Kidney Cancer

What is kidney cancer?

Kidney cancer is a disease in which cells in one or both kidneys begin to grow out of control and form a tumor (an abnormal mass of tissue). The kidneys are two bean-shaped organs, each about the size of a fist, located on either side of the spine just below the rib cage. Their main job is to filter waste products and extra fluid from the blood and turn them into urine. They also help control blood pressure and support the production of red blood cells.

The most common type of kidney cancer in adults is renal cell carcinoma (RCC), which starts in the lining of the tiny tubes inside the kidney that filter the blood. Renal cell carcinoma accounts for the large majority of adult kidney cancers. Less common types include transitional cell carcinoma (also called urothelial carcinoma), which begins in the area where the kidney joins the tube that carries urine to the bladder, and Wilms tumor, a form of kidney cancer that mainly affects young children.

Kidney cancer is more common in adults over the age of 50 and occurs more often in men than in women. Many kidney tumors are now found at an early stage, often by chance, when a person has an imaging scan of the abdomen for an unrelated reason. Finding the disease early generally makes it easier to treat.

Symptoms of kidney cancer

In its early stages, kidney cancer often causes no symptoms at all. The kidneys sit deep inside the body, so a small tumor can grow for some time without being felt or noticed. This is one reason why many cases are discovered incidentally during scans done for other health problems.

When kidney cancer symptoms do appear, they may include:

• Blood in the urine (hematuria) — the urine may look pink, red, or cola-colored, and the blood may come and go
• Pain in the side or lower back that does not go away and is not caused by an injury
• A lump or mass that can be felt in the side or abdomen
• Unexplained weight loss without changes in diet or activity
• Loss of appetite
• Persistent tiredness (fatigue) that rest does not relieve
• Fever that keeps coming back and is not caused by an infection
• Anemia — a low red blood cell count, which can cause paleness, weakness, and shortness of breath
• Swelling of the ankles or legs in some cases

Symptoms often depend on the stage of the disease. Early-stage tumors that are still confined to the kidney frequently cause no noticeable problems. As a tumor grows larger, it is more likely to cause blood in the urine, flank pain, or a lump that can be felt. If kidney cancer spreads to other parts of the body (a process called metastasis), it can cause symptoms related to those areas — for example, bone pain if it spreads to the bones, or a persistent cough or shortness of breath if it spreads to the lungs.

It is important to remember that all of these symptoms can also be caused by conditions that are not cancer, such as kidney stones, urinary tract infections, or benign (noncancerous) cysts. Only a medical evaluation can determine the cause. However, blood in the urine should always be checked by a doctor, even if it happens only once.

Causes and risk factors

Doctors do not always know the exact kidney cancer causes in an individual person. Cancer develops when changes (mutations) occur in the DNA of kidney cells, causing them to grow and divide abnormally. Why these changes happen in one person and not another is often unclear, but research has identified several factors that increase the risk of developing the disease.

• Smoking: People who smoke tobacco have a higher risk of kidney cancer than nonsmokers. The risk tends to decrease over time after quitting.
• Obesity: Carrying excess body weight is linked to a higher risk, possibly because of hormonal changes associated with obesity.
• High blood pressure (hypertension): Long-standing high blood pressure is associated with an increased risk of kidney cancer.
• Older age: The risk rises with age, and most cases are diagnosed in people over 50.
• Male sex: Men develop kidney cancer more often than women.
• Family history: Having a close relative, such as a parent or sibling, with kidney cancer increases risk.
• Inherited conditions: Certain rare genetic syndromes, such as von Hippel-Lindau disease (an inherited disorder that causes tumors and cysts in several organs), raise the risk of kidney cancer, often at a younger age.
• Long-term dialysis: People with advanced chronic kidney disease who receive dialysis (a treatment that filters the blood when the kidneys fail) for many years have a higher risk.
• Workplace exposures: Long-term exposure to certain substances, such as trichloroethylene (an industrial solvent), has been linked to kidney cancer.
• Certain pain medications: Heavy, long-term use of some pain relievers has been associated with an increased risk in some studies.

Having one or more risk factors does not mean a person will definitely develop kidney cancer, and some people who develop the disease have no known risk factors. Still, not smoking, maintaining a healthy weight, and managing blood pressure are sensible steps that may lower risk and benefit overall health.

Diagnosis of kidney cancer

Kidney cancer diagnosis usually begins with a discussion of symptoms and medical history, followed by a physical examination. If a kidney problem is suspected, doctors use a combination of laboratory tests and imaging studies to look for a tumor and, if one is found, to learn how far it may have spread.

