Risk of thyroid cancer, brain cancer, and non-Hodgkin lymphoma after adult leukemia: a nationwide study.

Patients with childhood leukemia surviving into adulthood have elevated risk of developing thyroid cancer, brain cancer, and non-Hodgkin lymphoma (NHL); these risks cannot automatically be extrapolated to patients surviving adult leukemia. We tested whether survivors of adult leukemia are at increased risk of developing thyroid cancer, brain cancer, and NHL. We included the entire adult Danish population (14 years of age or older), in a 28-year follow-up period from 1980 through 2007, composed of 6 542 639 persons; during this period, 18 834 developed adult leukemia, 4561 developed thyroid cancer, 13 362 developed brain cancer, and 15 967 developed NHL. In nested studies using Cox regression models on individual participant data, we found that, after adult leukemia, the multivariate adjusted hazard ratios were 4.9 (95% confidence interval [CI], 2.8-8.5) for thyroid cancer, 1.9 (95% CI, 1.2-3.1) for brain cancer, and 3.3 (95% CI, 2.5-4.4) for NHL. Corresponding hazard ratios after childhood leukemia were 10.4 (95% CI, 0.4-223) for thyroid cancer, 7.2 (95% CI, 2.0-26) for brain cancer, and 6.5 (95% CI, 0.4-110) for NHL. Patients with adult leukemia have excess risk of thyroid cancer, brain cancer, and NHL, similar to patients with childhood leukemia.