Metastatic renal cell carcinoma represents the advanced form of the most common type of kidney cancer in adults, where cancer cells have traveled beyond the kidney to other parts of the body. While this diagnosis brings significant challenges, understanding the condition and available treatments can help patients and families navigate this journey with greater confidence and clarity.

Understanding Metastatic Renal Cell Carcinoma

Metastatic renal cell carcinoma, also known as stage IV kidney cancer, begins in the tiny tubes inside the kidneys called tubules. These tubules play a vital role in filtering blood and removing waste products from your body. When cancer develops in these tubules, it forms a tumor that can eventually spread beyond the kidney.^[1]

The term “metastatic” means that cancer cells have traveled from their original location in the kidney to other parts of the body. This happens when cancer cells break away from the primary tumor and move through the bloodstream or lymph system — a network of vessels and nodes throughout your body that helps fight disease. Once these cells reach distant organs or tissues, they can form new tumors called metastases or secondary cancers.^[2]

Renal cell carcinoma accounts for approximately 90 percent of all kidney cancers in adults and is the most frequently diagnosed form of kidney cancer. Within this category, clear cell renal cell carcinoma is the most common subtype, making up about 85 percent of cases. The name comes from how the cancer cells appear under a microscope — they look clear or pale-colored.^[6]

How Cancer Spreads Throughout the Body

The journey of cancer from the kidney to other body parts follows specific pathways. As the original tumor grows larger, it begins to invade the fatty tissue surrounding the kidney and may reach major blood vessels nearby. The cancer might also spread to the adrenal gland, a small organ that sits on top of each kidney and produces important hormones.^[1]

Cancer cells have two main highways for spreading through your body. The first is through blood vessels. When cancer cells enter a vein or artery, they can travel to distant organs through your circulatory system. The second route is through the lymphatic system. This network runs throughout your entire body, much like your blood vessels, and is designed to help you fight infections and disease. However, when cancer cells enter lymph nodes, they can use this system to reach other parts of your body.^[1]

The most common destinations for kidney cancer cells are the lungs and bones. However, these cells can also travel to the brain, liver, and in some cases, reproductive organs such as the ovaries or testicles. In approximately 33 percent of cases, people already have metastatic spread when they are first diagnosed with renal cell cancer. In other situations, the cancer may return and spread months or even years after initial treatment of the kidney tumor.^[4]

Who Is Most Likely to Develop This Condition

Healthcare providers diagnose approximately 80,000 new cases of renal cell carcinoma each year in the United States, with about 400,000 cases worldwide. The condition can affect anyone, but certain patterns emerge when looking at large groups of patients. Men are more likely than women to develop renal cell carcinoma, and the disease is most commonly diagnosed in people between the ages of 60 and 80 years.^[6]

When doctors look at who develops metastatic disease specifically, they find that between 20 to 50 percent of patients who undergo surgery to remove a kidney tumor will later develop metastases. Additionally, about one-third of all renal cell cancer cases have already spread to other organs by the time of diagnosis. This means that a significant number of people with kidney cancer will face the challenges of advanced disease at some point in their journey.^[4]

What Increases Your Risk

While the exact causes of renal cell carcinoma remain unclear, researchers have identified several factors that increase a person’s chances of developing this cancer. Understanding these risk factors doesn’t mean you will definitely get kidney cancer, but it does mean your risk is higher than someone without these factors.^[3]

Smoking tobacco stands out as a major risk factor. The more a person smokes and the longer they continue smoking, the greater their risk becomes. The good news is that this is a risk factor you can change. Long-term use or misuse of certain pain medications, including some over-the-counter options, also increases risk. If you regularly take pain medicines, it’s worth discussing this with your doctor to ensure you’re using them safely.^[3]

Body weight plays a significant role as well. People carrying excess weight, especially those with a higher body mass index (BMI), face increased risk. The relationship appears to be direct — the higher the BMI, the greater the risk. High blood pressure, also called hypertension, is another modifiable risk factor. Keeping your blood pressure under control through lifestyle changes or medication may help reduce your risk.^[6]

Some risk factors cannot be changed. Having a family history of renal cell cancer means your genetic makeup may make you more susceptible. Certain inherited conditions, such as von Hippel-Lindau disease or hereditary papillary renal cancer, significantly increase kidney cancer risk. People with chronic kidney disease, especially those requiring long-term dialysis (a treatment that filters waste from blood when kidneys cannot), also face higher risk. Additionally, chronic hepatitis C infection has been linked to increased kidney cancer risk.^[3]

Recognizing the Signs and Symptoms

One of the most challenging aspects of renal cell carcinoma is that it typically produces no symptoms in its early stages. This is why many cases are discovered accidentally when a person undergoes a CT scan or ultrasound for an unrelated reason. When symptoms do appear, they often indicate that the tumor has grown large enough to affect nearby tissues or organs.^[6]

