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Medical Cancer man-made or junk science?

  1. Oct 18, 2010 #1

    Pengwuino

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    http://www.msnbc.msn.com/id/39687039/ns/health-cancer/

    Considering how short of a life expectancy humans had back then and all the other arguments against this study brought up, can this be considered anything except junk science?
     
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  3. Oct 18, 2010 #2

    Evo

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    The first error that strikes me is that mummies had all of their internal organs removed before mummification. Most cancers would be found in these organs.
     
  4. Oct 18, 2010 #3

    Andy Resnick

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    Referring to cancer as a single disease is another clue that it's junk. "Cancer" (AFAIK) is more properly considered as a large family of disease states, similar to ciliopathies.
     
  5. Oct 18, 2010 #4

    lisab

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    Yes I thought that too, when I saw that article the other day. For eons, human life span was ~20 years...life was nasty, brutish, and short. People generally didn't live long enough to develop diseases that are common today.

    You can make a long list of these so-called 'man-made diseases': Alzheimer's, heart disease, arthritis, strokes...all diseases that increase in frequency with age.
     
  6. Oct 18, 2010 #5

    Evo

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    I especially loved this part
    Gee, ya think? Considering that they didn't have x-rays or blood tests, no microscopes, the inability to do any extensive surgery, how would they even know to consider something like cancer, back then most ailments were blamed on evil spirits, demons, curses, they had no clue, and cutting open a dead body was taboo.
     
  7. Oct 18, 2010 #6

    Evo

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    Another issue is that a lot more women are carrying babies to term that otherwise would have never lived, and in some cases never even been conceived. Children that would have died from a genetic disease are living and procreating. If you start peeing in the gene pool... We know that if close relatives had some types of cancer that you are a more likely candidate, and you then pass that increased chance on to your children. Sure we know smoking causes cancer, but in older times due to the need for fire, many people developed tuberculosis and other lung diseases from inhaling the smoke from fire used for heating, lighting, and cooking.
     
  8. Oct 18, 2010 #7
    Average life expectancy was on the order of 20-25 years, because of child mortality in double digit percentages (approaching 50% in some particularly nasty places, like medieval Paris and London). Among those who made it to the sixteenth birthday, many survived past 60. Most well-known ancient Greek mathematicians died aged 70 or older.
     
    Last edited: Oct 18, 2010
  9. Oct 18, 2010 #8

    lisab

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    You're thinking fairly recently; I was thinking of long before that...say, 100,000 years ago.
     
  10. Oct 18, 2010 #9

    bobze

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    In ancient Egypt, if you weren't from a privileged social class you didn't likely have a chance of reaching the ripe old age of 40, let alone 60.

    I agree with what you said, but you need to consider the age distribution of the population. Not just the outliers. Of course, the royalty, who were better educated, better fed and better cared for were more likely to live longer, healthier lives.

    This is a post I made on another form regarding the same topic;

    First and foremost, as has been alluded too, cancer is a disease of age. Why?

    When your cells replicate, the protein machinery which copies the DNA can make errors. The rate of error is very low, maybe like 10-8 per base pair, per gene. We see a couple of things which refute what some posters have said on this topic. Firstly, cancers are more common in tissues which continuously divide throughout the life of the organism, like epithelia tissues. Secondly, as others have pointed out, cancer is normally a disease that is associated with "older folks". Hmmmmmm.....A clue?

    Yes in deed. It was incorrectly pointed out that cancers were an "old adaptation to cell growth". This is incorrect. When a cell is going to replicate, it has various checks and balances which occur during interphase of the cell cycle. These checks say things like "DNA for such and such gene is too damaged, therefore you should not replicate and instead die". Cells do a heroic little then, called apoptosis--In which they choose termination over potentially dangerous growth.

    The problems occur, because over the course of a lifetime, you accumulate (despite the low error rate) errors to this system of checks and balances. And a cell will be more likely to "break away on his own" than follow the colony rules. That cell's progeny (he keeps dividing) also inherit his selfish approach to colony live and thus a tumor is born.

    This in itself wouldn't be that big of a problem, because your body has specialized white blood cells which can still induce apoptosis in these "breakaway" cell lines, dubbed natural killer (NK) cells. These NK cells work by affecting a "death receptor" on the surface cancerous cells activating a signal transduction pathway that ends with a special type of protease (think of them as little pac-mans for proteins) destroying the cell from the inside out. If you are over the age of 20ish, this is a process which happens in your body every day. Problem solved, back to life as usual. But is it?

