It occurred to me that only certain kinds of cancer are routinely screened for, namely cervical cancer, breast cancer, and colon cancer. Why pick a couple of cancers and screen for them before there are any symptoms, and not others? I know as a many decade smoker before I quit, I’m a good candidate for lung cancer as well, but no doctors want to do a chest scan every year. No one has ever wanted to give me a head to toe for melanoma, also a nasty and often fatal flavor of cancer, even though I once had a skin cancer at a very young age.
Anyone know of a reasonable explanation for this? It seems quite strange to me.
I would assume a statistical analysis of the reliability of any particular screening technique in identifying markers for potential or early stages of cancer, and the likelihood of there being an effective early or preventive intervention to ward off the worst - on a population-wide basis.
You don’t need an expensive screening technique to tell you to stop smoking or how to protect yourself from the sun.
The rarer a disease is the more likely afalse positivebecomes. As the treatment for cancer (even if is just further, more invasive tests) is generally pretty dangerous (if you don’t have cancer). So testing for rarer cancers would be counter productive.
There is even some push back against the amount of testing that is done for common cancers, there is a pretty good argument that we are testing too much, and as a result treating too many people who do not in fact have cancer.
From here, the biggest cancers in terms of deaths in the US are:
Lung
Colo-rectal
Pancreatic
Breast
Prostate is a bit further down but there’s a lot of cases. The lab test for prostate cancer is questionable so they are doing it less often.
You get checked for lung cancer (X-ray or other scans) if you are/were a smoker and have any sort of lung issue.
The remaining big one is pancreatic. No good cheap, reliable test yet. It is often found too late and it has a high fatality rate.
Melanoma is fairly far down the list but has a large incidence rate. Since they start on the skin, much easier to see earlier. Screening helps quite a bit.
For the others, in general, you only get checked for them if there seems to be a problem involving that part of the body.
So if a cancer is rarer than anything on that list, definitely a waste of resources to routinely check for them. Remember, money is a finite quantity. It has to be suitably used.
Considering the specifics of the op - lung cancer and melanoma screening. Broad screening doesn’t past the muster but arguments are in fact made for screening someone of higher risk.
For lung cancer screening the effective test is low dose chest CT and for some it may make sense.
Why the narrow population? Maybe cost effectiveness was part of the consideration. It’s on the higher end for per QALY.
Head to toe visual screening for melanoma with a focused head to toe skin exam does appear to make cost-effective sense with the question being of what frequency for whom. For our op with a personal history of early skin cancer having that done every other year, if not every year, seems like a very rational approach, especially if part of an already scheduled appointment. If a generalist sees something suspicious then referring onto derm for assessment and possible biopsy/removal. And of course regular systematic self-exam is cheap, albeit of unclear sensitivity and specificity.
But yes applying screening to specific populations at higher risk with guidelines changing as technologies and evidence changes makes sense. It does not always get implemented as well as universal screening does though.
It also depends on what counts as “screening”. For prostate cancer, my GP includes a digital exam (in this case “digital” unfortunately does not imply something entirely in cyberspace) in my yearly checkup, as well as including the PSA in my blood test. For cancers around my mouth and throat, my dentist feels around my jaw and under my chin. I think these actions are specifically done to look for cancer, and am sure various other more general observations would have a heightened sensitivity to cancer as well as other kinds of problems. But I’m not going for a prostate cancer screening or an oral cancer screening.
When they post those lists of the Seven Deadly Warning Signs of Cancer, they are trying to increase awareness of what we should notice in ourselves. It’d be an exaggeration, I suppose, to categorize that awareness as a “screening”, but where exactly is the line?
Others have addressed the population-level cost / benefit analysis and the false positive risks. The bolded part brings up another point.
Some screening tests have negligible adverse outcomes from the screening itself. Not very many blood draws directly result in patient harm. And even fewer urinalyses.
Chest “scans” = X-rays are different. The tech improves every year, but somebody who got a chest X-ray every year from 1990 to now has a significantly increased likelihood of developing cancer just from the X-rays.
So that’s another reason not to do them routinely. As DSeid’s link says, the risk can be statistically overcome if you’re doing it to a group already very likely to be having problems. The hard part is deciding how *very *is very enough.
There are now some blood tests that screen for some cancers. The PSA for prostate cancer was an early example albeit one now of controversial net benefit. There are more all the time. In 20 years it may make sense to screen everybody annually for early lung cancer by an annual inexpensive blood draw or urine sample. But not yet.
