Relation between CA125 levels and second-look operation for ovarian cancer

We investigated the relationship between the serum level of CA125 before a second-look operation (SLO) and SLO findings in 196 patients with adenocarcinoma of the ovary. SLO findings were positive in 38 (19.4%) of 196 patients. The positive rate tended to increase with the clinical stage, but SLO findings were positive even in a patient with stage Ia disease. The pre-SLO serum level of CA125 was positive in 11 patients before SLO, SLO findings were positive in 8 of these 11 patients. The highest diagnostic accuracy (37.9%) for the pre-SLO serum level of CA125 was obtained at a cut-off value of 11 U/ml. Our findings suggest that a positive pre-SLO serum level of CA125 does not necessarily indicate tumor positivity. In addition, we suggest that the cut-off value for prediction of SLO findings should be below 35 U/ml, which is a commonly used cut-off value.