Comparison of CA-125 and standard definitions of progression of ovarian cancer in the intergroup trial of cisplatin and paclitaxel versus cisplatin and cyclophosphamide.
OBJECTIVE
A definition for progression of ovarian cancer has been proposed based on either a confirmed doubling of CA-125 levels from the upper limit of normal or from the nadir level if levels are persistently elevated. Retrospectively, we determined whether the use of this CA-125 definition in a randomized trial would have shown the same magnitude of difference between the treatment arms as was shown when the standard progression definition was used.


METHODS
A retrospective analysis was performed on 680 patients in the Taxol Intergroup Trial with advanced epithelial ovarian carcinoma, of whom 628 were assessable according to CA-125. The date of progression according to clinical or radiologic criteria was compared with the date of progression according to CA-125.


RESULTS
Of the 628 patients assessable for both definitions, 556 clinical or radiologic progressions were determined compared with 389 according to the CA-125 definition. There was a highly significant difference in the hazard of progression between the paclitaxel and cisplatin arm (TP) compared with the cyclophosphamide and cisplatin arm (CP) when either standard or CA-125 criteria were used to define progression (standard, P = .002; CA-125, P = .011). The hazard ratio of TP/CP over time was similar when comparing the different methods of defining progression.


CONCLUSIONS
The results of this analysis show that the magnitude of the therapeutic benefit was similar whether CA-125 or standard criteria were used to define progression.
Rustin
Gordon J S
GJ
Department of Medical Oncology, Mount Vernon Cancer Centre, Northwood, Middlesex, United Kingdom. grustin@nhs.net
Timmers
Petra
P
Nelstrop
Ann
A
Shreeves
Gavin
G
Bentzen
Soeren M
SM
Baron
Benoit
B
Piccart
Martine J
MJ
Bertelsen
Kamma
K
Stuart
Gavin
G
Cassidy
James
J
Eisenhauer
Elizabeth
E
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D018394:CA-125 Antigen / Q000097:blood*; D002945:Cisplatin / Q000008:administration & dosage; D003520:Cyclophosphamide / Q000008:administration & dosage; D018450:Disease Progression; D005260:Female; D006801:Humans; D010051:Ovarian Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000401:mortality; D017239:Paclitaxel / Q000008:administration & dosage; D012189:Retrospective Studies
D018394:CA-125 Antigen; D003520:Cyclophosphamide; D017239:Paclitaxel; D002945:Cisplatin