Rising serum CA-125 levels within the normal range is strongly associated recurrence risk and survival of ovarian cancer

Abstract Background: In clinical practice alterations in CA125 concentration within normal range in patients with ovarian cancer after first-line treatment are common. Even minor increase in CA125 concentration is associated with patients’ anxiety and difficult interpretation and counselling for clinicians. The aim of this study was to evaluate the significance of CA125 fluctuations within reference level in patients who suffered from ovarian cancer with complete response after first-line treatment.Results: 168 patients with epithelial ovarian cancer, who achieved complete remission after first line treatment were enrolled in the study. CA125 concentration assessment was carried out during follow up visits. The recurrence of the disease was diagnosed on the first appearance of symptoms: clinical, radiological or histopathological/cytological. PFS and 5-year survival rate was calculated with Kaplan-Meier plots. Statistical analysis was performed with SAS / STAT® 9.4 / 14.4, SAS Institute Inc., Cary, NC, USA, 2017. Median concentration of CA125 after first-line therapy was 10 U/ml. Increasing CA125 concentration by > 5U/ml, 3 and 6 months after the treatment was associated with higher risk of relapse (HR=7.6, p<0.0001 and HR=5.29, p<0.0001 respectively). 5-year survival rate was significantly lower in patients with increased CA125 by 5 U/ml, 3 and 6 months after therapy (56.79% vs 0% and 50.62% vs 15.55%).Conclusions: Increased concentration of CA125 by > 5 U/ml within normal range, 3 and 6 months after treatment was unfavorable prognostic factor in ovarian cancer patients with complete response to primary therapy.