In fact, I don’t suspect that cancer rates have remained entirely steady. Dseid makes a good point that in 1900, there were no environmental controls and plenty of industry, but even at that, I think the majority of the population was relatively removed from it. Also, in 1900, they hadn’t grown up with it. These days, the genral population does have a number of exposures that weren’t present then. Whether this is higher risk or lower is part of what I would like to know.
I do think that, whatever the answer, those figures I presented are ludicrously misrepresented.
Indeed in 1900 about 2/3s of American were rural, compared to 2/3s urban now. And the urban had a much higher mortality rate in those days. But more from communicable diseases due to overcrowding and poor sanitation than cancer. In any case I did find this:
The rarity of cancer in antiquity is perhaps not so undisputed.
No doubt there are environmental triggers for cancer and that better nutrition (such as increased fiber intake) would reduce rates. Decreasing a host of known significant factors, like pollution from coal plants, in many parts of the world decreasing the indoor use of biomass, would also have major impacts. But looking through a broad historic lens our current environment is not particularly toxic.
I don’t know if there’s enough evidence to determine the rate of cancer in ancient times, but from 1900 on we should have a fairly good sequence of measurements that indicate whether the cancer rate is increasing, decreasing or staying the same. Since it indicates a very stable rate, it’s hard to justify that the figures from 100 years are some kind of anomaly.
Since genetics appears to be a factor in some forms of cancer, there’s no general reason to suspect an increase in those types of cancer. There are types of cancer whose cause is suspected to be environmental, and it might be expected to see an increase in those types. But at the same time, people knowing this, also take more steps to maintain a better environment for themselves. This would lead to a decrease independently, and cancel out some of the environmental cancer cases that do develop.
However, since people are living longer, one might expect an increase in the rate as a result of that. I didn’t go through all the links, but did any of them break down the data into rates based on the number of years of life? I’d like to see data on the rate of cancer per human year of life. I suspect it has noticeably decreased, or cancer is not so much age related as people think.
Please note, this is NOT a scientific paper as you would normally think of one. This is a perspective. It’s basically an opinion piece based on a review of scientific evidence. It is not primary literature.
In fact, I read his argument. I do not agree with it. At best, it suggests a lack of cancer in **paleolithic **humans. But not in my opinion the age of civilization. His argument for greek/Egyptian era societies appears to hinge on the fact that there are very few medical texts which can be verified as cancer cases. So what? This is backwards science. A lack of evidence doesn’t mean it’s false.
Beyond that it’s not like you can control for what kind of texts survive. He doesn’t even consider this question. Heck, the word for carcinoma comes from the greeks(he does put this in the paper)
His conclusion does not follow the evidence in my opinion. With the exception with of the argument he makes for paleolithic humans. (Many thousands of skeletons found with very few cancers, including those of bone growth cancers which generally effect young people). But even that is very tentative considering the rarity of fossils and the kind of conditions needed to make them.
Apparently you are not alone in being unimpressed. (Read the article. It’s a very interesting short read.)
So let’s recap:
In recent years cancer rates and deaths unequivocally overall decreasing.
Since 1900 cancer rates stable per unit of population (according to at least one academic source) despite the fact that fewer lived into an age that cancer more commonly presents (dying earlier, including in infancy, of things like infectious diseases). Cancer lower on cause of death because so much else killed people first. And as to the non-Gaussian bit? The bar graph on this page is informative. In NJ as a case study 82.3% of all deaths were in those older than 60 in 2000, compared to only 25.5% in 1900. Relatively few making to the ages when cancer most commonly presents. The biggest chunk of deaths in 1900 was in the 20 to 59 crowd (damn infectious diseases). Again, live long enough and you’ll die. Live longer and the odds that you will have a cancer diagnosis before you die increases.
Since ancient times? Well here I plead guilty to having accepted surreal’s initial argument too readily, as it fit in well with my preconceptions that ancestral humans’ diets and active life style, coupled with fewer environmental carcinogens, would provide a highly significant degree of protection from cancer. Perhaps to some degree but the evidence overall (albeit sparse) is not so much as I would think. Huh. That’s discouraging.
