PSA screening of little or no value?
Two large studies recently published strongly suggest that PSA screening for prostate cancer does not save lives. The studies are enormous, with an American study following 77,000 men and a European study involving 180,000 men. The men were followed in both studies for more than a decade.
The researchers concluded that 48 men were informed that they have prostate cancer and needlessly treated for every one life saved. The problem is that the cancer is a notoriously slow-growing one, and the screening fails to distinguish unusual, aggressive tumors that may not be treatable, even with early diagnosis. As a result, 49 of 50 men treated for prostate cancer would not have died from slow-growing cancer, but undergo expensive and life-altering treatment modalities. Prostate cancer treatment often results in impotence, incontinence, painful defecation or chronic diarrhea.
The American study found that the death rate among patients was 13 percent lower in the unscreened group after 7 years, while the European study found no statistical difference between screened and unscreened patients' survival. Similar issues apply in breast cancer screening, however, prostate cancer tends to be more benign, and therefore failing to screen carries fewer untoward consequences. It is estimated that 10 women receive unnecessary treatment for ultimately benign breast tumors for every one life saved by screening.