Signs and Symptoms of Kidney Cancer

The kidneys play a crucial role in filtering waste products from the blood and removing toxins from the body through urine. They also help regulate electrolytes and signal the bone marrow to produce red blood cells. However, when cells in the kidney begin to grow uncontrollably, kidney cancer can develop.

Kidney cancer is relatively uncommon, accounting for about 2% of all cancers in the United States. Most individuals with kidney cancer do not experience symptoms in the early stages. Symptoms typically manifest when the cancer has advanced or when tumors grow larger. Common symptoms include blood in the urine, lower back pain, and unexplained weight loss.

Common Symptoms

In the early stages, many people with kidney cancer remain asymptomatic. Kidney cancer is often detected incidentally during routine physical exams or imaging tests such as X-rays or MRIs.

There are three primary types of kidney cancers: renal cell carcinoma, transitional cell carcinoma, and Wilms tumors. As the cancer progresses, the following symptoms may develop, which are common across all three types:

• Blood in the urine
• Lower back pain not caused by injury
• A lump in the lower back or side of the abdomen
• Loss of appetite
• Unexplained weight loss
• Fever
• Anemia

Renal Cell Carcinoma Symptoms

Renal cell carcinoma, also known as renal adenocarcinoma or hypernephroma, is the most prevalent type of kidney cancer, accounting for approximately 85% of cases. It is more common in males than in females, although the reason for this disparity is unclear.

This type of cancer forms in the main part of the kidneys. In the early stages, the tumor is small and often does not cause symptoms. About 25% of people with renal cell carcinoma are asymptomatic. If symptoms do occur, they may include blood in the urine, a lump in the lower back or side, and lower back pain. However, only about 10% of individuals with renal cell carcinoma experience all these symptoms simultaneously.

Transitional Cell Carcinoma Symptoms

Transitional cell carcinoma comprises about 7% of all kidney cancers. Unlike renal cell carcinoma, it begins in the renal pelvis, the upper part of the ureter that connects the kidney to the bladder. The cancer can remain in the renal pelvis or spread to the kidney or bladder as it progresses.

The cells lining the ureter are called transitional cells because they share characteristics with cells in the kidneys and bladder and can change shape and stretch. Transitional cell carcinomas are also found in about 4% of bladder cancer cases.

In the early stages, transitional cell carcinoma typically does not cause symptoms. As the cancer grows, symptoms may include the common symptoms of kidney cancer along with extreme fatigue and painful or frequent urination.

Wilms Tumor Symptoms

Wilms tumor, or nephroblastoma, is a type of kidney cancer that occurs in children, usually between the ages of 3 and 5. Tumors can develop in one or both kidneys, making Wilms tumor the most common pediatric kidney and abdominal cancer and the fourth most common type of pediatric cancer overall.

Children with Wilms tumor often do not exhibit symptoms until the cancer has spread. A swollen or enlarged abdomen is typically the first symptom noticed by caregivers. Abdominal pain, present in 30-40% of children with Wilms tumors, is the most common symptom.

Other symptoms may include high blood pressure and nausea. Approximately 25% of children with Wilms tumor have high blood pressure, which often decreases once the tumor is removed.

When to Contact a Healthcare Provider

Kidney cancers are often detected during routine healthcare visits. However, if you notice symptoms such as blood in the urine, a lump or pain in the kidney area, or sudden weight loss, it is important to see a healthcare provider promptly.

If kidney cancer is suspected, your healthcare provider may refer you to a urologist (a specialist in the urinary tract) or an oncologist (a specialist in cancer diagnosis and treatment). These specialists can conduct tests to confirm the diagnosis and develop a treatment plan.

Questions To Ask Your Provider

If you have symptoms of kidney cancer and are visiting your healthcare provider, consider asking the following questions to better understand your condition and ease your concerns:

• Could blood in my urine indicate other conditions?
• What is involved in the kidney cancer testing process?
• What treatment options are available if I am diagnosed with kidney cancer?
• What symptoms indicate that my cancer is worsening?
• What is the life expectancy for someone with kidney cancer?

A Quick Review

Kidney cancer is a rare disease, comprising about 2% of all U.S. cancer cases. Early stages often present no symptoms, but as it progresses, signs such as blood in the urine, lower back pain, and unexplained weight loss may appear. Routine check-ups and awareness of these symptoms can lead to early detection and better outcomes.