ObjectiveGynecologic surgery for benign disease in contrast to oncologic surgery rarely includes significant dissection of the retroperitoneum. Because early ovarian cancer may be found incidentally at the time of benign surgery or during pathologic evaluation without having obtained a preoperative CA-125 value, the purpose of this study was to quantify the change in CA-125 during the current average duration of stay after benign gynecologic surgery.MethodsPreoperative and postoperative (day 2) serum CA-125 values were obtained on women who underwent laparotomy for a benign gynecologic condition.ResultsTwenty-five patients had preoperative and postoperative CA-125 values obtained. An unexpected yet statistically significant decrease in the postoperative CA-125 value was noted (P < 0.05).ConclusionsBenign gynecologic surgery alone results in a decrease in CA-125 in the period 36–48 hours postoperatively. Therefore, in a patient found to have an ovarian malignancy at benign surgery, and therefore not staged, a significantly elevated (> 50 U/mL) postoperative CA-125 value should not be attributed to the operation, but rather should raise suspicion of residual ovarian cancer.