Cancer Screening Harms Some Doctors Aren’t Talking About

Cancer screening harms of overdiagnosis and overtreatment were not discussed by all doctors

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) While detecting cancer early is essential to beating the disease, some screenings can overdiagnose — that is, they might pick up cancers that won’t ever be a problem, which can lead to unnecessary treatment.

A small study has found that some physicians rarely discussed the risks of overdiagnosis or overtreatment when discussing cancer screenings with their patients.

The study showed that just over half of these patients were unprepared to start cancer screening programs that could lead to overdiagnosis, while even more of the patients would continue the screenings regardless of the potential harms.

"Weigh the risks and benefits of cancer screening with your doctor."

Odette Wegwarth, PhD, and Gerd Gigerenzer, PhD, researchers at the Max Planck Institute for Human Development of the Harding Center for Risk Literacy in Berlin, Germany, conducted an online interview with 317 American men and women between the ages of 50 and 69 to learn if their doctors counseled them on cancer screening statistics.

“Overdiagnosis is the detection of pseudodisease — screening-detected abnormalities that meet the pathologic definition of cancer but will never progress to cause symptoms. The consequence of overdiagnosis is overtreatment — surgery, chemotherapy, or radiation — that provides the patient no benefits, but only adverse effects,” the researchers wrote.

As an example, the researchers reported that for every 2,000 women having mammograms during a 10-year period, one fewer woman dies, while 10 women are diagnosed with “pseudodisease” and undergo unnecessary treatment.

Most of the participants interviewed in this study had received at least one cancer screening, while 17 percent of the individuals had not had any cancer screening.

Breast cancer screening with mammography was the most common type of screening among women, and men reported receiving colonoscopy/sigmoidoscopy for colorectal cancer and prostate-specific antigen (PSA) tests to screen for prostate cancer most commonly.

Of the entire group, 9.5 percent (30 individuals) said their physicians had talked about overdiagnosis and overtreatment as potential outcomes of cancer screenings. 

However, only one of the individuals was given the correct statistics about the risks of being diagnosed with or treated for a non-life threatening cancer.

The researchers learned that 80 percent of the participants wanted to know more about the potential harms of cancer screening.

The study also revealed the following:

  • 34 percent of the individuals who had never been screened indicated that the possibility of overtreatment was one of the reasons they had not chosen to be tested.
  • 51 percent of the participants said they were “unprepared” to have screenings that resulted in more than one person being overtreated for every life the test saved.
  • 58.9 percent of the individuals reported they would continue regular cancer screenings even if the tests resulted in more than 10 people being overtreated for every person whose life was saved by the screen.

dailyRx News spoke with Deborah Gordon, MD, a nutrition and preventive medicine expert, about this study.

She began by referring to an earlier study published in JAMA that reviewed the state of cancer awareness and screening.

The authors of that earlier study wrote, "Although the goals of these efforts were to reduce the rate of late-stage disease and decrease cancer mortality, secular trends and clinical trials suggest that these goals have not been met; national data demonstrate significant increases in early-stage disease, without a proportional decline in later-stage disease."

Dr. Gordon called these words “chilling” but that the previous article summarized what she has come to believe.

“It is incumbent upon physicians who order screening tests (or prescribe medications, or counsel treatment plans) to be well informed of the potential risk and benefit of any course of action on which we advise our patients,” she said.

Dr. Gordon, an integrative physician at Madrona Homeopathy in Ashland, Oregon, continued, “Physicians are in a particularly good position to address the 69 percent of patients who might hesitate to start an unpromising screening plan: ‘Well, if you decline the risk of overtreatment inherent in annual mammograms, let's talk about breast cancer prevention.’

“As physicians, we must relinquish the false reassurance that our obligation to our patient is completed by ordering an annual mammogram. What is really asked of us is that we offer a well-informed point of view that addresses the original intention of frequent screening programs, namely to assist our patients do what they can to reduce the rate of late-stage disease,” Dr. Gordon said.

The current study was published October 21 as a Research Letter in JAMA Internal Medicine.

The study was funded by the Harding Center for Risk Literacy at the Max Planck Institute for Human Development, a nonprofit research site.

No conflicts of interest were declared.

Review Date: 
October 21, 2013
Last Updated:
October 22, 2013