what is.a.CA125 blood test
Subscribe to our Living With Cancer e-newsletter to stay up to date on cancer topics. A CA 125 test measures the amount of the protein CA 125 (cancer antigen 125) in your blood. A CA 125 test may be used to monitor certain cancers during and after treatment.ubscribe to our Living With Cancer e-newsletter to stay up to date on cancer topics. A CA 125 test measures the amount of the protein CA 125 (cancer antigen 125) in your blood. A CA 125 test may be used to monitor certain cancers during and after treatment.