Due to a bureaucratic tangle, 1,000 cancer patients at Memorial Sloan Kettering's new center in Basking Ridge, NJ, may be forced to find new doctors. The cancer center recently sent letters to patients covered by Horizon Blue Cross Blue Shield of New Jersey telling them they will be charged out-of-network prices after Sept. 1. The patients can avoid the higher charges by switching their care to Sloan Kettering's Manhattan hospital, the letter said.