Cumulative incidence rates for Hodgkin's disease and other hematologic malignancies, with special reference to age-related carcinogenesis

The cumulative incidence rate throughout the life span was analyzed for 4,865 Hodgkin's disease cases, in comparison with 16,015 malignant lymphomas (ML), 1,694 acute lymphocytic leukemias (ALL), 3,967 acute myeloid leukemias (AML), 2,109 chronic myeloid leukemias (CML), and 4,752 chronic lymphoid leukemias (CLL) in US white reported in the SEER program during 1973-1981. A log-linear increase was observed in ML, AML, CML, and CLL throughout the life-span, but only in childhood in ALL. Hodgkin's disease showed a steep increase until age 20-24, and then the increase became much more gradual. The cumulative incidence rates for males and females were parallel for ML and leukemias, but diverged for Hodgkin's disease (the rate for females had a lower slope than that for males after age 20-24). This difference was mainly caused by a lower frequency in females of mixed cellularity and lymphocyte predominance subtypes. The incidence curve of Hodgkin's disease was consistent with the two-stage model of carcinogenesis; it is likely that the proliferation of progenitor cells peaks at a young age and that the death rate of so-called intermediate cells is a primary influence during the subclinical stage. The cytogenesis of Hodgkin's disease and the histologic variation with special reference to the T-zone histiocytes suggest that a strong host defense mechanism against neoplastic change is involved, rather than different etiologic influences.