"UnitedHealthcare said Thursday it will expand its high-profile test of whether bundled payments for chemotherapy can help slow rising cancer treatment costs, part of a growing effort by insurers to find new ways to pay for care. Results from United's initial pilot test -- reported last year -- were puzzling: The overall cost of cancer care for patients in the study dropped by 34 percent, even as spending on chemotherapy drugs spiked significantly.... [R]esults from three other efforts showed decidedly smaller savings compared with United's stunning 34 percent drop[.]"