The Surprising Reason for the Decline in Cancer Mortality
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Last year, I called America a “rich death trap.” Americans are more likely to die than Europeans or other citizens of similarly wealthy nations at almost any given age and income level. Guns, drugs and cars account for most of the change, but record health care spending hasn’t bought much safety from the ravages of common pathogens. While much of the developed world saw its death rates improve in the second year of the coronavirus pandemic, more Americans died of COVID after the introduction of vaccines than before.
But this week, America finally got some good news in the all-important category of keeping its citizens alive. Since the early 1990s, the cancer death rate in the US has fallen by a third, according to a new report from the American Cancer Society.
When I first read the news in The Wall Street Journal, my assumption was that this achievement in health outcomes was largely due to medical advances. Since the War on Cancer was declared by President Richard Nixon in 1971, the US has spent hundreds of billions of dollars on cancer research and drug development. We’ve conducted tens of thousands of clinical trials for drugs to treat late-stage cancer in that time. Surely, I thought, these Herculean research efforts are the main drivers of reducing cancer mortality.
However, as it turns out, behavioral changes and screenings appear to be just as important as treatments, if not more so.
Let’s start with an obvious but crucial point: There is no individual disease called “cancer”. (Regarding that, nothing like a “cancer cure” is likely to materialize anytime soon, if ever.) Rather, what we call cancer is a large group of diseases in which the uncontrolled growth of abnormal cells it makes people sick and possibly death. Different cancers have different causes and screening protocols, and as a result, progress can be rapid for one cancer and depressingly slow for another.
The decline in cancer mortality for men over the past 30 years is almost entirely due to a handful of cancers – lung, prostate, colon and rectal. Little progress has been made in other deadly cancers.
Consider the different histories of the two cancers. In 1930, the death rates for lung cancer and pancreatic cancer were measured to be equally low among the American male population. However, by the 1990s, lung cancer mortality had exploded and the disease became one of the leading causes of death for American men. Since 1990, lung cancer rates have fallen by more than half. Meanwhile, pancreatic cancer death rates rose steadily until the 1970s and have essentially declined since then.
What explains these different trajectories? In the case of lung cancer, Americans in the 20th century massively participated in behaviors (especially smoking) that dramatically increased their risk of developing the disease. Scientists discovered and reported the risk, then public health campaigns and policy changes encouraged a large reduction in smoking, which gradually reduced lung cancer mortality. However, in the case of pancreatic cancer, the causes are mysterious and the disease is tragically and extremely difficult to diagnose.
Treatments for late-stage lung cancer have improved in recent decades, according to the American Cancer Society. But for all the money we’ve spent on treatments, most of the decline in deaths over the past three decades appears to be the result of behavioral changes. Smoking in America fell from an all-time high of about 4,500 cigarettes per person per year in 1963—enough for any adult to smoke more than half a pack a day—to fewer than 2,000 by the end of the century. It has fallen further since then.
Another possible factor in reducing cancer mortality is better screening, although the question of how much should be screened is still controversial. In the early 1990s, doctors began using blood tests that detected specific prostate toxins. This period coincided with a decline in prostate cancer. But many positive results from these tests were false alarms, resulting in asymptomatic cases that would never have blossomed into serious cancers. As a result, the federal government discouraged these prostate cancer tests for men in the 2010s. Since then, advanced prostate cancer diagnoses have increased and the death rate has stopped falling—suggesting that the earlier testing regimen may have be better after all.
This cancer screening debate could define the next generation of medicine. As I wrote in last year’s Advances of the Year , companies such as Grail now offer blood tests that look for circulating tumor DNA to detect 50 types of cancer. As these types of tests become cheaper and more widely available, they may reduce the mortality of more cancers, just as antigen tests have helped reduce prostate cancer death rates. On their face, these advances seem simply wonderful. But deploying them effectively will require a delicate balancing act on the part of regulators. After all, how much information is too much information for patients if many cancer tests turn up false alarms? “They sound great, but we don’t have enough information,” said Lori Minasian of the National Cancer Institute about these tests. “We don’t have conclusive data showing that they will reduce the risk of dying from cancer.”
The Biden administration’s Cancer Moonshot initiative should heed the lessons of this latest report. Much of the decline in cancer mortality since the 1990s has come from upstream factors, such as behavioral changes and improved screening, although the vast majority of cancer research and clinical trial spending is on cancer therapies. cancer in the last stage. A cure for cancer can be elusive. But a moonshot for cancer screenings and tests may be the most important front in the future fight against cancer.
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