BENEFITS TUMOR MARKER FOR EARLY DETECTION, DIAGNOSIS, TREATMENT RESPONSE AND PROGNOSIS OF MALIGNANCY.
Advancement of science and technology in terms of immunology, bringing progress in early diteksi field of oncology (cancer). Also included in the problem diagnosis, determining prognosis and monitoring of cancer recently much attention is directed to a variety of substances which are supposed to provide clues about the development of malignant tumors and the complications it causes.Identification of the substance is expected to help establish the diagnosis, determine prognosis and predict the course of the disease.
With the development of laboratory technology, particularly developments in biotechnology, is now possible to detect a marker of malignant, not only within the extracellular environment or at the cellular level but also at the molecular level so that the marker for malignant not only used for the above purposes but, in particular markers molecular malignant, are also used to detect residual cancer cells (minimal residual disease, MRD), even in certain circumstances can be used as a predictive factor of malignancy or risk factors.
Because the clinical symptoms of cancer begins with uncontrolled cell growth, cancer as a disease called pathological cells or tissues and organ disease because the cells that grow out of control it can infiltrate the network of organs and interfere with organ function in question. But it is now widely accepted that cancer is caused by the accumulation of abnormalities or mutations of certain genes, because cancer is also called genetic diseases. In addition to causing symptoms that are directly caused by cancer or sebarnya children, the cancer may provide other systemic effects that arise as the body's response to cancer. The symptoms are known as a syndrome that often causes complications paraneoplasia or suffering even worse, because the cancer can also be considered a systemic disease.
Thus, in using and interpreting the results of tumor markers and other clinical laboratory tests for cancer management needs to be understood completely different genetic abnormalities, cell and organ as well as the body's response to cancer.
In general, tumor markers are changes that can be detected and indicate the presence of tumors, especially malignant tumor or cancer.
Serologic tumor markers are defined as products derived from the tumor, where levels of blood is a reflection of tumor mass in the body. At first there was hope, that these products are such a sensitive and specific tests that can be used as a cancer to a particular tumor. In this case the tumor or residif conclusively be determined in a phase of very early, even preclinical. These expectations are not met. Only a few markers so sensitive and specificity that can be used for screening or follow up patients are asymptomatic
The purpose of this paper to be used as reading material, discussion and knowledge about tumor markers for malignancy in the cervix and can be used as the clinical application.
I.1 TUMOR IMMUNOLOGY
It is known that the proliferation and maturation or differentiation of normal cells are tightly regulated by a number of proto-oncogenes that stimulate the growth and variety of anti-oncogenes or suppressor genes (tumor suppressor genes) that inhibit growth.Activation of proto-oncogenes in excess can occur through changes in gene structure, chromosomal translocations, increased expression of genes or mutations in the elements that control gene expression in question. Such mutations are often seen in cells that are actively proliferating. Can be prevented by excessive proliferation of suppressor genes that inhibit growth, but the inactivation of suppressor genes or mutations causing loss of growth suppression function. Amplification of oncogenes and or inactivation of suppressor genes involved in the regulation of cell growth resulting in loss of growth control with the risk of malignant transformation., And showed cell growth properties and other biological properties of the abnormal.
These genetic changes result in a population of cells with the properties of uncontrolled growth, which is characteristic of cancer cells, and have the ability to invade surrounding normal tissue as well as the ability to metastasize and grow in a place far away from the home network. In addition to expressing molecules that determine the malignant nature, cancer cells also often show dysregulation of genes whose products are not directly related to the nature of growth and invasive properties of cells. Genetic dysregulation of which causes changes in the expression of various surface molecules, disruption of transcription and translation of various types of intracellular protein molecules and various substances that are secreted, so that the cells or tumor tissue, which is basically derived from its own network, be it foreign or immunogenic Because the immune system actually which normally should be able to recognize these abnormal cells and destroy them .. Function is a function of the immune system to recognize and destroy protekttif abnormal cells before developing a tumor or killed if the tumor has grown. The role of the immune system is called immune surveillance.
Although the tumor originated from the network itself (self), tumors generally express the antigen recognized by the immune system as foreign antigens. Tumor antigen expression is generally describe the changes in the genetic material from cell transformation, but the molecular mechanisms that generate tumor antigen was mixed.Tumor antigen strangeness is due to mutations and dysregulation of genes that cause produced a new protein (neoantigen) which is never expressed in normal circumstances, or in tumors caused by oncogenic viruses, usually expressed viral proteins.