Laboratory tests

Blood and urine tests cannot confirm kidney cancer on their own, but they provide important clues. A urine test (urinalysis) can detect blood or abnormal cells in the urine. Blood tests can check kidney function, look for anemia, and measure other substances that may be affected by a kidney tumor.

Imaging tests

Imaging is the main way doctors find and evaluate kidney tumors:

• Ultrasound: Uses sound waves to create pictures of the kidneys. It can often tell the difference between a fluid-filled cyst, which is usually harmless, and a solid mass, which needs further investigation.
• Computed tomography (CT) scan: A detailed X-ray study, often performed with a contrast dye injected into a vein, that shows the size, shape, and location of a tumor. CT is one of the most important tests for diagnosing and staging kidney cancer.
• Magnetic resonance imaging (MRI): Uses magnets and radio waves to create detailed images. It may be used when CT is not suitable, for example in people who cannot receive certain contrast dyes, or to check whether a tumor has grown into nearby blood vessels.
• Chest X-ray or chest CT and bone scans: These may be ordered to check whether the cancer has spread to the lungs or bones.

Biopsy

A biopsy is the removal of a small sample of tissue so it can be examined under a microscope. For many kidney tumors, imaging findings are clear enough that doctors can proceed to treatment without a biopsy, and the diagnosis is confirmed when the tumor is removed surgically. In some situations — for example, when the diagnosis is uncertain, when nonsurgical treatment is being considered, or when the cancer has already spread — a needle biopsy may be performed to confirm the type of cancer.

Staging

Once kidney cancer is confirmed, doctors determine its stage, which describes the size of the tumor and whether it has spread. Staging typically ranges from stage 1 (a small tumor confined to the kidney) to stage 4 (cancer that has spread to distant organs). The stage guides treatment decisions and helps doctors discuss the likely outlook.

Treatment options for kidney cancer

Kidney cancer treatment depends on the size, stage, and type of the tumor, as well as a person’s age, kidney function, and overall health. Care is usually planned by a team that may include urologists (surgeons who specialize in the urinary system), medical oncologists (doctors who treat cancer with medicines), and radiation specialists. In many hospitals, including Acibadem, systemic treatment for kidney cancer is coordinated through the Medical Oncology Department in collaboration with urology and radiology teams.

Active surveillance (watchful waiting)

For very small kidney tumors, especially in older adults or people with other serious health conditions, doctors may recommend active surveillance. This means monitoring the tumor closely with regular imaging scans rather than treating it right away. Many small kidney tumors grow slowly, and some may never cause harm during a person’s lifetime. Treatment can be started later if the tumor grows or changes.

Surgery

Surgery is the main treatment for kidney cancer that has not spread beyond the kidney, and in many cases it can be curative. There are two main operations:

• Partial nephrectomy: Removal of the tumor along with a margin of surrounding tissue while preserving the rest of the kidney. This is often preferred for smaller tumors because it helps protect long-term kidney function.
• Radical nephrectomy: Removal of the entire affected kidney, sometimes together with nearby lymph nodes or the adrenal gland (a small hormone-producing gland that sits on top of the kidney). Most people can live a healthy life with one kidney.

Both operations can often be performed using minimally invasive techniques, such as laparoscopic or robot-assisted surgery, which use small incisions and may allow a shorter recovery in suitable patients. Your surgeon will recommend the approach best suited to your situation.

Ablation and other local procedures

For people who cannot have surgery, small tumors can sometimes be destroyed without an operation. Cryoablation freezes the tumor, while radiofrequency ablation uses heat generated by electrical energy. These procedures are usually done through a needle guided by imaging.

Targeted therapy

Targeted therapy uses medicines that block specific molecules cancer cells need to grow, such as the signals that help tumors build new blood vessels. These drugs are commonly used when kidney cancer has spread or cannot be removed surgically. They do not usually cure advanced disease, but in many cases they can slow its growth and help control symptoms.

Immunotherapy

Immunotherapy uses medicines that help the body’s own immune system recognize and attack cancer cells. Drugs known as checkpoint inhibitors have become an important part of treatment for advanced kidney cancer, sometimes combined with targeted therapy. Response varies from person to person, and your oncology team will discuss whether this approach is appropriate for you.

Radiation therapy

Kidney cancer is generally less sensitive to radiation than some other cancers, so radiation is not usually the main treatment. However, it can be helpful for relieving symptoms — for example, easing pain from cancer that has spread to the bones or treating spread to the brain.

Chemotherapy

Traditional chemotherapy is not very effective against the most common type of kidney cancer and is used only in select situations, such as certain rarer tumor types.

Detailed information about how this condition is evaluated and managed is available on the kidney cancer treatment page.

