Can manipulation of a pelvic tumour influence the serum level of cancer antigen 125 and cancer-associated serum antigen?

Cancer antigen 125 (CA 125) and cancer-associated serum antigen (CASA) were measured in 24 women with pelvic masses before and after a gynaecological examination and ultrasonography. CA 125 decreased median 16% after manipulation (P < 0.0001) and CASA decreased median 8% (P = 0.0077). The decline was found in patients with benign tumours as well as in patients with malignant tumours.