The Cancer Chronicles (8 page)

Maybe it helped to believe there was a reason—metallic poisoning from a mine. But no one knows what causes osteosarcoma. Then, as now, a few cases probably were hereditary, traced to chromosomal abnormalities. In modern times speculation turned for a while to
fluoride-treated water and, more plausibly,
radiation—therapeutic treatments for other disease or exposure to radioactive isotopes like
strontium-90, which is spread by
nuclear fallout. Strontium sits just below calcium in the periodic table of elements and imitates its behavior, incorporating itself tightly into bone. But most often osteosarcoma strikes for no apparent reason, leaving parents grasping to understand what remains as inexplicable as a meteor strike.

A
nother malignancy,
nasopharyngeal carcinoma, which affects the mucous membrane in the nose, can scar adjacent bone, and signs of it have been found in skeletons from
ancient Egypt. One woman’s face had been all but obliterated, and I tried to imagine her stumbling through life. “
The large size of the tumor, which caused such extensive destruction, suggests a relatively long-lasting process,” observed
Eugen Strouhal, the Czech anthropologist who documented the case. “The patient seems to have survived for a considerable time, and doubtless had pain and other symptoms. Survival would be impossible without the help and care of the patient’s fellow-men.” Here was another case where the horrors of
cancer punched through the flat veneer of scientific prose.

Multiple myeloma, a cancer of
plasma cells in
bone marrow, can leave skeletal marks.
Traces were found in the skull of a woman who lived in medieval times. Plasma cells are part of the
immune system and when behaving normally they produce antibodies called
immunoglobulins. In multiple myeloma, one type is generated at the expense of the others. A chemical test found antibodies that the researchers considered confirmation of the disease.

Osteosarcoma, nasopharyngeal carcinoma, multiple myeloma—these are
primary cancers, those found at the site of origin. They are debilitating enough.
Most skeletal cancers by far come from metastases originating elsewhere. They also show up with greater frequency in the fossil record—and with devastating results. Metastatic
bone cancer has been
discovered in Egyptian tombs,
in a Portuguese necropolis, in a prehistoric grave
in the Tennessee River valley,
in a leper skeleton from a medieval cemetery in England. Buried
near the Tower of London the skeleton of a thirty-one-year-old woman was marked with metastatic lesions. We even know her name from a lead coffin plate:
Ann Sumpter. She died on May 25, 1794.

In 2001 archaeologists
excavated a 2,700-year-old burial mound in the
Russian republic of Tuva, where nomadic horsemen called the
Scythians once thundered across the Eurasian steppes, their leaders exquisitely dressed in gold. Digging down through two wooden ceilings,
the scientists came upon a subterranean chamber. Its floor, covered with a black felt blanket, cushioned two skeletons. Crouched together like lovers, both man and woman wore what remained of their royal vestments. Around the man’s neck was a heavy band of twisted gold decorated with a frieze of panthers, ibex, camels, and other beasts. Near his head lay pieces of a headdress: four gold horses and a deer. Golden panthers, more than 2,500 of them, bedecked his cape. His riches couldn’t save him. When he died—he appeared to have been in his forties—
his skeleton was infested with tumors. A pathological analysis, including a close look with a scanning
electron microscope, concluded that the nature of the lesions and the pattern of their spread were characteristic of metastatic
prostate cancer. Biochemical tests revealed high levels of prostate-specific antigen, or PSA. For all the false positives these tests can produce, this result was apparently genuine.

Metastasizing prostate cancer has been diagnosed in
the partially cremated pelvis of a first-century Roman and in
a skeleton from a fourteenth-century graveyard in Canterbury. While prostate cancer tends to be
osteoblastic, adding unwanted mass to the skeleton,
breast cancer is
osteolytic, gnawing mothlike at the
bone. Of all cancers, prostate and breast
show the strongest appetite for skeletal tissue. Depending on the gender of the victim they are the first choice for diagnosis when bone metastases are found.

