Kidney cancer, also known as renal cancer, is a disease in which kidney cells become malignant (cancerous) and grow out of control, forming a tumor. Almost all kidney cancers first appear in the lining of tiny tubes (tubules) in the kidney; this type of kidney cancer is called renal cell carcinoma. The kidneys are two bean-shaped organs, each about the size of a fist, located behind the abdominal organs, with one kidney on each side of the spine. They play a vital role in filtering blood, removing waste through urine, balancing electrolytes, and maintaining blood pressure. Kidney cancer is among the top ten most common cancers in both men and women.
Causes
The exact cause of kidney cancer is unknown, but several risk factors may increase the likelihood of developing the disease:
- Smoking: Smoking doubles the risk of kidney cancer. The risk decreases after quitting.
- Obesity: Higher body weight is associated with an increased risk of kidney cancer.
- High Blood Pressure (Hypertension): High blood pressure increases the risk, though it’s unclear whether the condition itself or the medication used to treat it is the cause.
- Family History: Having a family member with kidney cancer increases the risk.
- Certain Genetic Conditions: Conditions like von Hippel-Lindau disease, hereditary papillary renal cell carcinoma, or Birt-Hogg-Dubé syndrome increase the risk.
- Long-term Dialysis: A treatment for chronic kidney failure, long-term dialysis can increase the risk of developing kidney cysts and, subsequently, kidney cancer.
- Occupational Exposure: Exposure to certain substances, such as trichloroethylene in the workplace, may increase the risk.
Symptoms
In its early stages, kidney cancer rarely causes noticeable symptoms. As the tumor grows, symptoms may include:
- Blood in the Urine (Hematuria): This can appear pink, red, or cola-colored.
- Back or Side Pain: Pain on one side of the body that doesn’t go away is a common symptom.
- Loss of Appetite: Unexplained weight loss or lack of interest in eating.
- Fatigue: Feeling unusually tired without exertion.
- Intermittent Fever: Episodes of fever that come and go without any infection.
- Swelling in the Ankles or Legs: Due to fluid retention.
- A Lump in the Abdomen: A mass or lump in the area of the kidneys discovered during an examination.
Because these symptoms can be attributed to a range of other conditions, they may not immediately suggest kidney cancer. However, the presence of one or more symptoms warrants a thorough medical evaluation to determine the underlying cause and implement appropriate treatment if necessary. Early detection through imaging tests often leads to a diagnosis before symptoms appear, improving the likelihood of successful treatment.
Diagnostics
Diagnosing kidney cancer typically involves a combination of physical exams, imaging tests, and lab tests to confirm the presence of a tumor and assess its extent. Key diagnostic steps include:
- Physical Examination: Checking for general signs of health and any unusual signs, such as lumps in the abdomen.
- Blood and Urine Tests: Assess kidney function and look for signs of kidney cancer, such as blood in the urine (hematuria).
- Imaging Tests: Critical for diagnosing kidney cancer and may include:
- Ultrasound: Uses sound waves to create images of the kidneys, revealing tumors.
- Computed Tomography (CT) Scan: Provides detailed cross-sectional images of the body and can identify small tumors in the kidneys.
- Magnetic Resonance Imaging (MRI): Offers detailed images of soft tissues, including the kidneys.
- Bone Scan: Checks if cancer has spread to the bones (in cases of advanced cancer).
- Biopsy: Involves removing a small sample of kidney tissue, usually with a needle guided by imaging tests. However, a biopsy is not always necessary for diagnosis if imaging tests strongly suggest kidney cancer.
Treatment
Treatment for kidney cancer depends on the type, stage of the cancer, overall health, and personal treatment preferences. Options include:
- Surgery: The primary treatment for localized kidney cancer.
- Nephrectomy: Removal of the entire kidney, often along with some surrounding tissue and possibly nearby lymph nodes. It can be radical (complete kidney removal) or simple (only the kidney is removed).
- Partial Nephrectomy: Removes the cancer within the kidney along with some surrounding tissue. It’s preferred to save as much kidney function as possible.
- Ablation and Other Local Therapies: Treat the tumor without surgery.
- Cryoablation: Freezes cancer cells.
- Radiofrequency Ablation (RFA): Uses electrical currents to heat and destroy cancer cells.
- Targeted Therapy: Uses drugs to target specific pathways or mutations involved in cancer cell growth and spread, sparing normal cells. Examples include tyrosine kinase inhibitors (TKIs) and mTOR inhibitors.
- Immunotherapy: Boosts the body’s immune system to fight cancer. Agents like nivolumab, ipilimumab, and pembrolizumab have been approved for treating advanced kidney cancer.
- Radiation Therapy: Although not a standard treatment for kidney cancer, it may be used to relieve symptoms in advanced cancer or when surgery isn’t an option.
- Chemotherapy: Rarely used for kidney cancer because it’s often resistant to chemotherapy drugs, but may be considered in certain cases.
Treatment plans often combine several of these options, especially for advanced stages of kidney cancer. The goal of treatment is to remove or destroy cancer cells while preserving kidney function whenever possible. Advances in understanding the biology of kidney cancer have led to the development of targeted therapies and immunotherapies, significantly improving outcomes for many patients with advanced disease. Ongoing research continues to explore new treatments and strategies to enhance survival and quality of life for patients with kidney cancer.
Prevention
While there’s no guaranteed way to prevent kidney cancer, certain lifestyle changes and actions can help lower the risk:
- Quit Smoking: Smoking is a significant risk factor for kidney cancer. Quitting smoking can reduce your risk.
- Maintain a Healthy Weight: Being overweight or obese can increase the risk of kidney cancer. Aiming for a healthy weight through diet and exercise can help lower this risk.
- Control High Blood Pressure: Managing hypertension with lifestyle changes and medication (when necessary) may reduce the risk of kidney cancer.
- Limit Exposure to Toxins: Minimize exposure to harmful substances like asbestos, cadmium, and certain organic solvents, which can increase cancer risk.
- Healthy Diet: Consuming a diet rich in fruits and vegetables and low in processed meats may help lower the risk of kidney and other cancers.
Complications
Kidney cancer can lead to several complications, particularly if it spreads (metastasizes) or becomes advanced:
- Reduced Kidney Function: Surgery to remove part or all of a kidney can affect the organ’s ability to filter blood effectively, especially if the other kidney isn’t fully functional.
- Spread of Cancer: Kidney cancer can spread to other parts of the body, such as the lungs, bones, liver, or brain, complicating treatment and management.
- Symptomatic Complications: Advanced kidney cancer can lead to pain, weight loss, fatigue, and other symptoms that affect quality of life.
- Treatment Side Effects: Treatments like surgery, targeted therapy, and immunotherapy can have side effects ranging from mild to severe, impacting overall health and well-being.
Conclusion
Kidney cancer poses significant health challenges, but understanding the risk factors and adopting preventive measures can help reduce its incidence. For those diagnosed, advancements in surgical techniques, targeted therapies, and immunotherapy offer hope for effective management and improved outcomes. Early detection is crucial, as it allows for a broader range of treatment options and a better prognosis. As research continues to evolve, there is optimism for new treatments and strategies to combat kidney cancer more effectively, aiming to enhance survival rates and the quality of life for affected individuals. The journey of managing kidney cancer underscores the importance of patient education, regular medical care, and support for patients and their families.