teniposide, rosmarinic acid, neomycin, erythromycin, epi-amycin, adriamycin, VM26. high positive rate is particularly effective against VP-16. The higher the rate of estrogen receptor (ER) – sex hormone action – cytosolic – positivity, the more effective the tumor is for endocrine therapy and the better the prognosis. The higher the rate of progesterone receptor (PR) – sex hormone action – cytokinesis – positivity, the more effective the tumor is to endocrine therapy and the better the prognosis. The higher the rate of C-erbB-2 – oncogene product – cytoplasm, the more malignant the tumor is. ER and PR positive but also C-erbB-2 positive, the less effective the treatment with triamcinolone acetonide. The higher the rate of Ki-67, a marker of cell proliferation – the nucleus – the more rapidly the tumor proliferates and the more malignant it is. Ki-67 is a marker of cell proliferation and is expressed in G1, S, G2, and M phases of the cell cycle, but is absent in G0 phase. It is closely related to the degree of differentiation, infiltration, metastasis, and prognosis of many tumors. PCNA (proliferating cell nuclear antigen). CEA is expressed in most adenocarcinomas. Rb (retinoblastoma retinoblastoma) gene is a tumor suppressor gene that regulates the cell cycle. P53 is mutated in immunohistochemistry, and the higher the positive rate, the worse the prognosis. The wild type has a very short half-life. Nm23 is a metastasis suppressor gene, and its positive expression and tumor metastasis are negatively correlated. It has been widely used in the detection of many malignant tumors such as breast cancer, non-small cell lung cancer, gastric cancer, colorectal cancer, liver cancer, and laryngeal cancer. Almost all studies have shown that patients with high nm23 protein expression have a relatively low rate of lymph node metastasis and a relatively long survival period. E-Ca E calcium adhesion protein, a transmembrane glycoprotein that mediates intercellular adhesion and whose loss of function causes disruption of intercellular junctions, is mainly used in studies of tumor invasion and metastasis. PS2 Estrogen-regulated protein, whose expression is related to ER expression, and can be used as one of the indicators for endocrine therapy and prognosis determination. CK18 is a low molecular weight keratin protein that mainly marks various monolayers of epithelium, including glandular epithelium, and is often negative for complex squamous epithelium, and is mainly used for the diagnosis of adenocarcinoma. CK19 is distributed in monolayer epithelium and mesothelium, often used for adenocarcinoma diagnosis, not expressed in hepatocytes, but positive for bile ducts. Hep par 1 hepatocyte antigen, positive for normal hepatocytes and highly differentiated hepatocellular carcinoma, mostly weakly positive or negative for poorly differentiated hepatocellular carcinoma. CK20 is used for the diagnosis of adenocarcinoma of the gastrointestinal tract, mucinous tumors of the ovary, and Merkel cell carcinoma of the skin. Often negative for squamous carcinoma, breast carcinoma, lung carcinoma, endometrial and ovarian non-mucinous tumors. CK7 Ovarian, lung and breast epithelium often positive, colon, prostate, gastrointestinal epithelium negative. Villin Villin, in normal tissues, is usually expressed only on cells with brush border, such as gastrointestinal epithelial cells, pancreatic and biliary epithelial cells, and in epithelial cells of the renal parenchyma (especially proximal tubules). Villin is highly expressed in gastrointestinal, pancreatic, gallbladder, and bile duct cancer tissues. The absence of villin expression on tumors with obvious adenoid structures makes it highly unlikely that the tumor is of gastrointestinal, pancreatic, gallbladder, or bile duct origin. Breast cancer is also often a disease to be differentially excluded in female patients with metastatic cancer of unknown primary site. Because significant villin immunohistochemical positive staining is observed on metastatic tissue, it is highly unlikely that the tumor is of breast origin. Other tumors that usually have negative villin immunohistochemical staining include ovarian plasmacytoma, urothelial migratory cell carcinoma, and prostate cancer. Mesothelioma is also frequently villin-negative, so in some cases villin may also be used as an antibody to differentiate mesothelioma from adenocarcinoma. However, there are also tumors of non-gastrointestinal origin that express villin, such as endometrioid adenocarcinoma, mucinous carcinoma of the ovary, renal cell carcinoma, and a small percentage of lung cancers. Some experts have also reported that villin is expressed in some cases of endocervical adenocarcinoma. Diagnosis of hepatocellular carcinoma: immunohistochemical staining for villin can reveal capillary bile duct structures, so it may also be useful in expressing tubular structures in some hepatocellular carcinomas. Polyclonal CEA is the first reagent used for this purpose and CD10 (CALLA) is also useful in expressing this structure in hepatocellular carcinoma. The expression of polyclonal CEA, villin and CD10(CALLA) on hepatocellular carcinoma cases does not conflict with each other in any way, and therefore it is recommended to use all three antibodies together to assist in the diagnosis of difficult cases if the possibility of hepatocellular carcinoma is suspected. Villin has also been useful in the study of neuroendocrine tumors. Villin is particularly useful in this context because villin expression has been reported in 85% of gastrointestinal carcinoid tumors, but no positive expression has been reported in islet cell tumors. villin expression in carcinoid tumors Villin expression in carcinoid tumors is usually cytosolic positive. In addition, there is some evidence that villin expression is higher in small cell carcinomas of the stomach and lower gastrointestinal tract than in small cell carcinomas of other sites. For example: lung, esophagus, bladder or prostate. It has been reported in the literature that about 40% of pulmonary carcinoid cases are villin positive, and villin is also expressed on some other neuroendocrine tumors, such as medullary thyroid carcinoma and a few Merkel cell tumors.