Читать книгу The Emperor of All Maladies - Siddhartha Mukherjee, Siddhartha Mukherjee - Страница 18

The Hard Tube and the Weak Light

We have found in [¹⁸⁷X-rays] a cure for the malady.

—Los Angeles Times, April 6, 1902

By way of illustration¹⁸⁸ [of the destructive power of X-rays]¹⁸⁹ let us recall that nearly all pioneers in the medical X-ray laboratories in the United States died of cancers induced by the burns.

—The Washington Post, 1945

In late October 1895, a few months after Halsted had unveiled the radical mastectomy in Baltimore, Wilhelm Röntgen, a lecturer at the Würzburg Institute in Germany, was working with an electron tube—a vacuum tube that shot electrons from one electrode to another—when he noticed a strange leakage. The radiant energy was powerful and invisible, capable of penetrating layers of blackened cardboard and producing a white phosphorescent glow on a barium screen accidentally left on a bench in the room.

Röntgen whisked his wife, Anna, into the lab and placed her hand between the source of his rays and a photographic plate. The rays penetrated through her hand and left a silhouette of her finger bones and her metallic wedding ring on the photographic plate—the inner anatomy of a hand seen as if through a magical lens. “I have seen my death,” Anna said—but her husband saw something else: a form of energy so powerful that it could pass through most living tissues. Röntgen called his form of light X-rays.

At first, X-rays were thought to be an artificial quirk of energy produced by electron tubes. But in 1896, just a few months after Röntgen’s discovery, Henri Becquerel, the French chemist, who knew of Röntgen’s work, discovered that certain natural materials—uranium among them—autonomously emitted their own invisible rays with properties similar to those of X-rays. In Paris, friends of Becquerel’s, a young physicist-chemist couple named Pierre and Marie Curie, began to scour the natural world for even more powerful chemical sources of X-rays. Pierre and Marie (then Maria Skłodowska, a penniless Polish immigrant living in a garret in Paris) had met at the Sorbonne and been drawn to each other because of a common interest in magnetism. In the mid-1880s, Pierre Curie had used minuscule quartz crystals to craft an instrument called an electrometer, capable of measuring exquisitely small doses of energy. Using this device, Marie had shown that even tiny amounts of radiation emitted by uranium ores could be quantified. With their new measuring instrument for radioactivity, Marie and Pierre began hunting for new sources of X-rays. Another monumental journey of scientific discovery was thus launched with measurement.

In a waste ore called pitchblende, a black sludge that came from the peaty forests of Joachimsthal in what is now the Czech Republic, the Curies found the first signal of a new element—an element many times more radioactive than uranium. The Curies set about distilling the boggy sludge to trap that potent radioactive source in its purest form. From several tons of pitchblende, four hundred tons of washing water, and hundreds of buckets of distilled sludge waste, they finally fished out one-tenth of a gram of the new element in 1902. The metal lay on the far edge of the periodic table, emitting X-rays with such feverish intensity that it glowered with a hypnotic blue light in the dark, consuming itself. Unstable, it was a strange chimera between matter and energy—matter decomposing into energy. Marie Curie called the new element radium, from the Greek word for “light.”

Radium, by virtue of its potency, revealed a new and unexpected property of X-rays: they could not only carry radiant energy through human tissues, but also deposit energy deep inside tissues. Röntgen had been able to photograph his wife’s hand because of the first property: his X-rays had traversed through flesh and bone and left a shadow of the tissue on the film. Marie Curie’s hands, in contrast, bore the painful legacy of the second effect: having distilled pitchblende into a millionth part for week after week in the hunt for purer and purer radioactivity, the skin in her palm had begun to chafe and peel off in blackened layers, as if the tissue had been burnt from the inside. A few milligrams of radium left in a vial in Pierre’s pocket scorched through the heavy tweed of his waistcoat and left a permanent scar on his chest. One man who gave “magical” demonstrations¹⁹⁰ at a public fair with a leaky, unshielded radium machine developed swollen and blistered lips, and his cheeks and nails fell out. Radiation would eventually burn into Marie Curie’s bone marrow, leaving her permanently anemic.

It would take biologists decades to fully decipher the mechanism that lay behind these effects, but the spectrum of damaged tissues—skin, lips, blood, gums, and nails—already provided an important clue: radium was attacking DNA. DNA is an inert molecule, exquisitely resistant to most chemical reactions, for its job is to maintain the stability of genetic information. But X-rays can shatter strands of DNA or generate toxic chemicals that corrode DNA. Cells respond to this damage by dying or, more often, by ceasing to divide. X-rays thus preferentially kill the most rapidly proliferating cells in the body, cells in the skin, nails, gums, and blood.

