Annals of Oncology Advance Access published online on November 20, 2007
Annals of Oncology, doi:10.1093/annonc/mdm486
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
© 2007 European Society for Medical Oncology
Correlation of changes between 2-year disease-free survival and 5-year overall survival in adjuvant breast cancer trials from 1966 to 2006
1 Department of Medical Oncology and Hematology, Princess Margaret Hospital, Faculty of Medicine, University of Toronto, Toronto
2 Biostatistics, Princess Margaret Hospital, Toronto, Canada
* Correspondence to: Dr E. Chen, Department of Medical Oncology and Hematology, Princess Margaret Hospital, Suite 5-719, 610 University Avenue, Toronto, Ontario, Canada M5G 2M9. Tel: +1 416-946-2263; Fax: +1 416-946-4467; E-mail: eric.chen{at}uhn.on.ca
Background: Although disease-free survival (DFS) is accepted as a valid end point in adjuvant breast cancer trials, improvement in 2-year DFS has never been formally established as an adequate correlate for 5-year overall survival (OS). We set out to ascertain if changes in 2-year DFS can be used to accurately predict 5-year OS changes.
Design: We conducted a systematic Medline search (1966–2006) for randomized adjuvant breast cancer trials of >100 patients per arm with 2-year DFS and 5-year OS data. A univariate regression model weighted by trial sample size was constructed to determine whether 2-year DFS differences between treatment arms within trials were predictive of 5-year OS differences.
Results: A total of 126 studies containing 149 treatment comparisons met the inclusion criteria. Difference in 2-year DFS was a significant predictor of difference in 5-year OS. For every 1% increase in 2-year DFS difference, the 5-year OS difference increased by 0.5%–0.55%. The proportion of variation explained ranged from 0.38 to 0.42, with a wide prediction interval.
Conclusion: There is a statistically significant correlation, of moderate strength, between difference in 2-year DFS between treatment comparisons and difference in 5-year OS but the correlation is not strong enough to be used as a predictor.
breast cancer, correlation, disease-free survival, overall survival
Received for publication July 18, 2007. Revision received September 13, 2007. Accepted for publication September 17, 2007.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  B. Seruga and I. F. Tannock Up-Front Use of Aromatase Inhibitors As Adjuvant Therapy for Breast Cancer: The Emperor Has No Clothes J. Clin. Oncol., February 20, 2009; 27(6): 840 - 842. [Full Text] [PDF]
|
|