Two Guards, Two Doors

You are imprisoned in a chamber with two doors as the only exit.  One door leads to death by cancer, filled with complications and malpractice; the other door leads to riches of jewelry, money and fine clothing for the rest of your life.  There are two guards standing before you: one guard always lies; the other always tells the truth.  Of course, you don’t know their identities.  You can ask only one question to save your life.  What should you ask?