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Kidney Cancer

(Adenocarcinoma of the Kidney; Renal Cell Carcinoma)


Thenappan Chandrasekar

, MD, University of California, Davis

Reviewed/Revised Nov 2023
Topic Resources

Most solid kidney tumors are cancerous, but purely fluid-filled tumors (cysts) generally are not. Almost all kidney cancer is renal cell carcinoma. Another kind of kidney cancer, Wilms tumor Wilms Tumor Wilms tumor is a specific kind of kidney cancer that occurs mainly in young children. The cause of Wilms tumor is not known, but some children may have a genetic abnormality that increases their... read more , occurs primarily in children.

  • Kidney cancer may cause blood in the urine, pain in the side, or fever.

  • Cancer is most often detected by accident when an imaging test is done for another reason.

  • Diagnosis is by computed tomography or magnetic resonance imaging.

  • Removing the kidney prolongs survival and may be curative if cancer has not spread.

The Kidneys

Kidney cancer accounts for about 2 to 3% of cancers in adults, affecting about twice as many men as women. About 81,800 people develop kidney cancer each year, and about 14,890 die of it (2023 estimates).

Symptoms of Kidney Cancer

Symptoms may not occur until the cancer has spread (metastasized) or become very large. Blood in the urine is the most common first symptom, but the amount of blood may be so small that it can be detected only under a microscope. On the other hand, the urine may be visibly red.

The next most common symptoms are pain in the area between the ribs and hip (the flank), fever, and weight loss. Infrequently, a kidney cancer is first detected when a doctor feels an enlargement or lump in the abdomen. Nonspecific symptoms of kidney cancer include fatigue, weight loss, and early satiety (feeling of fullness after a meal).

The red blood cell count may become abnormally high (polycythemia) because high levels of the hormone erythropoietin (which is produced by the diseased kidney or by the tumor itself) stimulate the bone marrow to increase the production of red blood cells. Symptoms of a high red blood cell count may be absent or may include headache, fatigue, dizziness, and vision disturbances. Conversely, kidney cancer may lead to a drop in the red blood cell count (anemia Overview of Anemia Anemia is a condition in which the number of red blood cells is low. Red blood cells contain hemoglobin, a protein that enables them to carry oxygen from the lungs and deliver it to all parts... read more ) because of slow bleeding into the urine. Anemia may cause easy fatigability or dizziness.

Blood pressure may increase, but high blood pressure may not cause symptoms.

Diagnosis of Kidney Cancer

  • Computed tomography or magnetic resonance imaging

  • Sometimes surgery

If cancer is diagnosed, other imaging tests (for example, chest x-ray, bone scan, or CT of the chest) as well as blood tests may be done to determine whether and where the cancer has spread. However, sometimes cancer that has recently spread (metastasized) cannot be detected. Occasionally, surgery is needed to confirm the diagnosis. Rarely, doctors recommend a biopsy of either the kidney mass or other areas of the body that are suspected of having metastases to confirm the diagnosis.

Treatment of Kidney Cancer

  • Surgery

When the cancer has not spread beyond the kidney, surgically removing the affected kidney provides a reasonable chance of cure. Alternatively, surgeons may remove only the tumor with a rim of adjacent normal tissue, which spares the remainder of the kidney. For very small masses in the kidney (smaller than 3 centimeters or about 1.2 inches), ablation (a procedure done by radiologists to burn or freeze the mass) may be an option. Active surveillance (close monitoring) may be an option for very small masses, typically in people too sick to tolerate surgery.

If the cancer has spread into adjacent sites, such as the renal vein or even the large vein that carries blood to the heart (vena cava), but has not spread to lymph nodes or distant sites, surgery may still provide a chance for cure. However, kidney cancer has a tendency to spread early, especially to the lungs, sometimes before symptoms develop. Because kidney cancer that has spread to distant sites may escape early diagnosis, metastasis sometimes becomes apparent only after doctors have surgically removed all of the kidney cancer that could be found.

