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BALTIMORE, MARYLAND. The number of men diagnosed with prostate cancer has
increased dramatically since the introduction of the PSA (prostate specific
antigen) test. Widespread use of the PSA test has led to more men undergoing
biopsies, prostate surgery, radiation therapy, and castration (orchidectomy) -
this despite the fact that no randomized clinical trial has ever demonstrated
that screening and treatment will increase the life expectancy of men diagnosed
with prostate cancer.
Researchers at the Johns Hopkins School of Hygiene and Public Health report that aggressive treatment of prostate cancer is associated with an increased risk of dying from other cancers. Their study involved 1996 prostate cancer patients (diagnosed from 1987 through 1989) and 6586 men with benign prostatic hyperplasia (enlarged prostate) who did not have prostate cancer. The men were all 67 years of age or older at the time of diagnosis. By the end of 1995 1207 of the patients in the prostate cancer group had died (60 per cent) as compared to 2906 patients in the non-prostate cancer group (44 per cent). Prostate cancer as such was the cause of death in 39 per cent of the prostate cancer group with the remaining 61 per cent dying from other causes such as heart disease, stroke, and other cancers. The percentage of prostate cancer patients who died from prostate cancer rather than from other causes was significantly higher among men with advanced prostate cancer than among men with localized tumors only. Combining all deaths from prostate cancer (no distinction was made by severity) it was found that patients who underwent radiation therapy had an 81 per cent higher risk of dying from prostate cancer than did men who received no treatment (watchful waiting). Patients who received hormones or were castrated increased their risk of dying by 85 per cent (compared with no treatment) while men who just underwent surgery with no additional treatment had a 23 per cent lower death rate (from prostate cancer) than did men who had not received any treatment.
Of particular interest is the finding that the adjusted odds of dying from other
cancers was 29.9 per cent among aggressively-treated prostate cancer patients as
compared to only 13.7 per cent among non-treated (watchful waiting) patients and
18.9 per cent among non-prostate cancer patients. It was also clear that the
risk of dying from prostate cancer decreases with age. Men whose prostate
cancer was diagnosed at age 85 or older had a 44 per cent lower risk of dying of
prostate cancer than did men whose cancer was diagnosed between the ages of 67
and 74 years. The researchers caution that bias in reporting cause of death may
have influenced the study results and recommend additional studies to support or
discard the hypothesis that early detection and treatment lead to decreased
prostate cancer mortality.
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