A middle-aged woman with osteolytic lesions was excavated from the northern Chilean Andes where she had died around 750 A.D. Her desiccated body was buried in a mummy pack along with her possessions: three woolen shirts, some feathers, corncobs, a wooden spoon, a gourd container, and a metal crucible. She was no Scythian queen. Her hair reached down her back in a long braid tied with a green cord. There were lesions in her spine, sternum, pelvis. On top of her skull, cancer had chomped a ragged hole 35 millimeters across. Cancer had feasted on her right femur, shortening her leg.

Osteolytic lesions are also found in men. They had spread throughout the skeleton of
a Late
Holocene hunter-gatherer exhumed in the
Argentine Pampas.
Men do get breast
cancer, but only very rarely.
Lung cancer can also leave osteolytic marks, but it is believed to have been exceedingly uncommon before cigarettes. His
diagnosis was left hanging. It was another case of what oncologists call “
primary unknown.”

Those words still haunt me when I think about the weeks that passed before finding the source of
Nancy’s
metastasis.
Like 90 percent of human cancers it was a carcinoma. It makes sense that these would be the most common.
Carcinomas arise in the epithelial tissues that line the organs and cavities of the body and envelop us with skin. As the layers are worn by the passage of food and waste or exposure to the elements, the outer cells are constantly dying. The cells beneath must divide to form replacements. And with every division there will be mistakes in the copying of genes—spontaneous
mutations or ones caused by
carcinogens in food, water, and air.
For
children, who are just beginning to withstand life’s wear and tear, only a fraction of cancers are carcinomas.

When it comes to hunting ancient cancer, primary carcinomas would almost always be lost with the decomposing tissues. And those that had metastasized would have
often spread first to the lung or liver, killing the victim before a record was left in bone.
Egyptian medical papyruses make ambiguous references to “
swellings” and “eatings,” and some evidence has survived in
mummies.
A
rectal carcinoma in a 1,600-year-old mummy was confirmed with a cellular analysis of the tissue. Another mummy was
diagnosed with
bladder cancer. Elsewhere in the world, a rare muscle tumor called a
rhabdomyosarcoma was found
on the face of a Chilean child who lived between 300 and 600 A.D. In Peru, two pathologists reported
metastatic
melanoma in skin and bone tissue of
nine pre-Columbian Incan mummies. In a whimsical digression, they quote an eighteenth-century ode in praise of female
beauty marks and then wryly remark: “Whereas [the poet] was inflamed, as were his contemporaries, by the beauty of a lady’s moles, we—some 240 prosaic years later—are romantically unmoved by any of them. They have given us nothing but trouble.”

Other evidence of ancient
cancer may have been destroyed by the invasive nature of Egyptian embalming rituals.
To prepare a pharaoh for passage to the afterlife, the first step was removing most of his organs. The brain was pulled out though the nostrils. The torso was sliced open to take out the abdominal and chest organs (with the exception of the heart, which was believed necessary for the ethereal voyage). Each organ was wrapped in resin-soaked linen and then placed back into the body or in what was called a canopic jar. There were other variations. To slow the process of decay a turpentine-like solution was sometimes injected as an enema to dissolve the digestive tract.

But
embalmed tumors can survive. Treated more gently, the mummified body of
Ferrante I of Aragon, who died in 1494 in his early sixties, harbored an
adeno
carcinoma that had metastasized to the muscles of his small pelvis. Some five hundred years after his death, a molecular study revealed a typographical
error in the DNA code that regulates cell division—a G had been flipped to A—a
genetic
mutation associated with
colorectal cancer. Maybe this was caused, the authors speculated, by an abundance of
red meat served in the royal court. Or, for all we know, by an errant cosmic ray.

