Kidney cancer is more common in men than in women, but it is still among the ten most common cancers in both sexes. There are several different types of both cancers and tumors. By far the most common type of kidney cancer is renal cell carcinoma, which affects 85 to 90 percent of patients.
Other types of kidney cancer include transitional cell carcinoma, renal sarcoma, and Wilms tumor. Types of benign tumors include angiomyolipoma, oncocytoma, and renal adenoma.
Kidney cancer is caused by mutations in the cells’ DNA that cause the cells to grow and reproduce abnormally fast. The cells can clump together and form a tumor that reaches beyond the kidney. Some cells may break off and metastasize or spread to another part of the body.
While doctors aren’t sure what causes kidney cancer in the first place, they have identified a number of risk factors. For example, kidney cancer is generally more common in older people. Wilms tumor is an exception and is found mainly in children.
People who are overweight and/or smoke have a higher risk of kidney cancer than the general population. High blood pressure also increases the risk of kidney cancer. Patients who have had dialysis for kidney failure also have a greater risk of kidney cancer. Those who work with cadmium or certain herbicides can have a higher risk of kidney cancer.
A family history of kidney cancer also increases a patient’s risk. Similarly, certain inherited disorders can increase the risk of kidney cancer. Examples of such conditions include Birt-Hogg-Dube syndrome, hereditary papillary renal cell carcinoma, and tuberous sclerosis complex.
Kidney cancers and tumors generally do not cause symptoms during the early stages when they are small. In fact, doctors find the tumor by accident in about 70 percent of cases while performing an imaging test like an MRI or CRT for another reason.
As the tumor gets bigger, it can cause hematuria, or blood in the urine. The amount of blood can range from microscopic to extremely visible. In advanced cases of kidney cancer, the patient will develop symptoms like chills, fatigue, and weakness.
Treatments for kidney cancer include chemotherapy, radiation therapy, and surgery. The doctor will choose a treatment based on the type of cancer, its size and location, and whether or not it has spread to another part of the body.
Surgery is the most common treatment for kidney cancer. In a partial or radical nephrectomy, the doctor will respectively remove part or all of the kidney. The surgeon can use non-surgical procedures like radiofrequency ablation or cryoablation to eliminate small tumors. Radiofrequency ablation uses heat to destroy the tumor while cryoablation uses intense cold to do the same.
In cases where the cancer has metastasized or recurred, the surgeon may also use radiation or various drugs to treat the cancer. Some of the drugs work by strengthening the patient’s immune system, while others target the cancer cells.