Use of CA-125 to define progression of ovarian cancer in patients with persistently elevated levels

Purpose: To determine an accurate definition for progression of ovarian can cer in patients with a persistently elevated serum CA-125. Patients and Methods: A retrospective analysis was performed on 300 patient s with epithelial ovarian carcinoma with at least one measurement of CA-125 . The date of progression according to clinical or radiologic criteria was ascertained in the 88 patients with persistently elevated CA-125 levels (> 23 U/ml.). This was compared with the date of progression according to CA-1 25, defined as the date on which the CA-125 level first increased to greate r than or equal to twice its nadir level, confirmed by,a second sample also greater than or equal to twice the nadir. Results: Eighty of the 88 patients had evidence of progression by both stan dard and CA-125 criteria, giving a sensitivity of 94%. In six of these pati ents, no sample was taken to confirm, CA-125 doubling. In 13 patients, CA-1 25 doubling occurred after the date of clinical progression. Only one patie nt had a. false-positive prediction of progression according to CA-125; the patient died as a result of a myocardial infarct before evidence of clinic al progression. Conclusion: In patients whose CA-125 level decreases to normal after chemot herapy, a doubling from the upper limit of: normal has been shown to predic t progression. In those with persistently elevated levels, doubling of CA-1 25 from its nadir level has now been shown to accurately define progression . If confirmed, these CA-125 criteria should be used as additional end poin ts in clinical trials.