One of the tropes that I keep reading in the vastness of the internet is that cancer is a modern disease. People keep claiming that cancer is caused by the modern diet, modern chemicals, modern lifestyle, modern agriculture, modern everything.
These trope-pushers want us to believe that our ancestors of just a few hundred years ago never got cancer because they lived some sort of magical life that avoided cancer. Well, of course, many of those people died of infectious diseases that we prevent with vaccines today, so I’m not sure their lives were so magical. And they died before they could develop cancer.
If one is going to make an extraordinary claim like “modern cancer is a man-made disease,” well I expect extraordinary evidence to support that claim. A paper published a few years ago made the claim that cancer was rare in Egyptians based on what has been seen in mummies. Let’s take a look at that, but also examine the evidence of whether cancer is a modern disease or as ancient as the earliest multicellular organisms crawling out of the ocean hundreds of millions of years ago.
Is modern cancer a man-made disease?
Much of the claims about cancer being a modern man-made disease comes from an article published by AR David and MR Zimmerman in Nature Review of Cancer, a highly respected cancer journal. So you all are saying, “wow, that’s evidence.”
Well only if the evidence is based on opinion. You see, the article by David and Zimmerman was published in the section of the journal called “Perspectives.” A perspective, especially in this context is a “point of view,” a “viewpoint”, a “stance”, or a “position.” But David and Zimmerman are highly respected anthropologists who have published extensively in real journals. But what do they know about cancer? Let’s look.
David and Zimmerman’s hypothesis would hold credence, except for lots of things. The first of which is that the validity of their epidemiological evidence is weak, possibly because they aren’t epidemiologists. Let’s look at the major issues with their “research”:
- Their major claim is that they found only one case of cancer in “hundreds of mummies.” But is this indicative of anything that could be useful to understanding cancer? Probably not.
- The average lifespan of an Egyptian would have been around 26 years old. Today it’s over 60, and closer to 78-80 in developed countries. For lots of reasons, cancer generally arises in later years, something not experienced by the Egyptians of that era.
- The researchers examined mummies, not a broad, unbiased population of ancient Egyptians. The best-preserved mummies generally came from the upper class of Egypt, which may or may not have had some advantage against cancer.
- There are three kinds of mummification in Egypt –depending on the deceased’s class, it went from the well-preserved type down to the cheap type. But it was clear that all three versions of mummification required the removal of organs, including the brain. Of the 200 or more different cancers, a bulk of them occurs in these organs, even at a younger age.
- If you assume most of the dead were in their 20s, most cancers would be very small and early in development. Something that could be missed just through observation, but hidden completely by the mummification. Critics of this study have stated that in fact with epidemiological and molecular studies of the mummies, it’s easy to come to the conclusion that cancer is an ancient disease.
More than just criticizing David and Zimmerman’s article, there is a lot of evidence, much of it qualifying as extraordinary evidence, that pretty much refutes the claims of the University of Manchester researchers:
- One group has found writings in ancient Egyptian manuscripts that describe both “modern” cancers and innovative (and sometimes ineffective” treatments for those cancers. If human cancer were so rare in Egypt, why would they be writing about it?
- In S. Mukherjee’s book, Emperor of all Maladies – a Biography of Cancer, one of my favorite books about the facts and science of cancer, Dr. Muhkerjee describes a papyrus from around 3000 BCE which generally is believed to be the earliest known description of cancer per se. In other words, we’ve got pretty fine evidence that humans were afflicted with cancer over 5000 years ago.
- M Binder et al., examined metastatic cancer in a skeleton from Nubia, about 3300 years ago. They mention that the lack of evidence of bone cancer in ancient skeletons has led to the common misconception that cancer was very rare in ancient times – probably because of a healthier living environment. However, Binder et al. show that the most common types of malignant cancer, particularly those causing secondary bone involvement, exhibit a strong correlation with age. And of course, modern humans are older.
- The assumption that all cancers are a result of some environmental challenge leads to many of these beliefs. Cancers result from genetic predisposition, random mutations, viral infections, obesity, and several other non-environmental causes. Yes, lots of cancers are caused by the environment – smoking (and secondhand smoke), air pollution, and radiation (from the sun or the environment), all lead to increases in cancer risk. But some of those risks existed before modern civilization arose.
Professor Rosalie David, one of the authors of the mummy study, claimed, from her analysis of the possible reference to the disease in classical literature, fossil records, and mummified bodies, claimed:
In industrialized societies, cancer is second only to cardiovascular disease as a cause of death. But in ancient times, it was extremely rare. There is nothing in the natural environment that can cause cancer. So it has to be a man-made disease, down to pollution and changes to our diet and lifestyle. The important thing about our study is that it gives a historical perspective to this disease. We can make very clear statements on the cancer rates in societies because we have a full overview. We have looked at millennia, not one hundred years, and have masses of data. Yet again extensive ancient Egyptian data, along with other data from across the millennia, has given modern society a clear message – cancer is man-made and something that we can and should address.
All that sounds good, except she’s lacking any evidence supporting her beliefs. And if she’s going to make an extraordinary claim, we demand extraordinary evidence. That doesn’t qualify.
Then Professor David made this unsupported claim – “There is nothing in the natural environment that can cause cancer.”
Except for radon gas which percolates from the soil. UV light from the sun can cause cancer. Aflatoxin from the mold Aspergillus flavus, a powerful carcinogen, is found in food. Human papillomavirus and hepatitis b viruses, both of which evolved “naturally,” and have infected the human population since humans arose can cause cancer. Random mutations because of translation and transcription errors of the human genome can lead to cancer. A random particle of radiation from the air or ground causes one mutation that ends up as cancer.
