Two widely used tests for prostate cancer failed to save lives in a new study, adding to the debate over whether men should be screened for the disease. The study was small — only 1,002 men — and will not be the final word on the issue. But it may hint at what lies ahead when the results of two large studies of prostate cancer screening appear in a few years. The researchers looked at two screening tests that are performed millions of times a year in the United States: a blood test that measures prostate specific antigen, or PSA, and a digital rectal exam, the rubber-glove test in which a doctor feels for abnormalities in the prostate through the rectal wall.
The uncertainty of prostate cancer screening with PSA blood tests and/or digital rectal exams to reduce prostate cancer deaths is not new, although this report describes the latest study to find no mortality benefit with screening. Overall, the story does a great job of discussing the real issues – that despite the popularity of prostate cancer screening (millions of tests in the US each year!), the effectiveness of prostate cancer screening has not been established. The story includes a note on when we might know more based on the estimated date of completion of two large, ongoing screening trials (as opposed to observational studies like this one). One weakness of the story was that study results were not quantified; instead the findings were already interpreted for the readers who were not able to see the actual data figures.
story made no mention of costs, societal, personal, or otherwise.
Benefits, or lack thereof in this case, were not
quantified. Instead, the journalist reported that men who were alive were no more likely to be screened for prostate cancer
than men who were deceased. But, the actual numbers of men alive and deceased were not provided nor the proportion who
indicated they had been screened or not screened.
The potential harms of screening are appropriately discussed, namely that screening
could be wrong (false positive or false negative), could lead to further testing (biopsy), and that detection could lead to
treatment which has serious side effects without knowing for sure whether the cancer would have harmed you in the first
study design is described to readers (e.g. that two groups were chosen during a particular time period and matched). IThe
story also talks about limitations–that this is a small study and that this is not the final word on screening (presumably
because study is observational and not a randomized clinical trial).
The natural history of prostate cancer is appropriately reflected here — that is, that prostate
cancer may not kill you or even cause problems because it is often slow-growing and that screening and early treatment may do
more harm than good. It tells readers in the opening lines that there is an on-going debate about screening.
The study co-author is quoted, but his relationship to the study
is disclosed. Representatives from medical organizations that issue recommendations about prostate cancer screening were
quoted as well, namely confirming the uncertainty of screening. A U.S. Preventive Services Task Force review from 2002 is
also mentioned, further providing support for uncertainty of screening based on an objective review of the evidence. These
sources also highlight that this uncertainty is not new.
This story does provide information on the alternative to screening, in other words, not to be screened. Phrases
such as “men should decide for themselves whether to get screened” and “for some men, detecting prostate cancer early can do
more harm than good” appropriately develop the concept of not being screened compared to being screened.
Disadvantages/advantages of screening and not screening are discussed (potential for downstream consequences, may not help
men live longer, etc.).
The story provides information on
how long screening has been available. Likewise, it also states that these screening tests are performed millions of times
each year in the U.S.
The story states that
results from study on prostate cancer screening are based on data from 24 through 129–the “early years of prostate cancer
screening.” So, the story does tell us that prostate cancer screening is not new.