Emperor Naruhito is set to take an MRI test in early November to check there is no disease in his prostate, the Imperial Household Agency said in a statement Monday.
The 62-year-old emperor will take the MRI test after the result from a separate prostate-specific antigen test showed values that were on a "somewhat concerning" trend, with the figures being slightly higher than the normal, the agency said.
The emperor underwent surgery to remove a polyp in the duodenum in 2007 when he was the crown prince, but has had no major health problems so far.
Last month, he attended the funeral of Britain's Queen Elizabeth II together with Empress Masako in his first overseas trip since ascending to the throne in May 2019.
Emperor Emeritus Akihito, the emperor's father, was diagnosed with prostate cancer in December 2012 when he was the emperor and underwent a surgery in January 2013 to remove his prostate gland at the University of Tokyo Hospital.