Introduction of PSA screening has reduced metastasis risk
MedWire News: Men diagnosed with prostate cancer after 1993 - when routine prostate-specific antigen (PSA) screening was introduced - are less likely to experience disease spread than men diagnosed before 1993, study findings show.
Participants who were diagnosed in the pre-PSA screening era were more than three times as likely to develop metastases in the 10 years after treatment as those diagnosed after the introduction of PSA screening, report the researchers.
Chandana Reddy (Cleveland Clinic, Ohio, USA), lead author of the study, commented on the value of diagnosing prostate cancer at an earlier stage using routine PSA screening, thus "allowing men to live more productive lives after treatment."
The group evaluated the associations between PSA screening and metastasis development in a cohort of 1721 prostate cancer patients treated between 1986 and 1996. The researchers believe metastasis may be a better measure of the efficacy of screening than overall survival "since we are unable to cure metastatic disease."
The men were stratified into high-, intermediate-, and low-risk disease categories, according to National Comprehensive Cancer Network criteria, and after a median follow-up of 10 years, 13% of all patients had developed metastatic disease.
Reddy et al found that the metastasis-free survival rates for pre-PSA screening patients (1986-1992; n=575) were lower than those who underwent routine PSA screening (1993-1996; n=1146), at 58% versus 82% for high-risk patients, 79% versus 93% for intermediate-risk patients, and 90% versus 98% for low-risk patients.
In addition, after adjusting for the severity of disease (T stage, biopsy Gleason score), multivariate analysis revealed that patients in the prescreening group had a 3.5-fold increased risk for developing metastatic disease compared with patients in the PSA screening group.
Reddy also suggested that the study findings may have wider implications for the cost of treating prostate cancer: "Our study shows that routine screening not only improves the patient's quality of life by stopping metastatic disease, but it also decreases the burden of care for this advanced disease that must be provided by the healthcare system," she said.
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By Sarah Guy