Warren Buffett, Berkshire Hathaway chairman and CEO, at a party in New York City in May 2011
In a statement addressed to the shareholders of his company, Berkshire Hathaway, Warren Buffett announced on Tuesday that he has Stage 1 prostate cancer. The 81-year-old described his disease as “not remotely life-threatening or even debilitating in any meaningful way.”
Buffett said that he was diagnosed last week and that a subsequent CAT scan, bone scan and MRI did not reveal any additional cancer elsewhere in his body. Buffett and his doctors decided on a two-month radiation treatment to begin in mid-July. “This regimen will restrict my travel during that period, but will not otherwise change my daily routine,” Buffett said.
The prognosis for such early-stage cancer is generally good, and because prostate cancer is typically so slow-growing, for older men it’s unlikely to be fatal — they will die with the disease not because of it. About 99% of men with prostate cancer at any stage will survive five years after their diagnosis, and almost all men who have cancers that have not spread beyond the prostate can expect to survive another five years.
Over a lifetime, 1 in 6 men will be diagnosed with the disease. The mortality rate is 1 in 35.
(MORE: Prostate Cancer Screening: What You Need to Know)
Some experts wondered why Buffett chose to get treated at all, rather than pursuing active surveillance in which the cancer is monitored for sudden growth but isn’t treated. “In men who are octogenarians with low-risk cancer of the prostate, where the likelihood of death is very low, the first thing that comes to mind is, can we put them on active surveillance?” Dr. Louis Potters, chairman of radiation medicine at North Shore-LIJ in New York, told Reuters.
Potters also questioned why Buffett was being screened for prostate cancer, which is not recommended for men over 70. Prostate cancer is often detected by a prostate-specific antigen (PSA) test, which checks the blood for a hormone produced by the prostate. Buffett said that his cancer was discovered because “my PSA level (an indicator my doctors had regularly checked for many years) recently jumped beyond its normal elevation,” which prompted a biopsy that turned up the cancer.
Elevated PSA scores can be a marker of cancer, but more often, they signal noncancerous conditions like enlarged prostate (the walnut-sized gland typically enlarges with age) or infection or inflammation of the prostate. Even ejaculation and riding a bicycle can push PSA levels higher. In fact, most elevated PSA results are false-positives: only 25% to 35% of men who have a biopsy due to a raised PSA level turn out to have cancer, according to the National Cancer Institute; unnecessary biopsies carry the risk of side effects like bleeding and infection.
Studies have questioned the value of routine PSA testing: in January, updated findings from one of the largest studies on prostate-cancer screening showed that PSA tests don’t save lives. And last fall, the U.S. Preventive Services Task Force concluded that healthy men should no longer be screened routinely for prostate cancer using the PSA test.
(MORE: When Cancer Screening Does More Harm than Good)
At Stage 1, however, a PSA test is generally the only way to detect prostate cancer; tumors are too small to be felt by a doctor performing a digital rectal exam or by scans. In most cases, the cancer is so nascent that it hasn’t had a chance to spread beyond the prostate gland itself. Treatment typically includes radiation or freezing of tissue to destroy the malignant growths. Another option is active surveillance.
Stage 2 cancers include disease that is more visible and detectable but remains localized in the prostate gland (actor Ryan O’Neal recently revealed that he has Stage 2 prostate cancer). Because the growths are larger, in some cases doctors may recommend surgery to remove the tumors, along with radiation or hormone therapy.
In Stage 3 cancers, the disease has begun to spread beyond the prostate and may have started to invade nearby tissues. Surgery may still remove the largest masses, while radiation can address smaller metastases.
In the most advanced prostate cancer, the tumors have spread from the organ to the lymph nodes, bones, liver or lungs and is more difficult to treat.
(MORE: Experimental Prostate Cancer Treatment Shows Promise)
Buffett has said that his early-stage cancer isn’t slowing him down any. “I feel great — as if I were in my normal excellent health — and my energy level is 100 percent,” he told shareholders, giving no indication that he planned to step down as chairman or CEO of Berkshire anytime soon. As if to prove the point, he kept up a high-energy schedule after his diagnosis last Wednesday: according to Carol Loomis of Fortune, he lunched with Jimmy Buffett on Thursday; hosted 160 international business students for visits to Berkshire Hathaway, a Q&A with the CEO and lunch at one of Buffett’s favorite restaurants on Friday; and went to a Jimmy Buffett concert on Saturday. He was back at the doctor’s office at 7:30 a.m. on Monday to discuss treatment.
“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,” Buffett said.
Nevertheless, the chairman’s — and 2012 TIME 100 honoree’s — cancer news has got shareholders and observers thinking about the company’s succession plan — which our colleagues at TIME Business weigh in on here.
Alice Park is a writer at TIME. Find her on Twitter at @aliceparkny. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.