It’s undeniably good news: The cancer death rate in the United States has declined by 27 percent in the past 25 years, according to a recent report from the American Cancer Society. While this milestone translates into more than 2.6 million deaths avoided between 1991 and 2016, not all populations are benefiting.
Cancer death rates in poorer regions are higher than in wealthier areas, and obesity-related cancer deaths are rising.
We discussed the report and what it means for the future of cancer care with Lisa Carey, MD, physician-in-chief of the N.C. Cancer Hospital and associate director of clinical research at UNC Lineberger Comprehensive Cancer Center.
Why have cancer death rates in the United States declined?
There are several reasons: There’s been a pretty steady improvement in cancer treatment, we have improved screenings for many tumor types and we have prevention strategies for some tumor types. For example, the likelihood of getting lung cancer is directly related to smoking. And as smoking habits have changed in the United States, the likelihood of getting the disease has dropped.
For breast cancer, we now have pretty effective screening tools and much better treatment. And it’s a similar story for colon cancer. So if you just take some of the big-volume cancers, there have been real advances made in early detection as well as treatment strategies.
The report states that most of the cancer deaths that are increasing are linked to obesity. What does that tell us?
It’s long been known that obesity is related to many cancers, not any particular one. Exactly why is an area of active research.
And we also know that obesity is linked to many diseases, not just cancer. Risk factors for cancer are often the same risk factors for many other health issues. The things that are good for preventing cancer—such as maintaining a healthy weight—are also the things that are good for preventing a whole bunch of other diseases that you don’t want, like diabetes and heart disease.
The report describes a socioeconomic disparity: The rate of cancer death is higher in people who live in poorer counties when compared with their wealthier counterparts. What factors stand in the way of cancer prevention and treatment for people of low income?
When we had no therapy for cancer, it sort of didn’t matter if you were rich or poor. If you got the disease, it was going to be devastating. As we get better treatments, that (socioeconomic) gap starts widening. As the overall death rate goes down, then the disparities start to become more apparent because the rising tide doesn’t lift all the boats. It lifts the boats that have access and the boats that have resources, so you start to see widening disparities. You cannot discount the impact of simply having access to care.
It’s also true that lower socioeconomic groups are more likely to be obese. It’s easier to be healthy if you have access to great food. I also think that some of the other cancer risk factors, such as smoking and alcohol abuse, tend to vary by socioeconomic status.
One of the findings was that prostate cancer death rates are flattening—they didn’t go down like other cancer types. Why is that?
I don’t think anybody really knows, but a decrease in mortality started flattening out when they stopped testing everybody with the prostate-specific antigen, or PSA, test, which came back with a lot of false positives and fell out of favor as a routine screening test. I suspect we’re going to have to get a little more sophisticated about testing. It is true they were identifying a lot of clinically insignificant disease (with the PSA), but it’s also true that they may have thrown out the baby with the bathwater—because we now might be missing disease that testing would have caught early.
What are other key takeaways from this report?
First, it’s important to note that these rates take into account changes in our population, which has more older people than in years past. Older people are always more likely to get cancer than younger, so it’s particularly important for us to be successful in managing cancer better. This report says that we can be very reassured that things we’re doing are working. They’re working faster in certain types of cancer that we have strategies for, and they’re working less quickly in some other ones, such as liver cancer. It’s not that common a cancer, but it’s a bad one. And we haven’t budged it. Screening doesn’t work in relatively uncommon cancers, so we need to focus on prevention of those.
If we’re going to make real inroads, we’re going to have to get back to the fundamental health of the population, which is deteriorating. So we’re fixing some things, like smoking, and making other things worse, like obesity. If we can improve the general health of the American population, it would have benefits for cancer as well as a bunch of other things.
What does this report mean for the future of cancer care?
I’m super enthusiastic. You may remember the narrative a few years ago was we’re doing all this research in cancer, and we’re not seeing improvements in mortality. This is because the impact of the research is always several years behind the research itself. This report shows that investment in really smart researchers trying to figure out ways to grab hold of the cancer problem is working. This is clearly a wonderfully positive trend. We’re going to have to keep going. We can’t rest on our laurels. We’re not done.
Are you concerned about your cancer risk? Talk to your doctor about available screenings that might be right for you. Find a provider near you.