[Multiple primary cancers in patients with malignant lymphoma].

This study of 502 patients with malignant lymphoma revealed the following: In all, 18 cases (3.6%) of histologically confirmed multiple primary cancers were found. Eleven cases of second malignancies were observed after diagnosis of malignant lymphoma, whereas 7 cases of malignant lymphoma occurred after other malignancies. The expected number of second malignancies in 502 patients with malignant lymphoma was calculated as 4.94 by the person-years approach. The observed number (11) was significantly higher than the expected (p less than 0.01). There was, however, no case of second malignancy considered to be related to the previous radiotherapy.