US Oncology is one of the largest health care service networks in the United States that offers specialized cancer treatment, research and community-based cancer care. Its network of more than 1,000 affiliated physicians delivers care to over 1 million cancer patients each year. The network operates nearly 440 sites of services, including approximately 90 cancer centers and radiation facilities in more than 35 states. US Oncology s pharmaceutical services division offers a range of services, including purchasing, admixture, on-site pharmacy operation and utilization reviews. It also maintains a cancer center services division that enables physicians to establish their own freestanding cancer centers integrating various aspects of patient diagnosis and treatment in convenient, patient-friendly locations. With a facility in Fort Worth, Texas, the network also has a cancer research services division.