To the Editor.—
The summary of the National Institutes of Health Consensus Development Conference on treatment of primary breast cancer (1980;244:797) requires some comment. Moxley et al in discussing the series of Samuel Hellman, MD, of 135 breast cancers treated by primary radiation lists the five-year survival rate for stage I tumors as 91%. Since only 30 patients were followed up for five years, I think that the authors should have made it clear to the profession that 91% represented an actuarial likelihood of survival and not a true five-year survival. This figure may well change when all of the 129 patients in this series are followed up for five years.