Significance of preoperative serum CA-125 levels in the prediction of lymph node metastasis in epithelial ovarian cancer.

OBJECTIVE: To investigate preoperative serum CA-125 levels as a predictive factor for evaluation of lymph node metastasis in epithelial ovarian cancer.

DESIGN: Retrospective study.

SETTING: Medical records at Seoul National University Hospital.

POPULATION: Ninety-nine patients with epithelial ovarian cancer between January 2004 and March 2007.

METHODS: The significance of the preoperative serum CA-125 level for the prediction of lymph node metastasis was determined using the receiver operating characteristic (ROC) curve, McNemar's test and logistic regression analysis. Clinical prognostic factors affecting survival were evaluated using the Kaplan-Meier analysis with the log-rank test and Cox's proportional hazard analysis.

RESULTS: The ROC curve showed the best cut-off value (535 U/mL) of the preoperative serum CA-125 level with regard to sensitivity (70.0%) and specificity (83.1%). Imaging studies combined with the preoperative serum CA-125 level showed the highest sensitivity (90.0%), whereas imaging studies alone showed the highest specificity (89.8%) for the prediction of lymph node metastasis. FIGO stage III-IV, the preoperative serum CA-125 level (> or =535 U/mL) and lymph node involvement on imaging studies were significant factors for the prediction of lymph node metastasis (p<0.05). Suboptimal debulking surgery and lymph node metastasis were poor prognostic factors for progression-free survival and overall survival, respectively (p<0.05).

CONCLUSIONS: The preoperative serum CA-125 level (> or =535 U/mL) may be important for the prediction of lymph node metastasis in patients with epithelial ovarian cancer. Furthermore, it can be helpful in selecting patients who should undergo systemic lymphadenectomy for the detection of hidden lymph node metastasis.