Lance Armstrong's Livestrong Legacy Stained By Doping-Cancer Link

01/17/2013 01:03pm ET | Updated March 19, 2013
AUSTIN, TX - JANUARY 14: In this handout photo provided by the Oprah Winfrey Network, Oprah Winfrey (not pictured) speaks with Lance Armstrong during an interview regarding the controversy surrounding his cycling career January 14, 2013 in Austin, Texas. Oprah Winfrey’s exclusive no-holds-barred interview with Lance Armstrong, 'Oprah and Lance Armstrong: The Worldwide Exclusive,' has expanded to air as a two-night event on OWN: Oprah Winfrey Network. The special episode of 'Oprah’s Next Chapter' will air Thursday, January 17 from 9-10:30 p.m. ET/PT (as previously announced) and Friday, January 18 at 9 p.m. ET/PT. The interview will be simultaneously streamed LIVE worldwide both nights on Oprah.com. (Photo by George Burns/Oprah Winfrey Network via Getty Images)

Now that Armstrong's titles have been tainted by his admitted use of performance-enhancing drugs, questions have also been raised about whether those banned substances caused or contributed to his cancer.