PSA screening has profoundly changed the natural history of prostate cancer in the United States. During the prostate cancer screening era, from 1992-2014, there was a 75% decrease in the percentage of men diagnosed with metastases and 53% decrease in the prostate cancer mortality rate. The Cancer Intervention and Surveillance Modeling Network (CISNET) estimated that 45%-70% of the mortality decrease is attributable directly to PSA screening.
Published results from a number of randomized clinical trials evaluating PSA screening also show benefits from testing. In these trials, men were randomly assigned to a screening arm and underwent PSA testing, or they were assigned to an unscreened or control arm. The study authors then compared rates of death and metastases between the two groups. The Goteborg trial reported 35% lower prostate cancer mortality in the screening arm. In the European Randomized Study of Prostate Cancer Screening (ERSPC), prostate cancer death was reduced by 21% in the screening arm. For men with 10- 11 years of follow-up, mortality was reduced by 38%. Both studies revealed a lower rate of metastases at diagnosis as well, indicating that PSA testing led to men being diagnosed before their disease had spread.
The Prostate, Lung, Colorectal, and Ovarian (PLCO) trial reported no mortality benefit; however, a recent CISNET statistical modeling study examining the conflicting ERSPC and PLCO results focused on differences in implementation of screening between the trials. This study reported that screening produced a significant reduction in prostate cancer mortality in both the trials: 25%-31% in ERSPC and 27%-32% in PLCO.
Prostate Cancer Overtakes Breast Cancer Deaths in the UK
According to the the charity Prostate Cancer UK, prostate cancer is the third deadliest cancer in the UK, following lung and bowel cancer.
In a statement, Prostate Cancer UK said that breast cancer has benefitted from a screening program and significant investment in research; there have been more than twice the number of studies published on breast cancer than prostate cancer.
Another possible cause could be that men are less likely to go see their doctors annually. According to the UK's Daily Mail, a recent study of 800,000 English patients found that women were twice as likely to have seen their general practitioner in the last year, indicating that UK men may be less likely to be checked for prostate cancer annually. Many prostate cancers grow slowly and often by the time men develop symptoms, the disease has spread outside of the prostate and it is more difficult to cure.
Key U.S. Statistics for Prostate Cancer
In 2018, the American Cancer Society estimates there will be about 164,690 new cases of prostate cancer and about 29,430 deaths from the disease.
Prostate cancer is the second leading cause of cancer death in U.S. men, behind lung cancer. About 1 man in 41 will die of prostate cancer in the U.S.