A man receives kidney dialysis. A new study suggests people with kidney disease may be at higher risk for cancer. Photo by Anna Frodesiak/Wikimedia Commons
April 8 (UPI) -- Adults with kidney disease appear to be at greater risk for cancer, and more likely to die from the malignancy than those with healthy kidneys, a study published Friday by the American Journal of Kidney Diseases found.
People with mild to moderate kidney disease, as measured by levels of kidney function, have an 8% higher risk for developing cancer compared to those with healthy kidneys, the data showed.
Those who have undergone a kidney transplant have a 25% higher risk for developing cancer than those who have their own, healthy kidneys, the researchers said.
Advanced kidney disease sufferers also are nearly 50% more likely to die from cancer, while those with mild to moderate kidney disease have a 25% to 30% higher risk for cancer death, according to the researchers.
This may be because people with kidney disease are more likely to be diagnosed with cancer later than those with healthy kidneys, meaning they have more advanced tumors that have metastasized, or spread, to other organs, the researchers said.
Those with kidney disease were particularly prone to bladder and kidney cancers, as well as multiple myeloma, or blood cancer, the data showed.
"Many patients with kidney disease in our study will go on to develop cancer, even those with mild to moderate kidney disease," study co-author Dr. Abhijat Kitchlu told UPI in a phone interview.
"They also have a higher risk for dying from cancer, likely because they are diagnosed with cancer when the disease is already at a later stage," said Kitchlu, a staff nephrologist and clinician investigator at the University of Toronto.
The findings are based on an analysis of data for nearly 5.9 million adults in Ontario, Canada, who had undergone tests for kidney function between 2007 and 2016.
Nearly 440,000 of these patients had evidence of compromised kidney function, while nearly 30,000 were on dialysis treatment for kidney disease and nearly 5,000 had undergone a kidney transplant, the researchers said.
Among all study participants, more than 325,000 developed cancer and more than 72,000 died from the disease, according to the researchers.
About half of the participants who developed cancer had been diagnosed with kidney disease, the data showed.
In addition, many of these patients may be deemed ineligible for cancer treatments, including chemotherapy, because of their kidney disease, Kitchlu said.
Roughly one in seven adults, or 37 million people, in the United States have some form of kidney disease, the National Institute of Diabetes and Digestive and Kidney Diseases estimates.
Healthy kidneys filter about a half cup of blood every minute, removing waste and excess water to produce urine, the institute says.
If the kidneys are not functioning properly, this waste and excess fluid remain in the body, generating unhealthy levels of water, salts and minerals such as sodium, calcium, phosphorus and potassium in the blood, according to the institute.
This can compromise the function of multiple organs in the body, including the heart and immune system, it says.
As a result, many people with kidney disease have other health problems, such as heart disease, high blood pressure, Type 2 diabetes and obesity, all of which may also increase their risk for cancer, Kitchlu said.
In addition, managing these other health problems on top of kidney disease may move "routine cancer screening ... to the back burner," he said.
"If the kidneys are unable to get rid of all the toxins in the blood, this can increase inflammation throughout the body, which in turn can increase the risk for cancer," Kitchlu said.
"People with kidney disease should make sure they are screened for cancer, and those treating them should do all they can to ensure they receive the care they need if they have cancer," he said.