    Remember we said that cancerous cells require an accumulation of errors to become "cancerous". They also acquire more errors which do a funny thing, they begin to excrete soluble copies of these death receptors so that when NK cells come around, their surface ligands (the thing which binds to the death receptors) get blocked and are ineffective.

    Never fear, there is yet more checks and balances which can stop the cancerous colonies. Because these cells are quickly proliferating they require an increased supply of oxygen and nutrients. A cancerous colony will quickly burn itself out and die without the proper nutritional requirements met (for anyone who's ever taken a gross anatomy course and dissected a human, you'll note the many tumors and "pre-cancerous" growths found in the older cadavers, which did not kill them).

    So again, cancerous cells must "get lucky" with more errors. They have to have certain genes turned on which are expressed during regenerative healing or embryological development that stimulate the growth of vasculature (blood vessels) to the tumor, otherwise starvation will ensue (in deed a great many chemotheraputic agents target this ability for cancerous to acquire vasculature and work by "starving" the tumor).

    We are yet still faced with another problem for cancerous cells. As a tumor grows and gets crowded the cells, despite improved vasculature, will burn up nutrients and the tumor size will be self-limiting. This is why you could have a tumor in your leg or another "non vital place" for years and years with no problems.

    We come again to an accumulation of errors (see the repeating theme?). Some of the offspring in that tumor may happen upon another group of "lucky" errors which allow them to "pick up and move shop". This is of course, really bad for the over all health of the organism and is often the point of "terminal no return"-Or what we say in medicine, metastasis.

    Cancer is literally "a series of unfortunate events" (Great book by the way!), that take (in most cases a life time to accumulate).

    **This of course is a simplified description, the number of genes (oncogenes) and factors which lead to errors and cancer number in their hundreds, if not thousands.

    There are of course, more rare cancers which can manifest earlier in life and the genetic basis of these (with your new education now, I'm sure you could hazard a correct guess) is inherited mutations to these cell control cycles. For instance, a rather famous one(s) (really a group) comes from xeroderma pigmentosum. Mutations to the "repair machinery" which allows us to repair DNA damage caused by UV light (thymine-thymine dimerizations for any of you biology savvy people).

    In the case of these inherited dispositions to cancers, by damaging the repair or "checks and balances" machinery, cancerous growth is expedited and manifested at a much earlier age.




    So is cancer a "outcome of the modern world"? Inadvertently yes. Because people in the west don't die at the age of 30 from things like small pox, scarlet fever or diphtheria because of modern technology and medicine, your more likely to live a longer healthier life which gives your cell lines a chance to accumulate errors to the "point of no return". Of course, people argue about returning to a "healthier life-style" like that of the "ancients" and if living fast and dying young (<30 years of age) is your cup of tea then I'd encourage you to forgo the perks of "modern life-styles".

    The up note is that modern medicine is becoming exceedingly good at treating, preventing and stopping cancers before they become a problem.

    Patients often ask, why cancer? We get trained at the hospital to explain to patients, their families and loved ones, any number of causes and reasons for various types of cancer. From "just plain unlucky" to "maybe you shouldn't have smoked for 40 years" (of course we don't say it like that).

    But the real answer is in our old friend the American public loves to hate: evolution. Because, we are (as someone remarked above I think) vessels for our genes, our bodies only need to serve the purpose of replicating those genes. How long we live, is a function of the age needed to successfully replicate those genes. Because once you've won at the game of evolution (pass on your genes) anything that happens to you afterwords cannot be impacted by natural selection.

    From an evolutionary standpoint then, it makes little sense to evolve "better" replication machinery less prone to error. Because doing so would cost the organism in some areas that may require sacrifices which hurt the individual's chances of reproductive success-A very bad thing as far as your genes are concerned. They are much happier to take the approach that you live long enough to reproduce, then are free to die any kind of messy death you may or may not deserve. From their standpoint, your "job" is complete once you've replicated and from natural selection's standpoint replicating ensures no penalty against your genes.

    If you study reproductive biology, you'll see a wonderful correlation in the lifespan of an organism and its reproductive strategy.
     
