Spiral wrote:bridgetohealth wrote:I could give you all the statistics about the uselessness (or harms) of other kinds of screening (colonoscopies for example), but again since you started out saying that no type of study would persuade you, I'm not sure it's worth the effort. But even in the one area where I haven't seen evidence that the test shouldn't be done -- pap smears for cervical cancer screening -- they've drastically reduced the recommended frequency of those tests. Because again, it turns out that screening actually is more likely to help with slower-moving cancers rather than fast-moving ones.
bridgetohealth,
Two questions (if you'd like I can start a new thread):
[1] What's your opinion on treatments for breast cancer once someone has been diagnosed? Surgery. Chemotherapy. Radiation. I'm guessing that your opinion would depend on the stage of the cancer and other factors.
[2] Care to elaborate on your opinion of colonoscopies? Many of us McDougallers might be tempted to skip the whole colonoscopy and perhaps even skip other screenings because we consume a high fiber diet and a healthy diet generally. On the other hand, we do have a participant in this discussion forum who was diagnosed with colon cancer despite being a McDougaller for many years prior to diagnosis.
Well, first of all, no one's risk of any cancer is zero (well, your risk of cervical cancer is zero and my risk of testicular cancer is zero!) it's just that the higher risk you are then the more the benefits outweigh the risks of screening. So someone could be a strict McDougaller for 30 years and still get colon cancer, he or she would just be less likely to get it. I should point out that when giving my personal opinion on the matter I'm talking about people at normal risk. If I had a genetic disposition towards breast cancer then maybe I'd get a screening mammogram. Or at least I wouldn't think that in general it's not a good thing (whether I'd personally get the screening mammogram sort of depends on my answer to number one -- if all I'd do is try to eat better and include more garlic and onions --
http://nutritionfacts.org/video/1-anticancer-vegetable/ --maybe I should just do that anyway).
1) This is where I do agree with Jumpstart -- it's much easier to talk about this in the abstract, and most people when faced with the diagnosis will go the more conservative route. However, I know that Thrasymachus posted something awhile back about cancer treatment killing a large percentage of people that go through it (who otherwise wouldn't have died) and I know I've read a lot of surveys of oncologists who wouldn't personally choose the treatments they offer their patients, etc. So I would lean towards non-medical intervention, but like you say it depends on several factors of size prognosis etc. One thing is true that Dr McD. points out which is that usually when the surgeon or oncologist says "OMG you need surgery immediately!" that's not true, so I would carefully weigh my options and not race to the hospital. The percentage of women who spontaneously recover from breast cancer is quite large -- I think it's 20%. Then like I said there are those the treatment won't help anyway, either because it will kill them anyway, or because it's so slow-growing they'll die of something else in the meantime. Since I would have no way of knowing if I'm in the over diagnosis group or not, I probably wouldn't treat -- I'd rather that no one lop off part or all of my breast if it's not necessary. But I do agree that people change their minds when faced with the decision for real.
2)
Based on solid evidence, screening for colorectal cancer (CRC) reduces CRC mortality, but there is little evidence that it reduces all-cause mortality, possibly because of an observed increase in other causes of death.
That's from cancer.gov -- not some "radical" vegan guru! And that is referring to different kinds of screening, even fecal occult blood test!! How many doctors are aware of this?
So the question isn't whether we can get colon cancer (we can, just like I could get breast cancer despite being somewhat lower risk based on family history [though never having had a baby and thus never breastfeeding has also increased my risk]), it's whether screening does anything to save us: evidence is good enough that it doesn't that I'm not going to take any chances. Because for all of these, when we die from over diagnosis that is of course hastening our natural death.
The chart also shows that there is absolutely no mortality difference between sigmoidoscopy and colonoscopy, so if I were to get tested I would follow what Dr McD recommends and just get the sigmoidosopy.
The new DNA test real hadn't been used enough before a lot of these studies were done, so I'd be curious to see what studies show about that. I'm currently 50, and personally won't get screening until I'm 55, if then -- maybe I'd do the DNA if studies seem to suggest a benefit.The problem is that even the fecal occult blood test doesn't save lives because of the follow-up colonoscopies, so I'm not sure the DNA test will be much better, though it is more effective in finding cancers.
http://www.cancer.gov/cancertopics/pdq/screening/colorectal/HealthProfessional/page1(BTW, I have a genetic disposition for glaucoma, which has been in 3 immediate family members -- a lot -- and I make sure to be screened for that. But that's because I'm 100% sure I would take the treatment if I were tested positive, which are just eyedrops, and the test is totally non-evasive. It's practically a perfect screening test. We can't ask for all screening tests to be that good, but they should be better than they are before they are as popular as they are. And the cervical cancer screening I mentioned is also non-invasive, and test 2 if you have an abnormal result is relatively non-invasive [a punch biopsy of cervix which hurts like hell for a few seconds to minutes, but if it has possible complications I'm sure the chances of them are minuscule]. Basically with a lot of these it's because of the next steps in the process, which are dangerous to do if unnecessary, that the benefits stop outweighing the risks. So I think that should be something to take into consideration. I'm assuming that that's also why Dr McD has occasional checks for skin cancer on his list of "Do's" for screening -- non-evasive and the next test is also not terribly evasive, even if it hurts temporarily)