Is CT scan monitoring useful in patients with epithelial ovarian cancer and follow-up negative CA 125 serum levels?

We retrospectively reviewed our series of ovarian cancers to assess the benefit of routine follow-up abdominal computer tomography (CT) scans in asymptomatic patients with CA 125 levels <35 U/ml. A chart review was undertaken of all patients with a diagnosis of ovarian cancers treated and followed at the Institute of Obstetrics and Gynecology, University of Ancona, from January 1986 to January 1994. In asymptomatic patients, the routine follow-up consisted of physical examination and CA 125 serum level determination every three to four months for the first two years, and every six months thereafter for a minimum of 5 years. At each visit, a history and a bimanual vaginal examination were completed. The pelvic and abdomen CT scans were performed every six months for the first year and then annually. Inclusion criteria were CA 125 levels >35 U/ml prior to surgery or initial chemotherapy, and complete routine follow-up. Fifty-two patients (75%) satisfied the inclusion criteria. After surgery, 32 of the 52 CA 125 positive patients (61%) showed a decrease in CA 125 levels; 10 other patients showed a negativity of CA 125 after cisplatinum polychemotherapy. After a median time of 49 months (range 16-117 months), 9 of the 42 patients (21%) developed a relapse. The overall CA 125 sensitivity at the time of relapse was 78%, with a specificity of 94%; the sensitivity for early detection of relapses was 70%. Two-hundred and seventy-six abdominal and pelvic CT scans were performed and 8 were positive for tumor relapse, with an overall sensitivity of 89%. The sensitivity of CT scans was 33% for early detection of relapses. The routine performance of follow-up CT scans did not significantly improve the overall detection of early relapses in ovarian carcinoma. A longitudinal monitoring of serum CA 125 is a reliable method of follow-up. Abdominal and pelvic CT scans should be performed in patients who, after a period in which they have been classified as not having evidence of disease with normal CA 125 serum levels, show elevated and rising CA 125, with the aim of finding and characterizing relapses.