no he wasn't, there is a published journal article that shows lances physiology profile before and after cancer. basically had same aerobic capacity, but do to 3-5kg drop in weight (plus numerous drug interventions), his relative VO2 and power-weight ration rocketed.
That study has been heavily criticised by the scientific community;
http://www.sportsscientists.com/2008/09/coyle-and-armstrong-research-errors.html
http://www.sportsscientists.com/2008/09/coyle-armstrong-research-installment-2.html
Coyle also recorded Armstrong's weight;
Nov 1992: 78.9 kgs
Jan 1993: 76.5 kgs
Sep 1993: 75.1 kgs
Aug 1997: 79.5 kgs
Nov 1999: 79.7 kgs
Where's the 3-5 kgs drop in weight exactly?