[Double cancer in patients with adult T cell leukemia]

We have studied the incidence and characteristics of associated neoplasms in 210 ATL patients. Twelve patients had other primary neoplasms and the incidence of double cancer was 5.7%. The additional malignancies in ATL patients consisted of 4 cases of stomach, 3 cases of colon and one of each lung, ovary, uterus, liver and bladder cancer. In metachronous double cancer patients, the neoplasm was found before the time of diagnosis of ATL in 5 out of 6 patients. Immunodeficiency due to HTLV-I infection as well as chemotherapy for the preceding neoplasm are suggested to be related to the leukemogenesis of ATL.