Forty years ago, my father died instantly of a heart attack. He was 56. At the time I was a student embarking on what I thought would be a career in biomedical science. Though I detoured onto the path of science journalism, I have been paying close attention to the research for a long time.
Reflecting on dad’s death and some newly released health statistics leads me to think about how much progress I have witnessed in the area of heart disease — and also how much remains to be done for cancer, the other major killer in America, which took my mother’s life several decades later.
It is hardly surprising those two diseases claimed my parents. Thirty percent of Americans die of heart disease. Almost 23 percent die of cancer. When stroke, with risk factors similar to heart disease, is included, the three diseases account for 58 percent of all deaths in this country. So, any consideration of extending life in the U.S., a rich country where infectious disease is mostly controlled, starts with those diseases.
The fatal attack at 56 was not my father’s first. That hit at age 42 and there were a few more in between. In those days, the only treatment doctors offered for a heart attack was bed rest. Each successive heart attack damaged more of my father’s heart muscle so that he became weaker, struggling to breathe and move — a victim of what we now call heart failure. He was, in short, what doctors call a “cardiac cripple.” Those last 14 years of his life were an increasing struggle.
An enormous shift
Had my father been born a decade or so later he would have likely escaped all that suffering and, quite possibly, the sudden early death. Today, we have clot-dissolving drugs, angioplasty with stents and bypass surgery to open clogged arteries.
More importantly, we understand the familiar risk factors — saturated fats, lack of exercise, high blood pressure and smoking — that cause the buildup of plaque that clogs the arteries. For those who can’t or won’t take the right preventive steps, statins and other drugs are marvelous medicines that can control cholesterol and blood pressure.
While the numbers of people dying of heart disease and stroke have not changed much for decades, another more critical statistic has shown an enormous shift.
It is called the “age-adjusted death rate,” which recalculates the data to account for the aging population. With that measurement, the death rate for heart disease has dropped 56 percent from the 1950s and stroke by 70 percent. That means deaths from heart disease and stroke now occur mostly in people in their 70, 80s or even beyond. It is one of the greatest achievements of American medicine.
A different story
Cancer is a different story. Last week the government and the American Cancer Society released the "Annual Report to the Nation on the Status of Cancer." It details the age-adjusted incidence and death rates for all of the approximately 200 diseases called cancer.
The overall cancer death rate actually had been climbing slightly for years. Only in the past two years has it fallen a bit — due mostly to declines in tobacco use that began decades ago.
This lack of progress persists despite research spending from the National Cancer Institute approaching $30 billion a year and the “War on Cancer” declared by President Nixon 35 years ago.
Why the disparity between the major killers?
Biologists will sometimes joke that prevention and treatment of cardiovascular disease is nothing more than fixing a plumbing problem in the arteries leading to the heart. That dismisses immense amounts of outstanding research that led to the triumphs over heart disease.
But it does remind us of the difficulty of overcoming cancer. The process where a fertilized egg becomes a complex creature is one of the greatest wonders of nature. Trillions of cells must start and stop dividing at precisely the right moments. Cancer occurs when that exquisite system of controls goes awry and cells begin dividing out of control. What's amazing is that cancer doesn't occur even more often.
For decades, every great discovery in biology has been hailed as a possible step toward a quick cure for cancer, but it has not turned out that way.
The closer scientists get, the more complex cancer seems. In the late-1980s scientists begin a series of discoveries showing that cancer was due to specific changes in the DNA of adult cells. Those targets have multiplied enormously.
Just last week, researchers from Johns Hopkins and the National Institutes of Health published the complete DNA sequences of the tumors from 11 breast cancer and 11 colon cancer patients. In those 22 patients alone the scientists found 200 new mutations that seem to be involved in causing tumors.
The point is not to despair about cancer. The federal government must continue to fund the basic research that will ultimately unravel the problem. But any claims that we can soon expect the kind of progress against cancer that we have seen against heart disease should be met with skepticism.
We should never forget that 30 percent of all cancer (and a lot of a heart disease) results from smoking and 22 percent of Americans still smoke.
We can't stay complacent about heart disease, either. Some researchers predict the obesity epidemic could soon undo much of that progress.