Many cancer incidence rates decline over time, but kidney cancer is one of the few cancers with incidence rates that continue to rise year after year.
Currently, nearly 64,000 new cases of kidney cancer are diagnosed in the United States each year, and approximately 13,860 people die from it, according to the American Cancer Society. Men are much more likely than women to be diagnosed with the disease and to die from it.
But unlike other cancers, there is no formalized way to detect kidney cancer, which is why it’s important to know the disease's risk factors and symptoms. Here Sumanta Kumar Pal, M.D., co-director of the Kidney Cancer Program at City of Hope, explores both the factors behind the rise in kidney cancer and the disease's current treatments.
While most cancer incident rates continue to drop each year, kidney cancer is one of the few that continue to increase. Why is this?
Unlike breast cancer or colon cancer, kidney cancer is a disease for which we have no good screening modalities. At the moment, there’s no formalized way to actually detect kidney cancer before the onset of the disease. But as time has gone on, our imaging modalities have gotten better and better — what I’m referring to here are CT scans and MRIs — and as that happened, we've found more and more incidental diagnosis of kidney cancer.
What I mean by that is: Patients who go to the emergency room for an automobile accident or for abdominal pain may oftentimes have a CT scan or MRI, and it ends up showing small kidney cancers. That’s not to say the only rise in kidney cancer incidence is in small tumors, but having said that, it may certainly drive some of the increase.
Here at City of Hope, I have seen a massive increase in the number of kidney cancer patients in my clinic, certainly over the past five years that I’ve been on faculty. Every year, I’ve had a near-doubling of patients enrolled in clinical trials with the disease.
I don’t necessarily view that as a bad thing. I would suggest that perhaps this indicates that more and more patients are becoming educated about their disease and seeking out participation in clinical trials at academic medical centers like City of Hope.
Why is kidney cancer more common in men?
There does tend to be a gender predisposition to kidney cancer. The male-to-female ratio is estimated at somewhere between 3 to 4 to 1. This has been pretty consistent over the years. There is no underlying biology that seems to vary between males and females, but perhaps there might be an issue of risk factors.
For instance, there are several suggested risk factors for developing kidney cancer such as smoking history and obesity. It may be that these factors may potentially drive gender-based differences that we see in the incidence of kidney cancer — particularly smoking.
What other factors affect who may develop kidney cancer? Age, race?
At the moment, we definitely think of kidney cancer as being a disease of the elderly. What’s interesting is that the median age of diagnosis for kidney cancer, which is 65, is actually higher than the median age of diagnosis for prostate cancer, which is closer to 62. With that in mind, I think it is certainly important that we recognize cancer in older adults. Having said that, we now have some very interesting screening guidelines. Patients who are under the age of 46 are now encouraged to undergo genetic counseling. This is to detect any hereditary predisposition to kidney cancer.
Is the risk of kidney cancer influenced by genetics?
We think the majority of kidney cancers are due to what is called sporadic changes in genes. These are changes that occur over the course of time — perhaps an explanation of why kidney cancer may potentially occur in an older population. However, there’s certainly an increasingly recognized proportion of kidney cancers that are passed down from one generation to the next. These are genetic changes that are inherited. By virtue of that, they tend to manifest in younger patients.
What are some common symptoms of kidney cancer?
With kidney cancer we always think of symptoms such as pain in the flank — essentially the side of the back — and blood in the urine as classic hallmark signs. As time goes on, again because we’re using imaging studies more often (CT scans and MRIs), we’re starting to find more and more asymptomatic tumors.
What type of treatment should someone with kidney cancer expect?
I primarily treat patients who have advanced kidney cancer that has spread to their lungs, bones and other places. In that particular setting, we do have a number of therapies that have been approved in recent years — a total of seven drugs that have been approved since 2005. Although this is very encouraging, what I will say is that there’s a lot of overlap in the way these drugs work. Because of that, I would encourage patients to seek counseling in an academic medical center. In that setting they may have access to clinical trials that will give them state of the art drugs, perhaps even before they receive FDA approval.
What types of advancements in kidney cancer research/treatment should we expect in the next 10 years?
Interestingly, the treatments of kidney cancer two decades ago in the advanced stage were based on immunotherapy. These are drugs that modulate and advance the immune system to react against the cancer. These agents have fallen further and further from the spectrum of current therapies. I think over the next decade there will be research in some newer and more specific immune-based therapies that offer benefits to a greater proportion of patients with kidney cancer.
Who do the current immunotherapy treatments target?
At this point, immune-based therapies are really focused on patients with advanced disease. Right now there are a number of ongoing clinical trials that are exploring kidney cancer drugs applied in the advance settings in patients with more limited stages of the disease. The patients I’m referring to here are those who had their tumors completely receptive. However, those clinical trials evaluating treatments for limited stages of the disease have not yet been completed. Therefore the treatment should not be used yet in that setting outside of the study.
What is the likelihood of someone surviving kidney cancer?
The survival rate for advanced kidney cancer is really a moving target. If we were to quote data from just a decade ago, we might suggest the median survival for patients with kidney cancer was roughly one year. Now over the past 10 years, because of the multiple developments that we’ve had in the field, we have more than tripled the prognosis for the disease. And I see that only improving over the course of time with some of the newer treatment options.
How can someone lower his or her risk of kidney cancer?
There are no modalities that seem to decrease the risk of developing kidney cancer at the moment. However, what I might suggest is that patients who have a family history of kidney cancer, with multiple family members afflicted or patients who are diagnosed very young, should seek genetic counseling. This may potentially influence the management and work-up for other family members with the disease — and may allow for early detection.
What are the chances that someone with kidney cancer will be able to live a “normal” life?
Fortunately, there is a proportion of patients who have limited stages of kidney cancer, where after surgery the disease does not come back. In those settings, one may have a normal quality of life for decades. However, as the stage of kidney cancer increases, the risk of return increases as well.
As such, I would highly recommend patients with localized kidney cancer or limited stage kidney cancer to seek out clinical trials that may potentially medicate the risk of their tumors returning. Although there is no promise that clinical trials can reduce the risk of reoccurrence, I feel that this is an active approach that should be pursued.
Learn more about City of Hope's Kidney Cancer Program.
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