TUESDAY, Sept. 15 (HealthDay News) -- Older men diagnosed with prostate cancer who choose watchful waiting are doing better these days than in the era before screening with a test for prostate-specific antigen (PSA) became common, a new study finds.

"The most important message is that the long-term outcome for patients who don't have surgery or radiation is pretty good," said study author Dr. Grace L. Lu-Yao, an associate professor of medicine at the University of Medicine and Dentistry of New Jersey. Her report appears in the Sept. 16 issue of the Journal of the American Medical Association.

That message applies only to men over 65 when prostate cancer is diagnosed. Lu-Yao and her colleagues analyzed data on 14,516 such men whose diagnoses were made between 1992 and 2002, at an average age of 78, and who did not have surgery or radiation in the next six months. The researchers followed them for an average of 8.3 years.

The study separated men by their Gleason score, which measures the degree to which the prostate gland has lost its orderly structure. Greater disorder indicates greater danger from the cancer.

The 10-year death rate from prostate cancer was 8.3 percent for men with the least disordered tumors. Their death rate from all other causes was 59.8 percent. For men with moderately disordered tumors, the 10-year prostate cancer-specific death rate was 9.1 percent, compared to a 57.2 percent death rate from all other causes. The prostate cancer death rate for men with the most disordered tumors was 25.6 percent, compared to 56.5 percent for all other causes.

The cancer survival numbers are much better than for the pre-PSA screening era, possibly because "patients now are diagnosed at a much earlier stage compared to patients 10 and 20 years ago," Lu-Yao said. Earlier detection translates to apparent longer survival simply because the cancer has a longer time to grow.

But the information in the study shouldn't be applied to younger men, Lu-Yao stressed. The best available data indicate better survival with treatment for men under 65, she said.

So, the study might send the wrong message about PSA testing to those men, said Dr. Richard Greenberg, chief of urologic surgery at the Fox Chase Cancer Center in Philadelphia.

"My concern is that 50-year-old men with family histories of prostate cancer will be listening to these statements that there is too much screening, so they won't have screening because they think it isn't necessary," Greenberg said.

He is skeptical about watchful waiting, except in carefully selected cases. "I don't think anyone under 60 is a great candidate for watchful waiting unless they have another condition that is going to do them in within 10 years," Greenberg said.

Every man diagnosed with prostate cancer should understand that watchful waiting is one possible option, he said. "But you have to individualize the decision for every patient," Greenberg said. "If they have an aggressive cancer, they should be treated aggressively. You need to be very selective when you say when a conservative approach is appropriate."

Treatment or watchful waiting for cancer in men 70 and older "is an important question, but probably not the most important question," said Dr. Martin Sanda, director of the prostate cancer center at Beth Israel Deaconess Hospital in Boston.

Sanda recently reported a study of younger men whose average age when they were diagnosed with prostate cancer was about 60. That study indicated that "lower-risk tumors probably can be managed with watchful waiting in men anywhere from the 40s to the 70s," Sanda said, but the key issue is the nature of the tumor.

"For patients with poorly differentiated tumors, there is a fair amount of cancer deaths unless they are treated aggressively," he said.

More definitive information about watchful waiting versus treatment of prostate cancers is expected from a study recently started in Canada and now being done in medical centers there and in the United States, Greenberg said. But results of that study are not expected for at least 10 years, he noted, and meanwhile men and their doctors need to make treatment decisions based on each man's characteristics.

"We need to individualize these decisions, even in the elderly," Sanda said.

More information

Learn about prostate cancer from the U.S. National Cancer Institute.

SOURCES: Grace L. Lu-Yao, M.D., associate professor, medicine, University of Medicine and Dentistry of New Jersey, Piscataway, N.J.; Richard Greenberg, M.D., chief, urology surgery, Fox Chase Cancer Center, Philadelphia; Martin Sanda, director, prostate cancer center, Beth Israel Deaconess Hospital, Boston; Sept. 16, 2009, Journal of the American Medical Association

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