What is the normal range of ca 15-3 tumor marker?

Tumor marker ca 15-3. Used mainly to monitor breast cancer; normal level (varies from lab to lab) is usually less than 30 units/ml, but levels as high as 100 u/ml have been seen in women without cancer. Also may be elevated in lung & ovarian cancer and in some non-cancerous conditions, like benign breast conditions and hepatitis. [american cancer society].