In May, Biden’s postpresidential office announced that he had been diagnosed with prostate cancer and that it had spread to his bone. The discovery came after he reported urinary symptoms.

Prostate cancers are graded for aggressiveness using what is known as a Gleason score. The scores range from 6 to 10, with 8, 9 and 10 prostate cancers behaving more aggressively. Biden’s office said his score was 9, suggesting his cancer is among the most aggressive.

Last month, Biden had surgery to remove skin cancer lesions from his forehead.