[BCG vaccination, cancer and infectious mononucleosis. A retrospective study of hospitalized patients].

A retrospective study (1966--1976) of patients hospitalized for cancer was carried out to determine a possible relationship with BCG vaccination, with a control group matched for age and sex and a similar study concerning infectious mononucleosis. Among 105 patients with cancer, 54 (51.42%) had been previously vaccinated with BCG, 56 (53.33%) in the control group, and 22 (33.84%) among the 65 patients with infectious mononucleosis (p less than 0.05, x2). The mean age on admission for cancer or infectious mononucleosis among vaccinees is significantly older than among non-vaccinees, suggesting a transient protection afforded by vaccination. These results need to be confirmed by a prospective study with Epstein-Barr virus serology.