The Cancer Chronicles (7 page)

Like many of Leakey’s enthusiasms this one proved controversial.
One of his detractors thought the specimen looked
too
modern, that it was a more recent jawbone that had washed into much older surroundings. In later years anthropologists speculated that what Leakey called
Homo kanamensis
might actually be
a more distant relative like
Australopithecus
,
Neanderthal man, or
Homo habilis.
More recently
others have come to believe that the specimen may be Middle to Late Pleistocene, which would make it
no more than about 700,000 years old. Whatever its pedigree or precise age, Kanam man is no longer considered remarkable for its antiquity but for an abnormal growth on the left side of the jaw.

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, 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 in London, who
diagnosed it as
sarcoma of the
bone.

There was also a thin fracture in the jaw, one that had occurred long enough before death to heal. That, the doctor surmised, may have been how the
cancer had begun. Sensing the
trauma, as bone cells somehow do, they had begun rapidly dividing, replacing dead tissue. And somewhere along the way—the odds are vanishingly small—this carefully controlled process had gone askew. More than enough new cells had been produced to heal the wound, but they didn’t know when to stop. Because of some biological miscalculation, cells kept dividing and dividing, overflowing the crack. Plausible as it sounded, this was just speculation. Bone fractures have not been established as a trigger for osteosarcoma. Usually there is no obvious cause. However the cancer begins it often spreads to the
lungs. If the diagnosis is correct—some have had their doubts—that may be what killed Kanam man.

I first came across a mention of the Kanam jaw in a history of cancer timeline somewhere on the Web. That sent me digging into Leakey’s old books and papers, and after several e-mail exchanges I tracked down the fossil at the
Natural History Museum in South Kensington, London, where it had been in storage for decades. As far as I could tell it had never been on display. The specimen had been removed from the shelf now and then to be examined. The anthropologist
Ashley Montagu studied it in 1956, reporting that the tumor was so large and disfiguring that it was
impossible to tell what Kanam man’s chin had been like. Other anatomical details persuaded him, however, that the fossil was clearly human-like.
Another anthropologist disagreed, concluding that what Leakey thought was a chin was part of the tumor.

And so the disputes began. A London
oncologist,
George Stathopoulos, ventured that the tumor might not be osteosarcoma but
an entirely different cancer,
Burkitt’s lymphoma, a malignancy of the
lymphatic system endemic among
children today in central Africa, one that often damages bone.
Others were not so certain.
Osteomyelitis, a chronic infection, can also generate bony growths. But in his book
Diseases in Antiquity,
a standard reference on ancient pathology, Don
Brothwell concluded that Kanam man’s abnormality was
too thick and extensive to be from an infection. Like Leakey’s colleagues, he leaned toward a diagnosis of bone cancer. As recently as 2007, scientists
scanning the mandible with an
electron microscope concluded that the crack had indeed resulted in “
bone run amok” while remaining neutral on the nature of the disease.

I wanted to see the specimen for myself, and on a spring day I arrived, as previously arranged, at the museum’s staff and researcher entrance on Exhibition Road. The man at the guard desk called ahead to
Robert Kruszynski, curator of vertebrate paleontology. “He asks that you meet him by
the giant sloth.” It was easy enough to find. Hunched on its hind legs, the creature’s plaster cast skeleton towered over the heads of museumgoers as it prepared to chomp at the top of an artificial tree. It had been standing that way for 161 years, when it was assembled from the bones of two or more South American specimens and put on display. Behind me was a wall of
Ichthyosaurus
fossils, mounted in glass cases. As I examined them, marveling at how the same bony architecture runs throughout the vertebrate world, a door opened in the corner of the hall. Mr. Kruszynski came out to greet me and then led me into the museum’s inner sanctum.

Waiting for me on a table by a window was the brown cardboard box he had retrieved from the museum stores. The handwritten label identified the contents:

M
16509
KANAM MANDIBLE
.

