According to WSJ:

Breaking news from Warren Buffett and Berkshire Hathaway that is crossing the wires right now: He has been diagnosed with non life-threatening prostate cancer. Here is the release from Buffett, who says “I feel great.”

Reuters

To the Shareholders of Berkshire Hathaway:

This is to let you know that I have been diagnosed with stage I prostate cancer. The good news is that I’ve been told by my doctors that my condition is not remotely life-threatening or even debilitating in any meaningful way. I received my diagnosis last Wednesday. I then had a CAT scan and a bone scan on Thursday, followed by an MRI today. These tests showed no incidence of cancer elsewhere in my body.

My doctors and I have decided on a two-month treatment of daily radiation to begin in mid-July. This regimen will restrict my travel during that period, but will not otherwise change my daily routine.

I feel great — as if I were in my normal excellent health — and my energy level is 100 percent. I discovered the cancer because my PSA level (an indicator my doctors had regularly checked for many years) recently jumped beyond its normal elevation and a biopsy seemed warranted.

I will let shareholders know immediately should my health situation change. Eventually, of course, it will; but I believe that day is a long way off.

Warren E. Buffett