Older men with low-risk prostate cancer may be better off getting regular check-ups that rushing to get surgery or radiation, researchers using a computer model suggested on Tuesday.

That is largely because most men have at least one side effect from treatment, the team from the Dana-Farber Cancer Research Institute and Harvard Medical School in Boston said on Tuesday.

Their findings, published in the Journal of the American Medical Association, are based on a computer model that compares initial treatment with surgery or two common types of radiation with a program of close monitoring and routine testing called "active surveillance."

In this hypothetical model, they said a 65-year-old man with low-risk prostate cancer who got active surveillance came out ahead based on a scale that takes into account both quality of life and life expectancy.

Low-risk or early prostate cancer means that cancer cells have been found only in the prostate gland. Even without treatment, many men with low-risk prostate cancer will live with it until they eventually die of some other, unrelated cause.

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"The message is clear: active surveillance was associated with the highest benefit in terms of quality adjusted life expectancy (by at least 6 additional months) compared with other treatment options," Dr. Ian Thompson of the University of Texas Health Science Center at San Antonio and Dr. Laurence Klotz of Sunnybrook Health Science Center in Toronto wrote in a commentary.

Prostate cancer kills about 250,000 men a year globally and is the second most common cause of cancer death in men in the United States, after lung cancer.

Screening tests known as prostate specific antigen or PSA tests have reduced prostate cancer-related deaths, but PSA testing identifies many slow-growing cancers that may never need treatment.

Once diagnosed, more than 90 percent of men with low-grade prostate cancer get treated, most often with surgery or radiation. Both can cause lasting side effects including impotence or incontinence.

Dr. Julia Hayes of Dana-Farber and colleagues wanted to weigh the benefits and risks of these treatments with active surveillance in men with low-risk prostate cancer.

The team built a computer model comparing the impact of initial treatment with surgery or radiation therapy or a program of close monitoring, which included getting regular PSA tests, rectal exams and biopsies.

They found that active surveillance is associated with significant improvements in quality of life, even accounting for a slightly higher risk of cancer.

The study makes clear that for the majority of men with low-risk disease, delaying treatment and closely monitoring the disease offers an "attractive option that avoids adverse effects of treatment," Thompson and Klotz wrote.

They said lab and imaging tests are under development to help identify which cancers are most likely to progress, but until they become available, watching and waiting is a reasonable choice for many men with low-risk cancers.