Early Symptoms of Kidney Cancer

Short Explanatory Video

About Your Kidneys

The kidneys are a pair of bean-shaped organs below the rib cage on each side of your back. Each kidney is about 4-5 inches long, roughly the size of a large fist.

The primary function of the kidneys is to remove excess water, salt, and waste products from blood that enters the renal arteries, ensuring that the electrolyte levels in your body are balanced.

Waste is turned into urine and leaves the kidneys through long, slender tubes called ureters, connected to the bladder, where urine is stored until you urinate.

Other functions of the kidneys include releasing renin, which regulates blood pressure, and the production of erythropoietin, which signals for the bone marrow to produce more red blood cells.⁽¹⁾

About Cancer

Your body is composed of trillions of cells that grow and divide as needed.

Cancer develops when abnormal cells divide uncontrollably and start to crowd out normal cells, preventing their function.

There are more than 200 different types of cancer. While these cancers are similar in some ways, they can differ in terms of how they spread, grow, and respond to treatment. Some cancers grow and spread quickly; others progress at a slower rate.

Some cancers are more likely to spread to other parts of the body than others, while some remain local or restricted to a particular area. Surgery works best for some cancers, whereas drugs like chemotherapy work best for others.⁽²⁾

What Is Kidney Cancer?

Kidney cancer, also called renal cell carcinoma (RCC), is an abnormal growth on or within your kidneys. This can be caused by genetic factors, environmental toxins, or other causes.

The three main types of kidney cancer are:

• Clear cell RCC - accounts for 75% of RCC
• Papillary RCC - accounts for 15%
• Chromophobe RCC - accounts for 5%

In addition to RRC, other rare types of kidney cancer include transitional cell carcinoma (TCC), wilms tumour (nephroblastoma), and renal sarcoma.⁽²⁾

How Common Is It?

Every year in the UK, approximately 13,100 new cases of kidney cancer are discovered. This makes kidney cancer the seventh most common type of cancer.

Among these, the number of people assigned male at birth (AMAB) diagnosed with kidney cancers is twice that of people assigned female at birth (AFAB). This could be due to lifestyle differences, as people who are AMAB are statistically more likely to be smokers, and smoking increases your risk of getting kidney cancer.⁽¹⁾

Kidney cancer is uncommon in people under 45 years of age. Most people are diagnosed with kidney cancer in their later years, with an average age of 64 years old.

Causes

Although many risk factors have been associated with the development of kidney cancer, it is not yet clear how these risk factors cause kidney cells to become cancerous.

Generally, cancers are caused by changes (mutations) in DNA. DNA makes up our genes, which control how our cells function, grow, develop, and die. Two essential genes involved in cancer development are oncogenes and tumour suppressor genes. When these genes are changed, cells divide uncontrollably and spread to other organs, leading to cancer. Changes in many different genes are usually needed to cause kidney cancer.⁽³⁾  

Risk Factors

Modifiable risk factors

Some risk factors can be changed to reduce the risk of developing kidney cancer;

• Obesity: It causes around a quarter (24%) of kidney cancers, since being overweight causes changes in hormones in the body, particularly in women.
• Smoking: The risk increases with the length of time and the number of cigarettes you smoke. Your risk decreases if you stop smoking.
• Workplace: Exposure to certain substances, such as trichloroethylene (industrial solvents), increases the risk for RCC. 
• Medical Conditions: Other kidney diseases, high blood pressure, thyroid cancer, and diabetes can increase the risk of developing RCC.

Non-modifiable risk factors

Other risk factors such as your age or family history, cannot be changed.^(1,3)

• Age: The risk of kidney cancer increases as you age.
• Sex: RCC is about twice as common in people assigned male at birth than in people assigned female at birth. 
• Race: Those of African American descent have a slightly higher rate of RCC than others.
• Inheritance syndromes: Some people inherit rare genes that can increase their chances of developing kidney cancers, such as Von Hippel-Lindau (VHL) syndrome, Tuberous sclerosis, and Birt-Hogg-Dubé syndrome.
• Family history: People with a first-degree relative who has been diagnosed with kidney cancer have approximately twice the risk of developing RCC themselves.

Are there Early Signs & Symptoms of Kidney Cancer?

Early kidney cancers rarely show signs or symptoms, but larger, more advanced cancers may. The following are some of the signs and symptoms of kidney cancer⁽³⁾:

• Blood in the urine (hematuria)
• Low back pain on one side (not caused by injury)
• A mass (lump) on the side or lower back
• Fatigue (tiredness)
• Loss of appetite
• Weight loss not caused by dieting
• Fever that is not caused by an infection and that does not go away
• Anemia (low red blood cell counts)

How to Spot the Early Warnings

Most people diagnosed with kidney cancer do not have symptoms.

Some people may be undergoing tests for other reasons when a scan reveals that they have kidney cancer. This is referred to as an "incidental diagnosis", meaning that their cancer was discovered by chance while looking into something else. As these kidney cancers are usually discovered early, the survival rate is very high.

Some tests can detect some kidney cancers early, but none are recommended for people at average risk of kidney cancer⁽³⁾.

• A urine test may find small amounts of blood in the urine. 
• Imaging tests such as CT or MRI scans can often find small kidney cancers.

Genetic tests look for gene mutations in your DNA that cause some inherited syndromes as risk factors for kidney cancer, not kidney cancer itself.

If you have one of these conditions, your risk of kidney cancer may increase, but this does not mean that you already have or will develop kidney cancer.

Before taking the test, talk to a genetic counsellor or your doctor to determine what the results mean.

Additional Warning Signs of Kidney Cancer

Other warning signs of kidney cancer include⁽⁴⁾:

• Persistent high blood pressure
• Night sweats
• In men, swelling of the veins in the testicles
• Swollen glands in your neck
• Bone pain
• Coughing up blood

Prevention

Although there is no proven way to prevent kidney cancer completely, you may be able to reduce your risk by:

• Quitting smoking: Smoking is one of the leading causes of cancer and cancer-related death. Because tobacco products contain many chemicals that damage DNA, people who use tobacco products or are regularly exposed to tobacco smoke have a higher risk of cancer. Therefore, smokers are strongly encouraged to give up the habit, as stopping at the time of cancer diagnosis also reduces the risk of death. 
• Maintaining a healthy weight: People suffering from obesity are more likely to develop kidney cancers. Conversely, eating a healthy diet, regularly exercising, and maintaining an average weight may help reduce the risk of certain cancers and other diseases, such as heart disease, type 2 diabetes, and hypertension. Therefore, try to keep your overall weight and body mass index (BMI) within the normal range of 18.5-24.9.⁽⁵⁾
• Controlling high blood pressure: If you have been diagnosed with hypertension, take your medication regularly and get a regular blood pressure exam at home. You could also⁽⁴⁾:
  • Reduce your salt intake to less than 6g (a teaspoonful) a day
  • Reduce alcohol consumption to a maximum of 14 units a week, which is the equivalent of six glasses of wine per week.
  • Drink less caffeine

When to See a Doctor

It is recommended to seek medical advice if:

• You have any of the above symptoms
• Any of your family members have or have had kidney cancer
• You know that you have certain inherited syndromes