Initial presentation of stage III osteosarcoma with lung metastases depends on the resectability of the primary tumor and lung nodules, degree of necrosis of the primary tumor, and maybe the number of metastases. Overall survival prognosis is about 30%.Deaths due to malignant neoplasms of the bones and joints account for an unknown number of childhood cancer deaths. Mortality rates due to osteosarcoma have been declining at about 1.3% per year. Long-term survival probabilities for osteosarcoma have improved dramatically during the late 20th century and approximated 68% in 2009. Epidemiology
Osteosarcoma is the eighth-most common form of childhood cancer, comprising 2.4% of all malignancies in pediatric patients, and about 20% of all primary bone cancers.Incidence rates for osteosarcoma in U.S. patients under 20 years of age are estimated at 5.0 per million per year in the general population, with a slight variation between individuals of black, Hispanic, and white ethnicities (6.8, 6.5, and 4.6 per million per year, respectively). It is slightly more common in males (5.4 per million per year) than in females (4.0 per million per year).It originates more frequently in the metaphyseal region of tubular long bones, with 42% occurring in the femur, 19% in the tibia, and 10% in the humerus. About 8% of all cases occur in the skull and jaw, and another 8% in the pelvis.Around 300 of the 900 people diagnosed in the United States will die each year. A second peak in incidence occurs in the elderly, usually associated with an underlying bone pathology such as Pagets disease of bone.
Uridine triacetate (INN), formerly known as vistonuridine, is an orally active tri-acetylated prodrug of uridine used:

in the treatment of hereditary orotic aciduria (brand name Xuriden  ZOOR-ə-den);
to treat people following an overdose of chemotherapy drugs 5-fluorouracil (5-FU) or capecitabine regardless of the presence of symptoms, or who exhibit early-onset, severe or life-threatening toxicity affecting the cardiac or central nervous system, and/or early-onset, unusually severe adverse reactions (e.g., gastrointestinal toxicity and/or neutropenia) within 96 hours following the end of fluorouracil or capecitabine administration (brand name Vistogard).Uridine triacetate was developed, manufactured and distributed by Wellstat Therapeutics. It was granted breakthrough therapy designation by the U.S. Food and Drug Administration (FDA) and approved for use in the United States in 2015. References
External links
"Uridine triacetate". Drug Information Portal. U.S. National Library of Medicine.