Early detection of recurrence or progression disease in patients with ovarian cancer after primary debulking surgery. Correlation between CT findings and CA 125 levels.

Background: There are no standard approaches for follow up in advanced ovarian cancer (AOC) patients; the aim of this study is to evaluate correlation between computed tomography (CT) and CA 125 levels to assess early detection of recurrence or progression disease (PD).
Methods: We included 76 patients with AOC, who had prior debulking surgery, starting first or second line of chemotherapy and underwent follow-up CT examinations. Evaluation of tumor response to treatment by imaging was assessed using RECIST 1.1. Site of relapse was classified as: abdomen, chest and neck (observed in the upper chest scans).
Results: Change in CA 125 levels was calculated in respect previous evaluation at the end of treatment for each patient. The most suitable cut-offs could be identified in an increase in CA 125 levels >10.5% (sensitivity: 67.9%; specificity: 83.6%; LR+: 4.1; LR-: 0.4) in order to predict PD and in a change of -0.5% in order to exclude PD (sensitivity 83.0%; specificity: 69.6%; LR+: 2.7; LR-: 0.2). Site of relapse was abdomen (58.5%), abdomen and chest (33.9%), chest (3.8%), chest and neck (1.9%), and abdomen, chest and neck (1.9%).
Conclusions: Increase in CA 125 levels >10.5% could be sufficiently predictive of PD requiring CT examination. Change of -0.5% is sufficiently predictive of absence of PD. Increase <10.5% and >0.5% needs clinical correlation to establish correct timing and extension of CT examination. Attention must be played in reducing number and extent of CT examinations to reduce exposure dose.