eHealthWatch Special Report

According to the American Cancer Society almost 51,000 people in the United States are diagnosed with kidney cancer each year, and the incidence of kidney cancer is increasing – although it isn't clear why.

The most common type of kidney cancer is renal cell carcinoma, which begins in the cells that line the small tubes within the kidneys. One or more renal cell tumors may develop in one or both kidneys, and over time, the tumors grow in size and can invade surrounding tissues. In more advanced stages, kidney cancer can spread throughout the body, causing tumors to develop in other organs.

The most common type of kidney cancer is renal cell carcinoma, which begins in the cells that line the small tubes within the kidneys.

Risk Factors – Although the specific cause of kidney cancer is unknown, a number of factors can increase a person’s risk including:

• Age: Renal cell carcinoma occurs most commonly in people 50 and older.
• Sex: Men are more likely to develop renal cell carcinoma than women.
• Race: More common in blacks as compared to whites
• Smoking: Smokers have a greater risk of renal cell carcinoma than nonsmokers.
• Obesity: People who are obese have a higher risk of renal cell carcinoma than do people who are considered average weight.
• High blood pressure (hypertension): High blood pressure increases your risk of renal cell carcinoma, but it isn't clear why. Some research in animals has linked high blood pressure medications to an increased risk of kidney cancer, but studies in people have had conflicting results.
• Chemicals in the workplace: Occupational exposure to cadmium, asbestos, and certain petroleum byproducts increases the risk of kidney cancer.
• Treatment for kidney failure: Long-term dialysis to treat chronic kidney failure increases the risk of developing kidney cancer, and people who have a kidney transplant and receive immunosuppressant drugs are also more likely to develop kidney cancer.
• Analgesic abuse: Including aspirin and phenacetin (now banned in the United States)
• Genetic Factors: Such as Von Hippel-Lindau disease, people with this inherited disorder are likely to develop several kinds of tumors, including, in some cases, renal cell carcinoma.

Symptoms – Kidney cancer rarely causes signs or symptoms in its early stages. In the later stages, kidney cancer signs and symptoms may include:

• Blood in the urine, which may appear pink, red or cola-colored
• Pain in the side or back at the level of the lower rib cage
• Loss of appetite and weight loss
• Fatigue
• Night sweats
• Intermittent fever
• New growth in the abdomen

The cancer can also spread or metastasize to other organs causing additional symptoms. The most common sites of metastases are nearby lymph nodes, lungs, bones, liver, brain, nearby adrenal gland, and the opposite kidney.

Kidney cell cancers can sometimes produce excessive amounts of various hormones, which may disrupt body processes that are sensitive to these hormones. A range of laboratory abnormalities such as increasing red blood cell count, increasing levels of calcium in the blood may develop.

Most kidney cell cancers do not cause pain, and the most common first symptom is blood in the urine. In most cases, this doesn't mean you have kidney cancer because blood in the urine may be a sign of many other conditions, but if you notice blood in your urine see your doctor right away.

Diagnosis – A thorough history and physical examination, blood and urine tests followed by imaging studies, such as ultrasound, CT scan and MRI, and possibly a biopsy are the mainstays of diagnosing and staging kidney cancer.

After the diagnosis of kidney cancer is made, the next step is to determine the extent, or stage, of the cancer. Staging tests for kidney cancer may include additional CT scans, a chest X-ray or other specific imaging scans deemed necessary to estimate the possible extent of spread of the cancer.

The primary factors considered in the staging of kidney cancer are the size of the tumor (T), involvement of lymph nodes close to or distant from the kidney (N), and spread or “metastasis” to other organs (M).  Thus the TNM system of staging.

Kidney Cancer Stages

Stage I: Tumor size less than 7 cm, limited to the kidney
Stage II: Tumor size greater than 7 cm, limited to the kidney
Stage III: Tumor has invaded the adrenal gland which sits atop each kidney, tissue surrounding the kidney or major nearby vein such as the vena cava. Stage III also includes patients with enlarged abdominal lymph nodes.
Stage IV: Patients who have large tumors extending to surrounding tissues and/or metastases to other distant locations.