Reading more - the anecdotal report of cancer being rarely observed by someone of the West among Eskimos, is pretty silly. Cancer is seen in mummified frozen remains (pg 115). In 1925 most of the Labrador Eskimo population was dying young thanks to the infectious disease and exploitation caused by those of the West coming in; the population had gotten down to a third of its previous numbers (as was true for many native populations upon contact with the West). Wow, he didn’t see many new cases of cancer. So telling.
Yes, people died from unknown conditions, and no one bothered to find out exactly what killed them. My father’s parents died in 1927 and 1931, of… something. They think it was an infectious disease like influenza in both cases, but nobody really knows.
I also think it’s the case that diagnosis has gotten a lot better. Imagine that you ended up with, say, prostate cancer in Boston in 1750. Would your average MD have been able to diagnose it as cancer?
We probably don’t know the rate of prostate cancer now. It is non-fatal and non-detectable in many cases. I’ve heard someone theorize that large numbers of men die from other causes, but have prostate cancer that would not be detected unless they had lived much longer.
Comparing estimates of cancer incidence is highly problematic because detection rates vary so widely. Now days a little spec on a mammogram can lead to a cancer diagnosis. that would have gone undetected a number of years ago, and also probably an increase in false positives. The clearest case of this is prostate cancer in which we see great differences in prevelence and mortality between Europe and the US. In the US we are much more vigilant in finding low stage Prostate cancer, and often find cases that are so indolent they could be left alone with no significant affect to the patient. In Europe they are less likely to test for prostate cancer and so only detect the ones that are dangerously aggressive. The result is much higher perceived prostate cancer prevalence in the US, but much better prognosis for those diagnosed, since they are more likely to be indolent. As a result per capita mortality due to prostate cancer in the US and Europe are about the same.
Would “indolent prostate cancer” and “prostatitis” be different things? I know that strictu sensu the words have different ethymologies, but sometimes what a word’s current meaning and the original one end up being very different.
I’m wondering whether what’s called prostatitis in Spain might be what you’re calling indolent prostate cancer. I’ve never heard equivalent terms used for a cancer here. If it’s not agressive it’s called a tumor but not a cancer.
If you were over 50 years of age and busted your hip, you were dead.
Your family would help you to bed, the doctor would come by, and your family would be told to “make you comfortable.” Without the surgical talents of today, there would be no pin in your hip, no hip replacement, no way to splint and cast your hip allowing the bone to heal. You’d get to just lie in bed and hurt while your family did their best to keep you clean and dry. Every time they’d move you, the broken pieces would shift and grind and avoid healing. Finally, the inactivity would allow pneumonia to set in, and the doctor would call it, “The old person’s friend,” and you’d finally die.
You could probably get a similarly skewed study that would “show” cardiovascular disease is more prevalent in “modern” times, too.
~VOW
Yes, they’d be different. Prostatitis is symptomatic inflammation of the prostate, often causing painful urination. Occult prostate cancer is without symptoms and slow enough growing that often someone would die of another cause long before it would ever be found if not for aggressive screening. Hence the controversy over how aggressively to screen for prostate cancer in men 50 and over, with the U.S. Preventative Services Task Force recently concluding that, absent symptoms suspicious for prostate cancer, screening and potentially identifying prostate cancer before symptoms has more potential harms than benefits. Better to not have a cancer diagnosis when having one is more likely to do harm than good.
The same group has a slightly less strong, but strongly reacted to, position on breast cancer screening currently finding that mammography in lower risk women 40 to 50 may also have a greater likelihood of causing harms than benefit.
Is it? I think the fact that it was note-worthily rare as long ago as 1915 is some evidence in favor of cancer itself not being rare at that time, which makes WarmNPrickly rightfully suspicious of the claim that cancer was very rare in 1900.
The number of earthquakes recorded has increased hugely in the last a hundred years…although that’s because there’s far more recording stations all around the world, and a consistent approach to measuring them ;). (an analysis of ‘significant’ earthquakes of the last 100 years actually showed that the number of such earthquakes had decreased throughout the century, but not to a significant level).