Former U.S. President Joe Biden has been diagnosed with an aggressive form of prostate cancer that has metastasized to his bones, his office confirmed in a statement released Sunday afternoon.

The announcement comes after weeks of growing speculation about his health and marks a sobering moment in American politics.

The diagnosis was made on Friday after doctors discovered a small nodule on Biden’s prostate during an examination prompted by increasing urinary symptoms.

According to the official statement, the cancer was graded as a Gleason score of 9 (Grade Group 5), indicating a high-grade tumor.

While serious, the cancer is reportedly hormone-sensitive, a factor that opens the door to potentially effective treatment options.