Altogether I
counted about two hundred suspected cancer sightings in the archaeological record. As with the dinosaurs, I was left to wonder how big an iceberg lay floating beneath the tip. Mummies are a curiosity, and most skeletal evidence is
stumbled on by chance. Only recently have anthropologists really begun looking for cancer—with
CT scans,
x-rays, biochemical assays, and their own eyes. What they will never see, even in bone, are clues lost through what anthropologists call
taphonomic changes. In digging and transporting skeletal remains, markings can inadvertently be erased. Bone-eating osteolytic lesions can cause a specimen to crumble and disappear. Through erosion, decomposition, and the gnawing of rodents, taphonomic changes might also create the illusion of metastasis—
pseudopathology—a possibility that must be taken
into account along with alternative diagnoses like osteoporosis and infectious disease. But on balance it seems likely that the
evidence of ancient cancer is
significantly underreported. Most skeletons, after all, are incomplete. Metastases are
more likely to appear in certain bones like the vertebrae, pelvis, femur, and skull. Others rarely are affected. No one can know if a missing bone happened to be the one that was cancerous.

Hoping to cut through the uncertainty,
Tony Waldron, a paleopathologist at University College London, tried to get a feel for how much cancer archaeologists should be expected to find. First he had to come up with an estimate, no matter how crude, of the frequency with which
primary tumors might have occurred in earlier times. There wasn’t much to go on. The oldest records that seemed at all reliable were from the registrar general of Britain for causes of death between the years 1901 to 1905. Using that as his baseline, he took into account the likelihood that various cancers would come to roost in the skeleton, where they might be identified. The numbers, a range of approximations, came from modern autopsy reports. For
colorectal cancer the odds were low, 6 to 11 percent, as they were for
stomach cancer, 2 to 18 percent. On the high side were cancer of the breast (57 to 73 percent) and prostate (57 to 84 percent).

From these and other considerations, Waldron calculated that (depending on age at death) the proportion of cancers in a collection of old bones would be
between 0 and 2 percent for males and 4 and 7 percent for females. No matter how hard you looked, cases of ancient cancer would be sparse—even if the rate had been as high as that of industrial Britain. To test if his numbers were plausible, he tried them out on the remains of 623 people who had been placed in a crypt at Christ Church, Spitalfields in the East End of London between 1729 and 1857. Relying solely on visual inspection, he found one case of carcinoma among the women and none among the men. That was within the range of his formula, encouragement that it was not wildly wrong.

The next step was to try the predictions on much older and larger populations: 905 well-preserved skeletons buried at two sites in Egypt
between 3200 and 500 B.C. and 2,547 skeletons that had been placed in a southern German ossuary between 1400 and 1800 A.D. (The church cemetery was so small and crowded that remains, once they had decomposed, were periodically removed and put into storage.) Using
x-rays and
CT scans to confirm the diagnoses, pathologists in Munich found five cancers in the Egyptian skeletons and thirteen in the German ones—about what Waldron’s calculations predicted. For all the differences between life in ancient Egypt, Reformation
Germany, and early twentieth-century Britain, the frequency of cancer appeared to be about the same.

Since then the world has grown more complex. Longevity has soared along with the manufacture of cigarettes. Diets have changed drastically and the world is awash with synthetic substances. The medical system has gotten better at detecting cancer. Epidemiologists are still trying to untangle all the threads. Yet running beneath the surface there is a core rate of cancer, the legacy of being multicellular creatures in an imperfect world. There is no compelling evidence that this baseline is much different now than it was in ancient times.

While still immersed in the arcana of paleo-oncology, I had dinner with a friend, a scientist in her thirties who had recently been treated for
breast cancer. Like many people she suspected that there is far more cancer now than in the past, and a few weeks later she sent me a reference to
an article that had just appeared in
Nature Reviews Cancer
in which two Egyptologists concluded that there is “a striking rarity of malignancies” in ancient times.
In a news release from her university, one of the authors,
A. Rosalie David, made this claim:

Across the Internet, news reports jumped on the
information: “
Cancer Is a Man-Made Disease.” “Cure for Cancer: Live in Ancient Times.” By now I thought I had become familiar with the literature. Was there some important new evidence that had resolved the ambiguities? It was flat out wrong to say that nothing in the natural environment can cause cancer. What about sunlight, radium,
aflatoxin,
hepatitis virus, human
papillomavirus? I kept checking the university website assuming there would be a correction. None ever came.