Is cancer as prevalent as it was prehistorically?

[Question_]

Almost everyone I've known has had someone close to them have cancer in some form or another. When I was doing some reading on the matter I encountered a statistic saying that one in two Americans will have any form of cancer.

I really have a hard time understanding why so many people are getting cancer nowadays. By comparison, do you think caveman 'Bob' would have lived with the same chances of contracting cancer as modern day 'Bob'?

 

[Question_]

Just to substantiate the claim I made above about the statistic.

http://www.medicalnewstoday.com/articles/288916.php

https://www.cancer.org/cancer/cance...ility-of-developing-or-dying-from-cancer.html

 

[russ_watters]

I really have a hard time understanding why so many people are getting cancer nowadays. By comparison, do you think caveman 'Bob' would have lived with the same chances of contracting cancer as modern day 'Bob'?

No, cavemen didn't live anywhere near long enough to get most cancers.

 

[Question_]

No, cavemen didn't live anywhere near long enough to get most cancers.

I agree. Yet, why is cancer still so prevalent nowadays? The epidemiology of the disease isn't exclusive to old age nowadays and is affecting younger and younger age groups.

 

[russ_watters]

Yet, why is cancer still so prevalent nowadays?

That's a much more complex question. People get cancer because our genetic code makes mistakes. The reasons those mistakes happen are diverse and complex.

The epidemiology of the disease isn't exclusive to old age nowadays...

No, but even if it were evenly distributed (it isn't), you'd still see more than twice as many people with cancer today than in caveman times because of it. But the impact of the fact that cancers are more prevalent in old age (because genetic mistakes pile-up over time) will add several more multipliers.

...and is affecting younger and younger age groups.

I doubt that's true: do you have a source for it?

 

[russ_watters]

This might help:
http://scienceblog.cancerresearchuk.org/2015/02/04/why-are-cancer-rates-increasing/

 

[Question_]

This might help:
http://scienceblog.cancerresearchuk.org/2015/02/04/why-are-cancer-rates-increasing/

Thanks, will read it.

Edit: Answered all my questions. Guess you can lock it up, guys.

 

[davenn]

This might help:
http://scienceblog.cancerresearchuk.org/2015/02/04/why-are-cancer-rates-increasing/

interesting article

it would be interesting to see the stats on specific cancers and their increases or decreases
melanoma ( skin) vs bowel vs prostate vs breast for example and see how that varies for age/sex groups

going to have to do some searching

I know so many people personally that have got / been through / died from cancer

I lost my best man for my first marriage on the 1st anniv -- dead within a year of diagnosis, they couldn't stop it -- 42 yrs old
my mum had a cancerous kidney removed, she survived -- late 60's at time
my next door neighbour is in 5 yr battle with bowel cancer -- mid 60's

on and on and on

Yet, why is cancer still so prevalent nowadays?

a lot of the "increased prevalence" comes with the increased and better screening techniques

akin to people saying that there seems to be more earthquakes these days
the numbers of various sizes of quakes hasn't changed, what has is the much better and more widely distributed seismic detection network and the more active media reporting of events

That's a much more complex question. People get cancer because our genetic code makes mistakes. The reasons those mistakes happen are diverse and complex.

that's definitely some of the problem but doesn't cover all specific cancers ... skin, breast and bowel for example
As the article says ... life styles and natural exposure play a part that is totally unrelated to genetic breakdown assoc. with old age.

Environment ... more, unprotected sun-tanning (ozone depletion related) carcinogenic chemicals in the air, water etc
that our ancestors were not subject to, even if your went back only a few 100 years ( I suspect they were more likely to dies from various plagues than cancer )

Man is producing carcinogenic chemicals over the last 100 years that were never even heard of 100++ years ago
http://www.unc.edu/courses/2005spring/envr/132/001/Carcinogenesis.pdfjust a few thoughts Dave

 

[russ_watters]

a lot of the "increased prevalence" comes with the increased and better screening techniques

Yes, though hopefully the OP is aware that the ancients didn't have cancer screening techniques, so that should be an obvious difficulty in figuring how often they got cancer. I don't think it is possible to really know and at best we would have to assume demographically corrected rates are the same. Demographics alone tell us whereas somewhere around 1 out of 2 get cancer today, for the ancients it was more like 1 in 20(detected or not) - just because they only lived half as long.

that's definitely some of the problem but doesn't cover all specific cancers ... skin, breast and bowel for example
As the article says ... life styles and natural exposure play a part that is totally unrelated to genetic breakdown assoc. with old age.

