The ex-San Antonio mayor says he's going public to encourage more men to be tested.
Cisneros told the San Antonio Express-News, in a story Sunday, that he was diagnosed in January. He started radiation therapy in May.
The San Antonio native says he has "great faith" that the technology will beat his cancer.
Cisneros on June 11 turned 65. He recently published a book about aging called: "Independent for Life: Homes and Neighborhoods for an Aging America."
Cisneros served as HUD secretary in the 1990s. He's currently executive chairman of CityView, a Los Angeles-based investment company focused on urban development.