The New York Times, as previously mentioned, is reporting a shift in screening policy at the the American Cancer Society, which is now saying that the benefits of early detection of many cancers, especially breast and prostate, have been “overstated”.
“We don’t want people to panic,” Dr Otis Brawley, the Society’s chief medical officer told the NYT. “But I’m admitting that American medicine has overpromised when it comes to screening. The advantages to screening have been exaggerated.”
The LA Times has another slant on the story.
Professor Ian Olver, CEO of Cancer Council Australia, says it is important to consider the pros and cons of screening for each type of cancer, rather than making blanket statements.
He writes:
“It is not helpful to bundle prostate and breast cancer together in a discussion about the benefits of screening. The aim of screening is to diagnose cancer or pre-cancerous conditions early to significantly improve treatment outcomes. It should never be interpreted as guaranteeing cure for all individuals.
The term “over-diagnosis” can apply to people who have cancers detected by screening but who would have died of something else before the cancer would have been detected in the absence of screening. Obviously very slow-growing cancers would make over-diagnosis more likely.
After many years of mammographic screening for breast cancer, the International Agency for Research in Cancer has estimated that the reduction in the death rate from breast cancer in the main target group of 50 to 69 year olds is 35%, a significant mortality benefit, but not without some cost.
The estimate from the initial mammography trials of over-diagnosis is 2 to 3% (that is cancers that would not have progressed if left untreated). Adding in the pre-invasive DCIS (ductal carcinoma in situ) the range of estimates of over-diagnosis is around 9%. However, this still means that the vast majority of detected cancers did need treatment and that lives were saved.
Prostate cancer is quite different. There is no history of population screening programs to study. Two large randomised trials of PSA testing of asymptomatic men from last year had differing results.
No change in the death rate from prostate cancer was found in an American study while in the European study a 20% relative decrease in mortality was reported.
The overtreatment rate in this study was that for every 49 men who underwent prostatectomy only one life was saved, yet each was at risk of the side effects of impotence and incontinence.
Over-diagnosis and over-treatment are why Cancer Council Australia and a number of other health groups recommend PSA screening be an individual choice. Further research should be encouraged in this and other cancers to find better screening tests and tests that will identify indolent cancers which don’t need immediate treatment.
So, although it has always been known that not every individual will benefit from screening, in the proven population screening programs, for cervical cancer, breast cancer and colorectal cancer, the likelihood of reducing deaths from these diseases outweighs the chance of over-diagnosis.
Nonetheless individuals need to be informed of both the risks and benefits.
It would be a pity if doubts about over-diagnosis discouraged participation in these programs by the groups most likely to benefit or dissuaded government from completing the roll-out of the colorectal screening program, so that it could not reach its full potential of saving 30 Australian lives each week.”
Blanket statements about all screening for cancers are unhelpful.
Part of the problem is that the great unwashed, and many, if not most, health professionals don’t understand the economic and epidemiological basis and clinical for deciding to screen or not to screen on a population basis.
The current hold up in the National Bowel Cancer screening project is a disgrace. Combined with the lack of any innovative community based initiatives for bowel cancer screening makes one despair for any future commonwealth takeover of other programs. The bowel cancer program was launched without any real consultation with GPs who the commonwealth pays anyway and without any consultation with state services that have to do the follow up colonoscopies.
So that without even a full rollout of the program there are unacceptable queues for ‘scopes and only limited funding for the extra ‘scopes required.(in the public sector – not a great problem in the private sector)
The Feds have absolutely no idea how clinical services work (or how they are funded) on the ground.
The BCSP had names, postcodes, numbers who sent in a FOBT, numbers of positive tests etc – yet at no stage has that info been readily available – de-identified- to enable clinical serv ices or Div of Gps to do some community based work on getting more in. Not to mention that most GPs (and proceduralists) will not claim the rebates for the scheme because the paper work costs more to complete than the rebate is worth. – Sadly perhaps a sign of things to come when Canberra takes over.
We could free up colonoscopy availability by simply restricting ‘scopes to those with clear symptoms, a family history or positive FOBT. UK doesn’t fund colonoscopies unless FOBT, symptoms or history and they have a rate of ‘scopes per 1000 running at 25% of what we do here – we could have scope availability increased by 4!
Bowel cancer screening and follow up saves lives – no ifs or butts – and it pretty bloody cheap for lives saved.
Everyone is getting all excited about obesity. Its sexy, groovey and open to all kind of paternalism (or nannyism) and moralising (or finger pointing as Bobby Zimmerman would say) -great fun for all. We know bugger all about how induce behavioural change to reduce obesity in individuals and SFA about how to do it on a population basis. But it doesn’t stop us throwing $quillions at it.
Bowel cancer, unlike anti-obesity, isn’t groovey, doesn’t lend itself to blaming and faddish diets, or superior feelings if you miss out on it . Its a messy business that can save lives cheaply.
I did talk about public/private b ut as we all know that is just a form of words.
Public means a state run service partly funded by state partly by commonwealth – all paid for by taxpayers- and capped.
Private means colonoscopies done outside state services but largely funded by the commonwealth -paid for by taxpayers – with a small contribution by either patients or private (subsidised) health insurance – and uncapped.
Madness