The good effect of calusterone in patients with metastatic cancer of the breast, reported in this issue (p 483) by Gordan, will naturally arouse great interest. Results in 102 patients appear to justify his tentative opinion that calusterone is the most useful steroid now under study for treatment of this disease. More than twice as many objective regressions were observed as would have been expected with use of testosterone propionate.
Unfortunately, these observations and the others cited by Gordan are not adequate to establish the worth of calusterone, because they did not include appropriate controls. They are only pilot studies. Examples of equally promising therapeutic innovations which subsequently failed to pass more rigorous scrutiny are all too common, due to unintended selection of patients, or unsuspected bias in evaluations. As Gordan points out, a well-designed study for this type of agent requires (1) random assignment of patients among apparently comparable