The Wall Street Journal previously reported on his paid speeches and promotional videos for the company, including one in which he spoke of taking Mannatech products after a diagnosis of prostate cancer more than a decade ago. “Within about three weeks my symptoms went away, and I was really quite amazed,” he told sales associates, as captured in a 2004 video. Carson said he even considered passing on surgery, though he went ahead with the procedure and is cancer-free today.