Kidney Cancer (Renal Cell Carcinoma)

What kidney cancer is

The kidneys are two bean-shaped organs behind the abdomen that filter blood and make urine. Kidney cancer usually begins in the lining of the tiny tubules that make urine.

Types

Benign tumors such as oncocytomas and angiomyolipomas can look similar on scans.

Symptoms

Many kidney cancers are found by chance as a kidney mass on an ultrasound or CT scan. Symptoms usually mean a larger tumor:

• blood in the urine, visible or microscopic
• pain in the side or lower back (flank pain) not caused by injury
• a lump in the side or belly
• tiredness, weight loss and loss of appetite
• fever or night sweats
• anemia
• swelling of the legs or ankles
• a suddenly appearing varicocele, usually on the left

Kidney cancers can produce hormones that cause high calcium, high blood pressure or a high red cell count (paraneoplastic syndromes). Spread to the lungs or bones may cause cough, breathlessness or bone pain.

Risk factors

• Smoking: roughly doubles the risk
• Obesity
• High blood pressure
• Long-term dialysis, with acquired cystic kidney disease
• Male sex: about twice as common in men
• Age over 60
• Family history and inherited syndromes: von Hippel-Lindau disease, hereditary papillary RCC, Birt-Hogg-Dubé syndrome, tuberous sclerosis
• Workplace exposure to trichloroethylene and some other chemicals
• Long-term use of some pain medicines

Diagnosis

• CT scan with contrast of the abdomen and pelvis: the main test to characterize the mass and check spread; MRI is an alternative
• Chest CT: to look for spread to the lungs
• Blood tests: kidney function, blood count, calcium and liver tests
• Urine tests
• Biopsy: not always needed; used for small masses when it would change treatment, before ablation or systemic therapy, or when another diagnosis is possible
• Bone scan or brain MRI if symptoms suggest spread
• Genetic counseling for people under 46, with multiple or bilateral tumors, or a family history

Stages

Grade (how abnormal the cells look) and subtype also guide treatment.

Treatment

Small kidney cancers (under about 4 cm)

• Active surveillance: regular scans, especially for older people or those with other serious illnesses
• Thermal ablation: freezing (cryoablation) or heating (radiofrequency or microwave) through a needle
• Partial nephrectomy: removing the tumor while saving the rest of the kidney, preferred for most small tumors to protect kidney function

Localized larger cancers

• Partial or radical nephrectomy (removing the whole kidney), often by laparoscopic or robotic surgery
• Adjuvant immunotherapy (pembrolizumab) after surgery for people at higher risk of recurrence

Advanced or metastatic kidney cancer

• Immunotherapy combinations: immune checkpoint inhibitors (such as pembrolizumab or nivolumab) combined with another checkpoint inhibitor or with a targeted drug
• Targeted therapy: drugs that block blood vessel growth signals (VEGF), such as cabozantinib, axitinib and lenvatinib
• Belzutifan: a HIF-2 alpha inhibitor for some advanced RCC and for VHL-related tumors
• Cytoreductive nephrectomy in selected patients
• Radiation for bone or brain metastases and symptom control
• Surgery to remove isolated metastases in some cases

Traditional chemotherapy has little effect on most RCC.

Survival

Five-year relative survival, from US SEER data:

Survival for advanced disease has improved with immunotherapy, and some people have long-lasting responses.

Prevention

• stop smoking
• maintain a healthy weight
• control blood pressure
• limit exposure to industrial chemicals such as trichloroethylene
• surveillance scans for people with inherited syndromes

Frequently asked questions

What are the first signs of kidney cancer?

Early kidney cancer usually causes no symptoms and is often found by chance on a scan. When signs appear, the most common are blood in the urine, pain in the side or lower back, and a lump in the belly. Tiredness and weight loss can also occur.

Is kidney cancer curable?

Yes, especially when found early. Most small, localized kidney cancers are cured with surgery or ablation, with 5-year survival around 93%. Advanced kidney cancer is harder to cure, but immunotherapy and targeted drugs control it for years in many people.

What causes kidney cancer?

Exact causes are not fully known. Risk factors include smoking, obesity, high blood pressure, long-term dialysis, certain workplace chemicals and inherited conditions such as von Hippel-Lindau disease. Changes in genes controlling cell growth, such as VHL, drive most clear cell cancers.

Can you live with one kidney after kidney cancer?

Yes. Most people live normally with one healthy kidney. Your doctor will monitor kidney function, blood pressure and urine protein. Partial nephrectomy is preferred when possible to preserve as much kidney function as possible.

How fast does kidney cancer grow?

Many small kidney cancers grow slowly, often only a few millimeters a year, which is why surveillance is safe for some people. Larger or higher-grade cancers can grow and spread faster. Growth rate on repeat scans helps guide treatment.