Delay in Progression of Malignant Lymphoma after BCG Vaccination

Abstract

To determine the effect of BCG vaccination on the course of malignant lymphoma in remission, 50 patients with Stage IA or IIA, were randomly assigned in 1965–67 to serve as controls or to receive BCG vaccination. These patients had been staged and treated by technics associated with a 74 per cent relapse rate. Among the controls, 77 per cent relapsed within a follow-up period of six to eight years, with a mean time to the first new lesion of 10.6 months. Among the vaccinated patients, 61 per cent relapsed, with a mean time to the first new lesion of 25.9 months. The differences in relapse patterns were statistically significant, and could not be accounted for by differences in host, tumor or treatment characteristics. Clinical and immunologic data were consistent with the hypothesis that these differences were due to effects of BCG, operating over a period averaging about 2 1/2 years. (N Engl J Med 291:1226–1230, 1974)