Insurers are changing how they pay for cancer care, aiming to blunt soaring costs and push oncologists to adhere to standardized treatment guidelines. The largest effort yet is set to be unveiled by WellPoint Inc., WLP -0.31% which will begin offering oncologists a $350-per-month payment for each patient who is on one of the insurer's recommended regimens. WellPoint, the No. 2 insurer in the U.S., will roll out its new program July 1 in six states and through its entire network by the middle of next year. Initially, it will focus on breast, lung and colorectal cancer, but it will expand to other forms of the disease. [Subscription Required]