Fox Chase Cancer Center Review Distills Current Research on Kidney Cancer Epidemiology and Risk Factors

Laura Bukavina, MD, MPH

Kidney cancer is the 14th most common cancer worldwide and 9th among men. As such, considerable research has been conducted to improve detection, treatment, and prevention of it in the last two decades.

To synthesize these advancements and summarize their effects globally, Fox Chase Cancer Center Urologic Oncology Fellow Laura Bukavina, MD, MPH, spearheaded a recent review on the topic. The paper updates urologists and kidney cancer researchers on the epidemiology of the disease, along with its risk factors.

“There’s been a lot of different new mechanisms of risk development that have been formulated since then,” Bukavina said. “Plus, the first immune-based therapies for kidney cancer were introduced in 2006 and 2007, so we are just now looking at the effects to see if they have made any difference in kidney cancer survival.”

According to the Global Cancer Observatory, there were 431,288 new cases of kidney cancer in 2020. Bukavina’s review shows that incidence rates have been rising over the past decade, with higher rates, which are associated with greater median income, generally found in Europe and North America.

Bukavina and her coauthors hypothesize that the rising incidence rates are less attributable to a new or increased environmental exposure and are instead due to increased abdominal imaging, particularly in industrialized countries, which has led to more small renal masses being detected that might have been missed before.

Also supporting this hypothesis is the finding that morality rates have been steadily decreasing over the last five to 10 years. “As many of these small renal masses have limited oncologic potential to grow or metastasize, we are not seeing a rise in mortality,” Bukavina said.

A second reason for declining mortality rates may be the introduction of new and improved treatments. “Our therapy has gotten better—it’s gotten less toxic—so we are seeing increased survival, probably because of the introduction of novel immune-based therapies,” said Bukavina. In the United States specifically, kidney cancer mortality has decreased from its peak of 3.8 per 100,000 in 2002 to 3.1 per 100,000 in 2018.

Finally, the review looked at risk factors for kidney cancer. Most modifiable risk factors have been well known for years, and recent research confirms that the three main avoidable causes are smoking, obesity, and high blood pressure.

Research into genetic-related risk factors, however, has only been published in the last decade or so. Bukavina and her coauthors summarize germline (inherited) and somatic (environmentally caused) mutations that have been identified in the literature thus far.

“Every time we do more research on any sort of genetic variation in kidney cancer, we’re finding more and more genes that potentially could run in families or might be useful for therapy,” something that could inform the development of new treatments, she said.

“The ultimate goal is to start working on therapy that’s more goal-directed, more patient-directed. That way we can decrease the toxicity and just target the tumor directly, limiting collateral damange.”

The review, “Epidemiology of Renal Cell Carcinoma: 2022 Update,” was published in European Urology.