what exactly does Ca15-3 measure and should it show response to chemo?

[Lani]

1: BMC Cancer. 2006 Sep 5;6(1):220 [Epub ahead of print] Links
CA 15-3 is predictive of response and disease recurrence following treatment in locally advanced breast cancer.

Al-Azawi D,
Kelly G,
Myers E,
McDermott EW,
Hill AD.
ABSTRACT: BACKGROUND: Primary chemotherapy (PC) is used for down-staging locally advanced breast cancer (LABC). CA 15-3 measures the protein product of the MUC1 gene and is the most widely used serum marker in breast cancer. METHODS: We retrospectively investigated the role of CA 15-3 in conjunction with other clinico-pathological variables as a predictor of response and time to disease recurrence following treatment in LABC. Pre and post primary chemotherapy serum concentrations of CA 15-3 together with other variables were reviewed and related to four outcomes following primary chemotherapy (clinical response, pathological response, time to recurrence and time to progression). Persistently elevated CA 15-3 after PC was considered as consecutively high levels above the cut off point during and after PC. RESULTS: 73 patients were included in this study. Patients received PC (AC or AC-T regimen) for locally advanced breast cancer. 54 patients underwent surgery. The median follow up was 790 days. Patients with high concentrations of CA 15-3 before PC treatment had a poor clinical (p=0.013) and pathological (p=0.044) response. Together with Her-2/neu expression (p= 0.009) and tumour lympho-vascular space invasion (LVI) (p= 0.001), a persistently elevated CA 15-3 post PC (p=0.007) was an independent predictive factor of recurrence following treatment in LABC. CONCLUSIONS: Elevated CA 15-3 level is predictive of a poor response to chemotherapy. In addition, persistently elevated CA 15-3 levels post chemotherapy in conjunction with lympho-vascular invasion and HER2 status predict a reduced disease free survival following treatment in locally advanced breast cancer.
PMID: 16953875 [PubMed - as supplied by publisher]