Gary Schwitzer writes a nice piece on the hype surrounding cancer screening tests. Evidence-based guidelines from the USPSTF are often ignored by mainstream media, who write pieces glamorizing the latest, largely unproven, cancer screening modalities. Here are some reminders for journalists:
* Newer isn’t always better.
* More isn’t always better.
* Screening doesn’t make sense for everyone.
* Many screening tests do good; many also do harm.
To be clear, some tests like cervical cancer and breast cancer screening have been shown to save lives.
Too often however, mainstream media uncritically reports the benefits of ovarian or lung cancer screening, without adequate evidence to back up their claims. Equal footing needs to be written about the tests’ complications, such as false positives leading to unnecessary, invasive procedures.
topics: cancer screening, preventive medicine
Related posts:
- Should we start screening women for ovarian cancer?
- How does cancer screening cause harm?
- Are doctors doing too much cancer screening?
- Op-ed: Not all screening tests lead to early, better treatment
- 15 cancer screening posts you may have missed
- More tests is better medicine: Why the myth is hard to break
- CT scans and lung cancer screening redux
KevinMD.com on Facebook
{ 1 comment }
PSA and DRE screening of assymptomatic men for prostate cancer is probably the worst screening tests in clinical practice. Prostate cancer is the second most common type of cancer in American men, with over 200,000 cases detected annually and 30,000 deaths. Although men have a 16% chance of being diagnosed with prostate cancer in their lifetime there is only a 4% chance of dying from the disease. This is because the tumor is very slow growing and the median age at diagnosis is 72. Prostate cancer is detected at autopsy in 80% of men over 80 years old who died from causes other than prostate cancer. Although many medical associations recommend annual screening of asymptomatic men for prostate cancer beginning at age 50, the tests currently in use, PSA measurement and digital rectal exam (DRE), lack specificity and sensitivity. This is borne out by the fact that three out of four men with an elevated PSA are found not to have prostate cancer while one out of three men who have normal levels of PSA are found to have prostate cancer. The United States Preventive Services Task Force, an expert panel which makes recommendations about preventive care for healthy people, recommends that men under 75 years of age be counseled by their physicians about the ramifications of measuring PSA before drawing that tube of blood for PSA. Since an elevated PSA is not diagnostic of prostate cancer, further invasive procedures such as prostate biopsies must be performed to make the diagnosis of cancer. A second recommendation of the task force was not to screen men over 75 years old; screening did more harm than good!! About 15 years ago a clinical trial was initiated to test whether screening asymptomatic men with PSA and DRE reduced the number of deaths from prostate cancer (PLCO Trial, http://www.cancer.gov/cancertopics/factsheet/PLCOProstateFactSheet)). The results of this trial should be available within the next few years. Most people would think that the scientific evidence for screening would have been established before actually recommending screening; however, this was not the case. Indeed, much of medicine as it is practiced today is based on hunches rather than scientific evidence. The bottom line is prostate cancer is a slow growing disease which takes about 10 years to clinically manifest itself in asymptomatic men, so you have time to explore all your options. If you’re diagnosed with this disease get a second opinion because unless a pathologist sees hundreds of these cases he may not be experienced to make a correct diagnosis. If the diagnosis is confirmed take a deep breath, do your homework and get involved with your care so you get the right care.
Comments on this entry are closed.