Second primary malignancies among childhood medulloblastoma survivors: a population-based competing risk analysis.

The most frequent second primary malignancy types were brain/central nervous system tumors (n = 26; standardized incidence ratios = 63.64), thyroid cancer (n = 23; standardized incidence ratios = 75.17 in males), and leukemia (n = 19; standardized incidence ratios = 25.60), with acute myeloid leukemia exhibiting standardized incidence ratios of 99.41-100.95.

On Fine-Gray regression, more recent diagnosis era was the only factor statistically associated with second primary malignancy occurrence; compared with 2000-2005, sHRs were 1.72 (95% CI 1.05-2.83; P = 0.031) for 2012-2017 and 2.28 (95% CI 1.04-5.01; P = 0.039) for 2018-2023.