Predictive equation of metastasis in patients with malignant ovarian epithelial tumors with the Ca-125 marker

BACKGROUND: Cancer antigen (CA) 125 (CA-125) is used in ovarian cancer detection and monitoring, whose serum level has a positive correlation with tumor stage. The aim of this study was to obtain a prediction metastasis equation in a group of patients with ovarian cancer based on Ca-125. METHODS: A 2-group comparative observational study was conducted at a single oncologic institution (SOLCA) in Cuenca-Ecuador. All patients who were diagnosed with ovarian cancer between January 1996 and December 2016 were included in the current study. Group 1 (G1) patients with the I and II International Federation of Gynecology and Obstetrics (FIGO) stage and Metastasis Group (MG), with III and IV stage, were subdivided. A logistic regression equation was performed to predict metastasis based on Logarithm of serum Ca-125 levels. RESULTS: We included 85 cases in G1 and 64 patients in MG, with 47.8 ± 15 years (G1) and 57.5 ± 13.6 years (MG) of age (P < 0.001). Mortality in G1 was 2 cases (3.1%) and 53 cases (62.4%) in MG (P < 0.001). The CA-125 serum level was 163.5 ± 236 in G1 and 1220.9 ± 1940 u / ml in MG (P < 0.001). The equation to predict metastasis = (Age*0.053) + [(Logarithm Ca-125 value) * 1.078] − 8.163 with an OR 2.940 (CI 95% 2.046–4.223) P < 0.001. The sensitivity of the equation was 82.4% and the specificity was 79.7%. CONCLUSIONS: It is possible to predict the presence of metastasis in a group of patients with ovarian cancer based on Ca-125. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12885-018-4499-y) contains supplementary material, which is available to authorized users.