NLST data highlight probability of lung cancer overdiagnosis / overdiagnosis rate for bronchioloalveolar lung cancer was 78.9 percent

Contact: Shawn Farley PR@acr.org 703-648-8936 American College of Radiology

NLST data highlight probability of lung cancer overdiagnosis with low-dose CT screening

Philadelphia, PA—Data from the National Lung Cancer Screening Trial (NLST)—conducted by the American College of Radiology Imaging Network and National Cancer Institute Lung Screening Study—provided researchers the opportunity to investigate the probability that a cancer detected with screening low-dose computed tomography (LDCT) would not have progressed to become life threatening. The results of this investigation published online today in JAMA Internal Medicine suggest that up to 18 percent of the cancers detected by LDCT may not have progressed enough to affect patient health if left undetected.

“This is another piece of important information that helps us to better understand the benefits and risks of lung cancer screening,” says the study’s lead author, Edward F. Patz, Jr., M.D., a professor of radiology, and pharmacology and cancer biology at Duke University School of Medicine. Continue reading “NLST data highlight probability of lung cancer overdiagnosis / overdiagnosis rate for bronchioloalveolar lung cancer was 78.9 percent”

Harms from breast cancer screening outweigh benefits if death caused by treatment is included

Contact: Emma Dickinson edickinson@bmjgroup.com 44-020-738-36529 BMJ-British Medical Journal

Cancer expert remains to be convinced by breast screening review

Harms from breast cancer screening outweigh benefits if death caused by treatment is included

Michael Baum, Professor emeritus of surgery at University College London says that, while deaths from breast cancer may be avoided, any benefit will be more than outweighed by deaths due to the long term adverse effects of treatment.

He estimates that, for every 10, 000 women invited for screening, three to four breast cancer deaths are avoided at the cost of 2.72 to 9.25 deaths from the long term toxicity of radiotherapy.

These figures contrast with an independent report on breast cancer screening, led by Sir Michael Marmot and published in November last year. Marmot and his committee were charged with asking whether the screening programme should continue, and if so, what women should be told about the risks of overdiagnosis.

They concluded that screening should continue because it prevented 43 deaths from breast cancer for every 10,000 women invited for screening.

The downside was an estimated 19% rate of overdiagnosis: 129 of the 681 cancers detected in those 10,000 women would have done them no harm during their lifetime. However, those women would have undergone unnecessary treatment, including surgery, radiotherapy and chemotherapy.

But despite this higher than previous estimate of overdiagnosis, they concluded that the breast screening programme should continue.

The report also judged that screening reduces the risk of dying from breast cancer by 20%. But Professor Baum disputes these figures, saying the analysis takes no account of improvements in treatment since these trials were done, which will reduce the benefits of screening. Nor does it make use of more recent observational data.

With these data included, estimated rates of overdiagnosis as a result of screening increase to up to 50%, he argues.

This is important because it can change the decisions women make when invited for screening. In a study also published today, researchers at the University of Sydney explored attitudes to screening in a sample of 50 women. Many of the women were surprised when they were told about overdiagnosis and most said they would attend screening if overdiagnosis rates were 30% or lower, but a rate of 50% made most of them reconsider.

An accompanying editorial points out that the harms of screening will reduce as more effective diagnostic  processes develop to inform less harmful and more personalised treatments. In the meantime, it says women need up to date and transparent information about the benefits and harms of screening to help them make informed choices.

Overdiagnosis poses significant threat to human health

International conference: Preventing Overdiagnosis

Overdiagnosis poses a significant threat to human health by labeling healthy people as sick and wasting resources on unnecessary care, warns Ray Moynihan, Senior Research Fellow at Bond University in Australia, in a feature published on bmj.com today.

The feature comes as an international conference ‘Preventing Overdiagnosis’ is announced for Sept. 10-12, 2013, in the United States, hosted by The Dartmouth Institute for Health Policy and Clinical Practice, in partnership with the BMJ, the leading consumer organization Consumer Reports and Bond University, Australia.

The conference is timely, says Moynihan because “as evidence mounts that we’re harming the healthy, concern about overdiagnosis is giving way to concerted action on how to prevent it.”

“The Dartmouth Institute for Health Policy and Clinical Practice has long been a leader in understanding and communicating the problems of overdiagnosis,” say Drs. Steven Woloshin and Lisa Schwartz, professors of medicine at The Dartmouth Institute for Health Policy and Clinical Practice. “We are extremely excited to host this international conference to advance the science and develop concrete proposals to reduce overdiagnosis and its associated harms.”

Overdiagnosis occurs when people are diagnosed and treated for conditions that will never cause them harm and there’s growing evidence that this occurs for a wide range of conditions.

For example, a large Canadian study finds that almost a third of people diagnosed with asthma may not have the condition; a systematic review suggests up to one in three breast cancers detected through screenings may be overdiagnosed; and some researchers argue osteoporosis treatments may do more harm than good for women at very low risk of future fracture.

Many factors are driving overdiagnosis, including commercial and professional vested interests, legal incentives and cultural issues, say Moynihan and co-authors, Professors Jenny Doust and David Henry. Ever-more sensitive tests are detecting tiny “abnormalities” that will never progress, while widening disease definitions and lowering treatment thresholds mean people at ever lower risks receive permanent medical labels and life-long therapies that will fail to benefit many of them.

Added to this, is the cost of wasted resources that could be better used to prevent and treat genuine illness.

But Moynihan argues that the main problem of overdiagnosis lies in a strong cultural belief in early detection, fed by deep faith in medical technology. “Increasingly we’ve come to regard simply being ‘at risk’ of future disease as being a disease in its own right,” he says.

“It took many years for doctors to accept that bacteria caused peptic ulcers,” says co-author of the BMJ feature, Dr. David Henry, chief executive officer of the Institute for Clinical Evaluative Sciences, and professor in the Department of Medicine at the University of Toronto, Canada. “Likewise, it will be hard for doctors and the public to recognize that the earliest detection of disease is not always in the best interests of patients.”

So what can we do about overdiagnosis?