no one has collected the information I consider most important. The literature review underlying the USPSTF’s updated recommendations concludes “there is no accepted risk-assessment tool to help tailor colorectal screening” to patients with above-average risk; we still do not know the significance of small polyps; and, most stunning, “no [colorectal cancer] screening modality has been shown to reduce all-cause mortality.”
Because of my medical history (Crohn’s disease), a family friend who is probably the best gastroenterologist I know recommended that I get a colonoscopy screening every year! I have not done so, but I have gone for screening, which I probably would not have done at all if I had no history.
In order to prevent death, a colonoscopy must detect and remove polyps that will evolve into cancer that worsens rapidly enough to kill you before something else does. What we know is that a doctor can use colonoscopy to detect and remove polyps. The rest is much harder to pin down.
Most colonoscopies do not detect polyps, presumably because many people do not have them. These “clean” colonoscopies are a relief to patients, but they greatly increase the cost per life saved from routine colonoscopy screening. And if “all-cause mortality” is unaffected by the procedure, then the cost per life saved is infinite.
How often do doctors get them?
An FOB – Foecal Occult Blood – is a much better test for detection of tumours. Essentially tumours will tend to bleed and so it has a very high sensitivity. Specificity can be affected by say a nose bleed or something, but may also indicate the presence of a bleed further up the GI tract. Eating a bloody steak is not normally a problem as the antibodies are human specific.
I would however also want a colonoscopy if it were me – as there’s probably no substitute for a specialist having a look around.
In Arnold’s case I would recommend an FOB at the same time as a Calprotectin test – which presumably are occurring fairly regularly?
I’m not a medic but I do work in this field – please consult a professional, etc.
Well, the idea behind the routine colonoscopy is to catch the tumor before it turns malignant. My understanding is that FOB can often only catch the tumor after it is malignant.
Actually I’m not sure to be honest, as to whether it’s good at picking up polyps and other non-malignant stuff – good point.As I say, if I was in a high risk group I would want a scope. Not sure if Arnold has been recommended a colonoscopy for the cancer risk – I don’t think a clear link has been established with IBD and cancer. With Crohn’s I’d have thought he’d be getting regular scopes anyhoo.
…also, when I say better I mean cheaper and less invasive – but the tests are now much better also than they used to be.
How did the tests get better? I assume they got better (like most other things) through trial-and-error, which is to say, doing a lot of bad tests.
I’m not even against being someone’s lab rat. But I am against paying to subsidize being part of the problem. Third party payer subsidizes the tests, but it doesn’t subsidize closing the loop to make the tests better.
Oh, I’m in the UK and we’ve had bowel cancer screening for a while now – everyone over 60 or something. So a cheap test where the, um, sample could be sent through the post, etc. But technically a very poor test – and like so many of these initiatives no one’s sure yet what the lives saved, etc. is. The new test uses similar technology as a pregnancy test, but much better accuracy, precision, etc. And yes, they’ve been around for a while. There’s a constant process of improvement – kind of half private sector, half NHS. what’s dispiriting is when crappy tests are used for years – but – you know, costs. Better tests cost more money – it’s a difficult balance sometimes.
The experience is impressive for the amount of uncertainty that Cannon was actually able to uncover. I don’t think that would always be so easy for many diagnostic tests, even for an informed and resourceful patient.
“Mortality” is to medicine as “GDP” is to economy.
The majority of recommendations mentioned by MC are based on the population statistics. The problem with this approach is that every medical decision is individual. The disconnect between the need for patient-centric decision making and population-centric regulation and medical science is the focus of my book on decision making in medicine: https://www.amazon.com/Probabilistic-medical-decision-making-professionals/dp/1523205482
Actually, “individual risk assessment” recommended by the ACP is not such a bad advice. Individual risk, just like individual benefit, is difficult, but not impossible to quantify.