Several types of cancer can start in the kidney. The most common type is renal cell cancer, the most common type of kidney cancer in adults. It begins in the lining of the renal tubules in the kidney. The renal tubules filter the blood and produce urine. This type is sometimes called renal adenocarcinoma or hypernephroma.
Another type of cancer, transitional cell carcinoma, affects the renal pelvis. It is similar to bladder cancer and is often treated like bladder cancer. It develops in the lining of the bladder, ureter, or renal pelvis (the part of the kidney that collects, holds, and drains urine).
Many factors have been identified as potential causes of kidney cancer. Some of them include the following: cigarette smoking, which doubles the risk and contributes to as many as one-third of the cases; obesity; high blood pressure and high blood pressure-related medications.
Most kidney cancers are now found “accidentally”. Usually they are detected on ultrasound when investigating other conditions. However, symptoms of kidney cancer include:
- Blood in the urine (making the urine a slightly rusty to deep red colour)
- Pain in the side that does not go away
- A lump or mass in the side or the abdomen
- Weight loss
- Feeling very tired or having a general feeling of poor health
Most often, these symptoms do not mean cancer. An infection, a cyst, or another problem also can cause the same symptoms. A person with any of these symptoms should see a doctor so that any problem can be diagnosed and treated as early as possible.
Cancer is in the kidney only and the size of the tumour is less than or equal to 7.0 cm in diameter. The estimated five-year survival of patients with this stage is over 90 percent.
Cancer is in the kidney only and the size of the tumour is greater than 7.0 cm in diameter. The estimated five-year survival of patients with this stage is over 75 percent.
The tumour in the kidney may be any size, but does not extend beyond the layer of tissue (Gerota’s fascia) that encapsulates the kidney and adrenal gland. Additionally, cancer has spread to the main blood vessel that carries blood away from the kidney (the renal vein), to the blood vessel that carries blood from the lower part of the body to the heart (inferior vena cava), or to the adjacent adrenal gland. The estimated five-year survival of patients with this stage is over 65 percent, depending on involved sites.
Tumour in the kidney extends beyond Gerota’s fascia and/or cancer has spread to more than one lymph node near the kidney. Evidence that cancer has spread to other organs in the body, such as the lungs, liver, brain, bones, intestines or pancreas, also indicates Stage IV disease. The estimated five-year survival of patients with this stage is less than 10 percent.
People with kidney cancer usually have surgery, but other forms of treatment include arterial embolization, radiation therapy, biological therapy, or chemotherapy. Some may have a combination of treatments.
Surgery is the most common treatment for kidney cancer. It is a type of local therapy. It treats cancer in the kidney and the area close to the tumour.
An operation to remove the kidney is called a nephrectomy. There are several types of nephrectomies. The type depends mainly on the stage of the tumor. The doctor can explain each operation and discuss which is most suitable for the patient:
Kidney cancer is usually treated with radical nephrectomy. The surgeon removes the entire kidney along with the adrenal gland and some tissue around the kidney. Some lymph nodes in the area also may be removed.
Recently, laparoscopic techniques have been utilized in selected cases Laparoscopic surgery is a minimally invasive technique in which the surgeon views the anatomy and performs the operation using a camera and tools inserted through small holes in the patient’s skin. There are advantages and disadvantages to each approach, and several factors determine which technique is best suited for a particular patient. The adrenal gland, which sits above the kidney, may or may not be removed, depending on the individual situation.
The surgeon removes only the part of the kidney that contains the tumour. This type of surgery may be used when the person has only one kidney, or when the cancer affects both kidneys. Also, a person with a small kidney tumour (less than 4 centimetres may have this type of surgery. These techniques are also now performed laparoscopically in the correct patient – using a combination of laser and new glues to stop the bleeding
Arterial embolization is a type of local therapy that shrinks the tumour. Sometimes it is done before an operation to make surgery easier. When surgery is not possible, embolization may be used to help relieve the symptoms of kidney cancer.
Radiation therapy (also called radiotherapy) is another type of local therapy. It uses high-energy rays to kill cancer cells. It affects cancer cells only in the treated area. A large machine directs radiation at the body. The patient has treatment at the hospital or clinic, 5 days a week for several weeks. It is not widely used in clinical practice.
Biological therapy is a type of systemic therapy. It uses substances that travel through the bloodstream, reaching and affecting cells all over the body. Biological therapy uses the body’s natural ability (immune system) to fight cancer.
For patients with metastatic kidney cancer, the doctor may suggest interferon alpha or interleukin-2 (also called IL-2 or aldesleukin). The body normally produces these substances in small amounts in response to infections and other diseases. For cancer treatment, they are made in the laboratory in large amounts.
Chemotherapy is also a type of systemic therapy. Anticancer drugs enter the bloodstream and travel throughout the body. Although useful for many other cancers, anticancer drugs have shown limited use against renal cell cancer, but has some role in transitional cell cancer.