The grouping of tumor antigen in 4 main categories, namely: tumor antigens encoded by genes with specific expression of tumor (tumor-specific antigens), which occurs due to tumor antigen point mutation; differentiation antigens, and antigens encoded by genes that are expressed on several types of tumors over- . Another grouping is the antigen that can be detected by T lymphocytes and tumor antigen recognized by the antibody.
Several types of molecules on the surface of tumor cells to generate autologous antibody response. In addition, several types of molecules can be recognized by the antibody tumor xenogeneik obtained through immunization of experimental animals of other species with the corresponding antigen. The molecules that do not always have to generate an immune response in patients with tumor in question, but the antibodies that react with the antigen has an important significance for tumor diagnosis and therapy. Tumor antigen is largely expressed by various types of tumors derived from the same cell type, and most also expressed by normal cells or benign tumor cells. Therefore, this tumor antigen called tumor associated antigens. Most of these antigens do not stimulate an immune response in patients as it is the protein itself (self proteins), and although the antibody can bind to the antigen, the antibodies have no protective potential.
Onkofetal antigen was normal circumstances this antigen is only expressed by fetal tissues and is absent in adult tissues. Onkofetal antigens are not immunogenic. Antigen onkofetal long been used to support the diagnosis of certain tumors. Examples onkofetal antigen is carcinoembryonic antigen (CEA) and alpha-fetoprotein.(AFP).
I.2 RELATIONSHIP WITH oncogenesis tumor marker
As described above, in an uncontrolled growth of cells with abnormal cell differentiation generates a population of cells with new properties. Properties of a new population of cells undergoing transformation include the ability to proliferate without the need for external stimulation of cell growth factor (known as autocrine stimulation) and other properties.
New properties which are the cells can express antigens with excessive density, expressing a new antigen (neoantigen) or an unusual phenotype for the type and stage of differentiation of the cells in question. Perhaps also the cells loss of certain functional molecules, suggesting changes in the structure of chromosomes and abnormal DNA content (aneuploidy). Cells have increased proliferative capacity, become more invasive into the surrounding tissue can metastasize even further, losing the ability to apoptosis and others.
Abnormal properties that are then tested are identified and used as a marker or a marker for malignant tumors to support the diagnosis or confirmation of malignancy, determine prognosis and monitor the course of the disease. Most of the changes can be identified outside the cell, eg for substances which are secreted into body fluids so that levels can be measured. In general, levels of that substance in accordance with tumor progression. Much more can be detected in the cell or the cell surface and can be identified both qualitatively and quantitatively different ways. Much of the change in the gene can be identified so that the structure and nature of changes in these genes can be used as a molecular marker of malignant, for early detection, to determine the remaining cancer cells or as a predictive factor of cancer. In general, molecular markers or genetic markers are better able to describe the biological properties of tumors, so it can be used to determine a more precise prognosis.
In general, tumor markers are changes that can be detected and indicate the presence of tumors, especially malignant tumor or cancer Based on the changes that occur in cancer, both of which can be identified extracellular, cellular and molecular, there are differences in terms of tumor markers adopted several years ago to the one used at this time. According to the old definition, the term tumor markers (tumor marker) express a variety of substances secreted by cancer cells or benign cells into the extracellular fluid in response to the presence of cancer. With the development of science and technology laboratory which allows the detection of various substances at the molecular level, the meaning or definition of tumor markers (malignant) at this time is in addition to extracellular substances as above, also includes various components including a variety of genes and molecules associated with the development cancer and is known as a biomarker of malignancy.
Biological tumor markers are substances produced by tumor cells, enter the bloodstream, and can be detected amount / value with pemerikaan. Markers, tumor markers, ideally, have the potential to assist clinicians by giving a signal of disease activity in the absence of clinical manifestations, thus providing a method of screening for preclinical disease, monitor the status of the tumor during treatment, and detect early relapse. Because of advances in monoclonal antibody technology, many tumor markers can now be detected in a few samples of body fluids such as serum, urine, or ascites. Can be used clinically for the tumor marker must have a certain sensitivity and specificity, but it is a problem in clinical use is a marker of tumor specificity. In theory, tumor markers are "ideal" must have several attributes:
• Alert to be made by the tumor and the tumor was not present in healthy individuals or in individuals who have non-neoplastic disorders.
