Diagnose prostaatkanker: In 30 tot 44 procent van PSA verhoging is sprake van overdiagnose bij mannen met verdenking van prostaatkanker

We hebben dit bericht al eens eerder gemeld, zie elders op deze pagina, maar een grote epidemiologische studie (gepubliceerd d.d. 3 juli 2002 in the Journal of the National Cancer Institute) uitgevoerd door Dr. Ruth Etzioni aan het Fred Hutchinson Cancer Research Center in Seattle bevestigt dat veel mannen van boven de 60 jaar die worden gediagnosteerd via hun PSA test en beginnende tumoren onnodig worden geopereerd en behandeld voor hun prostaatkanker. Twee miljoen Amerikaanse mannen zijn via een computersimulatie gevolgd over een periode van tien jaar. Daarbij is gekeken hoeveel mannen op basis van statistische prognoses prostaatkanker zouden krijgen. Nu blijkt uit dit onderzoek dat 29% van de blanke mannen en 44% van de zwarte mannen die weliswaar 'positief' werden getest op een verhoging van hun PSA met bijbehorende kleine tumoren, maar volgens de statische prognoses niet stierven gecorrigeerd naar behandeling enz., aan hun prostaatkanker. Er is hier dan ook sprake van een ernstige vorm van overdiagnose zoals onderzoekleidster Dr. Ruth Etzioni stelt in een interview met CBS. Er is dan ook volgens dit onderzoek vaak sprake van zinloze, dure en levensbedreigende of in ieder geval levenskwaliteitbedreigende behandelingen bij mannen van boven de 60 met beginnende prostaatkanker. Het lijkt me zinnig als u als man van boven de 60 geconfronteerd wordt met een verhoogde PSA test en eventueel kleine tumoren om dan voor alle zekerheid een second opinion te doen en, maar dit is heel persoonlijk en zie dat niet als medisch advies, maar een aanpassing in eten en extra suppletie (vitamine E bv.) of starten met PC-SPES (zie bv. verhaal van Henk Trentelman) zou het overwegen waard zijn. Hiervoor zou ik u dan aanraden een consult bij een orthomoleculaire arts te doen. Ik ken inmiddels veel mannen die duidelijk gebaat zijn bij gezonde voeding en bepaalde suppletie en PC-SPES. Zoveel en zo vaak levensverlengend dat dit geen toeval of placebo-effect kan zijn. Maar nogmaals dit is een eigen keuze en ook hier is onze disclaimer uiteraard van toepassing. Hieronder hoe CBS News over dit bericht melding maakte. Is misschien interessant te zien hoe een Amerikaans nieuwsstation hiermee omgaat. In Nederland heb ik alleen een klein berichtje weggestopt in een bijlage van de Volkskrant kunnen vinden. Ons bericht van professor Schröder die hetzelfde beweerde op een heel groot internationaal congres heeft nooit de media in Nederland gehaald. Over selectiviteit gesproken. Alsof dit geen nieuws is voor de gemiddelde Nederlandse man.

Bron: CBS News
(CBS) Many men over 60 are receiving unnecessary surgery and other treatments for prostate cancer even though the disease is unlikely to progress far enough to cause health problems, according to one analysis.

A study in the Journal of the National Cancer Institute examined the use of a blood test to find prostate cancer in a group of patients 60-84 over a 10-year period. It concluded that 29 percent to 44 percent of the men were "over-diagnosed."

Those patients may have received surgery or radiation treatment for prostate cancer that would never have progressed so far that it threatened their health, said Ruth Etzioni, a biostatistician at the Fred Hutchinson Cancer Research Center in Seattle.

"Over those 10 years, of the men diagnosed as a result of the PSA test, up to 30 percent may have been treated unnecessarily," said Etzioni.

The findings, sure to be controversial in a society where men are often reluctant to be screened for cancer anyway, suggest doctors should be careful when discussing a prostate cancer diagnosis with patients.

The prostate specific antigen or PSA test was approved in 1986 by the U.S. Food and Drug Administration. It measures levels of a molecule produced only by prostate cells, and overproduced by prostate cancer cells.

The higher the levels, the more likely a man is to have prostate cancer. Prostate cancer is the second leading cancer killer of men, after lung cancer, affecting 189,000 men this year in the United States and killing 30,000.

The test doubled the number of men diagnosed with the disease.

Etzioni said prostate cancer is a slow-moving disease. Many older men may have prostate tumors that will never become life-threatening because they will die of other causes before the cancer has a chance to spread.

Over-diagnosis for prostate cancer is a concern because active treatment - surgery or radiation - can have debilitating side effects. Etzioni said that about 80 percent of men who have prostate cancer surgery experience impotence, often permanently. For those treated with exterior beam radiation, the impotence rate three years later is about 43 percent. About 10 percent are incontinent after surgery, she said.

Etzioni and colleagues used a computer simulation of 2 million hypothetical men aged between 60 and 84.

They compared what their model predicted would have been the prostate cancer rate between 1988 and 1998 if there was no PSA test, with what was actually registered in the National Cancer Institute's Surveillance, Epidemiology and End Results database.

They found about 29 percent of white men diagnosed with prostate cancer, and 44 percent of black men, would not have ever been diagnosed in the days before PSA testing. This suggests they had such a slow-growing form of cancer that it would never have caused significant symptoms.

The same researchers found in 1998 that only 9 percent of all American men were ever diagnosed with prostate cancer before 1986. Autopsy evidence has shown that 36 percent of white men and 28 percent of black men turn out to have had prostate cancer when they get an autopsy after dying of something else.

Based on this, the researchers said, only 4 percent of white men and 7 percent of all black men in the population will be diagnosed with cancer using a PSA test and thus over-diagnosed -- an argument that suggests most men do not risk getting an "over-diagnosis" of prostate cancer.

Dr. Darracott Vaughan, a New York urologist and a recent president of the American Urological Association, said that the Etzioni study fails to address the effect of PSA tests on the rate of survival among prostate cancer patients. Such studies are not yet complete, he said, and until they are "it's anybody's guess" about whether prostate cancer is being over-diagnosed.

He said some prostate cancer patients - those who have low PSA tests or who may be expected to die within 10 years - are now treated with "watchful waiting" instead of aggressive surgery or radiation. But he said the level of treatment should be a patient decision.

Vaughan said that PSA tests help find patients when they have a 75 percent chance of being cured of the disease. Without the test, the cancer is often not detected until symptoms develop; by then, it is 75 to 80 percent incurable because it has spread to the bones or other organs, he said.

"Our position on PSA is that we find out and then inform the patient," said Vaughan. "We give them the data about being at low risk, intermediate risk or high risk" and let them make the treatment decision.