To investigate clinical values of serum carcinoembryonic antigen 125 (CA₁₂₅) and plasma fibrinogen (Fib) in differential diagnosis of benign and malignant ovarian tumors.

From January 2015 to June 2017, a total of 367 cases of ovarian tumor patients who were first diagnosed as ovarian tumor and treated in the Department of Gynecology and Obstetrics, Chengdu Second People′s Hospital were selected as research subjects. Among them, 124 cases of malignant ovarian tumor patients were divided into epithelial ovarian cancer group (n=98) and borderline ovarian tumor group (n=26), respectively. And the other 243 patients with benign ovarian tumors were enrolled into control group. A single cohort retrospective study was performed to collect levels of serum CA₁₂₅ and plasma Fib when first diagnosed as ovarian tumor. The serum CA₁₂₅ and plasma Fib levels among the 3 groups of patients were compared by Kruskal-Wallis H rank sum test and one-way ANOVA analysis, respectively. The positive rates of serum CA₁₂₅ and plasma Fib among the 3 groups were compared by chi-square test. Wilcoxon rank sum test or Kruskal-Wallis H rank sum test were used to compare serum CA₁₂₅ levels in 124 cases of malignant ovarian tumor patients with different clinicopathological features. Independent-samples t test or one-way ANOVA analysis were used to compare plasma Fib levels in 124 cases of malignant ovarian tumor patients with different clinicopathological features. To assess the values of serum CA₁₂₅ and plasma Fib levels in differential diagnosis of benign and malignant ovarian tumors by using a contingency table analysis, such as sensitivity, specificity, positive predictive value, and negative predictive value. This study met the requirements of the World Medical Association Declaration of Helsinki revised in 2013. All the patients themselves signed informed consents of the clinical research. There was no statistical difference in the age among the 3 groups (P>0.05).

①Among epithelial ovarian cancer group, borderline ovarian tumor group and control group, the serum CA₁₂₅ levels when first diagnosed as ovarian tumor were 1 410 kU/L (255-1 650 kU/L), 138 kU/L (25-423 kU/L), and 38 kU/L (0-122 kU/L), respectively; the plasma Fib levels were (477.6±148.4) g/L, (372.8±114.1) g/L and (346.9±99.7) g/L, respectively; the positive rates of serum CA₁₂₅ were 86.7% (85/98), 76.9% (20/26) and 40.3% (98/243), respectively; the positive rates of plasma Fib were 81.6% (80/98), 61.5% (16/26), and 23.9% (58/243), respectively. There were statistical differences in the serum CA₁₂₅ and plasma Fib levels and their positive rates among the 3 groups of patients (F=420.511, 44.73, P<0.001; χ²=66.129, 77.051, P<0.001). ②Among 124 cases of patients with malignant ovarian tumors, the serum CA₁₂₅ and plasma Fib levels of patients with advanced stage (stage Ⅲ+ Ⅳ) of malignant ovarian tumor were significantly higher than those of patients with early stage (stage Ⅰ+ Ⅱ) of malignant ovarian tumor according to the International Federation of Gynecology and Obstetrics (FIGO), and both the differences were statistically significant (Z=7.720, P<0.001; t=22.495, P=0.014). There were statistical differences in serum CA₁₂₅ levels among malignant ovarian tumor patients with different histological grades (high, moderate, and poorly differentiated) and histological types (serous, mucinous, endometrioid, and other histological types) (χ²=14.570, P<0.001; χ²=7.882, P=0.004). ③The sensitivities of serum CA₁₂₅, plasma Fib, serum CA₁₂₅ combined with plasma Fib, serum CA₁₂₅ or plasma Fib in differential diagnosis of benign and malignant ovarian tumors were 86.7%, 81.6%, 73.5% and 89.8%, respectively; and the specificities were 59.7%, 76.1%, 54.7% and 79.0%, respectively; the positive predictive values were 46.4%, 58.0%, 39.6% and 63.3%, respectively; the negative predictive values were 91.8%, 91.1%, 83.6% and 95.0%, respectively.

The increasing of plasma Fib level is an important predictor of malignant ovarian tumors. Plasma Fib level combined with serum CA₁₂₅ level has a certain clinical value in the differential diagnosis of benign and malignant ovarian tumors.