Diagnosis and Treatment, Featured, Kidney Cancer

Renal cell carcinoma: Understanding a kidney cancer diagnosis

By Nicole Ferrara • March 12, 2025

Estimated reading time: 5 minutes

Editor's note: March is Kidney Cancer Awareness Month.

By Sara Youngblood Gregory

An estimated 81,610 Americans were diagnosed with kidney cancer in 2024. The most common type of kidney cancer is renal cell carcinoma, which accounts for about 90% of kidney cancers.

It can take time to fully process a renal cell carcinoma diagnosis and what it may mean for you or a loved one. However, having a good understanding of your disease and how it is diagnosed can help you set realistic expectations and actively participate in your treatment plan.

Bradley C. Leibovich, M.D., a Mayo Clinic urologist, explains what you need to know about renal cell carcinoma:

What is renal cell carcinoma?

The kidneys are two bean-shaped organs located on each side of the spine. They perform important functions for the body, including filtering waste and managing acid and fluid balance. The kidneys help maintain a delicate balance of water, salt and minerals in the blood and help ensure that all systems in the body function correctly.

Renal cell carcinoma typically develops as a single tumor in one kidney. Rarely, two or more tumors develop in one or both kidneys. In the early stages of the disease, kidney cancer doesn’t usually cause any symptoms. As the disease progresses, symptoms such as anemia, weight loss, night sweats and fever, blood in the urine, and consistent pain in the side or back may develop.

Because there are initially so few symptoms, kidney cancer is often a surprising diagnosis — particularly because people with the condition may be feeling completely well. An estimated 50% of all kidney cancers are discovered by chance, meaning they are found by accident when scans are being performed to evaluate unrelated issues. Unfortunately, no screening tests are available for kidney cancer, notes Dr. Leibovich.

Cancer stage versus tumor grade — understanding how kidney cancer is diagnosed

Your care team may use blood and urine tests, CT, MRI, or other imaging scans to evaluate your kidney cancer. Sometimes, a biopsy is performed to obtain a tissue sample. These tests help determine the clinical stage of the cancer, which is represented by a number — 1, 2, 3 or 4 — that indicates how extensive the disease is believed to be.

At stages 1 and 2, the cancer is limited, or localized, to the kidney, says Dr. Leibovich. “At stage 3, the cancer involves other tissues, such as the fat surrounding the outside or inside of the kidney, or blood vessels that drain the kidney,” he says. At stage 4, the cancer has spread beyond the kidney. This is called metastatic cancer or metastatic disease. Most people are diagnosed at earlier stages of the disease. Between 2009 and 2015, 65% of renal cell carcinomas were localized to the kidneys.

You may also hear the term “tumor grade,” which describes how aggressively a kidney cancer is expected to behave, says Dr. Leibovich. Cancer cells are examined under a microscope to see how different they look from noncancerous cells to determine the grade. Just like with the cancer stage, the tumor grade ranges from 1 to 4. Grade 1 and 2 cancers are expected to behave less aggressively, while grade 4 means aggressive cancer cells.

Staging and grading are tools that help you and your care team determine the best possible treatment plan.

How to talk with your care team about renal cell carcinoma

It can be overwhelming to discuss new medical information. Don’t be afraid to ask your care team to slow down, repeat key information or rephrase something you don’t understand. Consider writing down your most pressing questions before speaking with your healthcare team and taking notes during your discussion.

To help get you started, Dr. Leibovich recommends asking the following questions:

How likely is my tumor to be cancerous versus benign?
What additional testing do I need?
What is the clinical stage of the cancer?
What treatment options are available? Is it possible the tumor requires observation only?
Why do you recommend certain treatments over others? What are my alternative options?
What is the expected outcome of treatment?
Should I expect changes to my quality of life? How so?
How likely am I to be cured?

Renal cell carcinoma treatment options are often successful

Dr. Leibovich says a renal cell carcinoma diagnosis does not usually impact quality of life, and a cure may be possible for certain people. “More than 60% of those with renal cell carcinoma are cured with surgery alone, though success rates depend on multiple factors,” he says.

Treatment options have advanced dramatically over the past few decades. In recent years, the Food and Drug Administration (FDA) has approved several treatment options for kidney cancer. “Even in cases of advanced disease where we could not have done much to help people in the past, a combination of therapies — targeted therapies and immunotherapies — can significantly extend life and even cure certain people,” says Dr. Leibovich. “For people that we can’t cure, we are now able to keep them going long enough that the new generation of drugs hopefully will extend their lives even more or eventually cure them.”