"Biologically Based Methods for Cancer Risk Assessment", an Advanced Research Workshop, (ARW) sponsored by the North Atlantic Treaty Organization (NATO) was held in Corfu, Greece in June, 1989. The intent of the workshop was to survey available pharmacokinetic and pharmacodynamic methods in cancer risk assessment and identify methodological gaps and research needs for biologically based methods in cancer risk assessment. Incorporation of such methods represents one of the most challenging areas for risk assessment. The workshop included an international group of invited experts in the field and provided for a dynamic exchange of ideas and accomplishments. Some of the major topics discussed were: * Inventory of available pharmacokinetic and pharmacodynamic methods for cancer risk assessment. * Identification of methodology gaps and research needs in biologically based methods in cancer risk assessment. * Development of a general framework to guide future cancer risk assessment research. This book is a compilation of the papers presented at the workshop and is intended to provide guidance for future research to reduce uncertainties in the cancer risk assessment process. The primary sponsorship of this ARW by NATO and the advice and cooperation of Dr. C. Sinclair of the Scientific affairs Division are gratefully acknowledged. Acknowledgement is also given to the National Science Foundation for its support. The organization of the ARW and the preparation of this book have required considerable help from many other sources.