Lee will undergo surgery to remove his prostate gland on Monday, and will be on medical leave for a week. Lee had undergone an MRI in January which showed suspicious lesions, the statement said.
Lee previously battled cancer in 1992, when he was diagnosed with intermediate grade malignant lymphoma. He was cleared in 1993 after undergoing chemotheraphy.
The press statement cited data from the Memorial Sloan Kettering Cancer Centre showing that "patients with a similar medical profile and treatment have a cancer specific survival rate of 99 per cent at 15 years.
"Singapore's previous prime minister, Goh Chok Tong, underwent surgery for prostate cancer last November.