July 16, 2012 -- Although the United States Preventive Services Task Force (USPSTF) recently recommended against routine screening for prostate cancer for most men, a panel of experts from the American Society for Clinical Oncology (ASCO) says that many men could benefit from regular testing.
The panel of ASCO experts recommended that men with more than 10 years to live discuss with their doctors the risks and benefits of screening and whether they should get their levels of prostate-specific antigen (PSA) tested. A high level of PSA may indicate the presence of cancer. The USPSTF, on the other hand, said back in May that there is not enough scientific evidence that the benefits of screening outweigh the risks. Routine PSA screening could lead to false positives, which in turn could mean overdiagnosis and overtreatment.
Treatment for prostate cancer, the task force noted, may cause a number of problems including erectile dysfunction and urinary incontinence.
ASCO, however, agreed with USPSTF that screening is not recommended for men with 10 years or less to live. Additionally, ASCO did not include a specific age recommendation, only life expectancy. Doctors are not required to abide by ASCO or USPSTF guidelines -- they are only recommendations.
"A lot of men that have a long life expectancy would benefit from screening, especially those that will be diagnosed with aggressive forms of prostate cancer," said Dr. Robert Nam, an ASCO panel co-chair and head of genitourinary cancer care at the Sunnybrook Research Institute in Toronto. "Men with aggressive prostate cancer can benefit from early treatment."
Nam added that the ASCO recommendations include talking with health care providers about other factors to take under consideration, including family history.
He also said that the panel agreed with USPSTF's concern about overtreatment, but is urging men who find out they have high PSA levels to learn how significant the results really are before getting treatment.
"The meaning of a result may be entirely different for different people, he said. "For example, the risk is much greater for an African American male with a family history of prostate cancer than it is for a Caucasian male with no family history, even if they have the same PSA score."
In response to the USPSTF guidelines, the American Urological Association said men "who are in good health and have a 10-15 year life expectancy should have the choice to be tested and not be discouraged from doing so." The association also said the USPSTF's "blanket statement" should not be applied to at-risk populations, such as African Americans.
But Dr. Michael LeFevre, a co-vice chair of the task force, said "the existing science shows that the benefit does not outweigh the harms, and therefore recommends against screening."
However, he added that the recommendations do not aim to prevent men who choose to be screened from doing so, but say those who are tested should be fully aware of the risks.
Conflicting Data Complicate Recommendations
Nam said despite the recommendations, there is no clear answer on how beneficial PSA testing is. The panel based its decisions on a systematic review of studies done by the Agency for Healthcare Research and Quality (AHRQ). The USPSTF also used AHRQ data, but according to Nam, the data were a bit older and a couple of the studies were not very reliable.
Several doctors told ABC News they approach screening with their patients in a way that is more consistent with ASCO's recommendations.
"It's a much more reasonable and balanced approach than the USPSTF," said Dr. Peter Scardino, chief of surgery at Memorial Sloan-Kettering Cancer Center in New York. "The idea that we stop recommending PSA screening altogether is not tenable."
Scardino said some strong studies have found PSA testing led to a reduction in cancer-specific and overall mortality. Other studies, however, have found PSA testing to have no effect on the number of deaths.
"I now explain to my male patients that we do not think in general that prostate screening will reduce the risk of death from prostate cancer in general," said Dr. John Messmer of the Penn State Hershey Medical Group in Palmyra, Penn. "But if the man is willing to accept that he might find he has an elevated PSA, and a biopsy shows cancer, it is not a straight line to surgery or radiation." Messmer said he discourages routine screening unless there are other risk factors for prostate cancer or patients are willing to accept the risks of testing.
Dr. Gerald Andriole, chief of urologic surgery at Washington University School of Medicine in St. Louis, said after discussing the risks and benefits of screening with his patients, many of them still opt for testing.
"They are worried about having prostate cancer and generally would prefer to have the test, knowing it is imperfect, than not getting tested at all. At least it gives them some information on which to make health decisions," he said.
Low-Risk Prostate Cancers May Not Require Treatment
"I understand about the reasons the USPSTF was concerned -- they were disturbed by the false positive results and overdiagnosis and overtreatment," said Scardino. "It's very important for people to know that many low-risk prostate cancers do not need to be treated. They can be monitored with little risk. Prostate cancer is not uniformly lethal."
An approach known as active surveillance involves monitoring low-risk cancers, but not treating them.
"Data to date suggest that with this approach we can identify the more aggressive, large cancers and still successfully treat them," said Andriole. "Active surveillance is apt to be better than early treatment with surgery or radiation therapy for many men with low-risk cancers and should lessen overtreatment."
Experts also agree that the development of better testing could someday provide a more definitive answer to questions about whether to perform routine screening.
Messmer explained there needs to be a better way to determine who needs treatment.
"We need genetic analysis of diagnosed prostate cancers to determine which ones will be fast growing and spread and which will not," he said.