Young diseases

Introduction

Each year, more than 28,000 people in the United States learn that they have kidney cancer. The National Cancer Institute (NCI) has written this booklet to help people with kidney cancer and their families and friends better understand this disease. We hope others will read it as well to learn more about kidney cancer.

Definitions of words that may be new to readers and other terms related to kidney cancer can be found in the Glossary. For some words, a "sounds-like" spelling is also given.

This booklet discusses symptoms, diagnosis, treatment, and followup care. It also has information to help patients cope with kidney cancer.

Our knowledge about kidney cancer keeps increasing. For up-to-date information or to order this publication, call the NCI-supported Cancer Information Service (CIS) toll free at 1-800-4-CANCER (1-800-422-6237).

The CIS staff uses a National Cancer Institute cancer information database called PDQ and other NCI resources to answer callers' questions. Cancer information specialists can send callers information from PDQ and other NCI materials about cancer, its treatment, and living with the disease.

The Kidneys

The kidneys are two reddish-brown, bean-shaped organs located just above the waist, one on each side of the spine. They are part of the urinary system. Their main function is to filter blood and produce urine to rid the body of waste. As blood flows through the kidneys, they remove waste products and unneeded water. The resulting liquid, urine, collects in the middle of each kidney in an area called the renal pelvis. Urine drains from each kidney through a long tube, the ureter, into the bladder, where it is stored. Urine leaves the body through another tube, called the urethra.

The kidneys also produce substances that help control blood pressure and regulate the formation of red blood cells.

What Is Cancer?

Cancer is a group of many different diseases that have some important things in common. They all affect cells, the body's basic unit of life. To understand cancer, it is helpful to know about normal cells and about what happens when cells become cancerous.

The body is made up of many types of cells. Normally, cells grow and divide to produce more cells only when the body needs them. This orderly process helps keep the body healthy. Sometimes cells keep dividing when new cells are not needed. A mass of extra tissue forms, and this mass is called a growth or tumor. Tumors can be benign or malignant.

* Benign tumors are not cancer. They often can be removed and, in most cases, they do not come back. Cells in benign tumors do not spread to other parts of the body. Most important, benign tumors are rarely a threat to life.
* Malignant tumors are cancer. Cells in malignant tumors are abnormal and divide without control or order. These cancer cells can invade and destroy the tissue around them. Also, cancer cells can break away from a malignant tumor and enter the bloodstream or lymphatic system. This process is how cancer spreads from the original (primary) tumor to form new tumors in other parts of the body. The spread of cancer is called metastasis.

Kidney Cancer

Several types of cancer can develop in the kidney. This booklet discusses renal cell cancer, the most common form of kidney cancer in adults. Transitional cell cancer (carcinoma), which affects the renal pelvis, is a less common form of kidney cancer. It is similar to cancer that occurs in the bladder and is often treated like bladder cancer. Wilms' tumor, the most common type of childhood kidney cancer, is different from kidney cancer in adults. The Cancer Information Service can provide information about transitional cell cancer and Wilms' tumor.

As kidney cancer grows, it may invade organs near the kidney, such as the liver, colon, or pancreas. Kidney cancer cells may also break away from the original tumor and spread (metastasize) to other parts of the body. When kidney cancer spreads, cancer cells may appear in the lymph nodes. For this reason, lymph nodes near the kidney may be removed during surgery. If the pathologist finds cancer cells in the lymph nodes, it may mean that the disease has spread to other parts of the body. Kidney cancer may spread and form new tumors, most often in the bones or lungs. The new tumors have the same kind of abnormal cells and the same name as the original (primary) tumor in the kidney. For example, if kidney cancer spreads to the lungs, the cancer cells in the lungs are kidney cancer cells. The disease is metastatic kidney cancer; it is not lung cancer.

Symptoms

In its early stages, kidney cancer usually causes no obvious signs or troublesome symptoms. However, as a kidney tumor grows, symptoms may occur. These may include:

* Blood in the urine. Blood may be present one day and not the next. In some cases, a person can actually see the blood, or traces of it may be found in urinalysis, a lab test often performed as part of a regular medical checkup.
* A lump or mass in the kidney area.

Other less common symptoms may include:

* Fatigue;
* Loss of appetite;
* Weight loss;
* Recurrent fevers;
* A pain in the side that doesn't go away; and/or
* A general feeling of poor health.

High blood pressure or a lower than normal number of red cells in the blood (anemia ) may also signal a kidney tumor; however, these symptoms occur less often.

These symptoms may be caused by cancer or by other, less serious problems such as an infection or a cyst. Only a doctor can make a diagnoses. People with any of these symptoms may see their family doctor or a urologist, a doctor who specializes in diseases of the urinary system. Usually, early cancer does not cause pain; it is important not to wait to feel pain before seeing a doctor.

In most cases, the earlier cancer is diagnosed and treated, the better a person's chance for a full recovery.