Tumor Syndromes Predisposing to Osteosarcoma.

Osteosarcoma (OS) is the most common primary bone tumor affecting predominantly adolescents and young adults. It accounts for about 5% of all childhood cancers. Although the majority of OSs are sporadic, a small percentage occur as a component of hereditary cancer syndromes. Early onset, bilateral, multifocal, and metachronous tumors suggest genetic predisposition. The inheritance patterns can be autosomal dominant or recessive. These syndromes predispose to a wide variety of mesenchymal and epithelial cancers with propensity for certain mutations being prevalent in specific cancer subtypes. Li-Fraumeni syndrome, retinoblastoma, Rothmund-Thompson syndrome (type 2), Werner syndrome, and Bloom syndrome, constitute the majority of the tumor syndromes predisposing to OS and will be the focus for this review.