Too Much Cancer Screening, or Too Little? Opinions Split

Cancer overdetection for conditions like breast cancer and prostate cancer had no widely accepted rate

(RxWiki News) It may seem strange at first, but in certain cases, some patients would prefer to never discover their cancer. Experts recently examined the complicated issue of cancer overdetection and found that opinions varied widely.

A new study found that public opinion on cancer overdetection varied, perhaps suggesting that informed personal decisions should play a key role in individual cases.

This study focused on the overdetection of cancer — or the discovery of a cancerous growth (through cancer screenings) that would have never caused any symptoms or an early death.

"It is considered the most harmful effect of cancer screening as it unnecessarily labels people as 'cancer patients,' leads to treatments causing harm but no benefit, and diverts healthcare activity from patients who genuinely need it," explained the authors of this new study, led by Ann Van den Bruel, MD, PhD, of the University of Oxford in the UK.

Overdetection usually concerns slow-growing cancers that may never lead to symptoms during the life of the patient. Because of this, other health conditions and age are issues to consider when thinking about overdetection.

Dr. Van den Bruel and colleagues explained that overdetection can lead to unnecessary treatments and side effects. For breast cancer patients, this might include mastectomy (surgery to remove the breast). For prostate cancer patients, issues like erectile dysfunction and bowel problems might develop after radiation treatment, these researchers noted.

"Because cancer screening can lead to benefit in some people and harm in others, there is general consensus that people should be allowed to make an informed choice before deciding to participate," Dr. Van den Bruel and team wrote.

To explore what most people might consider an acceptable level of overdetection, these researchers performed an online survey of 1,000 people in the UK. Female patients were asked about breast and bowel cancer. Male patients were asked about prostate and bowel cancer.

These patients were given information on the cancers, along with treatment methods and potential side effects.

Dr. Van den Bruel and team found no clear consensus on overdetection.

"There was large variability between respondents in the level of overdetection they would find acceptable, with medians ranging from 113 to 313 cases of overdetection per 1000 people screened," Dr. Van den Bruel and team wrote.

In an editorial about this study, Alexandra Barratt, PhD of the University of Sydney in Australia, noted the public attention that overdetection in breast cancer has received.

"More than any other debate about overdiagnosis the discussion of breast cancer has spilt from the pages of specialist medical press and become heated arguments squarely in the public eye," Dr. Barratt wrote.

Dr. Barratt noted that, after mammography screenings were introduced in several countries, rates of early-stage cancer increased without affecting the rates of advanced-stage cancer — suggesting that overdetection could be at play.

"Many women continue to be 'prescribed' or encouraged to undergo screening rather than being supported to make an informed choice," wrote Dr. Barratt, who, like Dr. Van den Bruel and team, stressed the importance of patients being informed about the risks and benefits of cancer screening.

Patients should discuss this complex issue with their doctor to decide what is best for them. Further research is needed to better understand the risks and benefits of cancer screenings and overdetection, Dr. Van den Bruel and team said.

The study and editorial were published March 3 in The BMJ.

The National Institute for Health Research Diagnostic Evidence Co-operative Oxford funded this research. Dr. Van den Bruel and team disclosed no conflicts of interest.


Review Date: 
March 5, 2015