This ability of X-rays to selectively kill rapidly dividing cells did not go unnoticed—especially by cancer researchers. In 1896, barely a year after Röntgen¹⁹¹ had discovered his X-rays, a twenty-one-year-old Chicago medical student, Emil Grubbe, had the inspired notion of using X-rays to treat cancer. Flamboyant, adventurous, and fiercely inventive, Grubbe had worked in a factory in Chicago that produced vacuum X-ray tubes, and he had built a crude version of a tube for his own experiments. Having encountered X-ray-exposed factory workers with peeling skin and nails—his own hands had also become chapped and swollen from repeated exposures—Grubbe quickly extended the logic of this cell death to tumors.

On March 29, 1896, in a tube factory on Halsted Street (the name bears no connection to Halsted the surgeon) in Chicago, Grubbe began to bombard Rose Lee, an elderly woman with breast cancer, with radiation using an improvised X-ray tube. Lee’s cancer had relapsed after a mastectomy, and the tumor had exploded into a painful mass in her breast. She had been referred to Grubbe as a last-ditch measure, more to satisfy his experimental curiosity than to provide any clinical benefit. Grubbe looked through the factory for something to cover the rest of the breast, and finding no sheet of metal, wrapped Lee’s chest in some tinfoil that he found in the bottom of a Chinese tea box. He irradiated her cancer every night for eighteen consecutive days. The treatment was painful—but somewhat successful. The tumor in Lee’s breast ulcerated, tightened, and shrank, producing the first documented local response in the history of X-ray therapy. A few months after the initial treatment, though, Lee became dizzy and nauseated. The cancer had metastasized to her spine, brain, and liver, and she died shortly after. Grubbe had stumbled on another important observation: X-rays could only be used to treat cancer locally, with little effect on tumors that had already metastasized.*

Inspired by the response, even if it had been temporary, Grubbe began using X-ray therapy to treat scores of other patients with local tumors. A new branch of cancer medicine, radiation oncology, was born, with X-ray clinics mushrooming up in Europe and America. By the early 1900s, less than a decade after Röntgen’s discovery, doctors waxed ecstatic about the possibility of curing cancer with radiation. “I believe this treatment is an absolute cure¹⁹² for all forms of cancer,” a Chicago physician noted in 1901. “I do not know what its limitations are.”

With the Curies’ discovery of radium in 1902, surgeons could beam thousandfold more powerful bursts of energy on tumors. Conferences and societies on high-dose radiation therapy were organized in a flurry of excitement. Radium was infused into gold wires and stitched directly into tumors, to produce even higher local doses of X-rays. Surgeons implanted radon pellets into abdominal tumors. By the 1930s and ’40s, America had a national surplus of radium, so much so that it was being advertised for sale to laypeople¹⁹³ in the back pages of journals. Vacuum-tube technology advanced in parallel; by the mid-1950s variants of these tubes could deliver blisteringly high doses of X-ray energy into cancerous tissues.

Radiation therapy catapulted cancer medicine into its atomic age—an age replete with both promise and peril. Certainly, the vocabulary, the images, and the metaphors bore the potent symbolism of atomic power unleashed on cancer. There were “cyclotrons” and “supervoltage rays” and “linear accelerators” and “neutron beams.” One man was asked to think of his X-ray therapy as “millions of tiny bullets of energy.”¹⁹⁴ Another account of a radiation treatment is imbued with the thrill and horror of a space journey: “The patient is put on a stretcher¹⁹⁵ that is placed in the oxygen chamber. As a team of six doctors, nurses, and technicians hover at chamber-side, the radiologist maneuvers a betatron into position. After slamming shut a hatch at the end of the chamber, technicians force oxygen in. After fifteen minutes under full pressure . . . the radiologist turns on the betatron and shoots radiation at the tumor. Following treatment, the patient is decompressed in deep-sea-diver fashion and taken to the recovery room.”

Stuffed into chambers, herded in and out of hatches, hovered upon, monitored through closed-circuit television, pressurized, oxygenated, decompressed, and sent back to a room to recover, patients weathered the onslaught of radiation therapy as if it were an invisible benediction.

And for certain forms of cancer, it was a benediction. Like surgery, radiation was remarkably effective at obliterating locally confined cancers. Breast tumors were pulverized with X-rays. Lymphoma lumps melted away. One woman with a brain tumor¹⁹⁶ woke up from her yearlong coma to watch a basketball game in her hospital room.