• Alert tumor secreted into the circulation in large quantities so that the levels in serum increased in a state of a relatively small number of cells that are tumor markers will kanker.Kadar seusuai the volume and extent of neoplasia so that levels of the series will accurately reflect the clinical progression of disease and regression to the normal levels will be associated with healing.
CLASSIFICATION OF TUMOR MARKER II.2
A. Serologic tumor markers.
Substance produced by cancer cells or secreted and released by benign cells in response to the presence of cancer is generally a macromolecule or protein with carbohydrate or lipid components that can be classified as an antigen, the levels in the blood or other body fluids can be measured quantitatively. Levels of these substances within certain limits showed a correlation with growth tumor.12 Until now many types of substances are known to be associated with serologic tumor (tumor associated antigens), and used in clinics are often classified into several groups according to their nature or function. Because of the many types of tumor markers exist, then in its application in clinical serologic tumor markers are classified in several categories, namely:
A. Marker for patient response (host response marker)
Marker for patient response is generally associated with the presence of inflammation, either in response to the presence of the tumor itself, in response to the destruction of normal tissue due to invasion kankler and response to infection associated with cancer.Tumor markers are frequently used in the clinic is alkaline phosphatase, γ GT, CRP, α2-makroglobulin etc.
2. Indication of growth and destruction of cells (cell turnover marker)
Cell turnover marker that has long been the LDH, placental alkaline phosphatase and acid sialat (scialic acid). Some of which is a product of cells undergoing destruction, such as cytokeratin CK8, CK18, and CK19 or Cyfra21.1. are often released into the serum or body fluids due to decomposition of the network.
3. Marker of proliferation (proliferation marker)
Describe the intensity of the proliferation marker of cell proliferation, ie the number of new cells produced per unit time. Proliferation markers released by cells that are actively dividing and is an indicator of cancer growth activities. Some examples of this class of tumor markers are Ki67, PCNA (proliferating cell nuclear antigen) and TPS (tissue polypeptide specific antigen). Expression of these antigens showed good correlation with DNA synthesis, which can be used as an index of cell proliferation.
4 Alert differentiation (differentiation marker)
Differentiation markers are substances produced by certain cells or tissues, including the various types of proteins, enzymes, isoenzymes and hormones. Tumors derived from cells producing the substance in question is usually in excess, although in some cases there are exceptions. The most important role of measurement is to determine the levels of differentiation markers asalusul primary tumor or tumor type in patients with metastatic asalusul primary tumor is not clear. Some of which have long been the PSA (prostate specific antigen) that is used to detect prostate cancer, β-HCG (human choriogonadotropin) used to monitor patients after hydatidiform mole and choriocarcinoma and early detection of other germ cell tumor. Other proteins that are widely used AFP (alfafetoprotein) is onkofetal protein, which until now regarded as a relatively specific tumor marker for liver cancer, CA15.3 and MUC-1 for breast cancer, SCC (squamous cell carcinoma antigen) for cervical cancer and other cancers derived from squamous cells, CA125 for ovarian cancer CA19.9 for pancreatic cancer and colorectal cancer, and CEA (carcinoembryonic antigen) for the type of cancer originating from embryonic tissue. Recent developments reveal that different types of cytokines and soluble receptors that can also be used as tumor markers, such as IL-2 and SIL-2R, IL-6 and SIL-6R, TNF-α and several other types of cytokines. As with other serological tumor markers, the dynamic changes in serum cytokine levels are also in accordance with the progression and regression of tumors.
B. Tumor markers Mobile
Although no morphological markers present only in cancer cells and absent in normal cells, there are some traits that are common in malignant cell populations. Cells that are transformed into biologically malignant transformation and usually it resulted in changes in the nature and function of living. Biological transformation can be identified as a change in the structure of the various cellular components and or changes in the nature and pace of growth, and these are things that are identified as markers of malignancy / tumor cell marker.
