Objective: The intraperitoneal (IP) catheter has the potential to cause peritoneal irritation, which may contribute to an elevated CA125 level. We hypothesize that patients undergoing IP chemotherapy may have elevated CA125 values when compared with patients receiving intravenous (IV) chemotherapy.

Methods: From February 2006 to July 2007, optimally debulked patients with stage III and stage IV ovarian carcinoma from a single institution were offered an outpatient IV/IP chemotherapy regimen modified from Gynecologic Oncology Group 172. They were matched to a cohort of similar patients who received IV paclitaxel and carboplatin. Demographic data and CA125 levels were collected before each cycle of chemotherapy and after the removal of the IP catheter. Statistical analysis was completed using a χ² test with a significance level of P < 0.05.

Results: Fifty patients received the standard IV regimen, and 38 patients completed the modified IV/IP regimen. There was no statistical difference in the median CA125 values between the 2 groups during the treatment. After 6 cycles of therapy, 68.4% (26/38) of the IP cohort had a normal CA125 level before IP catheter removal compared with 78% (39/50) in the IV chemotherapy cohort (P = 0.44). After removal of the IP catheter, 86.8% (33/38) of the patients had a normal CA125 value (68.4% vs 86.8%, P = 0.049).

Conclusions: After removal of the IP catheter, an additional 18.2% (7/38) of patients in the IP group had normalized their CA125 level. Because CA125 levels at the end of the treatment have prognostic significance, the role of the IP catheter in an elevated CA125 level must be considered.