JACKSON, Miss. - A World War II veteran who received the nation's highest military honor when he was only 17 is in the fight of his life, battling cancer, his biographer said. Eighty-year-old Jack Lucas, who lied his way into the Marines at age 14, was nearly killed when he used his body to shield his fellow Marines from grenades on Iwo Jima in February 1945. He was just a few days past his 17th birthday at the time. He received the Medal of Honor from President Truman later that year, becoming the youngest Marine to receive the award. D.K....