I meant to word that a bit more generally; it is not just internal mistakes, but externally caused genetic damage also accumulates.

Environment ... more, unprotected sun-tanning (ozone depletion related) carcinogenic chemicals in the air, water etc
that our ancestors were not subject to, even if your went back only a few 100 years ( I suspect they were more likely to dies from various plagues than cancer )

Man is producing carcinogenic chemicals over the last 100 years that were never even heard of 100++ years ago

While that is obviously true, I would caution against falling victim to the "naturalistic fallacy"(natural = better) that probably is either the cause or effect (or both) of the thinking in the OP.

Difficulty normalizing screening accuracy aside, the link I posted included a graph showing the drop in lung cancer rates (in the UK) recently due to the drop in smoking rates. So clearly, human-caused carcinogens matter. But the ancients smoked too. How much, I don't know. The second leading cause of lung cancer, at least in the USA, is radon. Presumably an ancient who lived in a tent wouldn't be subject to it, but an ancient who lived in a cave might have had worse exposure.

Other factors that may have increased cancer rates in ancients:
--Increased sun exposure
--Poorer hygeine
--Poorer sanitation
--Poorer food quality and preservation

Though admittedly, I'm not sure how much of those last three were cancer causing and how much they just made people sick in other ways. But a quick google tells me that salt meat preservation (common before refrigeration), for example, may cause cancer.
[edit]

Man is producing carcinogenic chemicals over the last 100 years that were never even heard of 100++ years ago
http://www.unc.edu/courses/2005spring/envr/132/001/Carcinogenesis.pdf

Interesting link. Page 3 shows charts of death rates (age adjusted), and I'm going to assume that prior to about 1950 we had essentially no treatment options for cancer (other than perhaps removing tumors), so the substantial drops in death rates for uterine and scomach cancers are likely due primarily due to other advances in medicine and standard of living. E.G., I'm speculating that it is the invention/proliferation of refrigeration that caused stomach cancers to drop by 2/3 from 1930 to 1960 (half for men, 80% for women).

 

[Greg Bernhardt]

This might help:
http://scienceblog.cancerresearchuk.org/2015/02/04/why-are-cancer-rates-increasing/

"Half of us will hear the words “you have cancer” at some point in our lives."

I wonder why we aren't spending more resources in cancer research. If I really have a 50% chance of getting some cancer. Perhaps I should be donating to research a bit more often!

 

[Vanadium 50]

I wonder why we aren't spending more resources in cancer research.

How much should we spend? And do you know how much we are spending now?

I remember a discussion with a woman who argued that the Federal R&D budget be slashed to 10% of the total. It's actually about 3-1/2%.

 

[russ_watters]

I wonder why we aren't spending more resources in cancer research.

More than what? We spend a vast amount of money on cancer research (public and private), but squeaky wheels get greased, so you can probably guess which one(s) get the most funding. It isn't necessarily aligned with the biggest incidence/death rates.

And though people say we can't "cure" cancer, really we can -- and do it vastly better than even 20 or 30 years ago. We're getting a substantial tangable benefit for that substantial investment.

 

[Greg Bernhardt]

How much should we spend? And do you know how much we are spending now?

More and I guess not enough (or we are all just betting by the time we get the call, medicine will have advanced enough to feel ok about it)

And by "we", I mean as individuals. Personal donations. However, I suppose it does matter at what age I get the call. If at 50, well yeah, I would like medicine to save me. If at 85, maybe it's time to go anyway and I could have used the money in other ways.

 

[russ_watters]

However, I suppose it does matter at what age I get the call. If at 50, well yeah, I would like medicine to save me. If at 85, maybe it's time to go anyway and I could have used the money in other ways.

Not to derail the thread, but that attitude is growing and will become essential to ensuring healthcare spending doesn't bankrupt us in the near future. Needless to say, I agree.