Another classification of tumor markers based on:
A. Products produced by the tumor cells themselves (tumor - derived product). Onkofetal form of antigen, consisting of the compounds produced by embryonic cells and tumor cells. These compounds are also produced by normal cells are "undifferentiated" but in very small quantities. And levels of these compounds will increase significantly in patients with cancer.Example: - carcinoembryonic antigen (CEA) - Alpha - fetoprotein (AFP)
2. Products that accompany the process of malignancy (tumor - associated product).
This product is secondary compounds formed as a result of the malignancy, and the levels will also be increased significantly in patients cancer.
- Carbohydrate antigen 19-9 (CA 19-9)
- Cancer Antigen 125 (CA 125)
- B2 microglobulin
VALUE "CUT - OFF values"
The determination limit (Cut - Off) on the use of tumor markers, either for ujisaring diagnosis, prognosis and therapy monitoring greatly affect the interpretation of test results. Because the determination of cut-off will determine the sensitivity and specificity of diagnosis that we kehendaki.Sebagai example if we use a cut-off value of 35 U / ml in the examination of CA 125 for ovarian cancer (35 U / ml = average normal woman + 3 SD) . Elevated levels above 35 U / ml will be seen in 82% of patients with ovarian cancer, 1% in normal women and 6% in non-malignant disease.
Other Classification of Tumors Alert
• Antigen Fetus
• Antigen Network
• Antigen Fetus
• Antigen Network
III.1 Alfafetoprotein (AFP)
Onkofetal proteins expressed during fetal development and by various tumors. Alfafetoprotein (AFP) is the first of these proteins are widely studied. AFP was isolated in 1956 and was associated with malignancy in 1963. AFP is a serum protein is predominant in the fetus and is made in the egg yolks, liver, and gastrointestinal tract. AFP is a glikoprotain, had a 30% homologous to albumin, and have the same molecular weight (69,000). Circulating AFP levels are very low in adults, except in pregnancy when the flood of the fetal circulation that causes a significant increase. AFP serves as a useful marker for liver cancer, testicular cancer, and tumor-specific germ cell tumors of the ovary. AFP is also elevated in benign liver diseases and in a small percentage of the lung and gastrointestinal cancers.
AFP can help diagnose and guide treatment of liver cancer (hepatocellular carcinoma). Normal AFP levels are usually less than 10 ng / mL (nanograms per milliliter). (Nanogram is one billionth of a gram.) AFP levels are elevated in most patients with liver cancer.AFP is also elevated in acute and chronic hepatitis, but rarely gets above 100 ng / mL in this disease.
In a person with a liver tumor, AFP levels above a certain value can mean that people who have liver cancer. In people without heart problems, that value was 400 ng / mL. But in people with chronic hepatitis who have liver tumors, AFP levels over 4,000 ng / mL sign of liver cancer.
AFP is also useful in following response to treatment for liver cancer. If the cancer is completely removed by surgery, the AFP should be down to normal. If the level goes back up again, it often means that the cancer had returned.
AFP was also higher in certain germ cell tumors, such as some cancer testis (embryonal cells that contain and what kind of endodermal sinus), a specific rare type of ovarian cancer (yolk sac tumor or mixed germ cell cancer), and germ cell tumor that starts in the chest ( mediastinal germ cell tumor). AFP is used to monitor response to treatment, because high levels have come down with a successful treatment. If the cancer has gone to treatment should be back to normal levels. After that, any increase may be a sign that the cancer had returned.
III.2 Karsinoembrionik Antigen (CEA)
Onkofetal other tumor markers, namely karsinoembrionik antigen (CEA), was first identified in 1965 in patients with colon adenocarcinoma patients. Furthermore, CEA is found overexpressed in colon, liver, and pancreas of the fetus. CEA is a cell surface membrane glycoprotein with a molecular weight of 200,000. increased serum CEA levels in patients with colon and pancreatic cancer but can also be elevated in benign gastrointestinal disorders and in smokers. Tissue CEA expression could be shown in many gynecological malignancy imunohistokimiawi but serum levels vary widely. As a consequence of the absence of correlation between tumor volume and serum levels, CEA did not prove to be a useful screening tool. However, in individual patients, CEA can be a sensitive marker. Increased levels of CEA after initial remission is highly indicative for tumor recurrence and may result in premature institutionalization for secondary treatment. However, for kanker2 such as colon carcinoma that does not have an effective salvage therapy, early knowledge of recurrence can not improve life expectancy.
