As I sat on my couch last night, laptop sitting in front of me, I awaited the Ken Burns adaptation of Siddartha Mukherjee’s excellent book The Emperor of All Maladies into a three part television documentary to air on PBS. I’m not sure whether I’ll blog the show or not, but if I do I’ll probably wait until all three episodes have aired. In the meantime, this seems as good a time as any to go back to a story that I saw a week ago but somehow, thanks to grants, traveling to Houston, and other distractions that I wanted to blog about more, never got around to. Since The Emperor of All Maladies, the book at least, is billed as “a biography of cancer,” I’d indulge my interest in ancient medicine, including ancient Egyptian medicine starting when I first wrote about the Edwin Smith papyrus, which I saw at the Metropolitan Museum of Art in New York nearly ten years ago.
If there’s one claim that irritates me that various proponents of alternative medicine like to make, it’s that cancer is a “modern” disease, that it was rare (or even didn’t exist) before the rise of modern societies, particularly the industrial revolution. This viewpoint bubbled up five years ago, when a commentary in Nature Reviews Cancer (yep, the same journal in which I published my opinion piece on integrative oncology a few months ago) that argued strongly that cancer was almost unknown (or at least very rare) in the ancient world based on the lack of finding it in mummies in Egypt and South America. They also looked at ancient texts and literature from Egypt and Greece, and say that there’s little sign that cancer was a common ailment. After all, cancer is mainly a disease of the elderly, with three-quarters of cases being diagnosed in people over 60 and more than a third of cases diagnosed in people 75 or older. Life expectancy was much shorter in ancient times; so relatively few people made it to cancer-prone ages. Most probably didn’t make it past age 40.
In any case, what caught my attention was a story reporting the finding of the oldest example of breast cancer:
Researchers working in Egypt say they have found the oldest example of breast cancer in the 4,200-year-old remains of an Egyptian woman — a discovery that casts further doubt on the common perception of cancer as a modern disease associated with today’s lifestyles.
Here’s the announcement from the Egyptian Ministry of Antiquities:
See:
Antiquities Minister, Dr. Mamdouh el-Damaty announces the discovery of the oldest evidence of breast cancer in the world. This discovery was made along the seventh archaeological season carried out by University of Jaen (Spain) in the necropolis of Qubbet el-Hawa (West Asuan). Dr. Miguel Botella (University of Granada) and his team of anthropologists have identified on the bones of an adult woman an extraordinary deterioration in all her skeleton. The study of her remains shows the typical destructive damages provoked by the extension of a breast cancer as a metastasis in the bones.
The team from University of Jaen has confirmed that the woman lived at the end of the 6th Dynasty (2200 BCE) and was part of the élite of the southernmost town of Egypt, Elephantine. The virulence of the disease impeded her to carry out any kind of labor, but she was treated and taken care during a long period until her death.
It turns out that the apparently low incidence of cancer in mummies, skeletons, and other ancient remains might be an illusion. For example, investigators from the United Kingdom reported a year ago on the case of 3,000 year old skeleton found in Sudan of a man who appeared to have had metastatic prostate cancer, which they published in PLoS One by Michaela Binder and colleagues. It was the oldest complete example of a skeleton of an ancient human with cancer. The authors wrote:
The apparent absence of cancer in archaeological remains may also partly be an illusion created by issues of bone preservation, and due to the fact that methods of analysis are inadequate to detect initial changes within bone. Due to financial, time and logistical reasons, human remains are usually not systematically radiographed, and bone metastases originating in cancellous tissue only penetrate the bone surface in their advanced stages. If the immune system was already compromised by other negative influences in a person’s life, people may not have survived long enough to develop full skeletal metastases. Thus, evidence for a large proportion of tumours could be missed when skeletal remains are analysed [72]. Another challenge in detecting cancer in ancient human remains is the poor preservation of bone which often prevents the clear identification of lytic lesions and precludes the diagnosis of incomplete remains [27]. With increasing numbers of skeletal collections and more detailed analysis, as well as more readily available standard radiographic equipment, the evidence for cancer in antiquity could increase significantly.
In other words, for the most part, archaeologists haven’t been looking carefully for evidence of cancer in ancient remains, and if you don’t look for something you aren’t very likely to find it. Moreover, it’s not at all straightforward to find and confirm evidence of cancer in remains that are usually just skeletons and usually just fragments of skeletons at that. Comparatively speaking, there aren’t that many mummies and not that many remains with soft tissue that can be examined for evidence of cancer. In this case, the Binder et al studied the skeleton of a man aged 25-35 years recovered in 2013 from Amara West. It was found in a tomb with characteristics that suggest what the authors referred to as a “sub-elite” buried according to Egyptian customs.