 

[jim mcnamara]

Picture of human fossil toe bone (looks like phalanges mediae) with cancerous growth - 1.7M ya
http://news.nationalgeographic.com/2016/07/oldest-human-cancer-disease-origins-tumor-fossil-science/

 

[russ_watters]

Picture of human fossil toe bone (looks like phalanges mediae) with cancerous growth - 1.7M ya
http://news.nationalgeographic.com/2016/07/oldest-human-cancer-disease-origins-tumor-fossil-science/

Me no likey:

The discovery—which has just been published in the http://sajs.co.za/earliest-hominin-cancer-1-7-million-year-old-osteosarcoma-swartkrans-cave-south-africa/edward-j-odes-patrick-s-randolph-quinney-maryna-steyn-zach-throckmorton-jacqueline-s-smilg-bernhard—suggests that, while modern lifestyles have increased the incidences of cancer, especially in industrialized countries, the triggers for the disease are embedded deep within the human evolutionary past.

“You can opt for the paleo diet, you can have as clean a living environment as you want, but the capacity for these diseases is ancient, and it's within us regardless of what you do to yourselves,” says study co-author Edward Odes of the University of the Witwatersrand.

I'm going to have to look into this more, but this strikes me as claims not in evidence and naturalistic fallacy.

 

[jim mcnamara]

@russ_watters - I picked it for the picture. @Ygggdrasil has strong points to make on the subject.

I've seen papers with the environment's role in carcinogenesis given varying percents over time, all were non-zero. So I don't see that as a conflicting statement.
Possibly overstated. Remember this is a science reporter writing the story, and you know how that goes.

 

[Ygggdrasil]

The extent to which cancer can be prevented is an important and sometimes contentious issue. Probably the most widely cited estimate on the issue comes from Cancer Research UK, which estimates that 40% of cancer cases are preventable by changes in lifestyle (such as quitting smoking, maintaining a healthy bodyweight, and vaccinating against viruses that cause cancer like HPV and hepatitis). Estimates in the scientific literature vary; while some have estimated that as much as two-thirds of cancer are due to "bad luck" and unavoidable, others find that up to ~90% of cancers are due to environmental factors. Overall, there is agreement that many cancers are due to elements of modern life (e.g. obesity) and some are unavoidable byproducts of human aging, but the exact numbers attributable to each are still a subject of debate. See these previous threads on physics forums for more discussion on the topic:
https://www.physicsforums.com/threads/bad-luck-is-primary-cause-of-most-cancer.790125/
https://www.physicsforums.com/insights/causes-cancer-bad-luck-bad-lifestyles/
https://www.physicsforums.com/threads/cancer-causes-circa-67-are-replication-error.908823/

 

[Question_]

Sorry to go all nutty, but, isn't plastic a type of carcinogenic substance? I don't think drinking water contained in plastic exposed to high heat is a great idea.

 

[Ygggdrasil]

Sorry to go all nutty, but, isn't plastic a type of carcinogenic substance? I don't think drinking water contained in plastic exposed to high heat is a great idea.

From Cancer Research UK:

What does the evidence show about plastic and cancer?
People have claimed chemicals inside plastics leach into food or drink causing cancer. In particular there have been concerns about Bisphenol A (BPA) and dioxins in plastic bottles or plastic containers.

But there is no convincing evidence to show using plastic bottles or plastic containers increases the risk of cancer.

http://www.cancerresearchuk.org/abo...-controversies/plastic-bottles-and-cling-film

 

[Question_]

Thanks for that. Lots of valuable information to quell the suspicion that plastic is a cause of cancer, as I've heard anecdotally hereabouts.

This might be of interest:

For the new study, published in Science Translational Medicine, Martin Bergö, a cell biologist at the University of Gothenburg’s Sahlgrenska Cancer Center in Sweden, and his colleagues decided to look at melanoma because rates have been increasing and because the cancer is known to be sensitive to the effects of free radicals. They fed the antioxidant N-acetylcysteine (NAC) to mice that had been genetically engineered to be susceptible to melanoma. The per-weight dose they gave the mice was consistent with what people typically consume in supplements. Although the treated mice did not develop more skin tumors than similar mice that had not been fed the antioxidants, they developed twice as many tumors in their lymph nodes, a hallmark of the spread of cancer—a process called metastasis. When the researchers added NAC or a form of vitamin E to cultured human melanoma cells, they confirmed that the antioxidants improved the cells’ ability to move and invade a nearby membrane.

