Studies of the Mortality of A-Bomb Survivors: 7. Mortality, 1950-1978: Part I. Cancer Mortality

The present study extends an earlier one by 4 years, 1975-1978. We find leukemia as a cause of death among survivors has continued to decrease and now differs from the control group only in Hiroshima. For cancer other than leukemia the increase in absolute risk has become more marked as the cohort has aged and especially so in Nagasaki where it is now statistically significant for the first time. In addition to previously demonstrated sites, i.e., lung, breast, stomach, esophagus, and urinary tract, colon cancers and multiple myeloma can now be shown to be related to exposure. No significant relationship to radiation can as yet be established for malignant lymphoma, rectum, pancreas, and uterine cancer. The time from exposure to death is shortened for leukemia depending on dose but not for other cancers, and radiation-induced cancers other than leukemia seem to develop proportionally to the natural cancer rate for the attained age. For specific age-at-death intervals, both relative and absolute risks tend...