Anticancer cytotoxic agents go through a process by which their antitumor activity-on the basis of the amount of tumor shrinkage they could generate-has been investigated. In the late 1970s, the International Union Against Cancer and the World Health Organization introduced specific criteria for the codification of tumor response evaluation. In 1994, several organizations involved in clinical research combined forces to tackle the review of these criteria on the basis of the experience and knowledge acquired since then. After several years of intensive discussions, a new set of guidelines is ready that will supersede the former criteria. In parallel to this initiative, one of the participating groups developed a model by which response rates could be derived from unidimensional measurement of tumor lesions instead of the usual bidimensional approach. This new concept has been largely validated by the Response Evaluation Criteria in Solid Tumors Group and integrated into the present guidelines. This special article also provides some philosophic background to clarify the various purposes of response evaluation. It proposes a model by which a combined assessment of all existing lesions, characterized by target lesions (to be measured) and nontarget lesions, is used to extrapolate an overall response to treatment. Methods of assessing tumor lesions are better codified, briefly within the guidelines and in more detail in Appendix I. All other aspects of response evaluation have been discussed, reviewed, and amended whenever appropriate.
ContributorsTherasse, P. Arbuck, S. G. Eisenhauer, E. A. Wanders, J. Kaplan, R. S. Rubinstein, L. Verweij, J. Van Glabbeke, M. van Oosterom, A. T. Christian, M. C. Gwyther, S. G.
Disease Category: Cancer
Disease Name: Solid tumor
Age Range: 0 - 100
Sex: Either
Nature of Intervention: Any
- Academic research representatives
- Clinical experts
- Members of a clinical trial network.
- Pharmaceutical industry representatives
- Regulatory agency representatives
- Recommendations made
- Consensus meeting
These guidelines are the result of a large, international collaboration.
In 1994, the European Organization for Research and Treatment of Cancer (EORTC), the National Cancer Institute (NCI) of the United States, and the National Cancer Institute of Canada Clinical Trials Group set up a task force with the main objective of reviewing the existing sets of criteria used to evaluate response to treatment in solid tumors.
After 3 years of regular meetings and exchange of ideas within the task force, a draft revised version of the WHO criteria was produced and widely circulated. Comments received (response rate, 95%) were compiled and discussed within the task force before a second version of the document integrating relevant comments was issued. This second version of the document was again circulated to external reviewers who were also invited to participate in a consensus meeting (on behalf of the organization that they represented) to discuss and finalize unresolved problems (October 1998).