The Nobel Peace Prize winner said today that he and his family were surprised after doctors detected an increase in prostate-specific antigen during a routine checkup.
He said he will undertake the exams Thursday at Johns Hopkins Institute in Baltimore and return home the next day.
The president had surgery in 2012 to remove a tumor in his prostate.
Santos said that while he is in the US he will also meet with Vice President Joe Biden as well as Republican and Democrat leaders to explain a modified peace agreement reached over the weekend with leftist rebels.