Response rate accuracy in oncology trials: reasons for interobserver variability. Groupe Français d'Immunothérapie of the Fédération Nationale des Centres de Lutte Contre le Cancer.
OBJECTIVE
We evaluated the impact of an evaluation committee (EC) on patients' overall response status in a large multicenter trial in oncology. We identified reasons for disagreements between investigators and the EC.


METHODS
The Cancer Renal Cytokine (CRECY) study was a French multicenter trial that tested cytokine therapy in 489 patients with metastatic renal cell carcinoma. Objective response (OR) evaluation included medical imaging and was studied according to international guidelines. A blinded peer review of all responders and litigious cases was performed by an EC.


RESULTS
Major disagreements occurred in 40% and minor disagreements in 10.5% of the reviewed files. The number of significant tumor responses was reduced by 23.2% after review by the EC. Reasons for disagreements included errors in tumor measurements, errors in selection of measurable targets, intercurrent diseases, and radiologic technical problems. These reasons for disagreements are analyzed and discussed.


CONCLUSIONS
We conclude that all therapeutic trial results should be reviewed by peer analysis of all presumed responders by an EC. International guidelines for response evaluation should be updated by including more reliable methods of measurements and definition of minimal imaging procedures.
Thiesse
P
P
Department of Radiology, Centre Régional Léon Bérard, Lyon, France. thiesse@lyon.fnclcc.fr
Ollivier
L
L
Di Stefano-Louineau
D
D
Négrier
S
S
Savary
J
J
Pignard
K
K
Lasset
C
C
Escudier
B
B
D002986:Clinical Trials as Topic; D006801:Humans; D008495:Medical Oncology / Q000379:methods*; D015337:Multicenter Studies as Topic; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000628:therapy; D015588:Observer Variation; D017410:Practice Guidelines as Topic; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome