E. David Crawford, MD
The US Preventive Services Task Force (USPSTF) recommends against routine PSA-based screening for prostate cancer, citing concern for unnecessary and potentially harmful biopsies, surgery, and radiotherapy.
However, urologists and other prostate cancer specialists are concerned that limiting early detection measures like PSA screening could lead to more cases of prostate cancer being detected at an advanced stage, says E. David Crawford, MD.
“One of the biggest challenges right now in prostate cancer is early detection,” says Crawford, a professor of Surgery, Urology, and Radiation Oncology and an endowed chair in Urologic Oncology at the University of Colorado. “Because the USPSTF and other organizations kind of put a damper on the standard early detection methods, we need another solution.”
Crawford discussed possible early detection solutions at the 2016 International Prostate Cancer Update, which was held January 21 to 23, 2016, in Vail, Colorado. In an interview with OncLive
, he explains his view of the current role for PSA testing in prostate cancer and the need for continued innovation and advancement with new screening technologies.
OncLive: How has the use of PSA as a screening tool for prostate cancer risk changed over the years?
: A number of years ago, I was involved in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial, a large population-based randomized trial designed to determine the effects of screening on cancer-related mortality.
During that trial, I looked at a group of men stratified by their initial PSA and what happened to them during the 7 to 10 years of the trial. From that study, it was very obvious that if patients had a PSA of less than 1, their risk of having a PSA go above 4—the cutoff for biopsy—was around 0.3%. At the time, we presented our belief that if we follow the rule that if PSA is less than 1, then patients should come back in 5 years, and we could save the healthcare system $800 million to $1 billion.
About 4 years ago, we started working with the Henry Ford Health System database, which is very robust. Knowing that a PSA of 1 had been previously identified as a cutoff, we looked at people who had a PSA of less than 4 to see what happened to them over 5 years.
In an analysis of 22,000 men with an initial PSA between 1 and 4 in the cohort at Henry Ford, we found that those patients with a PSA of less than 1.5 had a 0.4% risk of being diagnosed with prostate cancer within 5 years. That is very low. For patients who had a PSA of 1.5 to 4, the risk of developing prostate cancer within 5 years was 8% to 12%, with the 12% representing African-American risk and the 8% representing Caucasian risk.
We felt that a PSA of 1.5 was a safety zone that represented patients who were not at risk for developing prostate cancer, while a PSA between 1.5 and 4 was a danger zone for prostate cancer risk and large prostate size.
What is the role of PSA now, and how can urologists utilize the test while still reducing the risk of overdiagnosis?
Most urologists are not ordering PSA tests. Internal medicine doctors order over 64% of tests, and family medicine doctors order another 23%. Urologists are only ordering 6% of PSA tests.
To address this issue, urologists need to work with family doctors. There was an initiative to get them to educate patients about screening choices and risks so they could make an informed decision. We felt that there should be an informed decision-making process with patients before a PSA is ordered because the test can set off a series of events, including unnecessary biopsies, overdiagnosis, and overtreatment. We gave them a lot of information to do this.
However, family practice doctors have, at maximum, a 30-minute visit with their patients. A lot of that time is taken up by other things they need to discuss with them. Finding time to help patients make an informed decision about prostate cancer screening was difficult. We tried to educate them on the importance of informed screening, and it just didn’t happen because it was too much. The initiative failed.
What other steps are being taken to educate family practitioners on how to best use PSA?
After that initiative failed, our next approach was to reinvestigate the 1.5 PSA and list it as a cutoff to family practice doctors. They needed a simple message. We were giving them all these facts of PSA and it was complex. With this approach, we told them that if patients have a PSA of 1.5 or less, they should come back in 5 years. You treat PSA like any other lab test a family practice does. Family practice doctors are not going to be able to talk to patients about an informed decision before giving a PSA test.
The question then becomes, “What percentage of men have a PSA of less than 1.5?” We determined that approximately 70% of men have a PSA of less than 1.5. Therefore, only 30% of patients require some attention.
What steps should be taken for men who have a PSA that is over 1.5? Is biopsy still the solution?
For those men, doctors should not necessarily order a biopsy, but they should go to the next step. There are new tests out, such as the 4KScore test and the PCA3 test. The PSA can also simply be repeated, and then doctors should take action behind that. Patients should only be biopsied if they have a PSA of more than 1.5. They undergo the next level of testing, and then it is determined if they are at high risk.
It is a step forward to find people who need to be biopsied and determine the cancers that could potentially benefit from treatment. Doctors need to be smart about it; there is a range to do early detection. It should not be done on 25-year-old men or 85-year-old men. For me, the range is 45 to 70 with a 10-year life expediency.