An increase of serum CA-125 to two times of nadir level strongly predicts the image-identified recurrence of serous ovarian cancer

Abstract

Abstract Using 35 U/ml as CA125 routine abnormal threshold may result in omissions in the recurrence detection of Ovarian cancer (OvCa). This study aimed to clarify the association between a biochemical recurrence (only the elevation of CA125) and an image-identified recurrence to predict the recurrent lesions better. 86 patients were enrolled from women diagnosed with stage I-IV serous ovarian, tubal, and peritoneal cancers from January 2013 to June 2019 at our center. The median CA125 level from 929.9 U/mL at diagnosis reduced to 7.8 U/mL at nadir during follow-up in all patients, and there was no difference between the neoadjuvant chemotherapy (NACT) and primary debulking surgery (PDS) group after initial treatment. Compared to CA125 level exceeding 35 U/ml, the 2×nadir of CA125 improve the sensitivity and the specificity of image-identified relapse (P<0.001); the 2×nadir value can act as an earlier warning relapse signal with a longer median time to image-identified recurrence (2.7 vs. 0 months, P<0.001). Compared with 35 U/ml, CA125 reaching 2×nadir during the follow-up process might be a more sensitive and early recurrence signal in patients with serous OvCa. This criterion may help guide patients to be recommended for imaging examination to detect potential recurrence in time.