CEA is not used to diagnose or screen for colorectal cancer, but it is the preferred tumor markers to help predict the outlook for patients with colorectal cancer. The normal range of blood levels vary from lab to lab, but a higher level of 3 ng / mL (nanograms per milliliter) is not normal. The higher the level of CEA in colorectal cancer when detected, the greater the likelihood that the cancer is advanced.
CEA is also a standard marker used to follow patients with colorectal cancer during and after treatment. In this way the level of CEA is used to see if the cancer responds to treatment or to see if he has come back (recur) after treatment.
CEA can be used for lung and breast cancer. These markers can be high in several other cancers, as well as thyroid, liver stomach pancreas, prostate, ovary, cervix, and bladder cancer. If a high CEA level at diagnosis, can be used to follow response to treatment.CEA can also be elevated in some non-cancerous diseases such as hepatitis, COPD, colitis, and pancreatitis, and in healthy smokers.
HORMONAL tumor marker
Belonging to the hormonal tumor markers are:
A. Human Chorionic Gonadotropin
2. Urinary gonadotropin fragment
3. Human Placental Lactogen
IV.1 Human Chorionic Gonadotropin (hCG)
Placental syncytiotrophoblast secrete a glycoprotein heterodimer with a molecular weight of 36 700. Glycosylated peptides act to stabilize the spine and extend molecule lifetimes in the serum. hCG has a structural and functional similarities with the LH (luteinizing hormone). Both of these hormones have a different segment of the beta and alpha subunits are identical. Thus, the assay for hCG usually using monoclonal antibodies specific for beta subunits to avoid cross-reactivity with LH. In the absence of pregnancy, serum hCG levels at wanita2 who did not have cancer in the range of assay sensitivity in most. HCG is the most common applications in gynecologic oncology is in diagnosing and management of gestational trophoblastic disease (GTD). This marker is also elevated in approximately 70% of non-seminomatous testicular cancer and occasionally in benign gastrointestinal disease. In addition, ectopic production of hCG by a small number of cancers arising from cells that normally do not produce this hormone will occur. Any increase in this marker in the absence of a warning of pregnancy follow-up to rule out malignancy.
IV.2 Human placental lactogen (hPL)
A placental hormone with laktogenik activity and growth hormone-like, human placental lactogen (hPL), is a small polypeptide with a molecular weight of 22 279. HPL has a 94% homologous to the sequence of growth hormone and 67% homologous to prolactin.This hormone is produced by the cells of the syncytiotrophoblast and intermediate trophoblast cells. Its main use in gynecologic oncology is to monitor the GTD, PSTT particular variant (placental-site trophoblastic tumor). A small number of non-trophoblastic tumors secrete this HPL.
Various estrogens, progestins, and androgens can be secreted by ovarian stromal tumors. Steroid2 can also be released if the adrenal tumor differentiation simulating adrenal cortex. In addition, in some cases of ovarian stromal hyperplasia may accompany epithelial ovarian tumors, which resulted in increased stromal steroidogenesis. Due to significant levels of steroid hormones are mostly in good health, caused by a tumor perubahan2 rarely serve as a reliable marker.
This hormone is a heterodimer glycoprotein produced by ovarian granulosa cells. Is the primary physiological function of inhibin suppress FSH release by the pituitary. This hormone is owned by the TGF-β super family of protein2 that modulate growth. Elevated levels of inhibin seen in the majority of granulosa cell tumor and serial levels have been useful in monitoring disease status.
NETWORK ANTIGEN tumor marker
Which include tumor marker antigen class network include:
