A mouse model for studying therapy-induced cancers.

As more pediatric cancer patients survive for longer periods following treatment with cytotoxic agents, therapy-induced second malignant neoplasms (SMNs) have become a major concern. In this issue of Cancer Cell, Chao et al. report that mice carrying a mutation in Nf1, the gene responsible for neurofibromatosis type 1, treated with radiation and/or cyclophosphamide, developed tumors similar to human SMNs at a significantly higher rate than did wild-type controls treated similarly. This model provides efficient and rational means for testing procedures and agents that could inform clinicians regarding second cancer risks associated with treatment and, perhaps, reducing them.