Debates at Society of Urologic Oncology Meeting on Continuing Controversies & Conundrums in Treating Prostate Cancer

BETHESDA, MD—Is early-stage prostate cancer underdiagnosed or overdiagnosed? What measures should be used to determine which men with early-stage prostate cancer need intervention and which do not? How large a role should age play in this determination? Physicians discussed and debated these and other continuing controversies at the recent Society of Urologic Oncology Annual Meeting, held here at the National Institutes of Health, sponsored jointly by the Society and the NCI.Figure: Laurence H. Klotz, MD, noted that there has been a trend toward shifting Gleason scores upward in the last 15 years, which he said could lead to more aggressive treatment—“The Gleason sixes of 20 years ago would probably be called sevens today.”“There are many men with low-risk prostate cancer whose disease is not biologically aggressive,” said Laurence H. Klotz, MD, Chief of the Division of Urology at Sunnybrook and Women's College Health Sciences Centre and Professor of Surgery at the University of Toronto. “I think it comes down to risk versus benefit. We know we are diagnosing a huge number of men with low-risk disease. If we don't reduce the amount of overtreatment in men with low-risk prostate cancer, we may throw the baby out with the bath water.” Dr. Klotz also noted that there has been a trend toward shifting Gleason scores upward in the last 15 years, which he said could lead to more aggressive treatment—“The Gleason sixes of 20 years ago would probably be called sevens today.” Dr. Klotz said that in his experience, a minority of prostate cancer patients, about 20%, will have a prostate-specific antigen doubling time of less than three years. He said patients who elect watchful waiting do accept the idea of PSA monitoring over time as a way to determine when and if a treatment intervention becomes advisable. And, Dr. Klotz said, electing watchful waiting does not appear to produce any more adverse psychological effects in patients than opting for a radical prostatectomy. But Patrick C. Walsh, MD, who pioneered nerve-sparing prostatectomy, cautioned that watchful waiting is not a clear-cut strategy. “The question is, who should be a watchful-waiting candidate? I don't think the answer is clear,” Dr. Walsh, Professor of Urology at Brady Urological Institute of Johns Hopkins Hospital, said in an interview. Current Terminology Noting that there are a large number of men in their 60s who have a small amount of cancer in their prostate, he said that the terms “expectant management” or “delayed intervention” now are considered more accurate than “watchful waiting” for describing medical management of patients with very early-stage prostate cancer. Some participants at the meeting raised the concern that expectant management that delays surgery may make it more difficult to perform a nerve-sparing radical prostatectomy should surgery be advised later on. Dr. Walsh cautioned that for those patients who do elect expectant management, PSA should not be used alone for monitoring their condition. “In men with cancer progression, 25% do not have an increase in PSA,” he warned. Thus, “PSA shouldn't be relied on as the only measure of [cancer] progression.” When PSA is used for clinical management, Dr. Walsh advised that PSA velocity (the measure indicating how rapidly a PSA level rises over time) is most valuable pre-treatment, while PSA doubling time is most valuable for monitoring patients who have been treated for prostate cancer. Specifically, recent studies discussed at the meeting have suggested that a man whose PSA level rises by more than 2.0 ng/mL in the year before diagnosis may have a high risk of dying from prostate cancer. Dr. Walsh, asked if he has noted any change in the rate of radical prostatectomies performed since watchful waiting with PSA monitoring has become more widely used, said that he thinks that the demand for radical prostatectomy has remained steady. Increased Survival Although prostate cancer treatment decisions may be challenging, there is no argument about the big strides that have been made in extending survival for men with prostate cancer. Currently, 90% of all prostate cancers are discovered in the local and regional stages, and the five-year relative survival rate for patients whose tumors are diagnosed at these stages is close to 100%, according to statistics from the American Cancer Society. The ACS attributes this and the dramatic improvement in 10-year relative survival from prostate cancer, now 92%, partly to earlier diagnosis and partly to treatment improvements.Figure: William J. Catalona, MD, said that over-diagnosis of prostate cancer—i.e., detection of very small, low-grade tumors—is more common in older men because they have a shorter lifespan and, if left untreated, may die of something else first. But, he noted, “We all know that localized tumors can acquire aggressive features over time.” He estimated that only about 10% to 15% of prostate cancers are over-diagnosed, while some 20% to 30% may be under-diagnosed. And, he stressed, “Over-diagnosis rates calculated in older men should not be extrapolated to younger men.”Figure: Patrick C. Walsh, MD, explained that the terms “expectant management” and “delayed intervention” are considered more accurate than “watchful waiting” to describe medical management of patients with very early-stage prostate cancer. Some participants at the meeting raised the concern that expectant