The evaluation of the efficacy and safety of a clinical tool, be it a diagnostic technique, a preventive methodology, or a therapeutic intervention, is an im portant responsibility of physicians. The history of medicine is characterized by the authoritarianisms of teachers and of organizations giving way to the clinical experience of physicians; authoritarian dictum was replaced by case report and then by case series. As physicians learned to substitute the analysis of data for the inconsistencies of dictums and anecdotes, the problems of the case series as an investigative tool became more...

When asked why he robbed banks, an astute and success- ful criminal is said to have replied "Because that's where the money is kept." Why study patients with multiple primary cancers? The answer follows the same practical approach. Because the intensive investigation of such patients is very likely to yield data useful to both the clinical and research on- cologist. Studies of this problem provide an immediate return for the clinician responsible for the care of cancer patients. With improved forms of therapy, these individuals are enjoying longer periods of survival. One important factor in...