Antioxidants may bolster protection of these dangerous cells. Bergö and his colleagues found higher levels of glutathione, an antioxidant made by the body, inside metastatic tumor cells in treated mice compared with untreated mice. The treated mice also had a higher ratio of glutathione to glutathione disulfide, the molecule that glutathione becomes after it neutralizes free radicals. These findings suggest that when the body is given extra antioxidants, its tumor cells get to keep more of the antioxidants that they already make themselves. The cells can store the surplus, improving their ability to survive damage. This idea is supported by work that shows some genes that drive cancer growth turn on other genes that make intrinsic antioxidants.

Source: Antioxidants May Make Cancer Worse.

 

[Drakkith]

Sorry to go all nutty, but, isn't plastic a type of carcinogenic substance? I don't think drinking water contained in plastic exposed to high heat is a great idea.

The overwhelming majority of substances the average person uses and are exposed to every day have not been shown to be carcinogenic. Known carcinogens have warning labels placed on them, are restricted to certain uses, or are only used in professional settings where exposure can be controlled/mitigated. Any claims you hear of X substance is carcinogenic, where X is a commonly used substance, such as the plastic in bottles, is almost certainly a false claim.

 

[Question_]

The overwhelming majority of substances the average person uses and are exposed to every day have not been shown to be carcinogenic. Known carcinogens have warning labels placed on them, are restricted to certain uses, or are only used in professional settings where exposure can be controlled/mitigated. Any claims you hear of X substance is carcinogenic, where X is a commonly used substance, such as the plastic in bottles, is almost certainly a false claim.

There are plenty of known carcinogens lurking in plain sight though. Take lead or asbestos for the matter. I'm pretty sure most houses built prior 1974 or 1980 will most likely still have asbestos lurking around somewhere. Of interest: http://www.constructiondeal.com/blogs/is-1980-an-appropriate-end-date-for-asbestos-use.258I'd like to shift the topic, if possible, as to how to prophylactically prevent cancer? I've read that cannabidiol, not THC (as I'm not interested in getting high every day), is quite a potent anti-cancer compound (meaning it actually kills cancer cells that are already present), there's also curcumin. Cannabidiol can be purchased through hemp extracts, mitigating the issue with the legality of the matter. Plenty of evidence in support of cannabidiol and cancer prevention. I'll have to do some research on the topic; but, again given that 1 in 2 people are likely to have cancer, I see no harm in taking some supplements that could help stave off the danger of getting cancer in one's lifetime. Is anyone already doing this and if so could you please list what supplements you are taking and any possible research papers in support of taking said supplements? I'm not sure if physicsforums allows such discussions; but, I'm quite adamant on minimizing my risk for getting cancer if at all possible, to think of it as a preventative measure or a type of investment in your future.

In essence, cancer seems to be a problem of the immune system or autoimmunological issues, and knowing that one's immune system will decrease with age, then I suppose enhancing or supporting your immune system might be of interest.

 

[Drakkith]

There are plenty of known carcinogens lurking in plain sight though. Take lead or asbestos for the matter. I'm pretty sure most houses built prior 1974 or 1980 will most likely still have asbestos lurking around somewhere.

Yes, and those substances are now severely limited in their uses and have warnings associated with their use, like I said.

I'd like to shift the topic, if possible, as to how to prophylactically prevent cancer?

There aren't any that I know of except to avoid known carcinogens as much as possible and to stay healthy (moderate exercise, keep your weight down, don't abuse drugs/medication, etc).

I've read that cannabidiol, not THC (as I'm not interested in getting high every day), is quite a potent anti-cancer compound (meaning it actually kills cancer cells that are already present), there's also curcumin.

I find this extremely difficult to believe. It's far more likely that some minor research results have been hyped up by the pro-cannabis crowd. This isn't unusual. Research results get hyped up by different groups all the time. Well, as long as they think it supports their view. Negative results aren't taken quite so well...

In essence, cancer seems to be a problem of the immune system or autoimmunological issues, and knowing that one's immune system will decrease with age, then I suppose enhancing or supporting your immune system might be of interest.

