CA 15-3 is a mucin tumor marker that is found in certain breast carcinomas.
- CA 15-3 is produced by healthy tissues of the liver and breast, but to lesser degrees than typically associated with malignancies.
- At a cut off level of 25 kU/L, CA 15-3 has been found to be elevated in 92% of breast carcinomas.2
- CA 15-3 is also elevated in other malignancies, including the colon, ovaries, and liver.
- CA 15-3 is not recommended as a primary diagnostic tool for primary breast cancer, because the frequency of elevation is low and the specificity falls short of being ideal.
- CA 15-3 is useful in monitoring the effectiveness of therapy.
- CA 15-3 has been used effectively in monitoring disease progression in metastatic breast cancer.8