Cancer antigen 15-3 (CA 15-3), a protein produced by normal breast cells, is used as a biomarker to monitor cancerous breast tumors. It helps in determining the effectiveness of treatment and disease recurrence. Normal levels of CA 15-3 protein are produced by breast cells, however, increased production is observed in the case of breast cancer. CA 15-3 levels are also elevated in individuals with other cancers or diseases, such as colorectal cancer, lung cancer, cirrhosis, Hepatitis, and Benign Breast Disease. Thyrocare offers this test at a discounted price, along with a free home collection facility.