management that delays surgery may make it more difficult to perform a nerve-sparing radical prostatectomy should surgery be advised later, but Dr. Walsh cautioned that for those patients who do elect expectant management, PSA should not be used alone for monitoring.The 75% decrease in the number of men with prostate cancer presenting with metastases and the 25% decrease in mortality from prostate cancer are remarkable, agreed William J. Catalona, MD, Professor of Urology at Northwestern University Medical Center and Director of the Clinical Prostate Cancer Program for the Robert H. Lurie Comprehensive Cancer Center at Northwestern. In a keynote award lecture, Dr. Catalona said that the prostate cancer mortality rate is decreasing fastest in the United States. Nonetheless, the treatment conundrum remains. “This is a burning question,” he noted. “How many men need to be diagnosed and treated?” Dr. Catalona said that over-diagnosis of prostate cancer—i.e., detection of very small, low-grade tumors—is more common in older men because they have a shorter lifespan and, if left untreated, they may die of something else first. But, he noted, “We all know that localized tumors can acquire aggressive features over time.” Dr. Catalona estimated that only about 10% to 15% of prostate cancers are over-diagnosed, while some 20% to 30% may be under-diagnosed. And, he stressed, “Over-diagnosis rates calculated in older men should not be extrapolated to younger men.” Noting that under-diagnosis is “more deleterious in a younger man,” Dr. Catalona said that under-diagnosed patients have 30% lower progression-free survival rates. ‘Need to Use PSA More Intelligently’ “We need to use PSA more intelligently,” advised Dr. Catalona, who pioneered the PSA test for prostate cancer detection. He said intelligent use of PSA provides a continuum of risk-assessment across time. He noted that today there are different PSA ratings, resulting from different PSA standards. “We need to find a cut-off for curable prostate cancer,” he said. What is known today, said Dr. Catalona, is that the higher the PSA level the more likely it is that the patient has prostate cancer, and if the patient's PSA is higher than the comparable median age-specific PSA, the risk of prostate cancer is higher than normal. Dr. Catalona also said that total PSA correlates with prostate cancer velocity and with aggressive cancer. There is an under-used PSA measure—PSA density—that can be clinically helpful, Dr. Catalona advised. “We have ignored PSA density,” he said, noting that this measure relating a man's PSA level to the size of his prostate is important because it correlates with tumor volume, Gleason grade, and progression-free survival. He said the PSA density measure should definitely be used on men with positive digital rectal examinations. PSA velocity is a useful measure for determining whether prostate cancer is aggressive, but Dr. Catalona cautioned that “prostatitis greatly confounds the use of PSA velocity for cancer detection,” such that “a very high velocity is more likely to be due to prostatitis.” Perform Radical Prostatectomy on 67-Year-Old Man with Low-Risk Prostate Cancer? During the meeting, the 273 registrants were asked for a show of hands on how many would perform a radical prostatectomy on a 67-year-old man with low-risk prostate cancer who requested the surgery. The majority of those in the audience raised their hands. Although deciding which patients need aggressive treatment and which do not remains unclear, participants at the meeting did agree that shared decision-making is the best way to approach prostate cancer treatment. “I do not make decisions for these patients,” Dr. Walsh emphasized. “I tell them what their options are.” ASCO's Views on Prostate Cancer Dilemma The American Society of Clinical Oncology's Clinical Cancer Advances 2005 report, released at the end of last year, notes that today many more prostate cancer patients are being diagnosed with early-stage disease due to widespread PSA testing, but that “there is no clear understanding about which patients require aggressive treatment.” This is especially true, the report says, for older men who may be more likely to die of other causes first. The ASCO report cites Scandinavian research showing that after 10 years, the risk of prostate cancer death among men with early-stage disease who had their prostates removed was 44% lower than among men who did not have surgery (the watchful waiting group). The benefits of surgery were greatest among men under age 65. “Based on these data, men under age 65 who have early-stage prostate cancer should undergo surgery to remove the prostate, while older men may choose watchful waiting,” the report concludes. A poster study presented at the Society of Urologic Oncology Annual Meeting of 5,509 patients treated by radical prostatectomy at the Mayo Clinic between 1987 and 1995 supports the ASCO report's conclusion. In the Mayo Clinic study, the men were divided into age categories of younger than 55, 55 to 59, 60 to 64, 65 to 69, and 70 and older. While the overall survival of older and younger men undergoing radical prostatectomy in this study was similar, the benefits were greater for younger men, whose life expectancy was longer at diagnosis. The Mayo Clinic researchers pointed out that “Given the greater proportionate impact of prostate cancer on survival, it is particularly important to pursue aggressive treatment for younger patients.”

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.