But like surgery, radiation medicine also struggled against its inherent limits. Emil Grubbe had already encountered the first of these limits with his earliest experimental treatments: since X-rays could only be directed locally, radiation was of limited use for cancers that had metastasized.* One could double and quadruple the doses of radiant energy, but this did not translate into more cures. Instead, indiscriminate irradiation left patients scarred, blinded, and scalded by doses that had far exceeded tolerability.

The second limit was far more insidious: radiation produced cancers. The very effect of X-rays killing rapidly dividing cells—DNA damage—also created cancer-causing mutations in genes. In the 1910s, soon after the Curies had discovered radium, a New Jersey corporation called U.S. Radium began to mix radium with paint to create a product called Undark—radium-infused paint that emitted a greenish white light at night. Although aware of the many injurious effects of radium, U.S. Radium promoted Undark for clock dials, boasting of glow-in-the-dark watches. Watch painting was a precise and artisanal craft, and young women with nimble, steady hands were commonly employed. These women were encouraged to use the paint without precautions, and to frequently lick the brushes with their tongues to produce sharp lettering on watches.

Radium workers soon began to complain of jaw pain, fatigue, and skin and tooth problems. In the late 1920s, medical investigations revealed that the bones in their jaws had necrosed, their tongues had been scarred by irradiation, and many had become chronically anemic (a sign of severe bone marrow damage). Some women, tested with radioactivity counters, were found to be glowing with radioactivity. Over the next decades, dozens of radium-induced tumors sprouted in these radium-exposed workers—sarcomas and leukemias, and bone, tongue, neck, and jaw tumors. In 1927, a group of five severely afflicted women in New Jersey—collectively termed “Radium girls”¹⁹⁷ by the media—sued U.S. Radium. None of them had yet developed cancers; they were suffering from the more acute effects of radium toxicity—jaw, skin, and tooth necrosis. A year later, the case was settled out of court with a compensation of $10,000 each to the girls, and $600 per year to cover living and medical expenses. The “compensation” was not widely collected. Many of the Radium girls, too weak even to raise their hands to take an oath in court, died of leukemia and other cancers soon after their case was settled.

Marie Curie died of leukemia¹⁹⁸ in July 1934. Emil Grubbe, who had been exposed to somewhat weaker X-rays, also succumbed to the deadly late effects of chronic radiation. By the mid-1940s, Grubbe’s fingers had been amputated¹⁹⁹ one by one to remove necrotic and gangrenous bones, and his face was cut up in repeated operations to remove radiation-induced tumors and premalignant warts. In 1960, at the age of eighty-five, he died in Chicago, with multiple forms of cancer that had spread throughout his body.

The complex intersection of radiation with cancer—cancer-curing at times, cancer-causing at others—dampened the initial enthusiasm of cancer scientists. Radiation was a powerful invisible knife—but still a knife. And a knife, no matter how deft or penetrating, could only reach so far in the battle against cancer. A more discriminating therapy was needed, especially for cancers that were nonlocalized.

In 1932, Willy Meyer²⁰⁰, the New York surgeon who had invented the radical mastectomy contemporaneously with Halsted, was asked to address the annual meeting of the American Surgical Association. Gravely ill and bedridden, Meyer knew he would be unable to attend the meeting, but he forwarded a brief, six-paragraph speech to be presented. On May 31, six weeks after Meyer’s death, his letter was read aloud to the roomful of surgeons. There is, in that letter, an unfailing recognition that cancer medicine had reached some terminus, that a new direction was needed. “If a biological systemic after-treatment were added in every instance,” Meyer wrote, “we believe the majority of such patients would remain cured after a properly conducted radical operation.”

Meyer had grasped a deep principle about cancer. Cancer, even when it begins locally, is inevitably waiting to explode out of its confinement. By the time many patients come to their doctor, the illness has often spread beyond surgical control and spilled into the body exactly like the black bile that Galen had envisioned so vividly nearly two thousand years ago.

In fact, Galen seemed to have been right after all—in the accidental, aphoristic way that Democritus had been right about the atom or Erasmus had made a conjecture about the Big Bang centuries before the discovery of galaxies. Galen had, of course, missed the actual cause of cancer. There was no black bile clogging up the body and bubbling out into tumors in frustration. But he had uncannily captured something essential about cancer in his dreamy and visceral metaphor. Cancer was often a humoral disease. Crablike and constantly mobile, it could burrow through invisible channels from one organ to another. It was a “systemic” illness, just as Galen had once made it out to be.