[Association of leukemias and tumors. Studies of 502 cases of leukemia].

Nineteen association of leukaemia and tumour were noted in a series of 502 cases of leukaemia: 12/180 (6.6%, compared with 4.7% of 5136 cases in the liteature) for Chr. L.L. (hypogammaglobulinaemia, reduction in single Ig. serious herpes zoster and the T-lymphocyte nature of leukaemia were not more frequent in these associations); 2/102 (1.9%, compared with 2.6% of 1267 cases in the literure) for Chr. M.L.; 5/220 (2.2%, compared with 2.19% of 1138 cases in the literature) for A.L. The mean age of the overall leukaemia series was virtually the same for A.L. (47 yr in a group composed of subjects aged over 12 yr) and Chr. M.L. (48 yr), with the same incidence of association (2.2 and 1.9%), whereas it was 64 yr and 6.6% incidence in Chr. L.L. The bilogarithmic increase in the incidence of tumours with age may itself explain the higher incidence of Chr. L.L. associations. The duration of leukaemia and the age of incidence must be taken into account in any discussion of the significance of such associations.