In the 1990s, colon cancer was considered a problem for older adults. That's why it was a complete shock for Katie Couric when her husband, Jay Monahan, was diagnosed with stage 4 colon cancer in 1997. He died nine months later after his 42nd birthday. Today, colon cancer has risen to the No. 1 cause of cancer-related deaths in people under 50. For decades, Couric has been campaigning for better awareness of colon cancer's risks and prevention habits. She said it's more important now than ever.