A. Ca 125
2. Ca 72-4
3. Ca 19-9
4. Ca 54/61
5. Ca 15-3
6. Sialat acid-related lipid
7. Sialyl - Mr.
8. Trypsin Inhibitor Tumor Assosiated
9. Follikel Regulatory Protein (FRP)
10. Macrophage Colony Stimulating Factor (M-CSF)
12. Tissue polypeptide antigen
14. Serum antigens associated with cancer
15. Ovarian serum antigen
16. Immunosupresive assidic Protein (IAP)
17. Interleukiin 2 receptor
19. Squamous cell carcinoma antigen (SCC)
20. Papilloma virus capsid
Is a cell surface glycoprotein of high molecular weight of more than 1000 kDa. Unlike many cell surface glycoprotein tumor marker for other, CA-125 is not considered to be a season because of carbohydrates (24%) less than 50%. Normal physiological function is unknown, but is released from the cell surface and has been detected in amniotic fluid, cervical mucus, endometrial gland lumina, semen, bronchial secretions, peritoneal fluid and serum of apparently healthy individu2. In adults, the CA-125 found on the surface of cells that line the fallopian tubes, endometrium, endocervix, peritoneum, pleura, pericardium, and bronchi. In the normal ovary Ca 125 is only rarely found., Although the antigen is sometimes found in the ovaries of inclusion cysts, benign papillary excretion, when the epithelium had metaplasia tubal.CA-125 is a fairly specific marker for ovarian cancer. Increased serum levels have been found in most patients with metastatic endometrial, fallopian tubes, endoservik, and pankretik carcinoma, and also in some patients with breast cancer, lung and colon. The highest incidence of increased CA-125 in non-gynecologic cancers seen in pancreatic cancer (60%). Consequently, CA-125 is not useful to determine the origin of primary adenocarcinoma in which the place is not visible.
Tumor marker CA 125 is the standard used to control women during or after treatment for epithelial ovarian cancer (the most common type of ovarian cancer). Normal blood levels are usually less than 35 U / ml (units / milliliter). More than 90% of women had levels of CA 125 when the cancer is advanced. If the CA-125 levels increased at the time of diagnosis, changes in CA 125 levels can be used during treatment to get an idea of how well it works.
This value is also increased in about half of women whose cancer has not spread beyond the ovary. This is why the CA 125 has been studied as a screening test. The problem with using it as a screening test is that it's still going to lose a lot of early cancers and other problems other than ovarian cancer can lead to an increase in CA 125 levels. For example, is often higher in women with uterine fibroids or endometriosis (having uterine cells in abnormal locations). It may also be higher in men and women with lung, pancreatic, breast, and colon cancer, and in people who have had cancer in the past. Because ovarian cancer is a disease that is rare, a rising CA 125 levels were more likely to be caused by something other than ovarian cancer.
V.2-CA 72-4 (TAG -72)
That recognize this antigen is a monoclonal antibody B72.3.Glycoprotein associated with the tumor (TAG-72) is found in most ovarian cancer. TAG-72 has been shown to be expressed by most types of adenocarcinoma, especially tipe2 of the gastrointestinal tract. Antigen has been studied extensively as a marker for ovarian cancer, especially as a tool to distinguish benign abnormalities from malignant disorders. Normal secretory endometrium and endometriotic lesi2 also been shown to express the amount of TAG-72 is significant.
CA-19-9 increased in serum from 29% to 48% wanita2 ovarian cancer patients. Some of these women do not experience an increase in CA-125. CA-19-9 can be useful in monitoring of patients with mucinous tumors. A small proportion of patients with cervical or endometrial cancer also have increased levels of CA-19-9nya.
CA 19-9 test was first developed for the detection of colorectal cancer, but more often used in patients with pancreatic cancer. In the very early disease levels are often normal, so it is not good as a screening test. However, it is the best tumor marker for detecting patients with pancreatic cancer.
Normal limit of CA 19-9 in the blood are below 37 U / mL (units / milliliter). A high level of CA 19-9 in patients with newly diagnosed usually means the disease is advanced.
CA 19-9 can also be used to detect colorectal cancer, but the CEA test is preferred for this type of colorectal cancer.
CA 19-9 can also be elevated in other forms of digestive tract cancers, especially cancers of the stomach and bile ducts, and in some non-cancerous conditions such as thyroid disease, inflammatory bowel disease, and pancreatitis (inflammation of the pancreas).
V.4 CA 15-3
CA 15-3 is mainly used to see patients with breast cancer.Hypertension was found less than 10% of patients with early disease and in approximately 70% of patients with advanced disease. Its value is usually dropped if treatment is working, but they can ride in the first few weeks after treatment began. This increase is caused when the cancer cells die spilling its contents into the bloodstream.
The normal level is usually less than 30 U / mL (units / milliliter), depending on the lab. But rates as high as 100 U / mL can sometimes be seen in women who do not have cancer. Levels of these markers may also be higher in other cancers such as lung and ovary, and in some non-cancerous conditions, such as benign breast conditions, and hepatitis.
