Skip to main content

Please note that this is a beta version of our website. Should you encounter any bugs, glitches, lack of functionality or other problems on the website, please let us know immediately so we can rectify these accordingly. Your help in this regard is greatly appreciated! You can email us.

Login to North West London Pathology – consumables service

If you need a new account or you have a query about your order, please telephone the pathology call centre on 0203 313 5353.

If you have forgotten your password you can reset this yourself. Please click here if you have forgotten your password.

Results Line and Enquiries

0203 313 5353

Cancer antigen 15-3 (CA 15-3)

Category Biochemistry >> Oncology
Test background

CA 15-3 is a high molecular weight (300-450 kDa) transmembrane glycoprotein encoded by the MUC1 gene. It is defined by reactivity with 2 monoclonal antibodies, DF3 and 115D8. CA 15-3 is expressed predominantly in breast cancer (raised in 30 % of localised disease, 75 % metastatic), though primary tumours of the lung, colon, pancreas, liver and endometrium may also give rise to elevations of CA 15-3. Elevations of CA 15-3 values have been reported in individuals with non-malignant conditions such as cirrhosis, hepatitis, autoimmune disorders and benign diseases of the ovary and breast. While increasing CA 15-3 can be the earliest sign of metastatic disease in ~70 % patients, there is little evidence showing that early diagnosis of progressive disease positively impacts survival or quality of life.

Clinicial Indications

Breast cancer

Diagnosis: since CA 15-3 may be elevated in normal individuals and benign conditions, and there is a low incidence of CA 15-3 elevation in early stage breast cancer, CA 15-3 should not be used for screening.

Treatment monitoring: when serum CA 15-3 level is elevated it may be used to monitor response to therapy in combination with imaging and clinical examination. For patients with metastatic disease in whom CA 15-3 is being monitored, the marker should be determined prior to each chemotherapy course and at 3 month intervals.

Surveillance: despite the lack of high level evidence, many patients opt to have serial levels of CA 15-3 determined following surgery.

Reference range

<32 kIU/L

Sample & container required SST (gold top) preferred, serum (red top) accepted
Sample volume 0.5mL
Turnaround time 4 days
Notes

Abbott Alinity