Breast Cancer Marker CA 15-3

October is Breast Cancer Awareness Month.

Take a moment to learn about the tumor marker CA 15-3, which is used to support the treatment response monitoring in breast cancer patients.

Mucin-1 (from gene MUC1) is a large glycoprotein normally expressed on epithelial cells including those in breast tissue. The glycoprotein forms a protective barrier of mucinous gel on the cell surface.

Illustration of a healthy epithelial cell with a branching mucin-1 attached.

Mucin-1 is overexpressed in cancer.
Compared to healthy cells, tumour-related mucin-1 has truncated sugar branches and lacks specific positioning on the cell surface.

In breast cancer, extracellular fragments of mucin-1 break off and shed into circulation.

A cancer cell releasing branched breast cancer mucin-1 proteins, some of which are shown detaching.

The two monoclonal antibodies 115D8 and DF3 recognise mucin-1-related antigen.

The 115D8 and DF3 antibodies are used in a sandwich immunoassay to detect mucin-1-related antigen in serum.

The serum marker CA 15-3 (Cancer Antigen 15-3) is videly used to support monitoring of breast cancer therapy.

Diagram illustrating a sandwich assay where two different antibodies, 115D8 and DF3, recognise mucin-1.

Safe treatment requires reliable data. Quality control is essential for producing reliable test results during treatment response monitoring.

Pink ribbon next to a Seronorm Immunoassay bottle, advertising its use for CA 15-3 quality control in breast cancer monitoring.

Sources:

Nath S, Mukherjee P. MUC1: a multifaceted oncoprotein with a key role in cancer progression. Trends Mol Med. 2014 Jun;20(6):332-42

Li X, Xu Y, Zhang L. Serum CA153 as biomarker for cancer and noncancer diseases. Prog Mol Biol Transl Sci. 2019;162:265-276