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).
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).
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%).
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.