“M” stood for “mammal.” In the upper right-hand corner of the label were two colored stickers—a red sunlike symbol and below that a blue star—indicating that the specimen in the box had been analyzed at various times by radioassay and
x-rays. Mr. Kruszynski carefully removed the lid. Inside was a smaller box, fashioned from balsa wood and cardboard and covered with a glass lid, and inside that was the Kanam jaw.

He placed it on a padded mat, two layers thick to cushion it from the hard surface of the table. “All yours to look at,” he said, and went off to search for another fossil I hoped to see: a femur retrieved from an early medieval
Saxon grave in Standlake, England, with an enormous growth that had also been diagnosed as a cancerous bone tumor.

I had thought I would be content just glimpsing the
Kanam
jaw. I never expected to be left alone with it and to be able to hold it in my hand. It was dark brown and unexpectedly heavy and dense. That shouldn’t have been surprising. It was a rock really, petrified bone. Once it had been part of a prehistoric man, or a protoman. Two yellowed teeth were still in place, and there was a deep hole where the root of another tooth had been.

Just below that, on the left inside curve of the jaw, was the tumor. It was bigger than I had expected, reminding me perversely of a type of candy from my childhood called a jawbreaker. There was also a slight swelling on the outside of the jaw, and I could understand how people might argue endlessly over whether it was part of a tumor or a chin. I could see where
Leakey had sliced through the mass (some of his colleagues considered this sacrilege) to remove a section for further analysis. I could almost picture the rest of the head, its vacant eyes pleading for relief from inexplicable pain.

Mr. Kruszynski returned half an hour later to see how I was doing with the fossil. “Don’t bring it too close to the edge,” he warned. I suddenly realized that the protective pad on the table was sloping toward my lap and how easily a sudden movement might have sent the Kanam mandible dropping onto the linoleum floor.

In the end Mr. Kruszynski was unable to find the cancerous femur I’d inquired about. “For another time,” he said. The museum stores were undergoing a renovation, he explained, and the bone had apparently been mislaid along with the rest of the skeleton—all except for the skull. He pulled it from its box and let me hold it for a minute—so lightweight compared to petrified bone—then escorted me back across the barrier to the public portion of the museum.
Hundreds of visitors of all ages coursed through the hallways. Some of them inevitably would get cancer, or they would love somebody who did. I wondered if anyone had been there for Kanam man.

Not much has been written about the obscure discipline of
paleo-oncology. Although research had gone on sporadically for decades, the word was introduced to literature only in 1983 when
a small group of Greek and Egyptian oncologists (from the Greek
onkos,
meaning “mass” or “burden”) began planning a symposium on human cancer in earlier times. The gathering took place the following year on a voyage between the island of Rhodes and the island of Kos, where
Hippocrates was born. What emerged was an elegantly published, sparsely printed little book,
Palaeo-Oncology.
I felt lucky to find a copy on the Internet for one hundred dollars. Its fifty-eight pages are bound in a blue cover with gilded print, and below the title is a drawing of a crab. “Crab” in Greek is
karkinos,
and Hippocrates, in the fifth century B.C., used the word—it became the root of “carcinogen” and “
carcinoma”—for the affliction whose Latin name is cancer.

It is not clear exactly why he chose the name. Some six hundred years later,
Galen of Pergamon speculated on the etymology: “
As a crab is furnished with claws on both sides of its body, so, in this disease, the veins which extend from the tumour represent with it a figure much like that of a crab.” The story is repeated in almost every history of cancer. Very few tumors, however, look like crabs.
Paul of Aegina, a seventh-century Byzantine Greek, suggested that the metaphor was meant to be taken more abstractly: “Some say that [cancer] is so called
because it adheres with such obstinacy to the part it seizes that, like the crab, it cannot be separated from it without great difficulty.” The word
karkinoi
was also applied to grasping tools like calipers.

