Cancer Antigen (CA) 27.29

CPT: 86300
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  • CA 27.29 Antigen
  • Truquant BR

Special Instructions

Values obtained with different assay methods should not be used interchangeably in serial testing. It is recommended that only one assay method be used consistently to monitor each patient's course of therapy. This procedure does not provide serial monitoring; it is intended for one-time use only. If serial monitoring is required, please order the serial monitoring test (480293).

Expected Turnaround Time

Within 1 day

Related Documents

Specimen Requirements




1 mL

Minimum Volume

0.3 mL (Note: This volume does not allow for repeat testing.)


Red-top tube or gel-barrier tube


If a red-top tube is used, transfer separated serum to a plastic transport tube.

Storage Instructions


Stability Requirements




5 days


>1 month

Causes for Rejection

Plasma other than EDTA plasma

Test Details


Manage patients with metastatic carcinoma of the breast


For the quantitative determination of CA 27.29 antigen in serum of patients previously treated for stage II or stage III breast cancer. Serial testing for CA 27.29 antigen in patients who are clinically free of disease should be used in conjunction with other clinical methods for the early detection of recurrence.


Immunochemiluminometric assay (ICMA)

Reference Interval

0−38.6 units/mL

Additional Information

CA 27.29 is a highly polymorphic glycoprotein belonging to the mucin family and is the product of the muc-1 gene. It is most useful using serial measurements to monitor both the course of disease and response to therapy because the direct correlation of changing levels of CA 27.29 with clinical status. In patients with known metastases, a reduction in levels of this marker indicates a good response to treatment while increasing levels indicate resistance to therapy and progressive disease and justify further clinical evaluation and regular monitoring. It has also recently been shown that an elevation of CA 27.29 levels above the upper limit of normal in patients with no clinical evidence of disease is an early indicator of recurrence. An elevated serum CA 27.29 level in patients in remission of stage II or III breast cancer provided a positive predictive value of 83.3% for recurrent disease, with an average lead time of 5.3 months before recurrence was clinically established.


Abbate I, Correale M, Musci MD, et al. Monoclonal antibody B27.29 against mucinous breast cancer associated antigen CA 27.29 in breast cancer. Br Cancer Res and Treatment. 1991; 19(2):123.
Chan DW, Beveridge RA, Muss H, et al. Use of Truquant BR radioimmunoassay for early detection of breast cancer recurrence in patients with stage II and stage III disease. J Clin Oncol. 1997 Jun; 15(6):2322-1318. 9196146
Hayes DF, Zurawski VR Jr, Kufe DW. Comparison of circulating CA 15-3 and carcinoembryonic antigen levels in patients with breast cancer. J Clin Oncol. 1986 Oct; 4(10):1542-1550. 2428949
Linsley PS, Brown JP, Magnani JL, Horn D. Monoclonal antibodies reactive with mucin glycoprotein found in sera from breast cancer patients. Cancer Res. 1988 Apr 15; 48(8):2138-2148. 2450646
Reddish MA, Helbrecht N, Almeida A, Madiyalakan R. Epitope mapping of Mab B27.29 within the peptide core of the malignant breast cancer associated mucin antigen coded for by the human MUC 1 gene. J Tumor Marker Oncol. 1992 Jan 1; 7(1):19-27.


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
140293 CA 27.29 17842-6 142134 CA 27.29 U/mL 17842-6

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