Why is there a sudden rise in CA 153?

Normal breast cells produce a protein known as Cancer Antigen 15-3 (CA 15-3). In case of cancerous breast tumors, the level of CA 15-3 rises along with CA 27.29. CA 15-3 is not responsible for cancer but is considered as a useful tumor marker that allows tracking of cancer progression. Tumor cells shed CA 15-3 which enters the blood stream and can be measured through blood tests.

Elevation of CA 15-3 is observed in less than 50% of women in early stages or localised breast cancer but it shoots up to about 80% in those with metastatic cancer. However, CA 15-3 screening test is not recommended to detect breast cancer because elevated CA 15-3 can also be seen in healthy individuals or those with other forms of cancer, hepatitis, cirrhosis and benign breast disorders.

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