1. General Aspects.- Prognostic Factors and Nosological Criteria of Breast Cancer from the Pathologist's Point of View.- Growth Rate of Tumours and Natural Life Expectancy.- The Reporting of Non-significant Results in Clinical Trials.- Notes on Clinical Trial Methodology.- 2. Design and Performance of Clinical Trials.- The Cardiff Mastectomy Trial.- Experiences from a Multicentric Trial of Adjuvant Chemotherapy.- Thirty Years Experience with Breast Cancer Clinical Trials at the Christie Hospital in Manchester - Clinical Aspects.- Thirty Years Experience of Breast Cancer Trials in Manchester - Statistical Aspects.- The King's/Cambridge Trial.- Operable Breast Cancer with Positive Axillary Nodes: The Experience of the Milan Cancer Institute.- 3. Treatment Departures.- Problems in Withdrawal of Patients in a Randomized Study, when Treatment in One of the Groups Cannot be Carried Out.- Treatment Departure and Survival Analysis in a Randomized Trial on the Value of Pre- and Postoperative Radiotherapy in Breast Cancer.- 4. Stochastic Models.- Stochastic Models in Clinical Trials.- 5. Regression Models.- Aspects of the Cox Model in the Analysis of Survival Data.- Time Dependend Covariates.- A Large Sample Study of the Estimate for the Survival Distribution in Cox's Regression Model.- 6. Competing Risks.- Comparing Treatments, Adjusting for Competing Risks.- Why the Present Approach to Competing Risks Should be Abandoned.- Competing Risk Models in Early Breast Cancer Trials.- 7. Log Rank Test.- Some Extensions of the Log Rank Test.- Discussion.- Appendix Controlled Illness Processes with Incomplete Information - A Re-examination of the Basic Hypothesis in Constructing Stochastic Models P. Tautu.- List of Participants.