  11. Oct 18, 2010 #10
    Short-sightedness is also a modern disease - nobody wore spectacles in ancient Rome.
     
  12. Oct 18, 2010 #11
    Obviously, back before the age of tools, a significant percentage of people ended up getting killed and eaten by wild animals, and that tended to depress the life expectancy. On the other hand, at that time people did not have plague, cholera, tuberculosis, or smallpox, so it's a wash. And the article in question specifically discusses the recent period (starting with ancient Egypt).

    We don't really know much about chances of people reaching a certain age in ancient Egypt. Ancient Egyptians simply didn't bother keeping such records, even for their pharaohs. That gives rise to all sorts of outlandish claims, such as "average age of death was 25". In places where we do have data, such as post-Caesar Rome, life expectancy at age 20 was around 30 for lower classes and 40 for higher classes (in other words, about half of all lower class Romans could expect to live past 50). There were some culture-specific variations. For example, life expectancies of Roman emperors were low: only three out of the first ten emperors managed to die from natural causes, the rest were murdered or committed suicide. (The three who did die from natural causes, did so at ages 77, 70, and 50). On the other hand, as we've seen with Greek mathematicians, if you tried to keep your temper down and your nose out of politics, you had a much better chance of a long life.
     
    Last edited: Oct 18, 2010
  13. Oct 19, 2010 #12

    bobze

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    Masali M, Chiarelli B. Demographic data on the remains of ancient egyptians. J Hum Evol 1972;1(2).

    A. R. ZINK, W. GRABNER, U. REISCHL, H. WOLF and A. G. NERLICH (2003). Molecular study on human tuberculosis in three geographically distinct and time delineated populations from ancient Egypt. Epidemiology and Infection, 130, pp 239-249 doi:10.1017/S0950268802008257


    That's two that took me literally 30 seconds, we know quite bit about life expectancy of ancient Egypt, whether they wrote it down or not (interestingly when they did write about how old Pharaohs where, they often put their age in the hundreds!), because of forensic medicine, archaeology etc.

    If you want to get an idea about what life is like in such conditions visit a refugee camp in Africa sometime, then imagine your days are spent in servitude to the the "better caste" citizens--And you'll not be far from the truth for the life of the common Joe.

    The point wasn't to argue about the exact life expectancy of ancient Egyptians (I agree with you, 20 is a little bit of a wild number, apparently those who study such things reckon its between 30-40 based on the skeletal remains we've found), the point was that life expectancy has increased in the modern world and this will inevitably increase the "frequency" we see and treat cancers.

    Again, cancer is a disease of age--An accumulation of gene maladies because the process of replicating biological information is not and cannot be perfect (of course, as I pointed out above, there are exceptions to the "rule")

    Anyway, for an fyi type of thing;

    uscncrrt.gif

    As the man says "disease of age"

    Interestingly we can look at the rate of cancer over a span of time;

    [PLAIN]http://img825.imageshack.us/img825/4818/acsdata2009uscancerdeat.jpg [Broken]


    And at first glance would appear to support the "cancer on the rise", but nicely overlaid by a change in life expectancy over a similar period of time;

    [PLAIN]http://divisionoflabour.com/archives/life%20expectancy.JPG [Broken]
     
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  14. Oct 19, 2010 #13
    It did. And it does increase the frequency we see cancers. 80% of the increase of life expectancy is due to the fact that we got child mortality almost all the way to zero, 10% is because we have a remarkably safe society where people are rarely murdered by their neighbors over a piece of bread or a woman or die in wars. However, the remaining 10% reflect the fact that we managed to eradicate tuberculosis and smallpox, and many 70-year-olds who would've died from one of those in ancient Egypt, die from cancer at 75 instead.

    The question is whether, once all the other confounding factors are properly accounted for, the rise in life expectancy (particularly among upper class, such as pharaohs) + smoking are sufficient to explain the difference in cancer rates.

    Here's another graph:

    http://go2.wordpress.com/?id=725X1342&site=doctorgrasshopper.wordpress.com&url=http%3A%2F%2Fdoctorgrasshopper.files.wordpress.com%2F2010%2F01%2Fcancer-deaths-male1.jpg&sref=http%3A%2F%2Fdoctorgrasshopper.wordpress.com%2F2010%2F06%2F30%2Ftools-for-the-toolbox-cancer%2F

    The lung & bronchus bulge is obviously 90% due to smoking. I'm not sure what the story is with the stomach. I wish we had that kind of chart going back to 1500. But we don't. That's where the studies like the one in OP come in.
     
