MONDAY, April 6, 2026 (HealthDay News) -- The annual incidence of treatment-related acute myeloid leukemia (tAML) has increased, in addition to an increase in the distribution of primary cancers, defined as the first preceding malignancy that was treated with chemotherapy and/or radiotherapy before tAML diagnosis, according to a study published online April 6 in Cancer.Kenji Kishimoto, M.D., M.P.H., Ph.D., from the Osaka International Cancer Institute in Japan, and colleagues examined changes in the incidence and primary cancers of tAML over 30 years in a population-based setting in Japan. Data from the Osaka Cancer Registry were used to identify patients diagnosed with AML between 1990 and 2020.The researchers found that 636 (6.5 percent) of 9,841 patients with AML had tAML. During the study period, there was an increase in the annual tAML incidence from 0.13 to 0.36 per 100,000 population. There was an almost doubling in the proportion of tAML cases among overall AML cases. An increased annual tAML incidence was seen in association with a recent year (adjusted incidence rate ratio per 10 years, 1.28). The most common primary cancer was hematological malignancy, followed by breast cancer, colorectal cancer, and gastric cancer (23.1, 14.6, 11.5, and 8.7 percent, respectively). Between diagnosis periods, there was a change in the distribution of primary cancers, with a prominent increase in breast cancer and decrease in gastric cancer."The study provides an important step towards better understanding how the nature of tAML is changing with the increasing number of cancer survivors," Kishimoto said in a statement.Abstract/Full Text (subscription or payment may be required).Sign up for our weekly HealthDay newsletter