Cancer which originates in the kidneys is known as kidney cancer. Kidneys are bean-shaped organs, about the size of a fist and 2 in number, with each kidney located on either side of the spine and behind the abdominal organs. Renal cell carcinoma is the most common type of kidney cancer found in adults. Wilms' tumor is a type of kidney cancer occurring mostly in kids. The prevalence of kidney cancer seems to be increasing, though the reason is not clear. Majority of the kidney cancers are found out during procedures done for other conditions. Imaging studies such as computerized tomography (CT) help in detecting kidney cancers, so they are being increasingly done. Treatment depends on the general health of the patient, type of kidney cancer, extent of the cancer and preference of the patient.
Stages of Kidney Cancer
- Stage I: In this stage, the size of the tumor can be around 2 ¾ inches (7 cm) in diameter and is confined to the kidney.
- Stage II: In this second stage, the size of the tumor is larger than stage I, but is still confined to the kidney.
- Stage III: In this stage, the tumor grows outside the kidney to the surrounding tissue. It may also spread to a nearby lymph node.
- Stage IV: In this stage, the cancer has spread beyond the kidney, to distant parts of the body (bones, brain, liver or lungs) along with spreading to multiple lymph nodes.
Causes of Kidney Cancer
The cause of kidney cancer is not clear. According to doctors, DNA mutations in the kidney cells lead to kidney cancer. Due to the mutations, there is rapid growth and division of the cells resulting in accumulation of the abnormal cells to form a tumor which can grow beyond the kidney. There may also be breaking off and spreading of these cells (metastasize) to distant parts of the body.
Risk Factors for Kidney Cancer
- As the age increases, so does the risk of kidney cancer.
- Gender, as men are at higher risk to develop kidney cancer.
- Smokers are at a higher risk for developing kidney cancer.
- Obesity or being overweight increases the risk of kidney cancer.
- High blood pressure (hypertension) also increases the risk of kidney cancer.
- Being exposed to chemicals (asbestos, cadmium) in certain occupations increases the risk of kidney cancer.
- Treatment for kidney failure such as, patients receiving long-term dialysis for chronic kidney failure, are at an increased risk for developing kidney cancer.
- Von Hippel-Lindau disease, which is an inherited disorder, increases the chances of developing different types of tumors, including kidney cancer.
- Hereditary papillary renal cell carcinoma is an inherited condition which increases the risk of developing kidney cancer.
Signs and Symptoms for Kidney Cancer
In early stages of renal cell carcinoma, patient rarely has any signs or symptoms. Signs and symptoms of later stages of kidney cancer include:
- Hematuria or blood in urine (pink, red or cola colored).
- Persistent pain in the back, under the ribs.
- Weight loss.
- Recurrent fever.
Tests to Diagnose Kidney Cancer
- Blood and urine tests.
- Imaging tests such as computerized tomography (CT) or magnetic resonance imaging (MRI) helps in assessing the kidney tumor or other abnormalities.
Treatment For Kidney Cancer
Treatment depends on the general health of the patient, type of kidney cancer, extent of the cancer and preference of the patient.
Surgery For Kidney Cancer:
This is the initial treatment for most of the kidney cancers. The doctor will recommend the type of surgery required according to the patient's cancer and its stage, as well as patient's general health. The complications of surgery are bleeding and infection. Surgical procedures for kidney cancer include:
- Nephrectomy: It comprises of removing the affected kidney. Radical nephrectomy comprises of removing the kidney, a border of healthy tissue and nearby lymph nodes. The adrenal gland also may be removed. Nephrectomy can be done laparoscopically or as an open operation.
- Nephron-Sparing Surgery: This comprises of removing the tumor from the kidney and is also known as partial nephrectomy. In this procedure, instead of removing the whole kidney, the tumor is removed along with a small margin of the surrounding healthy tissue. Nephron-sparing surgery can be done laparoscopically or as an open procedure. Nephron-sparing surgery is preferred in case of small kidney cancers or if only one kidney is affected. Nephron-sparing surgery is preferred over radical nephrectomy, as saving as much kidney tissue as possible reduces the chances of complications like kidney disease and the need for dialysis later in life.
Other Treatments Which Are Done When Surgery Is Not An Option:
- Cryoablation: This treatment involves freezing the cancer cells. Under X-ray guidance, a special needle is inserted through the skin and into the kidney tumor and gas is passed to cool down or freeze the cancer cells. This treatment is reserved for patients with small kidney tumors and who can't undergo other surgical procedures.
- Radio Frequency Ablation: This treatment involves heating the cancer cells. In this procedure, with the help of x-ray, a special needle is inserted via the skin and into the kidney tumor. An electrical current is passed through the needle and into the cancer cells, which causes heating up or burning of the cancer cells. Radio frequency ablation is reserved for patients with small kidney tumors and who can't undergo other surgical procedures.
- There is no cure for advanced and recurrent kidney cancer, but treatment can be done to control the cancer and make the patient comfortable. These treatments include:
- Surgery to remove as much of the kidney tumor as possible and also to remove cancer which has spread to other areas of the body.
- Biological Therapy or Immunotherapy is a treatment which uses the body's own immune system to fight the cancer. Drugs which come under this category are: Interferon and aldesleukin (Proleukin). These drugs are the synthetic versions of the chemicals produced in the body. Side effects include fever, chills, nausea, vomiting and loss of appetite.
- Targeted Therapy: This treatment acts on the specific parts of the cancer and blocks specific abnormal signals present in kidney cancer cells which allow them to multiply. These targeted drugs include axitinib (Inlyta), bevacizumab (Avastin), pazopanib (Votrient), sorafenib (Nexavar) and sunitinib (Sutent). Side effects include rash, diarrhea and fatigue.
- Radiation Therapy: This involves the use of high-powered energy beams, (such as x-rays) to destroy cancer cells. Radiation therapy can also be used to control or reduce symptoms of kidney cancer that has metastasized to other parts of the body, such as bones.
- Clinical Trials: These are studies of new treatments and new techniques which are developing for treating kidney cancer and other diseases. Patients can try these treatments in the hope of getting cured, but there is no guarantee of a cure.