In other words, Professor David may be an outstanding anthropologist and Egyptologist. But her lack of expertise in cancer epidemiology and biology makes me wonder how she could come to the conclusions that she did. And why the journal would publish the article.
Her conclusions just do not logically come from the evidence Professor David has set out.
Age is the major risk factor for cancer
I need to be blunt. We can invent all kinds of causes of cancer, but age is the major risk factor. Why? Because we accumulate genetic errors over time. Because we have more time to have contact with cancer-causing viruses like HPV and Hepatitis B. Because we have more time to experience various environmental challenges like smoking.
Cancer is generally a disease of the elderly. I know, many of the readers will repeat anecdotal stories about children with cancer – there is no argument that it does happen in children, but I’ve never claimed that it didn’t happen. It’s just that the bulk of cancer diagnoses today are in the elderly.
According to Cancer Research UK, three-quarters of cancer diagnoses are in people aged 60 and over, and more than a third (36%) of those are in people aged 75 and over. In other words, what researcher would be surprised that cancer was a very rare event in ancient populations where it would be a miracle if someone made it to 30 or 40 years old?
There’s really no evidence that cancer was rarer in ancient populations, especially if we rely upon studies that have a high amount of selection bias (mummies), and a lack of actually laying out how to define a diagnosis of cancer in a mummy. It may be impossible.
Yes, there is a relationship between the increased risk of cancer and some of our modern lifestyles. Smoking, obesity, alcohol consumption, not being vaccinated against cancer-causing viruses, sedentary living, and several other issues lead to higher risks of cancer. And even if you avoid all those lifestyle issues, a random particle of radiation from the sun can induce cancer.
Cancer in dinosaurs
If you really want to go back in time, scientists from Canada’s Royal Ontario Museum and McMaster University have discovered osteosarcoma, a malignant bone cancer, in the fibula of a Centrosaurus apertus, a plant-eating, single-horned, non-avian dinosaur that lived 76 to 77 million years ago.
The researchers brought in specialists in an array of fields, including pathology, radiology, orthopedic surgery, and paleopathology, to examine and diagnose the suspected tumor. They were able to visualize the progression of cancer through the bone by performing high-resolution CT scans of the fibula and examining thin sections of the bone at the cellular level under a microscope.
The team confirmed the diagnosis of osteosarcoma by comparing the bone to the fibula of a healthy centrosaurus and that of a human with osteosarcoma.
Now if you’re going to say that “but that was just one bone in one dinosaur,” you would be ignoring some critical issues:
- Soft tissue, which is more frequently at risk of cancer, does not preserve well in fossils. Most soft tissue is destroyed or eaten by scavengers before it can be preserved. Bone is usually what is preserved in fossils.
- No one has done a comprehensive review of every bone in every collection to determine if there are other fossils that preserve an occurrence of osteosarcoma. Identifying it requires skills that are beyond the average paleontologist, so that’s why this team included physicians who were trained in orthopedics.
- Dinosaur fossils are rarely complete skeletons, and we have a vanishingly small representation in fossils of all the dinosaurs that ever existed. Based on one sample, we have no idea how frequent or infrequent this type of cancer was in dinosaurs.
- Dinosaurs with cancer (whether in the bone or other organs) will probably be weaker than their fellow dinosaurs. And in a world filled with nasty predators, the weaker dinosaurs would become food, scattering the bones and organs everywhere, making it less likely that cancer will be seen.
The point of this research is that cancer has been identified in a non-avian dinosaur that lived over 70 million years before humans and their immediate ancestors arose in Africa.
A final word or two
Cancer has been around for tens of millions of years, maybe longer. In humans, we have observed cancer since early written history.
The trope that our modern environment contributes to cancer versus thousands of years ago just doesn’t make sense scientifically. Much of our environment is outside of our control, from background radiation to viruses to random mutations. And those factors lead to cancer.
Cancer is not a modern disease. And the scientific evidence supports that conclusion.
Key citations:
- Binder M, Roberts C, Spencer N, Antoine D, Cartwright C. On the antiquity of cancer: evidence for metastatic carcinoma in a young man from ancient Nubia (c. 1200 BC). PLoS One. 2014 Mar 17;9(3):e90924. doi: 10.1371/journal.pone.0090924. eCollection 2014. PubMed PMID: 24637948; PubMed Central PMCID: PMC3956457.
- David AR, Zimmerman MR. Cancer: an old disease, a new disease or something in between? Nat Rev Cancer. 2010 Oct;10(10):728-33. doi: 10.1038/nrc2914. Epub 2010 Sep 3. PubMed PMID: 20814420.
- Ekhtiari S, Chiba K, Popovic S, Crowther R, Wohl G, Kin On Wong A, Tanke DH, Dufault DM, Geen OD, Parasu N, Crowther MA, Evans DC. First case of osteosarcoma in a dinosaur: a multimodal diagnosis. Lancet Oncol. 2020 Aug;21(8):1021-1022. doi: 10.1016/S1470-2045(20)30171-6. PMID: 32758461.
- Faltas B. Cancer is an ancient disease: the case for better palaeoepidemiological and molecular studies. Nat Rev Cancer. 2011 Jan;11(1):76; author reply 76. doi: 10.1038/nrc2914-c1. PubMed PMID: 21179178.
- Karpozilos A, Pavlidis N. The treatment of cancer in Greek antiquity. Eur J Cancer. 2004 Sep;40(14):2033-40. PubMed PMID: 15341975.
