Prostate-Specific Antigen (PSA) testing performs optimally when conducted intelligently and combined with prompt, effective, high-quality treatment according to the updated NCCN Clinical Practice Guidelines in Oncology(TM) for Prostate Cancer Early Detection. In the wake of the recent confusion that ensued after the publication of two PSA screening trials, the European Randomized Study of Screening for Prostate Cancer (ERSPC) and the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO) conducted in the United States, the NCCN Guidelines Prostate Cancer Early Detection Panel Members stress that PSA testing is effective and needs to be more rigorous in high-risk populations.
"PSA testing has saved thousands of lives and continues to be an important tool in the fight against prostate cancer," says Mark Kawachi, M.D., Chair of the NCCN Guidelines for Prostate Early Detection and Associate Professor of Surgery, Urology and Urologic Oncology at City of Hope Comprehensive Cancer Center. "We are most likely to produce further declines in prostate cancer mortality if we focus on younger men who are more likely to die of prostate cancer than other causes and the diagnosing of aggressive prostate cancer in all men."
Information about the ERSPC trial is incorporated into the updated NCCN Guidelines in the 'Suggested Talking Points for Discussion with a Potential Screenee about the Pros and Cons of PSA Testing' section. The information summarizes the trial and reiterates the researchers' conclusions that PSA screening reduced the rate of death from prostate cancer in men who were screened, although it resulted in a high risk of overdiagnosis. This led to several reports suggesting that screening for prostate cancer saves few lives.
NCCN Guideline Panel Members note the importance of the ERSPC trial, but caution that it needs to be considered in view of its flaws.
"Past research indicates that African-American men as well as men with a family history of prostate cancer have a significantly increased risk of developing the disease," says Kawachi. "The European study (ERSPC) did not include any information about family history or specify the racial composition of its patients."
The PLCO trial from the United States, which reported that PSA screening did not reduce the risk of death from prostate cancer, also lacked in heterogeneity and included a very small number of patients with a family history of prostate cancer or African-American men.
This suggests that the majority of men who participated in the two trials were not at a high-risk of developing advanced prostate cancer, so it is not surprising that PSA screening would have little impact on their risk of death from the disease.
"Some of the controversy with the recent trials assessing the benefits of PSA testing stems from people confusing early detection with screening," says Kawachi. "It is imperative to distinguish the two terms from each other and understand that screening implies testing a random group of participants whereas early detection targets a select group of patients whose need is greatest."