Kidney cancer, medically referred to as renal cell carcinoma, is a malignancy that originates in the kidneys. These vital organs play a crucial role in filtering waste products from the bloodstream and producing urine. Kidney cancer often presents with few early symptoms, which can make early detection challenging. However, one of the most telltale signs is hematuria, the presence of blood in the urine. Other potential symptoms may include lower back pain, a palpable mass or lump in the abdomen, unexplained weight loss, fatigue, and occasionally, fever. The exact cause of kidney cancer is not always clear, but certain risk factors, such as smoking, obesity, and a family history of the disease, can increase one’s likelihood of developing it.
What is Kidney Cancer
Kidney cancer, medically known as renal cell carcinoma, is a type of cancer that originates in the kidneys. The kidneys are vital organs responsible for filtering waste products and excess fluids from the blood, producing urine, and helping to regulate blood pressure. Kidney cancer typically begins in the lining of small tubes within the kidney, known as renal tubules.
There are several subtypes of kidney cancer, with clear cell carcinoma being the most common. Risk factors for developing kidney cancer include smoking, obesity, high blood pressure, and a family history of the disease. In some cases, kidney cancer may also be associated with inherited genetic conditions.
Symptoms of kidney cancer can vary but may include blood in the urine, lower back pain on one side, a mass or lump in the abdomen, unexplained weight loss, fatigue, and fever. Diagnosis often involves imaging studies like CT scans or MRI, as well as a biopsy to confirm the presence of cancer.
Treatment for kidney cancer depends on the stage and extent of the disease. Surgical removal of the affected kidney, known as a nephrectomy, is a common approach. Other treatments may include targeted therapy, immunotherapy, radiation therapy, or, in some cases, active surveillance. Early detection and prompt medical intervention can improve the prognosis and quality of life for individuals with kidney cancer.
What are the signs and symptoms of kidney cancer?
Kidney cancer, also known as renal cell carcinoma, often does not cause noticeable symptoms in its early stages. However, as the cancer progresses, the following signs and symptoms may develop:
Blood in the urine (hematuria)
One of the most common signs of kidney cancer is blood in the urine. It may appear pink, red, or brown.
Lower back pain
Persistent pain in the lower back or on one side of the body, not related to an injury or strain, can be a symptom of kidney cancer.
Lump or mass
You may feel a lump or mass in the area where the affected kidney is located. This lump is often on the side of the body and can be felt during a physical examination.
Unexplained fatigue and general weakness can be a symptom of advanced kidney cancer, as the cancer can cause anemia and other metabolic changes.
Unintended weight loss
If you are losing weight without trying, it could be a sign of kidney cancer or another underlying health issue.
Loss of appetite
Kidney cancer can sometimes lead to a loss of appetite and a feeling of fullness even when you haven’t eaten much.
Fever and night sweats
Some people with kidney cancer experience fever and night sweats, which can be a result of the cancer’s impact on the body.
High blood pressure
In some cases, kidney cancer can cause elevated blood pressure, though this is not a definitive symptom as many other factors can contribute to high blood pressure.
Swelling in the legs and ankles
Kidney cancer may cause fluid buildup in the body, leading to swelling in the legs and ankles.
Causes of Kidney Cancer
Kidney cancer, also known as renal cell carcinoma, can develop for various reasons, and the exact cause of kidney cancer is often not clear. However, several risk factors have been identified that can increase the likelihood of developing kidney cancer. These risk factors include:
Age: Kidney cancer is most commonly diagnosed in individuals over the age of 45, with the highest incidence in people between the ages of 55 and 84.
Gender: Men are at a slightly higher risk of developing kidney cancer than women.
Smoking: Cigarette smoking is a significant risk factor for kidney cancer. Smokers are more likely to develop the disease than non-smokers.
Obesity: Being overweight or obese increases the risk of kidney cancer, possibly because excess fat can promote the growth of cancer cells.
High blood pressure (hypertension): People with long-standing, uncontrolled high blood pressure have an increased risk of kidney cancer.
Family history: If you have a family history of kidney cancer, especially in a first-degree relative (parent, sibling, or child), your risk may be higher.
Genetic factors: Certain hereditary conditions, such as von Hippel-Lindau disease and hereditary papillary renal cell carcinoma, can increase the risk of kidney cancer.
Exposure to certain chemicals: Long-term exposure to certain chemicals, such as asbestos, cadmium, or organic solvents, may increase the risk of kidney cancer.
Dialysis treatment: People who undergo long-term dialysis treatment due to kidney failure have an increased risk of kidney cancer.
Occupational exposure: Some jobs and occupations, particularly those involving exposure to certain chemicals or substances, may increase the risk of kidney cancer.
What are the types of kidney cancer?
