Risk of recurrence during follow-up for optimally treated advanced epithelial ovarian cancer (EOC) with a low-level increase of serum CA-125 levels

Background: Our group evaluated the risk of recurrence for optimally treated advanced epithelial ovarian cancer (adEOC) in patients with a low-level rising serum CA-125 concentration within the normal range (0-35 kU/l). In addition, we tested the new proposed early CA-125 signal of progressive disease (EPD) criterion in the same study population. Patients and methods: Patients treated from 1998 to 2006 for adEOC were identified at our institution. Inclusion criteria were as follows: CA-125 at time of diagnosis (> 35 kU/l); International Federation of Gynecology and Obstetrics stages III-IV treated with optimal primary treatment; and complete response (CR) to primary treatment with normalization of CA-125. Results: Median progression-free survival and overall survival for the recurrence group (n = 60) were 17.7 and 38.2 months, respectively. The median follow-up time from CR to last contact was 40.2 months for patients in the nonrecurrence group (n = 36). An absolute increase in serum CA-125 levels of >= 5 kU/l compared with baseline CA-125 nadir values was significantly predictive of recurrence (odds ratio for recurrence = 402.98, P < 0.0001). The progression date was predated by the EPD criterion in 77% of patients with known progressive disease (median, 58 days early) with a sensitivity of 90%, a positive predictive value of 96.4%, and a false-positive rate of 5.6%. Conclusions: Among patients with optimally treated adEOC in complete remission, a low-level increase in serum CA-125 concentration within the normal range is a strong independent predictive factor for disease recurrence. In this patient population, future prospective randomized trials should consider the evaluation of the EPD criterion.