Most patients with kidney cancer do not have symptoms. This is especially true in early stages of cancer when the tumor is small. But the affected kidneys grow in size and the tumour may grow through the wall of the kidney and invade nearby tissues and organs. This includes an invasion of the muscles around the spine, liver and large blood vessels nearby. This results in several signs and symptoms of the condition.

Symptoms of kidney cancer

Symptoms include:

• Presence of blood in urine. This called haematuria and may be painless. The episodes of haematuria may 'come and go' as the tumour bleeds. This is the first symptom in around 60% of all cases.
• Pain in the sides of the body or the back just below the ribs.
• A feeling of a lump in the abdomen. This could manifest as swelling of the abdomen.
• High blood pressure.
• Loss of appetite and increased thirst.
• Feeling tired and fatigued.
• There may be night sweats or increased perspiration at nights during sleep.
• High fever for a long duration with temperatures over 38C (100.4F). This fever is not usually explained by a cause and is called pyrexia of unknown origin.
• Unexplained weight loss.
• Anemia with too little blood and associated symptoms such as being pale and tired. There may be polycythemia in some individuals this means too much blood in body.
• Varicocele or presence of engorged and convoluted network of veins in the scrotum is seen in some cases.
• Both sided edema and swelling of the ankles.
• Excessive hair growth in females.
• If the cancer has spread to the liver there may be jaundice and other features of liver damage like raised liver enzymes, ascitis etc.
• If the cancer has spread to the bones there may be pathological and easy fractures. Hip fractures are commonly seen.
• If the cancer has spread to the lungs there may be presence of blood in the sputum.
• Paraneoplastic symptoms may occur in approximately 20-30% of patients. These include involvement of nerves, anemia, polycythemia, amyloidosis, elevated ESR, hypercalcaemia (raised blood calcium levels) and abnormal liver function tests.

Risk factors for renal cancers

Not all persons with risk factors may develop kidney cancers. However there are some factors that may raise the risk of getting kidney cancers. These include:-

• Smoking - Smoking tobacco is an important risk factor for kidney cancer. Smokers are at a greater risk of kidney cancers.
• Obesity – This is an important trend noted worldwide and is thought to be responsible for rising numbers of kidney cancers.
• High blood pressure or hypertension – Those with long term hypertension are at a greater risk.
• Family history of kidney cancer or genetic cancers of kidney cancers.
• Other conditions like tuberous sclerosis, renal transplant recipients, acquired renal cystic disease and von Hippel-Lindau disease. Von Hippel-Lindau (VHL) syndrome is a rare genetic disease caused by changes in the VHL gene. These individuals have an increased risk of kidney cancer and may also have cysts or tumors in the eyes, brain, or other organs.