There are several types of kidney cancer, with renal cell carcinoma (RCC) being the most common. The different types of kidney cancer are classified based on the specific cells in the kidney where the cancer originates. The main types of kidney cancer include:
Renal Cell Carcinoma (RCC)
- Clear Cell Renal Cell Carcinoma (ccRCC): This is the most common type of RCC, accounting for about 70-75% of all kidney cancers. It gets its name from the clear appearance of the cancer cells when viewed under a microscope.
- Papillary Renal Cell Carcinoma (pRCC): This type accounts for around 10-15% of RCC cases. It is characterized by the presence of small finger-like projections in the cancer cells.
- Chromophobe Renal Cell Carcinoma: This type is less common, representing about 5% of RCC cases. It consists of cells with distinctive features when examined microscopically.
Transitional Cell Carcinoma (TCC)
- This type of kidney cancer originates in the renal pelvis, where urine collects before entering the ureters. TCC is more similar to bladder cancer and is less common than RCC.
Collecting Duct Carcinoma
This is a rare and aggressive type of kidney cancer that begins in the collecting ducts of the kidney.
Medullary carcinoma is a rare and aggressive form of kidney cancer that typically occurs in individuals with sickle cell trait or disease.
Wilms Tumor (Nephroblastoma)
Wilms tumor is a type of kidney cancer that primarily affects children, usually between the ages of 2 and 5 years.
Renal oncocytoma is a benign (non-cancerous) kidney tumor that is often mistaken for RCC due to its appearance on imaging tests. It is usually not considered a type of kidney cancer.
Stages of kidney cancer
Kidney cancer, also known as renal cell carcinoma (RCC), typically progresses through several stages, which are classified based on the size of the tumor, its extent of invasion, and whether it has spread to nearby lymph nodes or other organs. The staging system commonly used for kidney cancer is the American Joint Committee on Cancer (AJCC) TNM system. The stages are often expressed as stages I through IV, with further subdivisions in some cases:
- Stage I: At this stage, the cancer is small and confined to the kidney. It has not spread to nearby lymph nodes or distant organs. Stage I is divided into two subcategories:
- Stage IA: Tumor is 4 cm (approximately 1.5 inches) or smaller and confined to the kidney.
- Stage IB: Tumor is larger than 4 cm but still confined to the kidney.
- Stage II: In this stage, the tumor has grown larger but remains localized within the kidney. Stage II is divided into two subcategories:
- Stage IIA: Tumor is 5 cm to 7 cm and confined to the kidney.
- Stage IIB: Tumor is larger than 7 cm and confined to the kidney.
- Stage III: At this stage, the cancer has extended beyond the kidney to nearby tissues, blood vessels, or nearby lymph nodes. Stage III is divided into three subcategories:
- Stage IIIA: Tumor has invaded the adrenal gland or spread to nearby lymph nodes.
- Stage IIIB: Cancer has invaded the major veins or perinephric tissues but has not spread to distant lymph nodes.
- Stage IIIC: The cancer may have spread to nearby lymph nodes and invaded the major veins or other nearby organs.
- Stage IV: In this advanced stage, the cancer has spread to distant organs or distant lymph nodes. Stage IV kidney cancer is divided into two subcategories:
- Stage IVA: Cancer has spread to just one distant organ or site.
- Stage IVB: The cancer may have spread to more than one distant organ or site.
Treatment options for kidney cancer
The treatment options for kidney cancer, also known as renal cell carcinoma, can vary depending on the stage and extent of the cancer, the patient’s overall health, and other factors. The main treatment options for kidney cancer include:
Nephrectomy The most common treatment for kidney cancer involves the surgical removal of the affected kidney. Depending on the extent of the cancer, this may involve either a partial nephrectomy (removal of the tumor and a portion of the kidney) or a radical nephrectomy (removal of the entire kidney).
A. Tyrosine Kinase Inhibitors: Medications like sunitinib, pazopanib, and axitinib can target specific proteins involved in the growth of cancer cells.
B. mTOR Inhibitors: Medications like temsirolimus and everolimus target the mTOR pathway and slow down cancer cell growth.
Immune checkpoint inhibitors such as nivolumab and pembrolizumab can help the immune system identify and attack cancer cells.
Radiation therapy may be used to treat kidney cancer in cases where surgery is not an option or to relieve pain and other symptoms in advanced stages.
Radiofrequency ablation (RFA), cryoablation, and microwave ablation are minimally invasive procedures that can be used to destroy small kidney tumors without removing the kidney.
For some small, localized tumors or in cases where the patient is not a good candidate for immediate treatment, a doctor may recommend active surveillance, where the tumor is closely monitored over time to ensure it doesn’t grow or spread.
Traditional chemotherapy is not very effective against kidney cancer, so it is rarely used. However, it may be considered in certain cases, such as when other treatments have failed.
Participation in clinical trials may offer access to new and experimental treatments for kidney cancer.
The Bottom Line
“Early detection and timely treatment are crucial for kidney cancer. Stay informed, prioritize regular check-ups, and consult a healthcare professional if you experience any symptoms or risk factors.”