New Swedish data suggest that screening DOES lower mortality


According to data published today in Lancet Oncology, a 14-year-long Swedish study has unequivocally demonstrated that PSA screening in men of 50 to 65 years of age does reduce the risk of prostate cancer-specific mortality — by about 50 percent. [Editorial comment: Interested readers may also wish to read a further and more detailed commentary on this study posted after we had been able to read a full copy of the study by Hugosson et al.]

There are already multiple reports about this study on various web sites, including Reuters, Bloomberg News, MedPage Today, and HealthDay. The original article by Hugosson et al. was published on line today, along with an editorial commentary by Neal.

As far as we can tell from the media reports, a group of researchers at the University of Gothenburg have been conducted a trial involving 20,000 men aged between 50 and 65 years who were randomized to either receive prostate screening based on PSA testing (once every 2 years) or not. The basic result of the study is that — after 14 years of follow-up — the prostate cancer-specific mortality rate among men in the screening group was about half that of the mortality rate among men in the unscreened group, as men were diagnosed and treated in time to stop the cancer from killing them.

Jonas Hugosson, who led the study, is quoted as stating that the results show that PSA screening of all men in this age group “can result in a relevant reduction in cancer mortality.”

He is also quoted as saying that, “Our study has a longer follow-up than previous studies, but shows that in those men invited [to the study], the risk of dying is only half of that in the control group. In men younger than 60 at study entry, the effect was even more pronounced — only one-quarter of expected deaths occurred.”

The research team reports that — in this study — the risk of over-diagnosis was also less than previously thought, with just 12 men needing to be diagnosed to save one life. However, since the benefit of PSA screening requires at least 10 years to be borne out, they question the value of PSA testing for men over 70 years of age.

Additional information about this study (as reported by the media) includes the following:

  • Men in the screening arm whose PSA levels were elevated were offered more tests, including a digital rectal exam and prostate biopsies.
  • 44 of the men who had PSA testing died from prostate cancer, compared to 78 men who had not had been screened.
  • 11.4 percent of screened men were diagnosed with prostate cancer, compared with 7.2 percent of unscreened men.
  • Of the men in the screened group diagnosed with prostate cancer, nearly 79 percent were diagnosed because they took part in the study.
  • Men in the screened group were more likely to have their cancer diagnosed while it was in an early stage.
  • 46 men in the screened group were diagnosed with advanced cancer, compared with 87 men in the unscreened group.

We have not yet had the opportunity to read the complete paper, so we cannot draw any major conclusions about the implications. However, one thing does seem to stand out — that is the 14-year follow-up that is built into this study and the clear distinction between the management of screened and unscreened men.

Recognized problems inherent in both the earlier major screening studies (the PLCO trial and the ERSPC study) — whose initial results were reported in the New England Journal of Medicine in early 2009 — were the relatively short period of follow-up and the fact that the trial protocols left a lot to be desired. (In the PCLO study at least half of the “unscreened” patient group was, in fact getting PSA testing outside the trial protocol; in the European study there were multiple different screening protocols being used.)

The “New” Prostate Cancer InfoLink will be able to comment on the current study with more intelligence just as soon as we can see a full copy of the actual study report.

6 Responses

  1. What a shock! Men who are getting checked find their cancer at an earlier (treatable) stage! Who would have believed it!?! We can only hope that the American Cancer Society and AARP read and HEED this study and stop sending confusing and ridiculous messages to men. Men NEED to get checked to find this cancer that has no symptoms before it is too late.

  2. Eureka!

    And, hats off to the Swedes.

    A reduction of 50 percent in prostate cancer mortality in a 14-year-long study involving 20,000 Swedish men cannot be ignored.

    The conclusions of the Gothenburg University study come as a surprise only to the heads-in-the sand epidemiologists and ill-informed leaders of the U.S. Preventative Services Task Force, the American Cancer Society, and the Centers for Disease Control who continue to insist, illogically, that over-diagnosis is the problem.

    The problem, clearly, is cancer, and the decisions to treat or not to treat, as well a how to treat.

    The solution is to learn more about how to discriminate between potentially deadly prostate tumors and those that are harmless.

  3. I do think that it is important to recognize that while the disease-specific deaths were reduced by 34 in the screening group, according to the linked Bloomberg article the all-cause deaths were 1,981 in the screening group and 1,982 in the unscreened group. That helps put the relative benefit into perspective. Is it worth the additional (approximately) 400 that are over-diagnosed? Different people will reach different conclusions.

    An interesting commentary appeared a month ago in the Journal of the National Cancer Institute on why clinical trials of cancer screening do not show a reduction of all-cause mortality even when disease-specific deaths do decrease. It will be interesting to see the reaction to that article.

  4. Is it wise to rely on media reports without reading the original study? After all, we have seen the media hype that tends to exaggerate the findings in studies. I realize you have covered yourself by saying As far as we can tell from the media reports …!

    One of the quotes that caught my attention was this, “In men younger than 60 at study entry, the effect was even more pronounced — only one-quarter of expected deaths occurred.” Hmmmmm … How were the “expected deaths” calculated in men under 60? If the Tyrol study is anything to go by that could be a very rubbery figure.

    And, according to the latest US figures, less than 3% of male deaths are due to prostate cancer and less than 5% of these deaths occur in men under the age of 60, so it seems that what is being discussed is a possible saving of 50% of 5% of 3% … that might be termed as not a very large figure — and at a risk of over-diagnosis of “only” 12 men needing to be diagnosed to save one life.

    And what does this phrase mean, in the Reuters report, “Prostate cancer is the second most common cancer in men after lung cancer …? It is certainly not the second most common cancer diagnosed in men — it is the most common cancer diagnosed. And it is only the second most common killer of men over the age of 80 — the statement is simply misleading as far as men younger than 80 are concerned.

    Does it matter? Probably not, but if the media can be so careless with ascertainable facts, how much can you trust them to report other, more contentious items accurately?

  5. The reductions in mortality at year 14 are no surprise to me. When I see 10-year studies in prostate cancer, they make me sick to my stomach when I also see the conclusions drawn by folks online. Prostate cancer is a 20-year disease and I bet when you extend out to 20 years on studies you’ll find that screening saves lives, all treatment modalities are not the same, and that residual effects on treatments vary greatly.

    As a man who has fought this fight starting at age 44 with T3b prostate cancer, I have spent more time in the long-term effects of treating the disease. I am amazed on how little data exists for someone like me.

    Tony

  6. Education is the key here. Informed decision-making requires that each individual be exposed to basic information and any peer-reviewed study results on the subject. An individual risk evaluation should be included in preparation as well. The informed individual then can determine best option(s) going forward with their medical team in a shared decision-making process.

    Personalized education by the medical community has historically been given short shrift. Support groups and some combined medical/survivor coalitions are addressing the need by offering targeted educational programs to individuals in like situations (i.e., considering screening, newly diagnosed, recurring, etc.) addressing their specific informational needs, questions, and concerns.

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