There is definitely some push back from me on this. I become very annoyed when I go to the doctor saying “My hip hurts and makes it hard for me to get around. I’ve got a sore on my inner thigh that’s been flaring up for intermittently for about three decades, which also affects my mobility.” And I come out with these issues ignored and sent out for a mammogram and referred for a colonoscopy. It seems that the doctors have their concerns, and I have mine, and never the twain shall meet. I worry about the things that hurt and interfere with my life and they worry about things I probably don’t even have. If I didn’t need prescriptions, at this point I probably wouldn’t go back at all in the absence of symptoms. It makes dealing all things medical extremely stressful.
pohjonen that’s less a cancer screening issue than a communication issue. Doctors vary in their skill at being able to sit back and hear what the patient’s priorities for the visit agenda are and have a variety of items that they feel they need to get through, may even be graded on (what fraction of their population covered by a particular plan who should have X done have had X done). Yes, to some, the list of other chronic complaints are distractions during a wellness visit from getting the various wellness tasks done.
I do not excuse them their lack of listening skills but the skills are what they are. You may be able to have your various potential problems addressed by scheduling a visit as a “sick” visit with those items listed as your “chief complaints” … or start the visit by literally handing the doc a list of the several items that are important for you have addressed that day:
Hip pain impeding mobility.
Chronically recurring sore on inner thigh which also impedes mobility.
Should I be screened for lung cancer?
I have past skin cancer. Should I see dermatology for a complete skin exam at this point or should you do it?
Help the doc do a better job and focus her or his attention. You’ll still leave with the order for a mammogram and a colonoscopy if they are appropriate but you’ll have a better chance of getting what is important to you addressed.
Your first point is extremely well made and is the big reason that the PSA screen has become so controversial. Screening is not always benign and can be associated with harms, both directly from the test in some cases, but also indirectly by a cascade of additional more invasive and risky testing or treatments that potentially cause more harms than goods.
And this to add to the other. Indeed “early days yet” and the rate of false positives and false negatives in high risk populations is not even known yet, let alone the rates in a general population, but a blood test that can cheaply detect pancreatic cancer when it is early enough to do something effective about? That would be amazing.
The complicated thing with prostate cancer is that the cancer itself is extremely common: From what I’ve heard, it’s something like 1 in 3 men will develop prostate cancer at some point in their lifespan. But it’s also usually extremely slow-growing, such that a man with prostate cancer will usually die of something else first, with the cancer never actually causing any trouble. Combine that with the extensive side effects of most cancer treatments, and for most prostate cancer cases, the best treatment really is just to do nothing at all. And if you’re going to be doing nothing at all anyway, what’s the point of the screening?
Actually I suppose I should state that my point in starting this thread was not that I wanted to have more cancer screenings. My point is that the screenings I mentioned, and also blood pressure and diabetes, seem to be the only things I can ever get my docs to address, no matter how much I bring up the other chronic, quality-of-life-sucking issues. It seems like they just look at me like I have two heads and I’m talking in a foreign language. I especially love when I bring up the pain and mobility issues, and ten minutes later they finish up my appointment by suggesting I get outside and walk now that the weather is better(!) That kind of stuff drives me absolutely crazy. I wish I could say it was rare. But in my experience, it’s been the norm.
A well trained primary care provider will not let an interview end without having elicited from her patient the answers to two questions: (1) “Why did you come to see me this day” and (2) “What were you expecting or hoping that I could do for you today?”
An experienced primary care physician also knows that if a patient comes in for reassurance and gets only a prescription for a drug, they will probably not take the drug, and that if a patient comes in for a prescription for a drug and only gets reassurance, they will probably find another doctor.
It sounds like you might need to train your doctor or find one who is better trained.
I’ve been saying for years that the best post ever on the SDMB was this one by Qadgop the Mercotan (post #2 in this thread):
There are an enormous number of medical tests that would be useful in finding certain medical problems. What a doctor has to consider in any patient visit is what tests would be worth the cost. Some tests only rarely find something important, and sometimes the side-effects of the test may be causing more problems than anything it would discover. Medical care is already expensive enough, and doctors have to make a choice in picking the ones worth the time and expense.
Can you find a better doctor? Your primary care physician ought to listen to your complaints and address them. Sometimes the answer is “sorry, we can’t fix that”, but if your doctor doesn’t understand what help you are seeking, and doesn’t address it, then that doctor isn’t doing their job.