Kidney cancer

The kidneys sit deep inside the body, one on each side of the spine beneath the lower ribs, and a tumour there can grow for a long time in silence: there is plenty of room around it, and the other kidney quietly takes on the work. That is why almost half of these tumours are found by accident, on an ultrasound or a scan requested for something entirely different. It appears mostly after the age of sixty and affects about twice as many men as women. Kidney cancer does have one important feature: while it is still confined to the kidney it can be removed completely, and the person goes on living with a single kidney without restrictions.

What sort of tumour grows in the kidney

Almost nine cases in ten are renal cell carcinoma, which starts in the cells of the tubules — the tiny channels where filtered fluid becomes urine. Less often the tumour arises from the lining of the renal pelvis, the funnel through which urine drains into the ureter; that type is closer in nature to bladder cancer and is treated differently. Children have a separate disease of their own, Wilms tumour, which has nothing to do with adult kidney cancer.

Not everything seen in a kidney is malignant. Simple cysts turn up in a great many people after forty and mean nothing at all. An angiomyolipoma is a benign lesion made of fat and blood vessels, and an oncocytoma is a benign tumour too. What tells them apart is not size but the way the lesion behaves on a scan with contrast.

How it makes itself known

• blood in the urine — pink, red or the colour of strong tea, often painless and often only once; it is precisely that single episode that misleads people into waiting;
• pain in the side or the small of the back, between rib and waist, lasting for weeks and unrelated to movement;
• a lump that can be felt in the flank or under the ribs;
• weight loss without dieting, and loss of appetite;
• a temperature that drags on or keeps coming back over weeks, and heavy sweating at night;
• tiredness and pallor, which often turn out to be anaemia picked up on a routine blood test;
• newly enlarged veins in the scrotum, more often on the left, that do not empty on lying down — an uncommon but valuable sign, because it means the tumour is pressing on the vein draining blood from the testicle.

A kidney tumour is capable of disturbing the metabolism of the whole body: it releases substances that raise the calcium in the blood, push up blood pressure and keep a temperature going. So the illness sometimes announces itself with no urinary complaint at all, but with unexplained weakness, thirst and constipation caused by a high calcium level. The classic combination of blood in the urine, pain and a lump is rare in practice and points to an advanced tumour — there is no sense in waiting for it.

What will not wait

Blood in the urine even once is reason to be seen within days, even if it stopped on its own and nothing hurts. Some situations will not wait at all:

• heavy bleeding with clots, particularly if urine stops coming and the lower abdomen feels tight and full: a clot has blocked the outlet and the bladder has to be emptied in hospital;
• sudden severe breathlessness, chest pain or blood when coughing;
• worsening back pain with numbness or weakness in the legs and retention or leaking of urine — in someone with a known tumour this points to pressure on the spinal cord, and it is counted in hours;
• confusion, relentless vomiting and intense thirst, which is how a sharp rise in calcium shows itself;
• a temperature above 38 °C in someone on drug treatment for cancer, even with nothing else wrong.

In these situations call an ambulance; across Spain, Italy, Portugal, Poland and Ukraine the single European number is 112.

What shifts the odds

• Smoking. Roughly doubles the risk, and the longer the habit the higher it goes. Stopping brings the risk down, but slowly — it takes years.
• Excess weight. One of the few factors where the link is firmly established: fatty tissue alters the hormones that govern how cells grow.
• High blood pressure. Raises the risk in its own right, whatever medicine is used to control it.
• Family history. A parent, brother or sister with kidney cancer increases the odds. Separate from that are the rare inherited syndromes — Von Hippel-Lindau disease, Birt-Hogg-Dubé syndrome, tuberous sclerosis — in which tumours appear early, often in both kidneys and several at once. If the diagnosis is made in a young person, or keeps recurring in a family, genetic testing is worth discussing.
• Many years of dialysis. Kidneys that stopped working long ago develop cysts, and tumours arise on that background more often, which is why these patients are checked regularly.
• Workplace exposures. Trichloroethylene, cadmium and by-products of coke production.

Only three of these are in anyone's hands: not smoking, keeping weight down and treating blood pressure. None of them offers a guarantee, since kidney cancer also occurs in people with no risk factor whatsoever — which is why symptoms need checking either way.

