Cancer incidence following infectious mononucleosis.

By means of a mailed questionnaire, the investigators examined the incidence of cancer among 2282 former college students in whom heterophile-positive infectious mononucleosis (IM) was diagnosed between 1949 and 1969 at five U.S. universities. Cancer incidence among these IM cases was compared both with national incidence rates and with an age and sex-matched group of 2779 non-IM students. No significant increase in cancer incidence was found. Three cases of Hodgkin's disease (HD) had occurred in the IM group (1.3 cases expected) and one case in the control group. All three post-IM cases of HD were in males. Intervals between diagnoses of IM and HD were three, four, and seven years, respectively. Only two other cases of lymphoma or leukemia were observed, and both were in the control group.