If surgical cure seems unlikely, other treatments can be used, although these are rarely curative. Treating the cancer by enhancing the immune system’s ability to destroy it causes some cancers to shrink and may prolong survival (see Immunotherapy Immunotherapy for Cancer Immunotherapy is used to stimulate the body's immune system against cancer. These treatments target specific genetic characteristics of the tumor cells. The genetic characteristics of tumors... read more ). Older immunotherapy treatments sometimes used for kidney cancer include interleukin-2 and interferon alfa-2b. Newer immunotherapies called checkpoint inhibitors block a molecule on cancer cells called PD-L1 (a "checkpoint"). PD-L1 can allow cancers to escape detection (and thus destruction) by the body's immune system. Combinations of medications that include checkpoint inhibitors are available. Often they are the treatment of choice in people with metastatic disease and after surgical resection of the cancer in people with intermediate to high risk of the cancer's recurrence.

Other medications sometimes used to treat kidney cancer include sunitinib, sorafenib, cabozantinib, axitinib, bevacizumab, pazopanib, lenvatinib, temsirolimus, and everolimus. These medications alter molecular pathways that affect the tumor and are thus called targeted therapies.

Various combinations of other interleukins, thalidomide, and even vaccines developed from cells removed from the kidney cancer are also being investigated. These treatments may be helpful for metastatic cancer, although the benefit is usually small. Rarely (in less than 1% of people), removing the affected kidney causes tumors elsewhere in the body to shrink. However, the slim possibility that tumor shrinkage will occur is not considered sufficient reason to remove a cancerous kidney when the cancer has already spread, unless removal is part of an overall plan that includes other treatments directed toward widespread cancer.

Prognosis for Kidney Cancer

Tumors Metastatic to the Kidney

Sometimes cancers in other areas of the body spread (metastasize) to the kidneys. Examples of such cancers include melanoma Melanoma Melanoma is a skin cancer that begins in the pigment-producing cells of the skin (melanocytes). Melanomas can begin on normal skin or in existing moles. They may be irregular, flat or raised... read more Melanoma ; cancers of the lung Lung Cancer Lung cancer is the leading cause of cancer death in both men and women. About 85% of cases are related to cigarette smoking. One common symptom is a persistent cough or a change in the character... read more Lung Cancer , breast Breast Cancer Breast cancer occurs when cells in the breast become abnormal and divide into more cells uncontrollably. Breast cancer usually starts in the glands that produce milk (lobules) or the tubes ... read more Breast Cancer , stomach Stomach Cancer A Helicobacter pylori infection is a major risk factor for stomach cancer. Vague abdominal discomfort, weight loss, and weakness are some typical symptoms. Diagnosis includes endoscopy... read more Stomach Cancer , female reproductive organs Overview of Female Reproductive System Cancers Cancers can occur in any part of the female reproductive system—the vulva, vagina, cervix, uterus, fallopian tubes, or ovaries. These cancers are called gynecologic cancers. The most common... read more , intestine Tumors of the Digestive System , and pancreas Pancreatic Cancer Smoking, chronic pancreatitis, obesity, and exposure to certain chemicals are risk factors for pancreatic cancer. Abdominal pain, weight loss, jaundice, and vomiting are some typical symptoms... read more ; leukemia Overview of Leukemia Leukemias are cancers of white blood cells or of cells that develop into white blood cells. White blood cells develop from stem cells in the bone marrow. Sometimes the development goes awry... read more ; and lymphoma Overview of Lymphoma Lymphomas are cancers of lymphocytes, which reside in the lymphatic system and in blood-forming organs. Lymphomas are cancers of a specific type of white blood cells known as lymphocytes. These... read more Overview of Lymphoma .

Such spread usually does not cause symptoms. Spread is usually diagnosed when tests are done to determine how far the original cancer has spread. Treatment is usually directed at the original cancer. Occasionally, if the original cancer is treated and the tumor in the kidney is growing, the kidney tumor is removed.

Drugs Mentioned In This Article

Generic Name Select Brand Names
Intron A, Intron A Multidose Pen
Cabometyx , COMETRIQ
Alymsys, Avastin, MVASI, Zirabev
Afinitor , Afinitor DISPERZ, Zortress
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