• CA - 125 is a reliable tumor marker associated with epithelial ovarian cancers predominantly non-mucinous cancers. Baseline levels measured prior to therapeutic intervention and followed later by serial periodical measurements will enable the treating doctor to predict outcome of the therapy. It also helps in early discovery of recurrences and relapses. • Tumor Marker levels are usually directly related to the tumor mass and the stage of the cancer. However, it is the rate of change of the tumor marker level which is more important rather than its absolute value. Combined use of CA - 125 and CA - 72.4 increases sensitivity, specificity and predictability of in OVARIAN CANCERS. • It must be emphasized that CA - 125 may also be elevated in PANCREATIC CANCERS, ADENOCARCINOMAS of other organs, certain non - malignant conditions like ENDOMETRIOSIS, LIVER CIRRHOSIS, PANCREATITIS and COLITIS and physiological states such as PREGNANCY and MENSTRUATION. Therefore, CA 125 alone is not sufficient to diagnose the presence or extent of disease. It should be used only as an aid in follow - up studies.