Tumor Marker – Part 9 – CA 15-3 , CA 27-29 (Cancer Antigen 15-3 and 27-29)

CA 15-3 and CA 27-29 are the markers for breast cancer.
Sample
- Venous blood needed to prepare the serum.
- Citrated plasma can be used.
- < 5 days can be stored at 2 to 8 °C.
- If more than 5 days then store at -20 °C.
Purpose of the test (Indication)
-
These tumor markers are used to monitor the treatment of breast cancer.
Pathophysiology
- This is also known as the cancer antigen breast.
- This is a glycoprotein, 400 KD, and is membrane -enriched breast cancer extract.
- CA 27-29 is a high molecular weight glycoprotein.
- Both CA 15-3 and CA 27-29 are the markers for breast cancer.
- These are not as sensitive as other breast tumor markers.
- The raised level of CA 15-3 indicates advanced breast cancer or bulky tumor.
- Only 50% of the patients show a high level of localized breast cancer or a small tumor.
- But 80% of the patient with metastatic cancer shows a high level of CA 15-3 and 65% has CA 27-29.
- Other causes of the raised level of CA 15-3 and CA 27-29 are:
- Benign breast diseases.
- Cancers of lung, pancreas, ovary, and prostate.
- These markers are good markers for the treatment of metastatic breast cancer.
- Remission will show a decreasing level.
- Persistently raised levels indicate progressive disease.
- CA 15-3 was the first tumor marker of breast cancer.
- These are not used for the screening of breast cancer.
- Most useful following the therapy response in metastatic breast cancers.
Normal
- CA 15-3 = <31 U/mL or <31 k units /L.
- CA 27-29 = <38 U/mL or <38 k units /L.
- In healthy subjects, the upper limit is 25 kU/L.
- 5.5% of the normal subjects.
- 23% of the primary breast disease.
- 69% with metastasis to the liver.
- In healthy subjects, the upper limit is 25 kU/L.
- Source 2
- CA 15-3 = <22 units/mL (<22 kU/L).
- CA 27-29 = <38 units/mL (<38 kU/L).
The raised level is seen in:
- Metastatic breast cancer.
- CA- 15-3 is raised in other malignancies like:
- Pancreatic cancer.
- Colorectal carcinoma.
- Liver.
- The raised level also was seen in benign diseases like;
- liver diseases.
- Benign breast diseases.
- Both CA 15-3 and CA 27-29 not needed to do at the same time. CA 15-3 is enough to perform. Both have the same purpose.
- Other benign and malignant conditions are:
- Lung cancer.
- Cirrhosis.
- Hepatitis.
- Fibrocystic diseases of the breast.
- Diseases of prostate, pancreas, and colon.