Many older men with low-grade prostate cancer may be able to live out the normal remainder of their lives without potentially dibilitating radiation or surgical treatment, researchers said Tuesday.

Scientists studying the medical records of 451 Connecticut men diagnosed with localized prostate cancer between 1971 and 1976 found that with little or no treatment, the men were no more likely to die sooner than healthy men of the same age group, 65 to 75 years.

However, the study also found that men in the same age range who were diagnosed with more aggressive, higher-grade prostate cancer had a six- to eight-year loss of life expectancy when the malignancy was treated conservatively with hormone therapy or no intervention.

The report, published Tuesday in the Journal of the American Medical Association, said that the findings suggest that more aggressive treatment of slow-growing and spreading tumors in older men is unwarranted.