A Gynecologic Oncology Group Study of serum CA-125 levels in patients with stage III optimally debulked ovarian cancer treated with intraperitoneal compared to intravenous chemotherapy: an analysis of patients enrolled in GOG 172.
OBJECTIVE
Serum CA-125 values have been advocated in the monitoring of ovarian cancer patients receiving intravenous (IV) chemotherapy. This evaluation sought to determine if the CA-125 test can be used to monitor treatment effect among patients receiving intraperitoneal chemotherapy (IP).


METHODS
Patient charts from a phase III clinical trial (GOG 172) were retrospectively reviewed. Serum CA-125 levels prior to each cycle of therapy were collected and compared between the IV and IP chemotherapy delivery. The association between CA-125 and progression-free survival (PFS) or overall survival (OS) was estimated and the homogeneity of the results between IP and IV chemotherapy was assessed.


RESULTS
A total of 177 patients were treated with IV chemotherapy and 165 patients with IP chemotherapy with CA-125 data available were included in this analysis. The observed difference was not statistically significant in median CA-125 levels between the IV and IP arms at any time point (P>0.05 for all). Following surgery and adjuvant chemotherapy, patients with an abnormal CA-125 >35 U/ml were 2.45 times more likely to have disease progression (95% CI: 1.52-3.95, P<0.001) and 2.78 times more likely to die of disease (95% CI: 1.66-4.65, P<0.001), compared to those with a CA-125 <35 U/ml. These results were consistent with IP and IV chemotherapy.


CONCLUSIONS
Serum CA-125 levels decrease in a similar manner during IP chemotherapy when compared to IV chemotherapy. Serum CA-125 algorithms for monitoring treatment effect that have been established for IV chemotherapy may also be applied for patients receiving IP chemotherapy.
Krivak
Thomas C
TC
Magee Womens Hospital of the University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA. Electronic address: tkrivak@mail.magee.edu.
Tian
Chunqiao
C
Gynecologic Oncology Group Statistical and Data Center, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
Rose
G Scott
GS
Walter Reed Army Medical Center, Washington DC, USA.
Armstrong
Deborah K
DK
Johns Hopkins Kimmel Cancer Center, Baltimore, MD 21231, USA.
Maxwell
G Larry
GL
Walter Reed Army Medical Center, Washington DC, USA.
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D018394:CA-125 Antigen / Q000097:blood*; D002945:Cisplatin / Q000008:administration & dosage; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007263:Infusions, Parenteral; D009367:Neoplasm Staging; D010051:Ovarian Neoplasms / Q000097:blood* / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D017239:Paclitaxel / Q000008:administration & dosage; D016016:Proportional Hazards Models; D012189:Retrospective Studies
D018394:CA-125 Antigen; D017239:Paclitaxel; D002945:Cisplatin