Earlier PSA Screening May Make Annual Testings Unnecessary
CHICAGO—PSA levels at the time of initial screening among men aged 44-50 years can accurately predict the risk that a man will die from prostate cancer (PCa) or develop metastatic PCa up to 30 years later, a Swedish study found.
Researchers concluded that an initial PSA test result for men in this age group makes it possible for approximately 50% of men to undergo just three PSA tests in their lifetime.
The study found that 44% of PCa deaths occurred in men in the top 10% of PSA levels (greater than 1.6 ng/mL) when they were tested between at ages 44-50. As a result, nearly half of all PCa deaths could potentially be prevented by intense surveillance of this small group of men. In addition, men with low PSA values for their age group are at comparatively lower risk of developing metastatic PCa or dying of PCa decades later. Thus, men with low PSA values need to be tested only three times in their lifetime.
“Doctors have urgently needed an effective PSA testing strategy that accurately distinguishes men at high risk for prostate cancer who need aggressive monitoring from those at low-risk of the disease, who can be safely spared from frequent testing,” said lead investigator Hans Lilja, MD, PhD, an attending research clinical chemist at Memorial Sloan-Kettering Cancer Center in New York. Dr. Lilja reported study findings at the 47th Annual Meeting of the American Society of Clinical Oncology.
The American Cancer Society recommends that men discuss PCa screening with their doctor at age 50 to determine whether it's appropriate for them. This study by Dr. Lilja's team suggests that men start that discussion with their doctor at an earlier age and receive their first PSA test at ages 44-50.
In the study, Dr. Lilja and his colleagues analyzed PSA levels in archived blood samples from 12,090 men provided between 1974 and 1986, and 4,999 repeat samples six year later as part of the Swedish Malmo Preventive Project. Using these samples, the investigators assessed the median PSA levels for ages 44-50, 51-55, and 60. The median levels at baseline served as the basis to distinguish men at high or low risk of dying from PCa or developing metastatic disease.
The investigators found that 28% of metastases or PCa deaths over the next 27 years occurred in men aged 44-50 who had a PSA below the median in the population (0.7 ng/mL). For men aged 51-55 with a PSA level below the median (0.8 ng/mL), the risk of metastatic disease or death was lower (18%). At age 60, only 0.5% of deaths or metastases occurred in men with a PSA less than the median for that age (1.1 ng/mL).
“This study supports other research showing that most men do not need annual PSA screenings,” said Peter Scardino, MD, Chairman of the Department of Surgery at Memorial Sloan-Kettering. “If men received their first PSA test at an earlier age, between 44 and 50, those with a low risk for developing a dangerous cancer could then be tested less frequently, reducing costs and the chances of overdiagnosis and overtreatment of indolent cancers.”