[Elderly cases of hematological malignancies with second malignancies].

Recently an increase of the elderly patients with hematological malignancies has been pointed out. We analyzed second malignancies in elderly patients with hematological malignancies (95 age 65 or more), and made a comparative study with non-elderly case for the past 5 years. Second malignancies were observed in 26 cases out of the total of 282 hematological malignancies (9.2%). The percentage of patients with second malignancies in the elderly group (19/95; 20%) was significantly higher than that of the non-elderly group (7/187; 3.7%). Among the all kinds of hematological malignancies, the second malignancies were mainly observed in cases with myelodysplastic syndrome and chronic myelo-proliferative disorder. Colon carcinoma, gastric carcinoma and lung carcinoma accounted for nearly half of all the second malignancies. On 11 of the 26 cases with second malignancies, the first malignancies had been treated with some anti-cancer drug such as alkylating agents. Development of a second cancer was greater in cases in which the first hematological malignancy was treated with alkylating agents more than in cases in which the first carcinoma was not treated with alkylating agents.