CA 27.29 is a protein that has its concentration increased in some situations, mainly in the recurrence of breast cancer, being, therefore, considered a tumor marker.
This marker has practically the same characteristics as the marker CA 15.3, however it is more advantageous with regard to the early diagnosis of recurrence and non-response to treatment against breast cancer.
What is it for
The CA 27-29 exam is usually requested by the doctor to monitor patients previously diagnosed with stage II and III breast cancer and who have already started treatment. Thus, this tumor marker is requested to identify breast cancer recurrence and response to treatment early, with 98% specificity and 58% sensitivity.
Despite having good specificity and sensitivity with regard to the identification of recurrence, this marker is not very specific when it comes to the diagnosis of breast cancer, and should be used in conjunction with other tests, such as the measurement of marker CA 15-3, AFP and CEA, and mammography. See which tests detect breast cancer.
How is done
The CA 27-29 exam is done by collecting a small blood sample in a suitable establishment, and the sample must be sent to the laboratory for analysis.
The reference value depends on the analysis methodology, which may vary according to the laboratories, with the normal reference value being less than 38 U / mL.
What can be the changed result
Results above 38 U / mL are usually indicative of breast cancer recurrence or the possibility of metastasis. In addition, it may indicate that there is resistance to treatment, requiring the doctor to re-evaluate the patient in order to establish another therapeutic approach.
The values may also be altered in other types of cancer, such as cancer of the ovary, cervix, kidney, liver and lung, in addition to other benign conditions, such as in endometriosis, presence of cysts in the ovary, benign breast disease, kidney stones and liver disease. Thus, in order for the diagnosis of breast cancer to be possible, the doctor usually requests additional tests, such as mammography and the measurement of the CA 15.3 marker. Learn more about the CA 15.3 exam.
