The surgery on Armstrong, 25, was successful and resulted in the removal of two ``superficial lesions'' during a procedure at Indiana University Hospital, according to a statement released by Bill Stapleton.
``I want to thank everyone around the world for the overwhelming show of support through cards, letters and e-mail messages,'' Armstrong said in the statement. ``These messages provided me with a daily dose of positive thoughts.''
He was the 1995 and 1996 Tour DuPont champion and finished 12th in the Olympic road race. He dropped out of this year's Tour de France after six days saying he was not in shape.
On Oct. 8 Armstrong announced that he had testicular cancer and it had spread to his abdomen. He said he had already undergone surgery a few days earlier to remove the cancerous testicle and had begun chemotherapy.
Thursday's statement said Armstrong will resume chemotherapy Monday at Indiana University Hospital and return home to Austin after a week. He will have to come back to Indiana on Nov. 18 for additional treatment.
Armstrong listed his e-mail address as lance@bmoh.com.