How the diagnosis is confirmed

It starts with the simple things: a urine test for blood, blood tests including creatinine, calcium and haemoglobin, and an ultrasound. Ultrasound shows a mass well but cannot say what it is. The decisive test is a CT scan with intravenous contrast: from the way the lesion takes up contrast, the radiologist tells a cyst from a tumour and judges whether it has grown into the vein or the fat around the kidney. The same scan takes in the chest, because the lungs are the commonest place for deposits. If contrast is unsafe because the kidneys are working poorly, an MRI is used instead.

Kidney cancer is one of the few cancers often diagnosed on imaging alone, without a biopsy: the appearance on a scan is characteristic enough, and the needle does not always reach a representative part. A biopsy is taken when the picture is unclear, when the plan is to destroy the tumour without surgery, or when drug treatment is being started and the subtype has to be known exactly. Bone scans and imaging of the head are not done for everyone, only when symptoms point that way.

Waiting for results is the hardest part. A few weeks is normal and is not a sign that something bad has been found. It is worth taking someone with you to the appointment where results are given: what is said that day tends to be remembered only in fragments.

What treatment is made of

The choice depends on the size of the tumour, where it sits, whether it has spread beyond the kidney and how the person is in general. The decision is not one doctor's but a team's: urologist, oncologist, radiologist and pathologist.

• Surgery. The mainstay while the tumour is still inside the kidney. If the size allows, only the tumour is removed with a margin of healthy tissue and the organ is preserved — which matters especially to anyone whose kidneys are already working imperfectly. Otherwise the whole kidney is taken out. Life with one kidney is entirely normal: the remaining one enlarges and takes over the load.
• Destroying the tumour without an incision. A needle is passed through the skin and the tissue is either frozen or heated with radio waves. This suits small tumours, particularly in older people and in anyone who would cope badly with an operation.
• Active surveillance. A small tumour in an older person with other serious illnesses often grows extremely slowly, and watching it with scans makes more sense than operating. This is not withholding care but a considered decision.
• Embolisation. The tumour is cut off from its blood supply by blocking the artery feeding it. It is used to stop bleeding or to shrink a tumour when surgery is not an option.
• Drug treatment for advanced disease. This now rests on immunotherapy: medicines that strip the tumour of its protection from the body's own immune system. They are given alone or alongside targeted drugs that choke off the growth of new blood vessels. That combination has changed the outlook in metastatic disease over the past decade.
• Radiotherapy. Kidney tumours themselves respond poorly to radiation, so it is used selectively: to ease pain from a bone deposit or to treat a lesion in the brain.
• Chemotherapy. It barely works in renal cell carcinoma and is used rarely, mainly for tumours arising in the renal pelvis.

After treatment

Anyone who has had surgery is followed up for several years with scans of the chest and abdomen, at intervals that depend on the stage and on how aggressive the tumour looked under the microscope. Relapses can appear many years later, so the schedule of visits is not something to stretch out on your own initiative.

The second task is to look after what is left. Once a year creatinine and protein in the urine are checked and blood pressure is monitored. Non-steroidal anti-inflammatory painkillers — ibuprofen, diclofenac, naproxen — should be taken with a single kidney only on a doctor's instruction and for a short course; paracetamol suits ordinary pain and fever better. Giving up smoking after surgery affects not only the chance of recurrence but also the risk of a second cancer.

When the disease cannot be stopped, treatment does not end — it changes its aim to holding the tumour back and relieving symptoms. Pain control and palliative care are a full part of the plan, not a sign that someone has been given up on, and it makes sense to bring them in early rather than waiting until things become very hard.

Online consultation

In an online consultation the doctor will go through exactly what worried you: when the blood in the urine appeared, how long the pain or the temperature has lasted, what the tests and scans already done are showing. They will explain which investigations are needed first and in what order, help you make sense of a scan report, and tell you which specialist to see in person and how urgently. If treatment is already under way, the appointment is the place to talk through side effects and work out which ones can wait for the planned review and which call for the same day.

This material is for information only and does not replace medical advice.