BOSTON — A 64-year-old cancer patient has received the nation’s first penis transplant, a groundbreaking operation that may also help accident victims and some of the many U.S. veterans maimed by roadside bombs. Manning, who is single, did not appear at the news conference but said in a statement: Today I begin a new chapter filled with personal hope and hope for others who have suffered genital injuries. [...] four additional hospitals around the country have permission from the United Network for Organ Sharing, which oversees the nation’s transplant system, to attempt the delicate surgery. The loss of a penis, whether from cancer, accident or war injury, is emotionally traumatic, affecting urination, sexual intimacy and the ability to conceive a child.