The serum markers CA125, CASA and TPS were compared, with particular reference to the clinical applications of these tumor markers in the management of patients with ovarian cancer (discrimination of benign and malignant disease; indicating prognosis; predicting preclinical recurrence), (i) Using recommended cut-off points, CASA (4 U ml-1 and TPS (80 U l-1 showed similar sensitivities in ovarian carcinoma (56% and 57% respectively), though these were lower than with CA125 (85% 35 U ml-1). The combined use of CA125 with either CASA or TPS at higher cut-off points excluding benign disease (CA125> 345 U ml-1; CASA> 6 U ml-1; TPS> 359 U l-1) improved the discrimination of ovarian cancer from benign adnexal masses (100% positive predictive value with 65% of ovarian cancers detected with CA125-CASA, 61% with CA125-TPS vs 46% with CA125 alone). The combined preoperative use of these markers may therefore assist the general gynecologist in avoiding potentially difficult oncologic surgery. (ii) TPS was the best preoperative indicator of prognosis, possibly due to its association with cell proliferation, while CASA was superior as a postoperative prechemotherapeutic prognostic indicator, possibly due to it being a more accurate indicator of residual disease than the other markers, or the surgeons' assessment. Similarly, CASA gave the best differentiation of patients with minimal residual disease (<1 cm) into those with a good or poor prognosis, (iii) CA125 and CASA each detected preclinical recurrence after surgery and adjuvant therapy in seven of 11 patients (mean lead times 4.6 and 3.1 months respectively) while TPS detected four of these patients (mean lead time 2.4 months). The combined use of CA125 with either assay led to the preclinical detection of eight of 11 patients, with the mean lead time increased to 5.3 months with the CA125-CASA combination. [ABSTRACT FROM AUTHOR]