CA-125
From Wikipedia, the free encyclopedia
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mucin 16, cell surface associated
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| Identifiers | |
| Symbol | MUC16 |
| Alt. Symbols | CA125, FLJ14303 |
| Entrez | 94025 |
| HUGO | 15582 |
| OMIM | 606154 |
| RefSeq | NM_024690 |
| UniProt | Q8WXI7 |
| Other data | |
| Locus | Chr. 19 p13.2 |
CA-125 (cancer antigen 125) also known as mucin 16 or MUC16 is a protein which in humans is encoded by the MUC16 gene.[1][2] MUC16 is a member of the mucin family glycoproteins.[3] CA-125 has found application as a tumor marker or biomarker that may be elevated in the blood of some patients with specific types of cancers.[4]
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[edit] As a biomarker
CA-125 is clinically approved for following the response to treatment and predicting prognosis after treatment. It is especially useful for detecting the recurrence of ovarian cancer. Its potential role for the early detection of ovarian cancer is controversial and has not yet been adopted for widespread screening efforts in asymptomatic women. The key problems in using the CA-125 test as a screening tool are its lack of sensitivity and its inability to detect early stage cancers. An operation would be necessary to confirm that a woman with elevated CA-125 has ovarian cancer, with the associated risk of death from major surgery. In addition, even if cancer was confirmed in such circumstances, it usually would be at an advanced stage where therapy is less effective. The goal of many cancer biologists is to develop a test that would be employed to diagnose ovarian cancer at an early stage, when the effects of therapeutic interventions are optimal.
[edit] Specificity and sensitivity
It is best known as a marker for ovarian cancer,[5] but it may also be elevated in other malignant cancers, including those originating in the endometrium, fallopian tubes, lungs, breast and gastrointestinal tract.[4] CA-125 may also be elevated in a number of relatively benign conditions, such as endometriosis,[6] several diseases of the ovary, and pregnancy.[7] It also tends to be elevated in the presence of any inflammatory condition in the abdominal area, both cancerous and benign.
Thus, CA-125 is not perfectly specific for cancer nor is it perfectly sensitive since not every patient with cancer will have elevated levels of CA-125 in the blood.[8] For example, 79% of all ovarian cancers are positive for CA-125, whereas the remainder do not express this antigen at all.[9]
[edit] Ranges in ovarian cancer
While this test is not generally regarded as useful for large scale screening by the medical community, a high value may be an indication that the woman should receive further diagnostic screening or treatment. Normal values range from 0 to 35 (μg/mL). Elevated levels in post-menopausal women are usually an indication that further screening is necessary. In pre-menopausal women, the test is less reliable as values are often elevated due to a number of non-cancerous causes, and a value above 35 is not necessarily a cause for concern.
[edit] Discovery
CA-125 was initially detected using the monoclonal antibody designated OC125. Dr.'s Robert Bast, Robert Knapp and their research team first isolated this monoclonal antibody in 1981.[10]
[edit] References
- ^ Yin BW, Lloyd KO (July 2001). "Molecular cloning of the CA125 ovarian cancer antigen: identification as a new mucin, MUC16". J. Biol. Chem. 276 (29): 27371–5. doi:. PMID 11369781.
- ^ Yin BW, Dnistrian A, Lloyd KO (April 2002). "Ovarian cancer antigen CA125 is encoded by the MUC16 mucin gene". Int. J. Cancer 98 (5): 737–40. doi:. PMID 11920644.
- ^ Duraisamy S, Ramasamy S, Kharbanda S, Kufe D (May 2006). "Distinct evolution of the human carcinoma-associated transmembrane mucins, MUC1, MUC4 AND MUC16". Gene 373: 28–34. doi:. PMID 16500040.
- ^ a b Bast RC, Xu FJ, Yu YH, Barnhill S, Zhang Z, Mills GB (1998). "CA 125: the past and the future". Int. J. Biol. Markers 13 (4): 179–87. PMID 10228898.
- ^ Osman N, O'Leary N, Mulcahy E, Barrett N, Wallis F, Hickey K, Gupta R (September 2008). "Correlation of serum CA125 with stage, grade and survival of patients with epithelial ovarian cancer at a single centre". Ir Med J 101 (8): 245–7. PMID 18990955.
- ^ Bagan P, Berna P, Assouad J, Hupertan V, Le Pimpec Barthes F, Riquet M (January 2008). "Value of cancer antigen 125 for diagnosis of pleural endometriosis in females with recurrent pneumothorax". Eur. Respir. J. 31 (1): 140–2. doi:. PMID 17804443.
- ^ Sarandakou A, Protonotariou E, Rizos D (2007). "Tumor markers in biological fluids associated with pregnancy". Crit Rev Clin Lab Sci 44 (2): 151–78. doi:. PMID 17364691.
- ^ "Screening Asymptomatic Women for Ovarian Cancer: American College of Preventive Medicine Practice Policy". http://www.acpm.org/ovary.htm. Retrieved on 2007-09-29.
- ^ Rosen DG, Wang L, Atkinson JN, Yu Y, Lu KH, Diamandis EP, Hellstrom I, Mok SC, Liu J, Bast RC (November 2005). "Potential markers that complement expression of CA125 in epithelial ovarian cancer". Gynecol. Oncol. 99 (2): 267–77. doi:. PMID 16061277.
- ^ Bast RC, Feeney M, Lazarus H, Nadler LM, Colvin RB, Knapp RC (November 1981). "Reactivity of a monoclonal antibody with human ovarian carcinoma". J. Clin. Invest. 68 (5): 1331–7. doi:. PMID 7028788.
[edit] External links
- CA-125 blood test urban legend at snopes.com
- MeSH CA-125+Antigen
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