Yale doctor seeks to limit surgeries for small kidney tumors

NEW HAVEN >> Not all kidney cancers are killers, and many small tumors can be left alone or watched over time because there is a low risk they will become dangerous, according to Dr. Brian Shuch at the Yale School of Medicine.

While doctors can detect more tumors because of increasingly sensitive tools, such as MRIs, surgery to remove the cancer is not called for in many cases, said Shuch, an assistant professor of urology and radiology.

“Many of these small tumors are very indolent or wimpy — low grade or low aggressiveness and low potential to spread or cause harm,” Shuch said. As many as 90 percent of tumors smaller than 4 centimeters fall into this category. Some actually turn out to be benign, he said.

Most surgeons will remove any cancerous tumor they find, out of concern for the risk of it growing, but also because they have a financial incentive to operate, as well as a fear of legal liability, Shuch said. This aggressive approach isn’t necessary and can lead to other issues later in life, such as dialysis, he said.

For their part, patients don’t look at the relatively low risk of a small, slow-growing tumor and opt for surgery, while ignoring major health issues such as smoking and obesity.

“It’s very difficult to convince a patient that they may not need a treatment,” Shuch said.

Over treatment?

About 64,000 cases of kidney cancer will be diagnosed this year, according to the American Cancer Society and 14,400 people will die from the disease.

“The number of kidney tumors has increased about threefold in the past 30 years because we’re accidentally or incidentally detecting them when they get scanned for other reasons,” Shuch said. “And by finding these small tumors, historically we’ve been operating on every one that we see.”

While kidney cancer surgeries have risen three or four times in the last 30 to 40 years, “there hasn’t been a change in the number of patients dying per year and that has led our epidemiologists to believe we’re grossly overtreating patients,” Shuch said.

His conclusion is that “people are probably having tumors treated that never really needed to be treated.”

“In the past, when patients would have an autopsy, they would be incidentally found to have a kidney tumor about 3 percent of the time and that shows that many of these patients are destined to die with a tumor from an unrelated cause than from the tumor itself,” Shuch said.

Shuch uses a fish analogy to describe his approach to small kidney tumors. “There are the sharks, which are the incredibly aggressive tumors, and those are very rare [but] are destined to cause trouble,” he said. These amount to 5 percent or fewer of small kidney tumors and must be removed.

“Then there are the guppies, which are going to cause no harm at all,” Shuch said. “Those are going to just sit there and be happy and cause no harm at all.

“The final category are the goldfish, where [with] the right environment or the right food they’ll continue to grow and grow and eventually can cause trouble if not treated.”

In the past, all of these would be surgically removed, Shuch said.

“Historically, a biopsy could not reliably distinguish cancer from benign, therefore everyone would go to surgery. But our program is working to develop … genetic markers to help distinguish benign tumors from the cancerous.”

Shuch and his colleagues use an approach for these small tumors called “active surveillance” in which, “rather than rush to the operating room, treating a small problem with a weapon of mass destruction, we decide to closely observe and we often, by watching a tumor, we can pick out the guppies from the goldfish.”

One technique used is molecular profiling, which can detect genetic mutations in the tumor “and often with that we can tease out what type of kidney tumor, whether it’s benign and, if it is cancer, what flavor of kidney cancer or what subtype” to determine how aggressive it is.

While a traditional biopsy looks at the shape of the tumor and is not totally reliable at distinguishing benign from malignant tumors, a molecular biopsy looks for changes in the genetic code. Tumors often have a different number of chromosomes and “that can be very suggestive if a tumor is benign or, if cancer, potentially what type of cancer and, within the type, sometimes it can predict aggressive behavior,” Shuch said.

Further study

An $800,000 grant from the National Institutes of Health is underwriting a study into molecular biopsies to see “how reliable a single biopsy is, and it’s very reliable,” Shuch said.

He said there are certainly times when surgery is appropriate for small tumors. “If an 80-year-old had a very indolent tumor, I would try to leave it alone,” he said. “If an 80-year-old had a very aggressive tumor, I would push them to intervene.

“If a 40-year-old had an indolent tumor, unless I could predict that it was benign, I would likely intervene if it had any chance of growth over the next 40 years of their life.”

These tumors that are hard to predict are the “goldfish” type. “Most of those patients, instead of following them for 30 or 40 years of their life, we would suggest consideration of treatment,” Shuch said. “You could still offer surveillance, but at some point they’re likely going to need treatment.”

Reducing kidney surgery is important because even partial removal can pose risks to patients’ health.

“Kidney function is essential for life, and if you lose kidney function you need dialysis to maintain your life,” Shuch said.

“In the past, we used to remove the whole kidney for cancer treatment, but we’ve realized that removing part of the kidney was safer and lowered the risk of cardiac and renal adverse events or complications.”

However, even a partial removal, or nephrectomy, “which may be less harmful than radical nephrectomy, still has adverse health consequences.”

Besides the inherent risk of surgery, “there are long-term health consequences,” Shuch said. Lowered kidney function can lead to a heart attack years later and can also cause high blood pressure, fluid retention and fatigue, he said.

“What we’re trying to convey is partial compared to nothing is still harmful, and long term we have recent data that shows there are probably three or four times the number of patients on dialysis attributed to kidney cancer treatment than in the 1980s.

“Approximately one in 200 individuals who are treated for kidney cancer ultimately will end up on dialysis and … that could be many years down the road,” Shuch said.

“I try to offer patients a way to avoid a major operation for a tumor that was likely not to harm them,” he said.

And he tries to give his patients perspective.

“Even though the risk of a kidney tumor is very low … if you could immediately lower that risk, a lot of people would pursue it when they’re much more likely to die of other factors and other medical conditions … that are much more difficult to treat,” such as smoking or heart trouble, Shuch said.

“The majority of patients who are found with kidney tumors are older … the average age is 64, and the majority of patients have pre-existing conditions,” he said.

“They’d be much better off with probably managing the things they’re more likely to die from.”

Call Ed Stannard at 203-680-9382.