The most common symptom is blood in the urine, medically known as hematuria. This might make your urine appear pink, red, or cola-colored. However, sometimes the amount of blood is so small it can only be detected through laboratory testing. Pain is another frequent symptom, typically felt in the flank — the area between your ribs and hips on either side of your body. This pain might also be felt in your lower back and usually doesn’t go away with rest or over-the-counter pain relievers.^[1]

Some people notice a firm lump or mass that can be felt in the abdomen, belly area, or lower back. Other symptoms are less specific but still important. These include recurring fevers that come and go without an obvious cause, severe night sweats that soak through your clothes or bed sheets, and unexplained weight loss when you haven’t changed your diet or exercise habits. A general sense of feeling unwell, extreme tiredness that doesn’t improve with rest, and loss of appetite are also common.^[1]

You might also develop symptoms of anemia — a condition where your body doesn’t have enough healthy red blood cells to carry oxygen to tissues. This can cause shortness of breath, weakness, dizziness, and overwhelming fatigue. When cancer has spread to specific organs, additional symptoms may appear in those locations. For example, if cancer reaches the bones, you might experience pain in that area. If it spreads to the lungs, you might develop a persistent cough or difficulty breathing.^[6]

Steps You Can Take to Lower Your Risk

While not all cases of renal cell carcinoma can be prevented, certain lifestyle modifications may help reduce your risk. These changes are beneficial for overall health regardless of whether they prevent cancer, making them worthwhile for everyone to consider.^[3]

If you smoke, quitting is the single most important step you can take. Tobacco use is a leading cause of cancer and cancer deaths overall. Resources are available to help you quit, including counseling, support groups, and medications that can ease withdrawal symptoms. Your healthcare provider can guide you to programs that have helped many people successfully stop smoking.

Maintaining a healthy weight through balanced nutrition and regular physical activity may help reduce risk. This doesn’t mean you need to achieve a “perfect” weight or follow an extreme diet. Rather, focus on gradual, sustainable changes such as eating more fruits and vegetables, choosing whole grains over processed foods, and finding physical activities you enjoy. Even modest weight loss in people who are overweight can have health benefits.^[3]

Managing high blood pressure is another important preventive measure. If you have hypertension, work with your healthcare provider to keep it under control through medication, dietary changes (such as reducing salt intake), regular exercise, stress management, and limiting alcohol consumption. Regular medical checkups allow your doctor to monitor your blood pressure and other health markers that might indicate increased risk.

Being mindful about pain medication use is also important. If you regularly take over-the-counter or prescription pain medicines, discuss this with your doctor to ensure you’re using them safely and only when necessary. Your healthcare provider might suggest alternative pain management strategies for chronic conditions.^[3]

How Cancer Changes Normal Body Function

To understand what happens with metastatic renal cell carcinoma, it helps to know how your kidneys normally work. Your two kidneys sit on either side of your backbone, just above your waist. They’re about the size of your fist and shaped like beans. Inside each kidney are approximately one million tiny filtering units. Blood flows through these filters continuously, and they remove waste products while keeping substances your body needs, like water and nutrients.^[3]

The waste products combine with water to form urine, which flows from each kidney through a tube called a ureter into your bladder. Your bladder stores urine until you’re ready to release it through another tube called the urethra. This entire system works automatically, filtering about 120 to 150 quarts of blood daily to produce about 1 to 2 quarts of urine.^[3]

When cancer develops in the kidney tubules, it disrupts this normal process. The cancer cells grow and multiply in an uncontrolled way, forming a tumor. As the tumor enlarges, it can damage the kidney tissue and interfere with the organ’s filtering function. Blood vessels in or near the tumor can become fragile and bleed, which is why blood in the urine is such a common symptom.^[7]

The cellular changes that lead to cancer often begin with alterations in the DNA of kidney cells. Research has shown that in many cases of clear cell renal carcinoma, there are changes to chromosome 3p, which contains several genes important for preventing cancer. One key gene is called VHL. When this gene is mutated or not working properly, it leads to the accumulation of certain proteins called hypoxia-inducible factors or HIFs. These proteins send signals that promote the growth of new blood vessels — a process called angiogenesis. Tumors use these new blood vessels to get the oxygen and nutrients they need to continue growing.^[7]

In some inherited forms of kidney cancer, such as von Hippel-Lindau disease, people are born with one mutated copy of the VHL gene in all their cells. This doesn’t mean they’ll definitely develop cancer, but it makes them much more vulnerable. If the second copy of the gene becomes damaged in kidney cells, cancer can develop. This is why people with von Hippel-Lindau syndrome have such a high risk of developing renal cell carcinoma — nearly 40 percent of them will develop this cancer during their lifetime.^[7]

When cancer spreads to other parts of the body, it creates new problems in those locations. Metastases in bones can weaken the bone structure and cause pain or fractures. Cancer in the lungs can interfere with breathing and oxygen exchange. Brain metastases can affect thinking, movement, or cause headaches and seizures. Liver metastases can disrupt the liver’s many functions, including processing nutrients and removing toxins from the blood. Each location where cancer spreads brings its own set of challenges and symptoms.^[1]