Carbohydrate Antigen 125 (CA 125), Serum analysis is a laboratory test mainly used as a biomarker to evaluate ovarian cancer. CA 125 is a protein produced in higher amounts in tumor conditions, making it an important tool for diagnosing the disease and monitoring its progression. This test is performed by taking a blood sample to measure CA 125 levels. Elevated levels may indicate the presence of ovarian cancer and can also be increased in other medical conditions such as pelvic inflammatory disease or uterine fibroids. This analysis helps physicians assess treatment response and adjust therapy doses, contributing to improved patient care. By monitoring CA 125 levels, disease management can be enhanced and the chances of successful treatment increased, making it a vital tool in supporting physicians in making informed treatment decisions.