The presence of delayed hypersensitivity reactions in patients toward cellular extracts of their malignant tumors 1.The role of tissue antigen, nonspecific reactions of nuclear material, and bacterial antigen as a cause for this phenomenon

Patients have a delayed hypersensitivity reaction toward extracts of cells of their malignant tumors in 26% of cases. This is not due to a nonspecific reaction to nuclear material in the majority of cases. It is unlikely to be due to tissue specific antigen. In carcinoma of the breast, bacterial antigen can be excluded as a cause of this phenomenon. In carcinoma of the gastrointestinal tract, it is shown that bacteria may not be a cause, although the natural contamination of these tumors makes it impossible to be dogmatic. The greatest reaction is seen toward the extract derived from centrifugation of tumor homogenate at 14,000 g, a fraction that probably contains external cellular membranes. No correlation can be made between the presence of the D.H.R. to tumor extracts and the reactivity shown by the patient to Varidase, a test agent toward which a high percentage of healthy adults react in a delayed fashion when tested intradermally.