In vitro reaction of cancer patients and others to Bacillus Calmette-Gueérin.

We examined the in vitro reaction of leukocytes from 71 cancer patients and 121 control donors (disease-free individuals or patients with non-malignant non-debilitating conditions) against Bacillus Calmette-Guérin using a one-stage capillary leukocyte migration assay. The proportion of reactive cancer patients and control donors increased with increasing BCG concentration, but the proportion of patients who reacted was less than that of control donors at all concentrations of BCG. As cancer stage advanced and the volume of clinically detectable tumor increased, the proportion of reactive patients decreased. There was a small age-related decline in reactivity in the control population. The results of simultaneous in vitro tests and Mantoux reactions were concurrent in a majority of normal individuals so tested.