The authors examined the bones and found lytic lesions (lesions that eat away bone tissue) affecting the ribs, vertebrae, clavicle, scapulae, pelvis, sternum, humeral and femoral heads of skeleton. Such lesions are very characteristic of some sorts of cancer metastases to bone. Radiographic, scanning electron microscope (SEM) images, and microscopic images were taken of the lesions, and a differential diagnosis constructed. The lesions were most consistent with bony metastases, but the authors had to rule out other potential causes of lytic lesions. These include metastatic carcinoma, multiple myeloma (a cancer of the plasma cells of the bone marrow that can produce lesions very similar to metastatic carcinoma), fungal infections, and taphonomic damage. Taphonomy is the study of what happens to an organism after its death and until its discovery as a fossil, including decomposition, post-mortem transport, burial, compaction, and other chemical, biologic, or physical activity which affects the remains of the organism. About this last possibility, the authors noted that “mall round holes similar to metastatic lesions can be caused by a variety of factors including roots, water, and termites [68] or dermatid beetles [69].” SEM examination, however, found characteristics more consistent with metastatic carcinoma than with any of the other things that can cause taphonomic damage.
The authors also reiterate:
The lack of evidence for cancer in antiquity may to a large extent, be the result of reduced life expectancy, and thus less time to develop skeletal lesions if the immune system is already compromised by an inadequate supply of nutrients and diseases. This represents one of the major problems in inferring the absence or presence of disease in the past in general [87]. The archaeological and historical record certainly provides plenty of evidence for possible causes of developing cancer. Despite recent advances, the genetic background for cancer predisposition is still far from being understood today [88], [89]. Even though it may perhaps remain unknown, there is no reason to assume that predisposing genetic factors were not present in the past. The man from Amara West does indicate that it was indeed possible to develop skeletal lesions of cancer, provides a glimpse into one individual’s life experience, and cautions against claims for the absence, or presence, of any disease based on skeletal evidence alone.
Besides, there’s also evidence that cancer has been with us since prehistoric times. For instance, there was Kanam Man, whose fossilized jawbone was found by Louis Leakey back in 1932, who called it, “Not only the oldest known human fragment from Africa, but the most ancient fragment of true Homo yet discovered anywhere in the world.” Kanam Man was controversial at the time, specifically whether it was what Leakey proclaimed it, but it also had an unusual feature:
At the time of the discovery, it had seemed like a bother, detracting from Leakey’s find. He was working in his rooms at St. John’s College at the University of Cambridge, carefully cleaning the specimen, when he felt a lump. He thought it was a rock. But as he kept picking, he could see that the lump was part of the fossilized jaw. He sent it to a specialist on mandibular abnormalities at the Royal College of Surgeons of England, who diagnosed it as osteosarcoma — a cancer of the bone.
Others have not been as certain. As recently as 2007, scientists scanning the mandible with an electron microscope concluded that this was indeed a case of “bone run amok” while remaining neutral on the nature of the pathology.
Of course, from a science-based perspective, none of this should be surprising. We might argue over how large a contribution of random chance there is to the development of cancer, but there’s little doubt that there is a large random component to it, a component of what can be called, for lack of a better term, “bad luck.” And, although cancer is primarily a disease of the elderly, young people can and do get it. As for cancer caused by the environment, there were also a lot of things that ancient humans encountered that could cause cancer: Sunlight leading to melanoma, infections that can cause cancer, radon, naturally occurring chemicals. The ancient world was hardly as pristine as it’s envisioned.
It’s not just cancer, either. Advocates of “paleo” diets, which, accurately or not, are designed to mimic what our paleolithic ancestors ate, frequently claim that heart disease would be virtually nonexistent if we all ate that way. Of course, as I’ve described on more than one occasion, ancient humans were prone to atherosclerotic heart disease as well. In fact, the evidence we have suggests that, for example, ancient Egyptians were prone to all manner of illnesses.
When it comes to cancer, in 1600 BC the Egyptian physician who wrote the Edwin Smith papyrus recommended cauterization of breast cancer with a tool called the “fire drill.” He also wrote about the disease, “There is no treatment.” If there’s one big difference between humans now and humans thousands of years ago, it was not biology or the factors that cause us to develop cancer. It was that there was no treatment. Now there is. What I’ve seen of The Emperor of All Maladies thus far demonstrates this.
from ScienceBlogs http://ift.tt/1GI3TQ5