  15. Oct 19, 2010 #14

    Evo

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    You will need to supply a study from a peer reviewed accepted mainstream scientific journal for this claim. Medical or scientific claims of this nature need documentation. Thanks.
     
  16. Oct 19, 2010 #15

    Evo

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    bobze & hamster, it would also seem logical that the apparent increase in the diagnosis of cancer would be due to our increased ability to diagnose it, no?
     
  17. Oct 19, 2010 #16
    First off, there is no such thing as "junk" science as far as I am concerned. Science isn't about junk.(1) So the title of this thread "Cancer man-made or junk science?" is not to my satisfaction. Ah well...I will share nonetheless to the this thread. (lol to myself)

    We have the following information about Hepatocellular Carcinoma/Primary Liver Cancer: "Primary hepatocellular carcinoma (HCC) is fifth in cancer incidence worldwide and the third leading cause of cancer death. It is also the fastest growing, in incidence, in the United States with a 5-year survival rate of less than 5%. The high mortality associated with HCC is primarily due to the advanced stage of disease at initial diagnosis when therapy is not successful. Infection with hepatitis B or hepatitis C virus (HBV and HCV) is responsible for at least 80% of all HCC. Since patients with cirrhosis (with or without HBV or HCV infection) are at significantly increased risk of developing HCC, surveillance of a clinically identifiable population is realistic and logical. Thus, screening for HCC focuses on patients with cirrhosis. By analyzing existing biomarker candidates as well as through its own proteomic program, EDRN identified three new leading biomarker candidates, two of which are the focus of a large multi-site validation trial." (National Cancer Institute, NIH Publication No. 07-6135, January 2008 p.41 http://edrn.nci.nih.gov/docs/progress-reports/edrn_4th-report_200801.pdf)

    1. Definitions of Evolutionary Terms from the National Academy of Sciences and Institute of Medicine:
     
    Last edited: Oct 19, 2010
  18. Oct 19, 2010 #17

    Evo

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    Hey Mars, the "junk science" the OP was referring to was an article by a couple of people claiming that looking at some egyptian mummies and not finding much cancer meant that cancer must be a new man made illness. Well, we know that all of the organs, stomach, liver, lungs, intestines, brains, etc... were all removed before mummification, so there was little of the body left to examine, even if they examined every inch of what was left.
     
  19. Oct 19, 2010 #18

    bobze

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    And that is another great point Evo.

    Cancer is about the most complex medical subject one can delve into and making definitive claims about such a complex and variable disease is teasing the bulldog in my opinion.

    For instance, Hodgkin's lymphoma was first described in the early-mid 19th century and we didn't really start understanding the disease from a diagnostic standpoint till the 20th century. Are we too believe that Hodgkin's lymphoma didn't kill people prior to that? Certainly not, it was however attributed to bad blood, bad spirits or any of the other maladies of the time.

    This goes back to just how complex cancer is. If users aren't familiar with cancer, they can go back and read my post on how it all "starts" on the first page. But the point is, cancer isn't attributable to any one factor. There are many things which "need to go wrong". We're just starting to understand also how things like corticoids affect NK cell activity and other stressors as well.

    I think when its all said an done, we need to be mindful that anything excessive is bad for our bodies-Even water. Staying active, trying to eat healthy and trying to keep a general positive outlook on life seems the best advice one can give.
     
  20. Oct 19, 2010 #19
    Hi Evo, the link (url) that the OP presented was to an article entitled, "Cancer is a man-made disease, controversial study claims- Rarity of cancer in Egyptian mummies suggests modern environmental factors." (http://www.msnbc.msn.com/id/39687039/ns/health-cancer/) David and Zimmerman are a 'couple of people' mentioned within the MSN article. Also, MSN isn't a scientific journal. :rofl: Here is what Nature REVIEWS has to offer pertaining to the MSN article:

    Here is Professor Rosalie David (OBE, BA, PhD, FRSA) - research.
    http://www.manchester.ac.uk/research/Rosalie.david/research

    And this might be helpful too:
    I still hold onto what I presented in my previous post, especially about the usage of the word "science" and my previous presentation of an example. Also, Nature and Science are peer-reviewed journals.
     
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  21. Oct 19, 2010 #20

    Evo

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    I intentionally referred to them as a "couple of people" because I can't imagine a professional scientist making this kind of claim with so little to go by.
     
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