Usefulness of cell surface glycoprotein components as markers in early detection of cancer and in monitoring progress during treatment has been evaluated. Total sialic acid (TSA), lipid bound sialic acid (LSA) and seromucoid fractions (SF) have been compared in the sera of healthy human volunteers and patients at different stages of diagnosis and treatment of leukemia, cancer of breast, cervix, and oral cavity. The levels of TSA, LSA and SF are found to be increased in cancer and is proportionate with malignancy. Their levels show decline in patients who respond well to treatment and show increase in patients with recurrence of cancer even before any clinical evidence of recurrence is available. Changes have also been noted in the glycoprotein fractions and their ratios.