An artist's rendering of a cancer cell
I don’t normally write about anniversaries, but this one seems worth noting. It’s been 40 years since President Richard Nixon signed the National Cancer Act in 1971, the historic legislation that focused attention — and perhaps more importantly, government funding — on the need to research and find treatments for cancer.
A lot has changed in the past four decades. The disease that doctors thought they knew then is very different from the cancer they’re studying today. For one thing, scientists have a much better understanding that cancer isn’t simply one disease in which cells suddenly start to grow out of control, but rather hundreds of different diseases. In fact, according to the American Association for Cancer Research (AACR) Cancer Progress Report, cancer is actually more like 200 distinct diseases, each spurred on by slightly different causes and requiring different treatments.
And instead of focusing so slavishly on the tumors themselves, as experts did initially, researchers have enlarged the window through which they study cancer, allowing the consideration of other critical features, such as how the patient’s own makeup might affect the disease. Scientists also look at how tumors tend to co-opt their environment for their own pathological needs, turning healthy tissues into diseased ones in a process that makes cancer increasingly difficult to control.
“In the haste to continue research and fund it, you sometimes need to stop and turn around and look back at what we’ve accomplished,” notes Dr. William Dalton, president, CEO and center director of the Moffitt Cancer Center and Research Institute and a co-chair of the AACR committee writing the report. “The reduction in death rates of many common cancers that has occurred over the last 40 years is incredible. That’s important because that’s huge progress against something that is probably the biggest health scare for any society.”
Indeed, the death rates for cancer in the U.S. have dropped by 22% for men and 14% for women between 1990 and 2007. And in 1975, only 50% of people diagnosed with cancer could expect to live for another five years; now nearly 70% do. Among children, the gains are even greater: 80% of youngsters can expect to survive their childhood cancer today, compared with 52% in 1975.
Much of that success can be attributed to two key milestones in cancer research: understanding the simple lifestyle factors that contribute to cancer and, on the opposite end of the technological spectrum, the mapping of the human genome in 2001. Behavioral changes such as quitting smoking and avoiding exposure to UV rays, for example, have played a significant role in preventing lung and skin cancers, while the Human Genome Project continues to yield new and useful information on the genetic drivers of cancer.
“If I were to rank developments over the past 40 years that have had the most impact on our understanding of cancer, I would say genetics is No. 1, and lifestyle factors are No. 2,” says Dalton.
Advances in genetics are making it possible to shift into the next phase of cancer care, a more personalized approach in which every patient’s cancer will be treated in the way that best suits his or her case. Already, in the past decade scientists have developed more tailored therapies that target cancer cells specifically, and as these approaches become more routine and refined, physicians will be better able to match the right therapies with the right cancers.
“When I think of the next 40 years, the ultimate goal is personalized medicine,” says Dalton. “I think personalized medicine will have the greatest impact on prevention.” Matching an individual’s cancer biology to the best treatments for that tumor will go a long way toward controlling illness and death from cancer, and personalized approaches can help identify people at highest risk of developing cancer as well.
Preventing cancer is just as important as treating it, he says, especially as the U.S. population ages. “By and large, cancer affects older people; the longer we live, the more likely we will be to develop cancer,” he says. That means that stopping the disease before it even starts will have a huge impact on controlling costs and deaths in coming decades. According to the National Institutes of Health, cancer care in 2010 cost $263.8 billion, including direct medical expenses as well as indirect costs due to lost productivity and early death.
So while the AACR report highlights how far researchers have come in understanding cancer, it’s clear that we’re not close to conquering cancer — at least not yet. Last year, more than 570,000 people died of cancer, still a sobering number that experts hope to shrink in coming years.
Alice Park is a writer at TIME. Find her on Twitter at @aliceparkny. You can also continue the discussion on TIME‘s Facebook page and on Twitter at @TIME.