“…I t must be concluded, therefore, that the mean duration of the disease in the present material was the same in untreated patients and in patients treated with radiation, urethane, and corticosteroids. This is in keeping with the findings of previous authors in larger series (5,17,36,47,49,51,53,57). A few authors, however, have found massive urethane therapy (37,40) and radiation (19,35) to prolong the duration of the disease.…”