All but forgotten is a very different derivation from Louis Westenra Sambon, a British expert on parasitology who, before his death in 1931, turned his attention to the study of cancer. There is a parasite,
Sacculina carcini,
that feasts on crabs in a manner eerily similar to the feasting of a
cancerous tumor. The process was described in 1936 in a report by the pathologist Sir
Alexander Haddow to the
Royal Society of Medicine:

Long before the days of Galen, disciples of Hippocrates, dining on crabs, may have noticed the similarities between the way the parasite overtakes its host and the way a cancer
metastasizes.

Whatever the reason for the name, ancient Greek texts describe what sound like cancer of the uterus and the breast. Driven by a belief in sympathetic magic, some physicians would treat a tumor
by placing a live crab on top of it. They also recommended powders and ointments (sometimes made from pulverized crabs) or cauterization (burning closed the ulceration). As for patients with internal tumors, Hippocrates warned that they might best be left alone: “
With treatment they soon die, whereas without treatment they survive for a long time.” The principle is part of the
Hippocratic oath: First do no harm.

With Galen the references become even sharper. He wrote an
entire book about tumors and included malignancies in
a category of growth called
“
praeter naturam”
—preternatural, meaning outside of nature.
Carcinoma, he wrote, is “
a tumor malignant and indurated, ulcerated or non-ulcerated.” He found breast
cancer to be the most
common and especially prevalent after
menopause. (In contradiction to what modern oncologists believe, he wrote that women who regularly menstruate don’t get cancer.) He writes about uterine, intestinal, and
anal cancer, and cancer of the palate. Sometimes he, like other Greek writers, uses the word
therioma,
“wild beast,” to mean malignant. “
The early cancer we have cured, but the one that rose to considerable size, without surgery, nobody has cured.”

The medieval surgeon Abu al-Qasim al-
Zahrawi was no luckier: “
When a cancer has lasted long and is large, you should not come near it. I have never been able to save any case of this kind, nor have I seen anyone else who has been successful.”

It is not so different now.

There is something comforting about knowing that cancer has always been with us, that it is not all our fault, that you can take every precaution and still something in the genetic coils can become unsprung. Usually it takes decades for the micro damage to accumulate—77 percent of cancer is
diagnosed in people fifty-five or older. With life spans in past centuries
hovering around thirty or forty years, finding cancer in the fossil record is like sighting a rare bird. People would have died first of something else. Yet in spite of the odds, cases continue to be discovered, some documented so vividly that you can almost imagine the ruined lives.

After my visit to London I received from the
Natural History Museum photographs of
the
Saxon skeleton whose tumorous femur I had hoped to examine. I had read that the growth was large—10 inches vertically by 11 inches horizontally—but I was astonished to see what looked like a basketball grafted onto the young man’s leg. The tumor shows a sunburst pattern that pathologists recognize as
a sign of
osteosarcoma. Th
ey see it most often in
adolescents whose limbs are undergoing hormone-induced spurts of growth—more evidence for one of
cancer’s few established rules: The more frequently cells are dividing, the more likely
mutations will occur. The right combination will
lead to a malignancy. Osteosarcoma is so rare that one would have to
comb through the bones of tens of thousands of people to find a single example. Yet ancient cases continue to turn up.

There were signs of the
cancer in an
Iron Age man in Switzerland and a fifth-century Visigoth from Spain. An osteosarcoma from
a medieval cemetery in the Black Forest Mountains of southern
Germany destroyed the top of a young child’s leg and ate into the hip joint. Bony growths inside the roof of the eye sockets indicated
anemia, which may have been an effect of the cancer. The authors of the report speculated on the cause: contamination from a nearby lead and silver mine. Cancer is especially hard to accept
in children, even in one from nine centuries ago, and the paper ended with a poignant note: “The tumour would certainly lead the child
to die a painful death.” Though child mortality was very high in those days, the authors noted, children who made it past the first few years might live into their forties. But not this time. “The flame of life in the affected child was extinguished just when the child had survived the first years of infant excess mortality.”