Tuberculin allergy and cancer risk

An excessive risk of cancer has been reported in rare patient populations with deficiencies of the cellular immunity. In this study the association between possible immunological factors and cancer incidence has been examined in the general human population. The size of the tuberculin reaction among reactors has been used as an index of the cellular immunity and correlated with the risk of developing malignant disease. The study population comprises 425,000 persons 20–44 yr old attending a mass campaign against tuberculosis in Denmark. Tuberculosis patients and previously BCG vaccinated persons were excluded from the study population. A total of 2661 deaths were identified during a 12 yr follow-up period where cancer was specified as primary or secondary cause of death on the death certificate. The analysis is based on a comparison of the tuberculin status in the group dying from cancer and the remainder of the study population. No differences can be demonstrated between the two groups regarding the prevalence of tuberculin reactors and the mean size of reactions among tuberculin reactors. It is pointed out that the negative results of this investigation do not necessarily preclude that a cellular immunity aginst cancer exists in the general population.