Living with kidney cancer and outlook

The outlook for kidney cancer varies widely and depends mainly on the stage at diagnosis, the type of tumor, and a person’s general health. When the cancer is found early and is still confined to the kidney, surgery often offers a good chance of cure. When the disease has spread beyond the kidney, treatment focuses on controlling the cancer, relieving symptoms, and maintaining quality of life for as long as possible. Modern targeted therapies and immunotherapies have improved outcomes for many people with advanced disease, although responses differ from person to person and no treatment can be guaranteed to work.

After treatment, regular follow-up is essential. This usually includes periodic imaging scans and blood tests to check kidney function and watch for any sign of the cancer returning. Follow-up schedules vary depending on the original stage and treatment, and your care team will explain what is right for you.

Living with one kidney is possible for most people, but protecting the remaining kidney becomes important. Doctors often advise controlling blood pressure, staying well hydrated, avoiding smoking, limiting medicines that can strain the kidneys (such as some over-the-counter pain relievers, unless approved by a doctor), and maintaining a healthy weight. Emotional support also matters: a cancer diagnosis can be stressful, and counseling, support groups, or talking openly with family and the care team can help many people cope.

Frequently asked questions

What is kidney cancer in simple terms?

Kidney cancer is a disease in which cells inside a kidney grow abnormally and form a tumor. The most common type in adults, renal cell carcinoma, starts in the tiny filtering tubes of the kidney. If not treated, the cancer can grow larger and, in some cases, spread to other parts of the body. Found early, it is often treatable with surgery.

Can kidney cancer be cured?

In many cases, yes — especially when the cancer is diagnosed while it is still confined to the kidney. Surgical removal of the tumor or the affected kidney can often cure early-stage disease. When the cancer has spread, a complete cure is less likely, but treatments such as immunotherapy and targeted therapy may control the disease for extended periods. Outcomes vary between individuals, so it is best to discuss your specific situation with your doctor.

How serious is kidney cancer?

Kidney cancer is a serious condition, but its seriousness depends heavily on the stage at diagnosis. Small tumors limited to the kidney generally have a favorable outlook after treatment. Cancers that have spread to lymph nodes or distant organs are harder to treat and usually require ongoing therapy. Because early disease often causes no symptoms, prompt evaluation of warning signs such as blood in the urine is important.

What are the first symptoms of kidney cancer?

Often there are no early symptoms at all, and many tumors are found by chance on scans done for other reasons. When kidney cancer symptoms do occur, the most common early signs are blood in the urine, a persistent ache in the side or lower back, unexplained weight loss, and ongoing tiredness. These symptoms can also have noncancerous causes, so a medical evaluation is needed to find the reason.

Can you live a normal life with one kidney?

Most people who have a kidney removed because of cancer go on to live full, active lives, because a single healthy kidney can usually do the work of two. Doctors generally recommend regular checkups, blood pressure control, healthy hydration, and caution with medicines that can affect the kidneys. Your care team will monitor your kidney function during follow-up visits.

How is kidney cancer diagnosed?

Diagnosis usually involves urine and blood tests followed by imaging studies such as ultrasound, CT, or MRI, which can show whether a mass is present and how large it is. In many cases, imaging is enough to plan treatment, and the diagnosis is confirmed when the tumor is removed. Sometimes a needle biopsy is done first to examine the tumor cells, particularly if the diagnosis is uncertain or nonsurgical treatment is planned.

How long is recovery after kidney cancer surgery?

Recovery time depends on the type of operation and a person’s overall health. After minimally invasive (laparoscopic or robot-assisted) surgery, many people leave the hospital within a few days and gradually return to normal activities over several weeks. Open surgery may require a longer recovery. Your surgical team will give you individual guidance on activity, wound care, and follow-up appointments.

When to see a doctor

Kidney cancer is most treatable when it is found early, so it is important not to ignore possible warning signs. Make an appointment with a doctor promptly if you notice any of the following:

• Blood in your urine, even if it appears only once or is painless
• Persistent pain in your side, back, or abdomen that lasts more than a few weeks and has no clear cause
• A lump or swelling you can feel in your side or abdomen
• Unexplained weight loss or loss of appetite
• Ongoing fatigue, fever, or night sweats without an obvious explanation
• New swelling in your legs or ankles

Seek urgent medical care if you have heavy bleeding in your urine, severe pain, difficulty passing urine, or sudden shortness of breath. These symptoms do not necessarily mean cancer — infections, kidney stones, and other conditions are far more common causes — but they always deserve a proper medical evaluation. If you have a family history of kidney cancer or an inherited condition that raises your risk, talk with your doctor about whether periodic checkups or imaging would be appropriate for you.