*2 When talking of diseases, people often use “infectious” and “contagious” interchangeably, but there is a difference. An infectious disease is one caused by a microbe; a contagious disease is one transmitted by contact.
21 WHEN THINGS GO VERY WRONG: CANCER
We are bodies. They go wrong.
—TOM LUBBOCK, UNTIL FURTHER NOTICE, I AM ALIVE
I
CANCER IS THE malady most of us fear more than any other, yet much of that dread is fairly recent.*1 In 1896, when the newly founded American Journal of Psychology asked people to name the health crises they most feared, hardly any mentioned cancer. Diphtheria, smallpox, and tuberculosis were the most worrying afflictions, but even lockjaw, drowning, being bitten by a rabid animal or caught in an earthquake were more fearsome to the average person than cancer.
Partly this was because people in the past often didn’t live long enough to get cancer in great numbers. As a colleague told Siddhartha Mukherjee, author of The Emperor of All Maladies, a history of cancer, “The early history of cancer is that there is very little early history of cancer.” It isn’t that cancer didn’t exist at all, but more that it didn’t register with people as something probable and fearful. In that sense it was rather like pneumonia now. Pneumonia is still the ninth most common cause of death, yet few of us greatly fear dying from it because we tend to associate it with frail elderly people who are about to shuffle off anyway. So it was for a very long time with cancer.
All that changed in the twentieth century. Between 1900 and 1940, cancer jumped from eighth place to second place (just behind heart disease) as a cause of death, and it has cast a long shadow over our perceptions of mortality ever since. Today some 40 percent of us will discover we have cancer at some point in our lives. Many, many more will have it without knowing it and will die of something else first. Half of men over sixty and three-quarters over seventy, for instance, have prostate cancer at death without being aware of it. It has been suggested, in fact, that if all men lived long enough, they would all get prostate cancer.
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Cancer in the twentieth century became not only the great dread but the great stigma. A survey of physicians in America in 1961 found that nine out of ten did not inform patients when they had cancer because the shame and horror of it were so great. Surveys in Britain at about the same time found that roughly 85 percent of cancer patients wished to know if they were dying but that between 70 and 90 percent of doctors declined to tell them anyway.
We tend to think of cancer as something we catch, like a bacterial infection. In fact, cancer is entirely internal, a case of the body turning on itself. In 2000, a landmark paper in the journal Cell listed six attributes in particular that all cancer cells have, namely:
They divide without limit.
They grow without direction or influence from outside agents like hormones.
They engage in angiogenesis, which is to say they trick the body into giving them a blood supply.
They disregard any signals to stop growing.
They fail to succumb to apoptosis, or programmed cell death.
They metastasize, or spread to other parts of the body.
What it comes down to really is cancer is, appallingly, your own body doing its best to kill you. It is suicide without permission.
“That’s why cancers aren’t contagious,” says Dr. Josef Vormoor, founding clinical director of pediatric hemato-oncology at the new Princess Máxima Center for childhood cancers in Utrecht, the Netherlands. “They are you attacking you.”
Vormoor is an old friend, whom I first met when he was in a previous post as director of the Northern Institute for Cancer Research at Newcastle University in England. He joined the Princess Máxima Center shortly before its opening in the summer of 2018.
Cancer cells are just like normal cells except that they are proliferating wildly. Because they are so seemingly normal, the body sometimes fails to detect them and doesn’t invoke an inflammatory response as it would with a foreign agent. That means that most cancers in their early stages are painless and invisible. It is only when tumors grow big enough to press on nerves or form a lump that we become aware that something is wrong. Some cancers can quietly accrete for decades before they become evident. Others never become evident at all.
Cancer is quite unlike other maladies. It is often relentless in its attacks. Victory against it is nearly always hard won and often at great cost to the victim’s overall health. It will retreat under an onslaught, regroup, and return in a more potent form. Even when seemingly defeated, it may leave behind “sleeper” cells that can lie dormant for years before springing to life again. Above all, cancer cells are selfish. Normally, human cells do their job, then die on command when instructed to by other cells for the good of the body. Cancer cells don’t. They proliferate entirely in their own interests.
“They have evolved to avoid detection,” says Vormoor. “They can hide from drugs. They can develop resistance. They can recruit other cells to help them. They can go into hibernation and wait for better conditions. They can do any number of things that make it hard for us to kill them.”
Something we have only recently realized is that before cancers metastasize, they are able to prepare the ground for an invasion in distant target organs, probably through some form of chemical signaling. “What this means,” Vormoor says, “is that when cancer cells spread to other organs, they don’t just turn up and hope for the best. They already have a base camp in the destination organ. Why certain cancers go to certain organs, often in distant parts of the body, has always been a mystery.”
We need to remind ourselves from time to time that these are brainless cells we are considering here. They are not willfully malevolent. They are not plotting to kill us. All they are doing is what all cells try to do—survive. “The world is a challenging place,” says Vormoor. “All cells have evolved a repertoire of programs that they use to help protect themselves from DNA damage. They are just doing what they are programmed to do.”
Or as one of Vormoor’s colleagues, Olaf Heidenreich, explained it to me, “Cancer is the price we pay for evolution. If our cells couldn’t mutate, we would never get cancer, but we also couldn’t evolve. We would be fixed forever. What this means in practice is that although evolution is sometimes tough on the individual, it’s beneficial for the species.”
Cancer is actually not one disease, but a suite of more than two hundred with lots of different causes and prognoses. Eighty percent of cancers, known as carcinomas, arise in epithelial cells—that is, the cells that make up the skin and the linings of organs. Breast cancers, for instance, don’t just grow randomly within the breast, but normally begin in the milk ducts. Epithelial cells are assumed to be particularly susceptible to cancers because they divide rapidly and often. Only about 1 percent of cancers are found in connective tissue; these are known as sarcomas.