The root cause has nothing to do with the immune system. It has to do with mutations within the cellular genome that eventually cause cells to stop their normal functions and to divide when they shouldn't be. The immune system does its best to stop this, but some mutations cause cancer cells to be "invisible" to even a healthy immune system. And some cancers are of cells of the immune system itself.

Besides, there are no known ways to enhance your immune system except by staying healthy.

 

[Question_]

I find this extremely difficult to believe. It's far more likely that some minor research results have been hyped up by the pro-cannabis crowd. This isn't unusual. Research results get hyped up by different groups all the time. Well, as long as they think it supports their view. Negative results aren't taken quite so well...

Yes, I agree. There's a bunch of cannabis evangelicals out there touting the plant as a panacea for all your ailments. However, I did list above a google scholar search in regards to the cannabinoid system and cancer. I'll look around for a meta-analysis on the matter from a well-respected institution and post what I find here if anyone is interested.

 

[Drakkith]

However, I did list above a google scholar search in regards to the cannabinoid system and cancer.

Ah, you must have been in the process of adding it to your post while I was replying. I'll take a look at it.

 

[Drakkith]

Well, I'm certainly no expert and I'm definitely not qualified to comment on the validity of any of the papers listed. I did learn something new from this paper though:

Currently, the term ‘cannabinoid’ refers to more than 100 terpenophenols derived from Cannabis sativa[16], as well as to synthetic compounds that directly or indirectly interact with cannabinoid receptors.

The paper also appears to give a good overview of the signaling system involved in cannabinoid use, the so-called "endocannabinoid system".

 

[Question_]

Well, I'm certainly no expert and I'm definitely not qualified to comment on the validity of any of the papers listed. I did learn something new from this paper though:

Currently, the term ‘cannabinoid’ refers to more than 100 terpenophenols derived from Cannabis sativa[16], as well as to synthetic compounds that directly or indirectly interact with cannabinoid receptors.

The paper also appears to give a good overview of the signaling system involved in cannabinoid use, the so-called "endocannabinoid system".

Nice paper (link doesn't work as provided). Lots of information. Unfortunate that there is some bias in it due to being funded by GW Pharmaceutical, which produces the product mentioned in the paper, Sativex.

I've heard that cannabidiol and THC work synergistically to prevent cancer. What was new to me was the doses used in the paper, total 10 mg for the Sativex preparation per day, compared to 10 mg per kg for cannabidiol alone. That's some strong synergism between the two compounds in reducing effective doses instead of 10 mg per kg for CBD alone.

Will have to consider getting a 'generic' preparation of said product due to my neurotic obsession with cancer prevention as of late.

 

[Drakkith]

Nice paper (link doesn't work as provided).

Fixed.

Will have to consider getting a 'generic' preparation of said product due to my neurotic obsession with cancer prevention as of late.

Or you could just stop worrying about it, try to live healthy, and make sure that take the necessary precautions for catching the most common forms of cancer early. There just isn't anything you can take that's going to prevent DNA damage in your cells.

 

[Question_]

Or you could just stop worrying about it, try to live healthy, and make sure that take the necessary precautions for catching the most common forms of cancer early. There just isn't anything you can take that's going to prevent DNA damage in your cells.

Well, I'm working under the assumption that I will have cancer. Since 10 mg of 1:1 CBD : THC is pretty cheap and has other health benefits, like reduction in anxiety and such issues with mood, I think it might be something I could incorporate into my lifestyle. Furthermore, I recently read that people who tend to score higher on the happiness index tend to have more anandamide floating around in their brains. No harm in increasing that, within certain bounds obviously.

Only issue is with the THC component. Then there's curcumin:

In Vivo Inhibition of Nitric Oxide Synthase Gene Expression by Curcumin, a Cancer Preventive Natural Product with Anti-Inflammatory Properties.
Curcumin and Cancer Cells: How Many Ways Can Curry Kill Tumor Cells Selectively?
Curcumin and cancer: An “old-age” disease with an “age-old” solution
The Multifaceted Role of Curcumin in Cancer Prevention and Treatment
Curcumin: An Anti-Inflammatory Molecule from a Curry Spice on the Path to Cancer Treatment