Treatment of Kidney Cell Cancer

The best approach to the treatment of kidney cell cancer depends on a number of factors, including general health of the patient, whether the cancer has spread and patient preferences for treatment.

Treatment for kidney cell cancer may include surgery, cryo or radio-frequency ablation, radiation, or medications such as immunotherapy and molecular targeted (antiangiogenic) therapy.

For stage I, II or III disease, potentially curative surgical treatment, when the cancer has not spread beyond the kidney, offers a reasonable chance for cure.  The surgery typically involves complete or radical removal of the affected kidney and surrounding lymph nodes, but in some cases just the tumor can be removed, preserving some of the affected kidney.

If surgery is not an option due to the patient’s underlying medical condition, cryo-ablation (destroying the tumor by freezing technique) or radiofrequency ablation (destroying the tumor by using radiofreqency heat energy) may be considered.

Kidney cell cancer medical therapy is meant for patients for whom potentially curative surgery is not an option or patients who have advanced kidney cell cancer whose cancer has grown or spread after surgery.

• Immunotherapy: Biological therapy (immunotherapy) uses the body's immune system to fight cancer. Drugs in this category include interferon and interleukin-2, which are synthetic versions of chemicals made in the body. Biological therapy drugs are sometimes used alone, in combination or after surgery.

The most active immunotherapy is interleukin-2. High dose interleukin-2 was previously standard treatment; however, it has serious and sometimes even toxic side effects. When completed, interleukin-2 produces tumor shrinkage in 15-20% of patients with nearly half of the tumor responses being complete and many being long-lasting.

• Molecularly Targeted Therapy: Targeted treatments block specific abnormal signals present in kidney cancer cells that allow them to proliferate. These drugs have shown promise in treating kidney cancer that has spread to other areas of the body.

• Two drugs in this category, sorafenib (Nexavar) and sunitinib (Sutent), target molecules on the surface of blood vessels within kidney cancer tumors eliminating the blood supply that is critical in growth and maintenance of tumors.
• Temsirolimus (Torisel), another targeted drug, acts by inhibiting an enzyme inside the cell called mammalian target of rapamycin (mTOR); this treatment has the potential to inhibit tumor growth and survival at multiple levels.
• Targeted therapy drugs can cause side effects, such as a rash that can be severe, fatigue, high blood pressure, nausea, diarrhea, sores of the mouth, gastrointestinal tract and thyroid problems, and changes in liver function tests.
• Targeted drugs can also be very expensive, sometimes costing thousands of dollars a month.
• These molecular targeted drugs do not produce long-term remission or cure. And additional clinical trials are ongoing to determine their optimal use.

In order to minimize your risk for kidney cancer and many other cancers as well try to eat more fruits and vegetables.

Take Control of Your Health

Early detection of any cancer is critical, so get in to see your physician at the first sign of any of the signs and symptoms mentioned above.  In order to minimize your risk for kidney cancer and many other cancers as well try to:

• Quit smoking
• Eat more fruits and vegetables
• Exercise regularly
• Maintain a healthy weight
• Control high blood pressure
• Reduce or avoid exposure to environmental toxins

Dr. Ashish V. Dalal graduated from the M.S. University Medical College of Baroda, Gujarat India. He was a clinical research associate in the Department of Oncology at Montifiore Medical Center in Bronx, New York. Dr. Dalal then completed his residency in internal medicine and a three year fellowship in hematology/oncology at Beth Israel Medical Center in New York. Dr. Dalal is board certified in internal medicine, hematology, and medical oncology and is a member of the American Society of Clinical Oncology and the Florida Society of Clinical Oncology. Dr. Dalal has been a physicians at Space Coast Cancer Center since 2003. His office locations include Titusville, Merritt Island and Rockledge. Dr. Dalal is an avid tennis player and musician–  and enjoys spending time with his family.

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