Kidney cancer is a malignancy that develops in the kidneys, two bean-shaped organs situated below the ribcage on either side of the spine. The main function of the kidneys is to remove excess water and salt from the blood, then transform those waste products into urine that flows out of the body during urination. Kidney cancer occurs when cells in one or both kidneys undergo abnormal DNA changes that cause the cells to grow and divide uncontrollably. The excess cells then bind together and form cancerous tumors.
The most common type of kidney cancer is renal cell carcinoma, which ranks among the top 10 most common cancers in the United States. Within the general medical community, the precise causes of kidney cancer are not yet well understood, but researchers have determined that some people are more at risk than others.
Although anyone can potentially develop kidney cancer, advanced age is known to be a key risk factor. Most people who have renal cell carcinoma were diagnosed after age 55, and the average age at the time of diagnosis is 71. The condition is relatively uncommon in people younger than age 45. Furthermore, research shows that kidney cancer tends to occur more frequently in men than women.
Risk Factors Beyond Age & Gender
Scientists have identified several additional factors that can make anyone more likely to develop kidney cancer, regardless of their age or gender. Those risk factors include:
- Smoking tobacco – The use of cigarettes, cigars and pipes can increase the likelihood of developing kidney tumors as well as many other types of cancer.
- Excess body weight – Being overweight or obese can heighten the risk of kidney cancer, particularly if the excess weight is a result of consuming a high-fat diet.
- Hypertension – Studies suggest that high blood pressure increases the risk of kidney cancer, regardless of whether the hypertension is controlled with medication.
- A family history of kidney cancer – Among those with a strong family history of renal cell carcinoma, the risk is highest among people who have an affected sibling, which may be related to shared genes, shared exposures or both.
- Advanced kidney disease and long-term dialysis – A treatment for kidney failure, dialysis assumes the function of healthy kidneys by mechanically filtering the blood to remove waste products.
- Certain hazardous substances – Exposure to arsenic, asbestos, cadmium, some herbicides, benzene or trichloroethylene (TCE), which are present in certain occupational settings, can increase the risk of kidney cancer.
- Certain hereditary conditions – Inherited conditions such as von Hippel-Lindau disease, Birt-Hogg-Dube syndrome, hereditary papillary renal cell carcinoma, hereditary renal oncocytoma and hereditary leiomyoma renal cell carcinoma have been linked to kidney tumors.
- Certain medications – Prolonged use of certain nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen, is a risk factor for kidney disease.
By gaining an understanding of the various risk factors associated with kidney cancer, you will be better prepared to take preventive steps to protect yourself.
Screening for High-Risk Individuals
Currently, there is no kidney cancer screening method that is reliable enough to be recommended for routine use among the general public. This can make early detection a challenge because a kidney tumor can potentially grow very large without causing noticeable symptoms. Some telltale signs to watch for include bloody urine, anemia, persistent fever, unexplained weight loss, stomach pain and fatigue.
Additionally, if you have one or more of the known risk factors for kidney cancer, your physician may suggest a preventive regimen of periodic imaging tests, such as:
- Intravenous pyelogram (IVP) – After a contrast dye is injected into the bloodstream, X-rays are taken as the dye travels through the kidneys, ureters and bladder. The resulting images may reveal tumors as well as kidney stones, obstructions and other abnormalities.
- Computed tomography (CT scans) – After a contrast dye is injected into the bloodstream, X-rays are taken from many different angles, then compiled to create cross-sectional images of the kidneys. A CT scan can provide detailed information about the size, shape, location and spread of a kidney tumor.
- Magnetic resonance imaging (MRI) scans – A powerful magnet and radio waves are used to create detailed images of the kidneys and nearby blood vessels. An MRI may be considered if a patient cannot receive contrast dye due to an allergy or impaired kidney function, or if there is a chance that the cancer has grown into a major blood vessel such as the inferior vena cava.
- Ultrasounds – Generated by an external machine, high-frequency sound waves reflect off internal organs and tissues and the resulting echoes collectively form a visual image known as a sonogram, which may reveal a kidney mass. Different ultrasound patterns can also help a physician distinguish between some types of benign (fluid-filled) and malignant (solid) kidney tumors.
The goal of kidney cancer screening is early detection. A prompt diagnosis followed by appropriate treatment can lead to the best possible outcome and quality of life.
If you would like to learn about your individual kidney cancer risk profile, we encourage you to meet with a specialist in the Urologic Oncology Program at Moffitt Cancer Center. To request an appointment, please call 1-888-663-3488 or complete our new patient registration formnew patient registration form online.