Diabetes can affect many different organs and systems inside your body, often in ways you don’t expect. Your kidneys are no exception, since people with diabetes have an increased risk of kidney cancer. This is the case even when there are no other other kidney cancer risk factors like smoking and hypertension (high blood pressure).

Diabetes may also have a negative impact on your kidney cancer prognosis (how your kidney cancer will progress over time). This may be the case for people with renal cell carcinoma (RCC), the most common type of kidney cancer.

In this article, we’ll take a look at how diabetes and kidney cancer are connected and why diabetes raises kidney cancer risk.

How Diabetes Can Damage Your Kidneys

Diabetes can damage your kidneys and may lead to kidney disease. Chronic kidney disease (CKD) is a risk factor for kidney cancer too. When CKD occurs as a diabetes complication, it can further raise the risk of kidney cancer.

High blood sugar in diabetes clogs and damages the tiny blood vessels inside your kidneys. These delicate blood vessels are called the glomeruli. They handle the first phase of blood filtering. Early stages of kidney disease often don’t cause symptoms. For that reason, your doctor might recommend getting a yearly urine test to check for a protein called albumin. Albumin in your urine (albuminuria) is a sign of kidney disease only detectable with a urinalysis.

If you have diabetes and kidney disease, your doctor can help you support your kidney health to prevent further kidney damage. There’s no guarantee of preventing kidney cancer. But they might suggest changing your diet, avoiding medications that can damage your kidneys, and controlling your blood sugar with diabetes treatment.

Diabetes and Kidney Disease: Shared Risk Factors

Diabetes and kidney disease also share some risk factors that make a person more likely to develop either or both of these conditions. You may be at an increased risk of developing diabetes and kidney disease if you:

• Smoke cigarettes
• Are older
• Live with obesity
• Have metabolic syndrome (a condition involving abdominal obesity, high blood sugar, high blood pressure, and high cholesterol)

Why Diabetes Influences Kidney Cancer Risk

Researchers have a few theories about how diabetes can increase the risk of kidney cancer. The connection still isn’t fully understood, but they’ve identified some specific ways that diabetes may raise kidney cancer risk.

Hyperinsulinemia

Hyperinsulinemia, which is common in people with diabetes, means you have high levels of insulin in your blood. This can be the result of insulin resistance, which is when your cells are unable to use insulin properly. Your pancreas then produces more insulin in an attempt to reduce your blood glucose levels, leading to hyperinsulinemia.

Hyperinsulinemia is linked to an increased risk of multiple cancer types and a poorer cancer prognosis. The link to kidney cancer isn’t well studied, but excess insulin appears to help cancer cells grow and multiply.

Hyperglycemia

Hyperglycemia, or high blood sugar, may also play a role in helping kidney cancer develop. People with hyperglycemia or with a family history of it have more than twice the risk of developing renal cell cancer than the general population.

Hyperglycemia can also increase inflammatory chemicals called proinflammatory cytokines in your tissues. Some of these cytokines help cells, including tumors, grow. Plus, hyperglycemia may feed the cancer cells the extra glucose they need to grow quickly.

Inflammation

Many people with diabetes have low-grade chronic inflammation. This means there’s ongoing inflammatory activity within their tissues.

Inflammation can change the way cells function and reproduce, which might promote tumor growth. Chronic inflammation is a well-established feature of RCC. It may also allow tumors to grow and spread faster by suppressing the immune system.

How Much Does Diabetes Raise Kidney Cancer Risk?

The risk of kidney cancer is 40 percent to 42 percent higher in a person with diabetes than in someone without it. The risk may be higher in those who use insulin to manage their diabetes. Some evidence suggests that people who take metformin for diabetes have slightly better RCC prognoses, but more research is needed to confirm this.

Progressive Diabetes and Kidney Cancer

Having progressive diabetes can mean you’ve had diabetes for a long time before being diagnosed or that you have poor glycemic control, even while taking diabetes medications. People with progressive diabetes are at an even higher risk of developing kidney cancer than those whose diabetes is well managed or diagnosed in early stages.

Kidney cancer risk is highest in people whose diabetes has caused CKD and in those who’ve had unmanaged diabetes for at least five years. Diabetic retinopathy (a diabetes complication involving the eyes) can also factor into a higher risk for kidney cancer.

Gender and Geographic Kidney Cancer Risk Factors in Diabetes

Some research has found that women with diabetes are at a slightly higher risk of developing kidney cancer than men with diabetes. The slight difference may be explained by women being less tolerant to high blood glucose. When diabetes isn’t a factor, men are generally more likely to develop kidney cancer than women.

People with diabetes who live in Asia may also be at a higher risk of developing kidney cancer than those in Europe and North America. Researchers believe this difference may be explained by genetics. More research is needed to find out which (if any) genes are responsible.

Survival Differences After Nephrectomy With Diabetes

Nephrectomy, or surgery to remove part or all of a kidney, is often used to treat RCC. Some research says that people with diabetes may have a shorter survival after nephrectomy for RCC than those without diabetes.

Age, gender, and kidney cancer stage can also affect survival rates after nephrectomy for RCC, with men having poorer outcomes than women. Be sure to follow your doctor’s instructions closely while preparing for and recovering from nephrectomy.

Discuss Your Risk With Your Doctor

If you have diabetes and kidney disease, discuss your kidney cancer risk factors with your doctor. They can walk you through your cancer risk and share ways to control both kidney disease and diabetes.

If you have diabetes and kidney cancer, be sure to talk to your kidney cancer specialist about what to expect during your treatment. They can also tell you your kidney cancer prognosis.

Your healthcare team can help you manage your conditions all at the same time, including kidney cancer, diabetes, and related conditions. They may suggest taking steps to support your kidney health, like limiting how much salt and protein you eat. Be sure to follow their instructions closely as you undergo treatment for kidney cancer.

Join the Conversation

On MyKidneyCancerTeam, people share their experiences with kidney cancer, get advice, and find support from others who understand.

What steps have you taken to manage kidney cancer with diabetes? Let others know in the comments below.