x Abu Dhabi, UAETuesday 25 July 2017

Book review: Science writer reveals that cancer has been with us for millennia

George Johnson, author of The Cancer Chronicles, tries to determine what causes normal cells in the human body to suddenly mutate and multiply in a destructive manner. Apart from smoking and obesity, Joan Oleck writes, the answer is hard to pin down

An image of a malignant tumour on the upper right lobe of a lung. In The Cancer Chronicles, author George Johnson points out that metastatic cancers have occurred in humans for millennia. BSIP / UIG Via Getty Images
An image of a malignant tumour on the upper right lobe of a lung. In The Cancer Chronicles, author George Johnson points out that metastatic cancers have occurred in humans for millennia. BSIP / UIG Via Getty Images

The Cancer Chronicles: Unlocking Medicine’s Deepest Mystery
George Johnson
Knopf

Only a few pages into George Johnson's elegant The Cancer Chronicles: Unlocking Medicine's Deepest Mystery, readers will likely experience alarm, if they have not already, at what a gamble life is. After all, writes Johnson, at any given moment an estimated four million cells in the human body are busily, aggressively dividing - and in the process of copy- ing their DNA, putting us at risk for a renegade mutation and malignant tumour that could end our lives.

The question, of course, is, why do mutations happen? And here Johnson acknowledges that despite the thousands of studies done to date, modern medicine is still basically clueless. Who knows? he ponders, listing the usual suspects: environmental poisons, lifestyle choices, heredity, viruses, and one more: "the elusive influence of bad luck".

The author, a New York Times science writer who has published eight previous books, knows bad luck well. Several years back, when Johnson's then-wife Nancy was diagnosed with metastatic uterine cancer, her gruelling chemotherapy and radiation treatments set him on a journalistic path to trace the evolution of our knowledge base about this terrible scourge. His personal experience with cancer combined with this research is what gives Chronicles its emotional depth.

"She had risk factors. She was forty-three and we had no children, a source of constant contention," he writes of his guilt that his not wanting children may have contributed to Nancy's cancer. In one of many passages detailing aspects of the disease not widely known, Johnson explains that heightened exposure to the hormone estrogen increases the chances a woman will get cancer - especially in today's western world, where exposure is higher owing to far fewer pregnancies and the lower age at which girls typically first menstruate.

"A teenager today may have already experienced more menstrual cycles than her grandmother did during her entire life," Johnson comments, alarmingly.

Chronicles, a worthy successor to Siddhartha Mukherjee's Pulitzer-winning The Emperor of All Maladies (2010), which was a "biography" of cancer (and is Ken Burns's next documentary subject), is certainly more whimsical than Mukherjee's work, describing cancer as "a single cell gone mad, a cell that had forgotten it was part of a community, that began running its own show…" and addressing the human blame, or lack thereof, that the disease provokes.

"One can find consolation in fatalism, the idea that cancer is an inevitable part of the biological process," Johnson writes. "But there is also comfort in believing that humans, through their own devices, have increased the likelihood of cancer."

Yet the reality, he warns, is more complicated and random than that. For, apart from smoking and obesity, cause-effect correlations have been hard to pin down.

What is clear is that cancer has been with us for millennia, dating back long before chemicals, pollution, and Frankenfoods came on the scene. Johnson travels to western Colorado and back in time (figuratively speaking) to the mid-Mesozoic period, 150 million years ago, when, according to paleontological findings, dinosaurs roamed the earth suffering from metastatic cancers. Tumours in humans also date way back: Johnson describes a Saxon skeleton in England with a tumorous femur, an Iron Age male in Switzerland with osteosarcoma, a first-century Roman with prostate cancer. Considering the much shorter life spans of those long-ago peoples, the discovery of cancer among the small number of ancient remains we have today is a real eye-opener: "On balance it seems likely that the evidence of ancient cancer is significantly underreported," Johnson writes.

Another issue tied to the past is how long it took ancient scientists to figure out exactly what those lumps and bumps on patients' bodies were. It wasn't until the 19th century that doctors understood cancer as involving abnormal cells; in 1889, the English surgeon Stephen Paget laid the groundwork for the discovery of metastasis by observing how malignant breast cancers usually travelled to their victims' livers.

Other revelations emerged: In 1775 another English surgeon correctly identified "soot warts" on the scrotums of chimney sweeps as malignancies from the black tars and dust of burnt coal. In the late 1800s Marie and Pierre Curie realised that pitchblende rock generated energy on its own - a discovery that would eventually prompt radiation treatments. In the 1970s, American biochemist Bruce Ames developed the Ames test to determine whether chemicals are mutagenic.

Eventually, scientists learned what cancer typically is: an altering of genetic information, regardless of the cause. But there was nothing simple here, because dozens and perhaps even hundreds of mutations may go into making just one malignant tumour.

What's more, viruses are an exception to the typical scenario of altered genetic information. Johnson describes viruses as "wandering genomes so simple that some consist of only three genes", ready to infiltrate their hosts and "commandeer the internal machinery".

Another problem is that tumours are not homogeneous masses of malignant cells but may also contain healthy cells that help produce the proteins tumors need to expand and gain a foothold in the blood supply. Yet another: The genetic changes that may create a cancer can occur in ways other than mutations, such as when molecular tags bind to genes and disable them, in an alternation labeled as "epigenetic".

Just as complex as what cancer is, is what causes it. In the '70s and '80s, it was all the rage to focus in on chemicals: "We worried about saccharine and Red Dye No 2 and later about Alar on apples," Johnson reminds us. And in 1981 an influential US study concluded that most cancer is avoidable - owing to choices like tobacco use, diet, alcohol and sexual behaviour. That finding is still credible, Johnson adds, quoting that study's authors, except for lung cancer: "Most of the types of cancer that are common today in the United States must be due mainly to factors that have been present for a long time."

In short, yes, environmental factors are to blame, but only in the broadest sense; other contributors are hereditary disposition and, as stated, simple dumb bad luck. "For all the horror it causes, cancer is a fascinating intellectual problem - a window into understanding life," Johnson writes. Indeed, some of his most intriguing passages describe the near-misses of researchers trying to pry open that window. An example was Harvard researcher Judah Folkman's discovery of the molecules that inhibit the means by which blood is supplied to newly created tissues. That could have been the cure that rocked the cancer research community right there; no less than James Watson was quoted as saying, "Judah is going to cure cancer in two years." But, alas, it was not to be.

And that near-miss, of course, was tragic because of the human toll cancer takes. Johnson makes us cringe in his details of Nancy's surgery, chemotherapy and radiation: the nausea, the lethargy, the dehydration. "I can't believe what they're doing to my poor body," she cries in anguish at one point.

Then another blow arrived for the Johnsons: The author's brother, Joe, discovered he had cancer of the jaw and Adam's apple. "I think I now realize just what a vile, evil sickness cancer is," Joe told the author. "The doctors keep chasing it around the body."

Joe did not survive. In an email to his minister before surgery, Joe wrote that he felt like Commander Adama on the sci-fi programme Battlestar Galactica: going in to remove the invader.

The invader won. And that sad ending made Johnson reflect on the fact that he - and we - have 10 trillion cells within our bodies that may be getting into mischief at any second of any day. "There are no labels, no genetic alphabet written anywhere," Johnson wrote. "There are no instructions. Somehow it all just works. And when it doesn't, we rage against the machine."

Joan Oleck is a freelance writer based in Brooklyn, New York.