The 36-year-old Armstrong qualified for Boston by finishing the 2007 New York City Marathon in 2 hours, 46 minutes, 43 seconds, good for 214th place. The Boston qualifying time is 3:15 for men ages 35 to 39.

"For him to qualify in New York and then to take that time and apply it to Boston says a lot about what Boston means to the sport of marathoning," said Jack Fleming, a spokesman for the Boston Athletic Association. "It's tough to call your marathon career complete without running Boston."

Armstrong was diagnosed in 1996 with testicular cancer that spread to his lungs and brain. But he recovered to win the world's premiere cycling event from 1999 to 2005.

The Lance Armstrong Foundation supports cancer research, prevention and better care for cancer survivors. Armstrong and others running for the foundation raised about $500,000 at last year's New York City Marathon.