The relevance of rising CA-125 levels within the normal range in predicting recurrence in patients with advanced stage ovarian cancer: A validation study

Abstract

e16521 Background: Small published series suggested that three progressively rising CA-125 values, doubling of CA-125, and an absolute rise of 5 U/mL from the nadir, all while remaining in the normal range were highly associated with disease recurrence. This study aims to validate these proposed criteria in a larger population. Methods: We conducted a retrospective review of the records of patients with stages IIIC and IV epithelial ovarian cancer treated with primary surgery and adjuvant chemotherapy between 1994 and 2006. Only patients who had a complete response to chemotherapy verified by normal CT scan, CA-125 and physical examination were included. Nadir CA-125 level was defined as the first CA-125 measurement after completing chemotherapy. Available CA-125 values from diagnosis to recurrence or to last follow up were collected and evaluated for meeting any of the criteria above. Results: 91 patients with a median age of 59 (42 - 88) met the inclusion criteria. 82 patients had stage IIIC (90%) and 9 patients (10%) had stage IV. 86 patients (94.5%) had papillary serous histology and 88 patients had grade 3 (96.7%) disease. Median follow up was 43.7 months (12.6 - 156). Table 1 shows the number of patients who met any of the above CA-125 criteria in total and divided by the presence or absence of recurrence. There was no statistically significant difference in meeting any of the CA-125 criteria between the recurrence and no recurrence groups. Meeting at least one of the CA-125 criteria had 50% sensitivity, 65% specificity, and 86% positive predictive value for recurrence. The median time to recurrence in patients who met at least one CA-125 criteria was 3.8 months (0.2 - 12.4) and the median follow up time after meeting one of the CA 125 criteria in patients who did not recur was 88.5 months (10.4 - 188) Conclusions: Rising CA-125 levels within the normal range that meet any of the above criteria are highly predictive (86%) of recurrence within 12 months and closer observation is warranted. [Table: see text] No significant financial relationships to disclose.