Innovations in the design of clinical trials in breast cancer.

The execution of clinical trials is perhaps the most difficult way of carrying out a scientific experiment. This is especially true of chronic diseases, such as breast cancer, which require long-term follow-up and large numbers of patients. As a result, it is necessary to involve many physicians who can contribute patients to these studies. Unfortunately, many physicians are not comfortable participating in randomized studies because they feel the patient-physician relationship may be compromised. This paper discusses new ways of planning randomized clinical trials which do not interfere with the patient-physician relationship. The new designs are called 'randomized consent' or 'prerandomized' designs. The study designs are discussed from the point of view of statistical efficiency and the new ethical problems which may arise.