Men under 65 with early prostate cancer had better survival odds if they had surgery right away instead of waiting for treatment only if their cancer got worse, a study in Sweden found.
That was true even for tumors thought to be low-risk because they didn't look very aggressive under a microscope.
Doctors have long debated whether and how to treat such early cases, and the study shows "there clearly is a benefit to getting the cancer out in the younger population," said Dr. Richard Greenberg, urology chief at Fox Chase Cancer Center in Philadelphia.
But there's a big caveat: The benefit may depend on how a man is diagnosed.
About 95 percent of the cancers in the Swedish study were found because they were causing symptoms. In the United States, however, most are found after a PSA blood test suggests a problem, long before symptoms appear. Most of these cancers will not prove life-threatening, but there's no sure-fire way to tell which ones will, so many men are get treatment they may not need.
The study is one of the longest-running attempts to look at this issue. It was led by researchers at University Hospital in Uppsala and the Karolinska Institute in Stockholm, and paid for by the U.S. National Institutes of Health and the Swedish Cancer Society. Results appear in Thursday's New England Journal of Medicine.
Starting in 1989, nearly 700 men under 75 were assigned to have surgery right away or to be monitored and treated if their cancer got worse. Most were having symptoms - urinary problems, blood in the urine or semen, trouble getting an erection, or pain in the lower back, hips or upper thighs.
After about 13 years of follow-up, there were fewer deaths among those who had surgery - 166 versus 201 of those being monitored. Prostate cancer was the cause for 55 and 81 of the deaths, respectively.
That means surgery lowered the risk of dying of prostate cancer within 15 years by 38 percent, researchers calculated. But the benefit was significant only for men under 65. In that age group, only seven men would need to be treated to save one life.
More men in the group initially assigned to monitoring saw their cancer spread beyond the prostate, and more of them wound up taking hormone treatments as a result.
Surgery had side effects - 58 percent of men reported at least some sexual problems and 32 percent had some urinary trouble. Researchers did not report how many men in the monitoring group had these problems, which are common as men age even if they don't have prostate cancer.
Surgery techniques have improved since the study began, and nerve-sparing approaches to minimize side effects are more common now.
The study "has provided important evidence that effective treatment is both necessary and possible for many men with early-stage prostate cancer," Dr. Matthew R. Smith of Massachusetts General Hospital wrote in an editorial in the journal.
But whether surgery benefits men with early cancers detected through PSA tests rather than symptoms remains to be seen, he added.
Two studies, one in the United States and one in the United Kingdom, are looking at this now, and include other options besides surgery, he notes.
About half of the 218,000 men diagnosed in the United States each year with prostate cancer have early, low-risk disease, and most choose to treat it right away with surgery, radiation or hormones. In Europe, most choose monitoring and treatment only if it gets worse.
Explore further: Very overweight teens may double their risk of bowel cancer in middle age
Prostate cancer info: www.cancer.gov/cancertopics/types/prostate
Risk calculator: tinyurl.com/riskcalculator
New England Journal: www.nejm.org