Tumor marker enzymes
Which is a tumor marker enzymes are:
• PSA (Prostate specific antigen)
• PAP (Prostate Acid Phosphate)
• Prostate-specific membrane antigen (PSMA)
• NSE (neuron specific enolase)
VI.1 Prostate-specific antigen (PSA)
PSA is a tumor marker for prostate cancer. This is the only marker used to screen for common types of cancer, but most medical groups do not recommend using on a regular basis to screen all men (not recommending that people make decisions for themselves about the test). PSA is a protein made by prostate gland cells, which are found only in men. The prostate gland makes a fluid in semen.
PSA levels in the blood can be elevated in prostate cancer, but PSA levels can be affected by other things as well. Men with benign prostatic hyperplasia (BPH), non-growth of prostate cancer, often have a higher level. PSA levels also tend to be higher in older men and those with a prostate infection or inflammation. It can also be increased for a day or two after ejaculation.
PSA is measured in nanograms per milliliter (ng / mL). Most doctors feel that the blood level of PSA below 4 ng / mL probably means no cancer. Levels greater than 10 ng / mL means the possibility of cancer. The area between 4 and 10 is a gray zone.Men with PSA levels in the range boundary has approximately 1 in 4 chance of having prostate cancer. A doctor may recommend a prostate biopsy (a sample of prostate tissue to look for cancer) for a man with a PSA level above 4 ng / mL.
Not all doctors agree with the cutoff points. This is because some men with prostate cancer do not have a high PSA level, while some others with high levels of boundary or will not have cancer.
Some doctors believe it is more useful to follow the PSA levels over time due to the increase from one year to the next may mean prostate cancer is more likely. This is called PSA velocity. Most doctors believe that PSA levels should be measured at least 3 times for at least 18 months to get an accurate PSA velocity. Even then, it's not clear if the measure PSA velocity is more rewarding than seeing each PSA level alone.
Doctors also look at the level of PSA in other ways to see if it might be more useful.
A helpful test when values of PSA in the range boundary (between 4 and 10 ng / mL) is to measure the free PSA (or percent free PSA).PSA in the blood in 2 forms - some are bound to the protein and some are free. Percent free PSA (fPSA) is the ratio of how much PSA circulates free compared with total PSA levels. Because the amount of free PSA rises, the less likely it is that there is prostate cancer. When PSA is free to make more than 25% of total PSA, prostate cancer is unlikely. If the free PSA is below 10%, possibly much higher prostate cancer and biopsy should be performed.(Total High PSA levels with low levels of free PSA was associated with a higher chance of having prostate cancer.)
The PSA test is valuable in monitoring response to treatment and follow-up of men with prostate cancer. For those who have been treated with surgery intended to cure disease, PSA should fall to undetectable levels. They were treated with radiation therapy should also have a PSA decrease after treatment (although it does not disappear entirely). The increase in PSA levels may be a sign of the cancer coming back.
Prostatic acid phosphatase VI.2 (PAP)
PAP (not to be confused with the Pap test for women) is a test for prostate cancer. It was used before the PSA test was developed but is rarely used now because the PSA test is better. It can also be used to help diagnose multiple myeloma and lung cancer.
VI.3 membrane Prostate-specific antigen (PSMA)
PSMA is a substance found in all cells of the prostate. Blood levels increased with age and with prostate cancer. PSMA is a highly sensitive marker, but so far has not proven to be better than PSA.Its use in the search or follow the cancer is still being studied. Use today is limited to a part of the nuclear scan (a type of imaging test) to look for the spread of prostate cancer in the body. Several potential treatment for prostate cancer immunotherapy based on PSMA is now under study.
VI.4 Neuron - The specific enolase (NSE)
As Chromogranin A, a marker for neuroendocrine tumors such as small cell lung cancer, neuroblastoma, and carcinoid tumor. Not used to skreening but especially useful for patients with small cell lung cancer or neuroblastomoa. Abnormal levels of NSE more than 9 ug / mL.
B2M levels will increase in multiple myeloma, chronic lymphocytic leukemia (CLL) and some lymphomas. Normal levels of less than 2.5 ug / mL. Patients with high B2M levels indicate poor prognosis.
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